public interface ServletContext
There is one context per "web application" per Java Virtual Machine. (A "web application" is a collection of servlets
and content installed under a specific subset of the server's URL namespace such as /catalog
and
possibly installed via a .war
file.)
In the case of a web application marked "distributed" in its deployment descriptor, there will be one context instance for each virtual machine. In this situation, the context cannot be used as a location to share global information (because the information won't be truly global). Use an external resource like a database instead.
The ServletContext
object is contained within the ServletConfig
object, which the Web server
provides the servlet when the servlet is initialized.
| Modifier and Type | Field and Description |
|---|---|
static java.lang.String |
ORDERED_LIBS
The name of the
ServletContext attribute whose value (of type
java.util.List<java.lang.String> ) contains the list of names of JAR files in
WEB-INF/lib ordered by their web fragment names (with possible exclusions if
<absolute-ordering> without any <others/> is being used), or null if no
absolute or relative ordering has been specified |
static java.lang.String |
TEMPDIR
The name of the ServletContext attribute which stores the private temporary directory (of type
java.io.File) provided by the servlet container for the ServletContext
|
| Modifier and Type | Method and Description |
|---|---|
FilterRegistration.Dynamic |
addFilter(java.lang.String filterName,
java.lang.Class<? extends Filter> filterClass)
Adds the filter with the given name and class type to this servlet context.
|
FilterRegistration.Dynamic |
addFilter(java.lang.String filterName,
Filter filter)
Registers the given filter instance with this ServletContext under the given filterName.
|
FilterRegistration.Dynamic |
addFilter(java.lang.String filterName,
java.lang.String className)
Adds the filter with the given name and class name to this servlet context.
|
ServletRegistration.Dynamic |
addJspFile(java.lang.String servletName,
java.lang.String jspFile)
Adds the servlet with the given jsp file to this servlet context.
|
void |
addListener(java.lang.Class<? extends java.util.EventListener> listenerClass)
Adds a listener of the given class type to this ServletContext.
|
void |
addListener(java.lang.String className)
Adds the listener with the given class name to this ServletContext.
|
<T extends java.util.EventListener> |
addListener(T t)
Adds the given listener to this ServletContext.
|
ServletRegistration.Dynamic |
addServlet(java.lang.String servletName,
java.lang.Class<? extends Servlet> servletClass)
Adds the servlet with the given name and class type to this servlet context.
|
ServletRegistration.Dynamic |
addServlet(java.lang.String servletName,
Servlet servlet)
Registers the given servlet instance with this ServletContext under the given servletName.
|
ServletRegistration.Dynamic |
addServlet(java.lang.String servletName,
java.lang.String className)
Adds the servlet with the given name and class name to this servlet context.
|
<T extends Filter> |
createFilter(java.lang.Class<T> clazz)
Instantiates the given Filter class.
|
<T extends java.util.EventListener> |
createListener(java.lang.Class<T> clazz)
Instantiates the given EventListener class.
|
<T extends Servlet> |
createServlet(java.lang.Class<T> clazz)
Instantiates the given Servlet class.
|
void |
declareRoles(java.lang.String... roleNames)
Declares role names that are tested using
isUserInRole . |
java.lang.Object |
getAttribute(java.lang.String name)
Returns the servlet container attribute with the given name, or
null if there is no attribute by
that name. |
java.util.Enumeration<java.lang.String> |
getAttributeNames()
Returns an
Enumeration containing the attribute names available within this ServletContext. |
java.lang.ClassLoader |
getClassLoader()
Gets the class loader of the web application represented by this ServletContext.
|
ServletContext |
getContext(java.lang.String uripath)
Returns a
ServletContext object that corresponds to a specified URL on the server. |
java.lang.String |
getContextPath()
Returns the context path of the web application.
|
java.util.Set<SessionTrackingMode> |
getDefaultSessionTrackingModes()
Gets the session tracking modes that are supported by default for this ServletContext.
|
int |
getEffectiveMajorVersion()
Gets the major version of the Servlet specification that the application represented by this ServletContext is
based on.
|
int |
getEffectiveMinorVersion()
Gets the minor version of the Servlet specification that the application represented by this ServletContext is
based on.
|
java.util.Set<SessionTrackingMode> |
getEffectiveSessionTrackingModes()
Gets the session tracking modes that are in effect for this ServletContext.
|
FilterRegistration |
getFilterRegistration(java.lang.String filterName)
Gets the FilterRegistration corresponding to the filter with the given filterName.
|
java.util.Map<java.lang.String,? extends FilterRegistration> |
getFilterRegistrations()
Gets a (possibly empty) Map of the FilterRegistration objects (keyed by filter name) corresponding to all filters
registered with this ServletContext.
|
java.lang.String |
getInitParameter(java.lang.String name)
Returns a
String containing the value of the named context-wide initialization parameter, or
null if the parameter does not exist. |
java.util.Enumeration<java.lang.String> |
getInitParameterNames()
Returns the names of the context's initialization parameters as an
Enumeration of
String objects, or an empty Enumeration if the context has no initialization
parameters. |
JspConfigDescriptor |
getJspConfigDescriptor()
Gets the
<jsp-config> related configuration that was aggregated from the web.xml
and web-fragment.xml descriptor files of the web application represented by this ServletContext. |
int |
getMajorVersion()
Returns the major version of Jakarta Servlet that this container supports.
|
java.lang.String |
getMimeType(java.lang.String file)
Returns the MIME type of the specified file, or
null if the MIME type is not known. |
int |
getMinorVersion()
Returns the minor version of Jakarta Servlet that this container supports.
|
RequestDispatcher |
getNamedDispatcher(java.lang.String name)
Returns a
RequestDispatcher object that acts as a wrapper for the named servlet. |
java.lang.String |
getRealPath(java.lang.String path)
Gets the real path corresponding to the given virtual path.
|
java.lang.String |
getRequestCharacterEncoding()
Gets the request character encoding that are supported by default for this ServletContext.
|
RequestDispatcher |
getRequestDispatcher(java.lang.String path)
Returns a
RequestDispatcher object that acts as a wrapper for the resource located at the given path. |
java.net.URL |
getResource(java.lang.String path)
Returns a URL to the resource that is mapped to the given path.
|
java.io.InputStream |
getResourceAsStream(java.lang.String path)
Returns the resource located at the named path as an
InputStream object. |
java.util.Set<java.lang.String> |
getResourcePaths(java.lang.String path)
Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path
matches the supplied path argument.
|
java.lang.String |
getResponseCharacterEncoding()
Gets the response character encoding that are supported by default for this ServletContext.
|
java.lang.String |
getServerInfo()
Returns the name and version of the servlet container on which the servlet is running.
|
Servlet |
getServlet(java.lang.String name)
Deprecated.
As of Java Servlet API 2.1, with no direct replacement.
This method was originally defined to retrieve a servlet from a
In lieu of this method, servlets can share information using the |
java.lang.String |
getServletContextName()
Returns the name of this web application corresponding to this ServletContext as specified in the deployment
descriptor for this web application by the display-name element.
|
java.util.Enumeration<java.lang.String> |
getServletNames()
Deprecated.
As of Java Servlet API 2.1, with no replacement.
This method was originally defined to return an |
ServletRegistration |
getServletRegistration(java.lang.String servletName)
Gets the ServletRegistration corresponding to the servlet with the given servletName.
|
java.util.Map<java.lang.String,? extends ServletRegistration> |
getServletRegistrations()
Gets a (possibly empty) Map of the ServletRegistration objects (keyed by servlet name) corresponding to all
servlets registered with this ServletContext.
|
java.util.Enumeration<Servlet> |
getServlets()
Deprecated.
As of Java Servlet API 2.0, with no replacement.
This method was originally defined to return an |
SessionCookieConfig |
getSessionCookieConfig()
Gets the
SessionCookieConfig object through which various properties of the session tracking cookies
created on behalf of this ServletContext may be configured. |
int |
getSessionTimeout()
Gets the session timeout in minutes that are supported by default for this ServletContext.
|
java.lang.String |
getVirtualServerName()
Returns the configuration name of the logical host on which the ServletContext is deployed.
|
void |
log(java.lang.Exception exception,
java.lang.String msg)
Deprecated.
As of Java Servlet API 2.1, use
log(String message, Throwable throwable) instead.
This method was originally defined to write an exception's stack trace and an explanatory error message to the servlet log file. |
void |
log(java.lang.String msg)
Writes the specified message to a servlet log file, usually an event log.
|
void |
log(java.lang.String message,
java.lang.Throwable throwable)
Writes an explanatory message and a stack trace for a given
Throwable exception to the servlet log
file. |
void |
removeAttribute(java.lang.String name)
Removes the attribute with the given name from this ServletContext.
|
void |
setAttribute(java.lang.String name,
java.lang.Object object)
Binds an object to a given attribute name in this ServletContext.
|
boolean |
setInitParameter(java.lang.String name,
java.lang.String value)
Sets the context initialization parameter with the given name and value on this ServletContext.
|
void |
setRequestCharacterEncoding(java.lang.String encoding)
Sets the request character encoding for this ServletContext.
|
void |
setResponseCharacterEncoding(java.lang.String encoding)
Sets the response character encoding for this ServletContext.
|
void |
setSessionTimeout(int sessionTimeout)
Sets the session timeout in minutes for this ServletContext.
|
void |
setSessionTrackingModes(java.util.Set<SessionTrackingMode> sessionTrackingModes)
Sets the session tracking modes that are to become effective for this ServletContext.
|
static final java.lang.String TEMPDIR
static final java.lang.String ORDERED_LIBS
ServletContext
attribute whose value (of type
java.util.List<java.lang.String>
) contains the list of names of JAR files in
WEB-INF/lib
ordered by their web fragment names (with possible exclusions if
<absolute-ordering>
without any <others/>
is being used), or null if no
absolute or relative ordering has been specifiedjava.lang.String getContextPath()
The context path is the portion of the request URI that is used to select the context of the request. The context path always comes first in a request URI. If this context is the "root" context rooted at the base of the Web server's URL name space, this path will be an empty string. Otherwise, if the context is not rooted at the root of the server's name space, the path starts with a / character but does not end with a / character.
It is possible that a servlet container may match a context by more than one context path. In such cases the
HttpServletRequest.getContextPath()
will return the actual context path used by the
request and it may differ from the path returned by this method. The context path returned by this method should
be considered as the prime or preferred context path of the application.
HttpServletRequest.getContextPath()
ServletContext getContext(java.lang.String uripath)
ServletContext
object that corresponds to a specified URL on the server.
This method allows servlets to gain access to the context for various parts of the server, and as needed obtain
RequestDispatcher
objects from the context. The given path must be begin with /, is interpreted
relative to the server's document root and is matched against the context roots of other web applications hosted
on this container.
In a security conscious environment, the servlet container may return null
for a given URL.
uripath
- a String
specifying the context path of another web application in the container.ServletContext
object that corresponds to the named URL, or null if either none exists
or the container wishes to restrict this access.RequestDispatcher
int getMajorVersion()
int getMinorVersion()
int getEffectiveMajorVersion()
The value returned may be different from getMajorVersion()
, which returns the major version of the Servlet
specification supported by the Servlet container.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
int getEffectiveMinorVersion()
The value returned may be different from getMinorVersion()
, which returns the minor version of the Servlet
specification supported by the Servlet container.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.String getMimeType(java.lang.String file)
null
if the MIME type is not known. The MIME type is
determined by the configuration of the servlet container, and may be specified in a web application deployment
descriptor. Common MIME types include text/html
and image/gif
.file
- a String
specifying the name of a fileString
specifying the file's MIME typejava.util.Set<java.lang.String> getResourcePaths(java.lang.String path)
Paths indicating subdirectory paths end with a /.
The returned paths are all relative to the root of the web application, or relative to the /META-INF/resources directory of a JAR file inside the web application's /WEB-INF/lib directory, and have a leading /.
The returned set is not backed by the ServletContext
object, so changes in the returned set are not
reflected in the ServletContext
object, and vice-versa.
For example, for a web application containing:
/welcome.html
/catalog/index.html
/catalog/products.html
/catalog/offers/books.html
/catalog/offers/music.html
/customer/login.jsp
/WEB-INF/web.xml
/WEB-INF/classes/com.acme.OrderServlet.class
/WEB-INF/lib/catalog.jar!/META-INF/resources/catalog/moreOffers/books.html
getResourcePaths("/") would return {"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"},
and getResourcePaths("/catalog/") would return {"/catalog/index.html", "/catalog/products.html",
"/catalog/offers/", "/catalog/moreOffers/"}.path
- the partial path used to match the resources, which must start with a /java.net.URL getResource(java.lang.String path) throws java.net.MalformedURLException
The path must begin with a / and is interpreted as relative to the current context root, or relative to the /META-INF/resources directory of a JAR file inside the web application's /WEB-INF/lib directory. This method will first search the document root of the web application for the requested resource, before searching any of the JAR files inside /WEB-INF/lib. The order in which the JAR files inside /WEB-INF/lib are searched is undefined.
This method allows the servlet container to make a resource available to servlets from any source. Resources can
be located on a local or remote file system, in a database, or in a .war
file.
The servlet container must implement the URL handlers and URLConnection
objects that are necessary
to access the resource.
This method returns null
if no resource is mapped to the pathname.
Some containers may allow writing to the URL returned by this method using the methods of the URL class.
The resource content is returned directly, so be aware that requesting a .jsp
page returns the JSP
source code. Use a RequestDispatcher
instead to include results of an execution.
This method has a different purpose than java.lang.Class.getResource
, which looks up resources based
on a class loader. This method does not use class loaders.
This method bypasses both implicit (no direct access to WEB-INF or META-INF) and explicit (defined by the web application) security constraints. Care should be taken both when constructing the path (e.g. avoid unsanitized user provided data) and when using the result not to create a security vulnerability in the application.
path
- a String
specifying the path to the resourcenull
if there is no resource at that pathjava.net.MalformedURLException
- if the pathname is not given in the correct formjava.io.InputStream getResourceAsStream(java.lang.String path)
InputStream
object.
The data in the InputStream
can be of any type or length. The path must be specified according to
the rules given in getResource
. This method returns null
if no resource exists at the
specified path.
Meta-information such as content length and content type that is available via getResource
method is
lost when using this method.
The servlet container must implement the URL handlers and URLConnection
objects necessary to access
the resource.
This method is different from java.lang.Class.getResourceAsStream
, which uses a class loader. This
method allows servlet containers to make a resource available to a servlet from any location, without using a
class loader.
This method bypasses both implicit (no direct access to WEB-INF or META-INF) and explicit (defined by the web application) security constraints. Care should be taken both when constructing the path (e.g. avoid unsanitized user provided data) and when using the result not to create a security vulnerability in the application.
path
- a String
specifying the path to the resourceInputStream
returned to the servlet, or null
if no resource exists at the
specified pathRequestDispatcher getRequestDispatcher(java.lang.String path)
RequestDispatcher
object that acts as a wrapper for the resource located at the given path. A
RequestDispatcher
object can be used to forward a request to the resource or to include the resource
in a response. The resource can be dynamic or static.
The pathname must begin with a / and is interpreted as relative to the current context root. Use
getContext
to obtain a RequestDispatcher
for resources in foreign contexts.
This method returns null
if the ServletContext
cannot return a
RequestDispatcher
.
path
- a String
specifying the pathname to the resourceRequestDispatcher
object that acts as a wrapper for the resource at the specified path, or
null
if the ServletContext
cannot return a RequestDispatcher
RequestDispatcher
,
getContext(java.lang.String)
RequestDispatcher getNamedDispatcher(java.lang.String name)
RequestDispatcher
object that acts as a wrapper for the named servlet.
Servlets (and JSP pages also) may be given names via server administration or via a web application deployment
descriptor. A servlet instance can determine its name using ServletConfig.getServletName()
.
This method returns null
if the ServletContext
cannot return a
RequestDispatcher
for any reason.
name
- a String
specifying the name of a servlet to wrapRequestDispatcher
object that acts as a wrapper for the named servlet, or
null
if the ServletContext
cannot return a RequestDispatcher
RequestDispatcher
,
getContext(java.lang.String)
,
ServletConfig.getServletName()
@Deprecated Servlet getServlet(java.lang.String name) throws ServletException
This method was originally defined to retrieve a servlet from a ServletContext
. In this
version, this method always returns null
and remains only to preserve binary
compatibility. This method will be permanently removed in a future version of Jakarta Servlets.
In lieu of this method, servlets can share information using the ServletContext
class
and can perform shared business logic by invoking methods on common non-servlet classes.
name
- the servlet namejavax.servlet.Servlet Servlet
with the given nameServletException
- if an exception has occurred that interfaces with servlet's normal operation@Deprecated java.util.Enumeration<Servlet> getServlets()
This method was originally defined to return an Enumeration
of all the servlets known to
this servlet context. In this version, this method always returns an empty enumeration and remains
only to preserve binary compatibility. This method will be permanently removed in a future version of
Jakarta Servlets.
Enumeration
of javax.servlet.Servlet Servlet
@Deprecated java.util.Enumeration<java.lang.String> getServletNames()
This method was originally defined to return an Enumeration
of all the servlet names
known to this context. In this version, this method always returns an empty Enumeration
and remains only to preserve binary compatibility. This method will be permanently removed in a
future version of Jakarta Servlets.
Enumeration
of javax.servlet.Servlet Servlet
namesvoid log(java.lang.String msg)
msg
- a String
specifying the message to be written to the log file@Deprecated void log(java.lang.Exception exception, java.lang.String msg)
log(String message, Throwable throwable)
instead.
This method was originally defined to write an exception's stack trace and an explanatory error message to the servlet log file.
exception
- the Exception
errormsg
- a String
that describes the exceptionvoid log(java.lang.String message, java.lang.Throwable throwable)
Throwable
exception to the servlet log
file. The name and type of the servlet log file is specific to the servlet container, usually an event log.message
- a String
that describes the error or exceptionthrowable
- the Throwable
error or exceptionjava.lang.String getRealPath(java.lang.String path)
For example, if path is equal to /index.html, this method will return the absolute file path on the server's filesystem to which a request of the form http://<host>:<port>/<contextPath>/index.html would be mapped, where <contextPath> corresponds to the context path of this ServletContext.
The real path returned will be in a form appropriate to the computer and operating system on which the servlet container is running, including the proper path separators.
Resources inside the /META-INF/resources directories of JAR files bundled in the application's /WEB-INF/lib directory must be considered only if the container has unpacked them from their containing JAR file, in which case the path to the unpacked location must be returned.
This method returns null
if the servlet container is unable to translate the given virtual
path to a real path.
path
- the virtual path to be translated to a real pathjava.lang.String getServerInfo()
The form of the returned string is servername/versionnumber. For example, the JavaServer Web
Development Kit may return the string JavaServer Web Dev Kit/1.0
.
The servlet container may return other optional information after the primary string in parentheses, for example,
JavaServer Web Dev Kit/1.0 (JDK 1.1.6; Windows NT 4.0 x86)
.
String
containing at least the servlet container name and version numberjava.lang.String getInitParameter(java.lang.String name)
String
containing the value of the named context-wide initialization parameter, or
null
if the parameter does not exist.
This method can make available configuration information useful to an entire web application. For example, it can provide a webmaster's email address or the name of a system that holds critical data.
name
- a String
containing the name of the parameter whose value is requestedString
containing the value of the context's initialization parameter, or
null
if the context's initialization parameter does not exist.java.lang.NullPointerException
- if the argument name
is null
ServletConfig.getInitParameter(java.lang.String)
java.util.Enumeration<java.lang.String> getInitParameterNames()
Enumeration
of
String
objects, or an empty Enumeration
if the context has no initialization
parameters.Enumeration
of String
objects containing the names of the context's
initialization parametersServletConfig.getInitParameter(java.lang.String)
boolean setInitParameter(java.lang.String name, java.lang.String value)
name
- the name of the context initialization parameter to setvalue
- the value of the context initialization parameter to setjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.NullPointerException
- if the name parameter is null
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.Object getAttribute(java.lang.String name)
null
if there is no attribute by
that name.
An attribute allows a servlet container to give the servlet additional information not already provided by this
interface. See your server documentation for information about its attributes. A list of supported attributes can
be retrieved using getAttributeNames
.
The attribute is returned as a java.lang.Object
or some subclass.
Attribute names should follow the same convention as package names. The Jakarta Servlet specification reserves
names matching java.*
, javax.*
, and sun.*
.
name
- a String
specifying the name of the attributeObject
containing the value of the attribute, or null
if no attribute exists
matching the given name.java.lang.NullPointerException
- if the argument name
is null
getAttributeNames()
java.util.Enumeration<java.lang.String> getAttributeNames()
Enumeration
containing the attribute names available within this ServletContext.
Use the getAttribute(java.lang.String)
method with an attribute name to get the value of an attribute.
Enumeration
of attribute namesgetAttribute(java.lang.String)
void setAttribute(java.lang.String name, java.lang.Object object)
If listeners are configured on the ServletContext
the container notifies them accordingly.
If a null value is passed, the effect is the same as calling removeAttribute()
.
Attribute names should follow the same convention as package names. The Jakarta Servlet specification reserves
names matching java.*
, javax.*
, and sun.*
.
name
- a String
specifying the name of the attributeobject
- an Object
representing the attribute to be boundjava.lang.NullPointerException
- if the name parameter is null
void removeAttribute(java.lang.String name)
getAttribute(java.lang.String)
to retrieve the attribute's value will return null
.
If listeners are configured on the ServletContext
the container notifies them accordingly.
name
- a String
specifying the name of the attribute to be removedjava.lang.String getServletContextName()
ServletRegistration.Dynamic addServlet(java.lang.String servletName, java.lang.String className)
The registered servlet may be further configured via the returned ServletRegistration
object.
The specified className will be loaded using the classloader associated with the application represented by this ServletContext.
If this ServletContext already contains a preliminary ServletRegistration for a servlet with the given servletName, it will be completed (by assigning the given className to it) and returned.
This method introspects the class with the given className for the
ServletSecurity
, MultipartConfig
,
javax.annotation.security.RunAs, and javax.annotation.security.DeclareRoles annotations. In
addition, this method supports resource injection if the class with the given className represents a
Managed Bean. See the Jakarta EE platform and CDI specifications for additional details about Managed Beans and
resource injection.
servletName
- the name of the servletclassName
- the fully qualified class name of the servletjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.IllegalArgumentException
- if servletName
is null or an empty Stringjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
ServletRegistration.Dynamic addServlet(java.lang.String servletName, Servlet servlet)
The registered servlet may be further configured via the returned ServletRegistration
object.
If this ServletContext already contains a preliminary ServletRegistration for a servlet with the given servletName, it will be completed (by assigning the class name of the given servlet instance to it) and returned.
servletName
- the name of the servletservlet
- the servlet instance to registerjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.IllegalArgumentException
- if the given servlet instance implements SingleThreadModel
, or
servletName
is null or an empty StringServletRegistration.Dynamic addServlet(java.lang.String servletName, java.lang.Class<? extends Servlet> servletClass)
The registered servlet may be further configured via the returned ServletRegistration
object.
If this ServletContext already contains a preliminary ServletRegistration for a servlet with the given servletName, it will be completed (by assigning the name of the given servletClass to it) and returned.
This method introspects the given servletClass for the ServletSecurity
,
MultipartConfig
, javax.annotation.security.RunAs, and
javax.annotation.security.DeclareRoles annotations. In addition, this method supports resource injection
if the given servletClass represents a Managed Bean. See the Jakarta EE platform and CDI specifications
for additional details about Managed Beans and resource injection.
servletName
- the name of the servletservletClass
- the class object from which the servlet will be instantiatedjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.IllegalArgumentException
- if servletName
is null or an empty Stringjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
ServletRegistration.Dynamic addJspFile(java.lang.String servletName, java.lang.String jspFile)
The registered servlet may be further configured via the returned ServletRegistration
object.
If this ServletContext already contains a preliminary ServletRegistration for a servlet with the given servletName, it will be completed (by assigning the given jspFile to it) and returned.
servletName
- the name of the servletjspFile
- the full path to a JSP file within the web application beginning with a `/'.java.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.IllegalArgumentException
- if servletName
is null or an empty Stringjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
<T extends Servlet> T createServlet(java.lang.Class<T> clazz) throws ServletException
The returned Servlet instance may be further customized before it is registered with this ServletContext via a
call to addServlet(String,Servlet)
.
The given Servlet class must define a zero argument constructor, which is used to instantiate it.
This method introspects the given clazz for the following annotations:
ServletSecurity
, MultipartConfig
,
javax.annotation.security.RunAs, and javax.annotation.security.DeclareRoles. In addition, this
method supports resource injection if the given clazz represents a Managed Bean. See the Jakarta EE
platform and CDI specifications for additional details about Managed Beans and resource injection.
T
- the class of the Servlet to createclazz
- the Servlet class to instantiateServletException
- if the given clazz fails to be instantiatedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
ServletRegistration getServletRegistration(java.lang.String servletName)
servletName
- the name of a servletjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.util.Map<java.lang.String,? extends ServletRegistration> getServletRegistrations()
The returned Map includes the ServletRegistration objects corresponding to all declared and annotated servlets, as well as the ServletRegistration objects corresponding to all servlets that have been added via one of the addServlet and addJspFile methods.
If permitted, any changes to the returned Map must not affect this ServletContext.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
FilterRegistration.Dynamic addFilter(java.lang.String filterName, java.lang.String className)
The registered filter may be further configured via the returned FilterRegistration
object.
The specified className will be loaded using the classloader associated with the application represented by this ServletContext.
If this ServletContext already contains a preliminary FilterRegistration for a filter with the given filterName, it will be completed (by assigning the given className to it) and returned.
This method supports resource injection if the class with the given className represents a Managed Bean. See the Jakarta EE platform and CDI specifications for additional details about Managed Beans and resource injection.
filterName
- the name of the filterclassName
- the fully qualified class name of the filterjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.IllegalArgumentException
- if filterName
is null or an empty Stringjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
FilterRegistration.Dynamic addFilter(java.lang.String filterName, Filter filter)
The registered filter may be further configured via the returned FilterRegistration
object.
If this ServletContext already contains a preliminary FilterRegistration for a filter with the given filterName, it will be completed (by assigning the class name of the given filter instance to it) and returned.
filterName
- the name of the filterfilter
- the filter instance to registerjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.IllegalArgumentException
- if filterName
is null or an empty Stringjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
FilterRegistration.Dynamic addFilter(java.lang.String filterName, java.lang.Class<? extends Filter> filterClass)
The registered filter may be further configured via the returned FilterRegistration
object.
If this ServletContext already contains a preliminary FilterRegistration for a filter with the given filterName, it will be completed (by assigning the name of the given filterClass to it) and returned.
This method supports resource injection if the given filterClass represents a Managed Bean. See the Java EE platform and CDI specifications for additional details about Managed Beans and resource injection.
filterName
- the name of the filterfilterClass
- the class object from which the filter will be instantiatedjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.IllegalArgumentException
- if filterName
is null or an empty Stringjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
<T extends Filter> T createFilter(java.lang.Class<T> clazz) throws ServletException
The returned Filter instance may be further customized before it is registered with this ServletContext via a
call to addFilter(String,Filter)
.
The given Filter class must define a zero argument constructor, which is used to instantiate it.
This method supports resource injection if the given clazz represents a Managed Bean. See the Jakarta EE platform and CDI specifications for additional details about Managed Beans and resource injection.
T
- the class of the Filter to createclazz
- the Filter class to instantiateServletException
- if the given clazz fails to be instantiatedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
FilterRegistration getFilterRegistration(java.lang.String filterName)
filterName
- the name of a filterjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.util.Map<java.lang.String,? extends FilterRegistration> getFilterRegistrations()
The returned Map includes the FilterRegistration objects corresponding to all declared and annotated filters, as well as the FilterRegistration objects corresponding to all filters that have been added via one of the addFilter methods.
Any changes to the returned Map must not affect this ServletContext.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
SessionCookieConfig getSessionCookieConfig()
SessionCookieConfig
object through which various properties of the session tracking cookies
created on behalf of this ServletContext may be configured.
Repeated invocations of this method will return the same SessionCookieConfig instance.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
void setSessionTrackingModes(java.util.Set<SessionTrackingMode> sessionTrackingModes)
The given sessionTrackingModes replaces any session tracking modes set by a previous invocation of this method on this ServletContext.
sessionTrackingModes
- the set of session tracking modes to become effective for this
ServletContextjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.IllegalArgumentException
- if sessionTrackingModes specifies a combination of
SessionTrackingMode.SSL with a session tracking mode other than
SessionTrackingMode.SSL, or if sessionTrackingModes
specifies a session tracking mode that is not supported by the servlet
containerjava.util.Set<SessionTrackingMode> getDefaultSessionTrackingModes()
The returned set is not backed by the ServletContext
object, so changes in the returned set are not
reflected in the ServletContext
object, and vice-versa.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.util.Set<SessionTrackingMode> getEffectiveSessionTrackingModes()
The session tracking modes in effect are those provided to setSessionTrackingModes
.
The returned set is not backed by the ServletContext
object, so changes in the returned set are not
reflected in the ServletContext
object, and vice-versa.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
void addListener(java.lang.String className)
The class with the given name will be loaded using the classloader associated with the application represented by this ServletContext, and must implement one or more of the following interfaces:
ServletContextAttributeListener
ServletRequestListener
ServletRequestAttributeListener
HttpSessionAttributeListener
HttpSessionIdListener
HttpSessionListener
If this ServletContext was passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, javax.servlet.ServletContext)
, then the class with the given
name may also implement ServletContextListener
, in addition to the interfaces listed above.
As part of this method call, the container must load the class with the specified class name to ensure that it implements one of the required interfaces.
If the class with the given name implements a listener interface whose invocation order corresponds to the
declaration order (i.e., if it implements ServletRequestListener
, ServletContextListener
, or
HttpSessionListener
), then the new listener will be added to the end of the ordered
list of listeners of that interface.
This method supports resource injection if the class with the given className represents a Managed Bean. See the Jakarta EE platform and CDI specifications for additional details about Managed Beans and resource injection.
className
- the fully qualified class name of the listenerjava.lang.IllegalArgumentException
- if the class with the given name does not implement any of the above
interfaces, or if it implements ServletContextListener
and this
ServletContext was not passed to
ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, javax.servlet.ServletContext)
java.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
<T extends java.util.EventListener> void addListener(T t)
The given listener must be an instance of one or more of the following interfaces:
ServletContextAttributeListener
ServletRequestListener
ServletRequestAttributeListener
HttpSessionAttributeListener
HttpSessionIdListener
HttpSessionListener
If this ServletContext was passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, javax.servlet.ServletContext)
, then the given listener may
also be an instance of ServletContextListener
, in addition to the interfaces listed above.
If the given listener is an instance of a listener interface whose invocation order corresponds to the
declaration order (i.e., if it is an instance of ServletRequestListener
, ServletContextListener
,
or HttpSessionListener
), then the listener will be added to the end of the ordered
list of listeners of that interface.
T
- the class of the EventListener to addt
- the listener to be addedjava.lang.IllegalArgumentException
- if the given listener is not an instance of any of the above interfaces, or
if it is an instance of ServletContextListener
and this
ServletContext was not passed to
ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, javax.servlet.ServletContext)
java.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
void addListener(java.lang.Class<? extends java.util.EventListener> listenerClass)
The given listenerClass must implement one or more of the following interfaces:
ServletContextAttributeListener
ServletRequestListener
ServletRequestAttributeListener
HttpSessionAttributeListener
HttpSessionIdListener
HttpSessionListener
If this ServletContext was passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, javax.servlet.ServletContext)
, then the given
listenerClass may also implement ServletContextListener
, in addition to the interfaces listed
above.
If the given listenerClass implements a listener interface whose invocation order corresponds to the
declaration order (i.e., if it implements ServletRequestListener
, ServletContextListener
, or
HttpSessionListener
), then the new listener will be added to the end of the ordered
list of listeners of that interface.
This method supports resource injection if the given listenerClass represents a Managed Bean. See the Jakarta EE platform and CDI specifications for additional details about Managed Beans and resource injection.
listenerClass
- the listener class to be instantiatedjava.lang.IllegalArgumentException
- if the given listenerClass does not implement any of the above
interfaces, or if it implements ServletContextListener
and this
ServletContext was not passed to
ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, javax.servlet.ServletContext)
java.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
<T extends java.util.EventListener> T createListener(java.lang.Class<T> clazz) throws ServletException
The specified EventListener class must implement at least one of the ServletContextListener
,
ServletContextAttributeListener
, ServletRequestListener
, ServletRequestAttributeListener
,
HttpSessionAttributeListener
, HttpSessionIdListener
, or
HttpSessionListener
interfaces.
The returned EventListener instance may be further customized before it is registered with this ServletContext
via a call to addListener(EventListener)
.
The given EventListener class must define a zero argument constructor, which is used to instantiate it.
This method supports resource injection if the given clazz represents a Managed Bean. See the Jakarta EE platform and CDI specifications for additional details about Managed Beans and resource injection.
T
- the class of the EventListener to createclazz
- the EventListener class to instantiateServletException
- if the given clazz fails to be instantiatedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.IllegalArgumentException
- if the specified EventListener class does not implement any of the
ServletContextListener
, ServletContextAttributeListener
,
ServletRequestListener
, ServletRequestAttributeListener
,
HttpSessionAttributeListener
,
HttpSessionIdListener
, or
HttpSessionListener
interfaces.JspConfigDescriptor getJspConfigDescriptor()
<jsp-config>
related configuration that was aggregated from the web.xml
and web-fragment.xml
descriptor files of the web application represented by this ServletContext.<jsp-config>
related configuration that was aggregated from the
web.xml
and web-fragment.xml
descriptor files of the web application
represented by this ServletContext, or null if no such configuration existsjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
JspConfigDescriptor
java.lang.ClassLoader getClassLoader()
If a security manager exists, and the caller's class loader is not the same as, or an ancestor of the requested
class loader, then the security manager's checkPermission
method is called with a
RuntimePermission("getClassLoader")
permission to check whether access to the requested class loader
should be granted.
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.SecurityException
- if a security manager denies access to the requested class loadervoid declareRoles(java.lang.String... roleNames)
isUserInRole
.
Roles that are implicitly declared as a result of their use within the
setServletSecurity
or
setRunAsRole
methods of the ServletRegistration
interface need not be declared.
roleNames
- the role names being declaredjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.IllegalArgumentException
- if any of the argument roleNames is null or the empty stringjava.lang.IllegalStateException
- if the ServletContext has already been initializedjava.lang.String getVirtualServerName()
String
containing the configuration name of the logical host on which the servlet context
is deployed.java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
int getSessionTimeout()
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
void setSessionTimeout(int sessionTimeout)
sessionTimeout
- session timeout in minutesjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.String getRequestCharacterEncoding()
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
void setRequestCharacterEncoding(java.lang.String encoding)
encoding
- request character encodingjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
java.lang.String getResponseCharacterEncoding()
java.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener
void setResponseCharacterEncoding(java.lang.String encoding)
encoding
- response character encodingjava.lang.IllegalStateException
- if this ServletContext has already been initializedjava.lang.UnsupportedOperationException
- if this ServletContext was passed to the
ServletContextListener.contextInitialized(javax.servlet.ServletContextEvent)
method of a
ServletContextListener
that was neither declared in
web.xml
or web-fragment.xml
, nor annotated with
WebListener


ZIP: 222 Title: Transparent Zcash Extensions Owners: Jack Grigg<EMAIL_ADDRESS>Kris Nuttycombe<EMAIL_ADDRESS>Credits: Zaki Manian Daira Emma Hopwood Sean Bowe Status: Draft Category: Consensus Created: 2019-07-01 License: MIT
The key words "MUST" and "MAY" in this document are to be interpreted as described in RFC 2119. 1
The term "network upgrade" in this document is to be interpreted as described in ZIP 200 6.
The term "prefix-free" in this document is to be interpreted as to mean that no valid encoding of a value may have the same binary representation as any prefix of the binary encoding of another value of the same type.
The term "non-malleable" in this document is to be interpreted as described in ZIP 244 7.
The value MAX_MONEY
is as defined in section 5.3 of the Zcash Protocol Specification 3.
This proposal defines a modification to the consensus rules that enables complex forms of transparent output preconditions to be deployed in network upgrades. This in turn enables the creation of "transparent Zcash extensions" that augment the network's functionality in a carefully-defined and auditable fashion.
Zcash supports a limited set of preconditions that may be imposed upon how funds, both transparent and shielded, may be spent. Spending limitations on transparent funds are defined by what may be encoded in Bitcoin script, and spending of shielded funds is even more restricted. As such, some use cases (for example, integration of BOLT support 9) are not yet supportable.
Transparent Zcash Extensions are intended to make it possible to incrementally add new functionality without modifying interpretation of the existing Bitcoin script, which is complex and potentially error-prone. Extensions may also serve as laboratories for evaluating demand for functionality which may eventually be candidates for inclusion in the consensus rules for shielded transactions.
Transparent Extensions are modular software components that are distributed as part of the code of consensus implementations. An extension defines interpretation rules for several new pieces of data that are included as part of a transaction.
A Transparent Extension is identified by a numeric type
. A Transparent Extension may also have several modes of operation, corresponding to different kinds of encumbrance within the extension's overall protocol.
The following three values are made available to the extension (in addition to type
):
mode
.precondition
containing an encoding of the precondition that is prefix-free within this (type, mode)
.witness
containing an encoding of evidence purporting to satisfy the precondition. This encoding MUST be prefix-free within this (type, mode)
.The extension is responsible for providing mode-specific parsing and serialization of these data fields. In addition, the extension MUST implement a deterministic verification algorithm tze_verify
that takes as arguments mode
, precondition
, witness
, and a context object. The context object provides deterministic public information about the transaction as well as the block chain (up to and including the block that the transaction is mined in). It returns true
if the precondition is satisfied in that context, and false
otherwise.
An extension MAY request that arbitrary public information about the transaction and block chain be included in the context object provided to it; these requirements MUST be satisfied by a caller integrating the extension at the integration point. Extensions SHOULD restrict the information requested to that which may be provided by node implementations in an efficient manner. For example, an extension SHOULD NOT require that it be provided full blocks in order to be able to construct or validate a precondition, and SHOULD minimize transaction data requested to that which are essential for its computational needs. In addition, while some preprocessing by the consensus-validating node may be requested, construction of such contextual data SHOULD NOT impose significant computational costs.
ZIPs that define a new transparent extension MUST completely specify the structure of all three of the specified values for each defined mode, as well as the behavior of tze_verify
and any contextual information required.
The encoded forms of precondition
and witness
are not required to be constant-length, but SHOULD be solely determined by the pair (type, mode)
.
The introduction of TZEs by this ZIP produces a new transparent unspent outpoint set, distinct from the UTXO set, such that indices into this set of outpoints may be referred to by TZE inputs in spending transactions.
We define a new transaction format that contains two new fields:
tze_outputs
: A list of pairs of:
tze_inputs
: A list of pairs of:
The transaction format is required to be non-malleable, in the sense that any change to the effects of the transaction will change its transaction ID, but any valid change to a witness
inside tze_inputs
will not change the transaction ID. This will be specified in a separate ZIP.
A new version <TBD> transaction format and corresponding version group identifier <TBD> will be introduced in the hard-fork network upgrade that introduces TZE functionality. The version <TBD> format differs from the version 4 transaction format as follows: a length-prefixed encoding of TZE inputs and outputs are added to the serialized transaction format immediately following the fields representing transparent inputs and outputs.
| Version | Field | Description | Type |
|---|---|---|---|
... |
... as before |
... |
... |
| >= 1 | tx_in_count |
variable-length integer | compactSize |
| >= 1 | tx_in |
list of inputs | vector |
| >= 1 | tx_out_count |
variable-length integer | compactSize |
| >= 1 | tx_out |
list of outputs | vector |
| >= <TBD> | tze_in_count |
variable-length integer | compactSize |
| >= <TBD> | tze_in |
list of TZE inputs | vector |
| >= <TBD> | tze_out_count |
variable-length integer | compactSize |
| >= <TBD> | tze_out |
list of TZE outputs | vector |
| >= 1 | lock_time |
block height or timestamp | uint32 |
... |
... as before |
... |
... |
Both tze_in
and tze_out
vectors make use of the common serialized form tze_data
described below. Serialization of all integer and vector types is as with Bitcoin.
tze_data
encoding:
| Field | Description | Type |
|---|---|---|
tze_id |
extension type |
compactSize |
tze_mode |
extension mode |
compactSize |
tze_data_payload_len |
length of precondition/witness data | compactSize |
tze_data_payload |
serialized precondition/witness data | tze_data_payload_len bytes |
TZE Input Encoding:
| Field | Description | Type |
|---|---|---|
prevout_hash |
previous txid | uint256 |
prevout_in |
index into previous txn's outputs | uint32 |
witness |
witness for prevout's precondition | tze_data |
TZE Output Encoding:
| Field | Description | Type |
|---|---|---|
amount |
spendable amount, in zatoshi | int64 |
precondition |
encodes a precondition encumbering amount |
tze_data |
Once this ZIP becomes active, the following new consensus rules are enforced:
(outpoint, witness)
pair in tze_inputs
:
outpoint
MUST reference a precondition of the same type and mode in an already-mined transaction.tze_verify(mode, precondition, witness, context)
MUST return true
.tze_inputs
and non-empty tze_outputs
, then every element in both fields MUST have the same type
in order to eliminate the possibility for cross-extension attacks. As this is not a consideration in the case that only tze_inputs
or only tze_outputs
are present, the extension type
MAY vary between elements in that case.tze_inputs
The above rule replaces [Sapling onward] At least one of tx_in_count,
nShieldedSpend, and nJoinSplit MUST be nonzero
in 4.
tze_outputs
amount
field values of tze_output
records MUST be nonnegative and not greater than MAX_MONEY
.vpub_old
values) MUST NOT exceed the sum of amounts going into that pool (that is, Bitcoin-style inputs and TZE inputs, plus JoinSplit vpub_new
values, plus the Sapling valueBalance
amount).This ZIP MUST be deployed in conjunction with or after ZIP 244 7, which defines new non-malleable transaction identifier and signature digest algorithms.
The newly added parts of the transaction, excluding witness information (i.e. not the witness
fields of TZE Input Encodings), will be included in transaction digests for transaction identifiers and signatures. See ZIP 245 8 for the specification of these new digests. If the changes in this ZIP are deployed, those described in ZIP 245 MUST be deployed as well.
Transactions that have both TZE inputs and outputs are required to use a single extension type, in order to prevent cross-protocol attacks. The downside is that this prevents all TZE-encumbered value from being spent directly into a different TZE type; the value needs to go through a regular address in between. This restriction might be relaxed in future ZIPs for specific combinations of (type, mode)
pairs that have been analyzed for cross-protocol attacks, but we opt here for a fail-safe default behaviour.
Transactions with TZE inputs which do not contain TZE outputs are not subject to single-extension or single-mode restrictions; likewise, transactions which contain TZE outputs without any TZE inputs may produce TZE outputs for multiple extension-type/mode pairs as the potential for cross-protocol attacks in this situation is negligible.
An earlier draft version of this ZIP stored the payloads inside transparent inputs and outputs. Although this had the advantage of not requiring a transaction format change, the consensus rules were significantly more complicated, and the design coupled the extension logic too tightly to the transparent address logic. Instead, this ZIP uses dedicated transaction fields, and a separate unspent output set.
This ZIP assumes that the base transaction format is non-malleable. However, the precondition
and witness
byte sequences are treated here as opaque. It is the responsibility of tze_verify
to enforce the following:
precondition
MUST be non-malleable: any malleation MUST cause tze_verify
to return false
.tze_verify(mode, precondition, witness, context)
MUST be deterministic.ZIPs defining new extension types MUST include a section explaining how any potential sources of malleability are handled.
This ZIP includes restrictions to prevent cross-protocol attacks, but the extension mode is another potential attack surface. It is the responsibility of ZIPs defining new extensions to examine the potential for cross-mode attacks within their security analysis, and/or appropriately restrict which modes may be combined within a single transaction.
The handler semantics of tze_verify
were suggested by Zaki Manian, drawing on the design of Cosmos. Daira Emma Hopwood and Sean Bowe gave useful feedback on an early draft of this ZIP, and helped to analyse the various sources of transaction ID malleability.
We would also like to thank the numerous other individuals who participated in discussions at Zcon1 that led to the earlier draft version of this ZIP.
| 1 | RFC 2119: Key words for use in RFCs to Indicate Requirement Levels |
|---|
| 2 | Zcash Protocol Specification, Version 2021.2.16 or later |
|---|
| 3 | Zcash Protocol Specification, Version 2021.2.16. Section 5.3: Constants |
|---|
| 4 | Zcash Protocol Specification, Version 2021.2.16. Section 7.1: Transaction Consensus Rules |
|---|
| 5 | ZIP 32: Shielded Hierarchical Deterministic Wallets |
|---|
| 6 | ZIP 200: Network Upgrade Mechanism |
|---|
| 7 | ZIP 244: Transaction Non-Malleability Support |
|---|
| 8 | ZIP 245: Transaction Identifier Digests & Signature Validation for Transparent Zcash Extensions |
|---|
| 9 | Draft ZIP: Add support for Blind Off-chain Lightweight Transactions (Bolt) protocol |
|---|
| 10 | Rust language reference implementation of TZE API |
|---|
| 11 | zcashd reference implementation of consensus rule changes |
|---|


JavaScript Events
In the following example, an onclick attribute (with code), is added to a button element:
The time is?


Money Play. Should Red double? If doubled, should White take?
pips Red=81 White=134
(CorrectAnswer= 0/0, ErrorScore= 0)
Basic backgammon theory says that you should wait to double a back game until you have only three points to clear in front of the defender's front-most anchor.
That is the case here and so Red should certainly double.
Unlike most back games Red has room to park checkers behind White's anchors and so when I saw this position I assumed White must have a clear drop,
This turns out not to be the case and this position is right on the borderline and White can take or pass. One reason is that when White does lose he loses fewer gammons than when his anchors are further back in Red's home board. Thus, he needs to win a lower percentage than normal to be able to accept the double.
Interestingly if you take a checker from White's 2-pt and put it on his mid-point the take becomes trivial because White won't have to give up one of his back game anchors so quickly.
That is the case here and so Red should certainly double.
Unlike most back games Red has room to park checkers behind White's anchors and so when I saw this position I assumed White must have a clear drop,
This turns out not to be the case and this position is right on the borderline and White can take or pass. One reason is that when White does lose he loses fewer gammons than when his anchors are further back in Red's home board. Thus, he needs to win a lower percentage than normal to be able to accept the double.
Interestingly if you take a checker from White's 2-pt and put it on his mid-point the take becomes trivial because White won't have to give up one of his back game anchors so quickly.
Cube analysis 2-ply cubeless equity +0.612 0.749 0.132 0.001 - 0.251 0.019 0.000 Cubeful equities: 1. Double, pass +1.000 2. Double, take +1.054 (+0.054) 3. No double +0.948 (-0.052) Proper cube action: Double, pass


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Once we have defined clients' key requirements, we start thinking deeper and wider to find out the best solutions in terms of web structure, web graphic design and technologies.
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We will provide a homepage design draft to clients to confirm that they like our ideas. Once we receive the confirmation we start building the website.
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NOTE:
If the links are NOT expanded when clicking on them (e.g. on Chrome, Firefox), please scroll down to the second part, where I have included all the expanded links which can be clicked and opened.
If the links are NOT expanded when clicking on them (e.g. on Chrome, Firefox), please scroll down to the second part, where I have included all the expanded links which can be clicked and opened.
Chapter: Personal Module For Data Analysis: bp
Personal Module: bp
A01: What does the Module Do? (GIF videos)
API usage
Data Visualization
Data Visualization using Plotly
Statistics
Model Evaluation
Time Series Analysis
Miscellaneous Usage
A02: Detailed Use of Module bp (Jupyter Notebooks)
Data Description
Data Visualization
Data Visualization using Plotly
EDA using Plotly
Miscellaneous Plots
Matplotib Styles
Deal with Colors
Statistics
Timeseries Analysis
Model Evaluation
Chapter 1: Data Science Projects
Section A: Regression
A01: King County Seattle House Price Prediction (Regression)
GitHub
README
Statistics Report
a01 Data Processing
a02 Data processing Script
a03 Regression Statistics
a04 Regression EDA
a05 Regression EDA: bokeh
a06 Regression EDA: plotly
a07 Regression EDA: pixiedust
a08 Regression EDA: pandas profiling
b01 Regression Modelling (Boosting): Hist Gradient Boosting
b02 Regression Modelling (Boosting): XGBoost
b03 Regression Modelling (Boosting): LightGBM
b04 Regression Modelling (Boosting): CatBoost
e01 Regression Modelling (Ensemble): Stacking and Blending
m01 Regression Modelling (sklearn): linear and polynomial regression
m02 Regression Modelling (sklearn): sklearn methods
m03 Regression Modelling (sklearn): Random Forest
m04 Regression Modelling (statsmodels): linear OLS
s01 Regression Modelling (Special): pycaret
s02 Feature Engineering (Featuretools): XGBoost
s03 Feature Engineering (Featuretools): LightGBM
s04 Feature Engineering (Featuretools): CatBoost
w01 Model Interpretation: Yellowbrick, Lime, Eli5
w02 Model Interpretation: What If Tool (WIT)
w03 Model Interpretation: Dalex
w04 Model Interpretation: Dtreeviz
x01 Big Data Analysis: PySpark
x02 Big Data Analysis: PySpark Random Forest Tuning
y01 Deep Learning: Keras
z01 Best Model: CatBoost
z02 Best Model: XGBoost
z03 Best Model: Overall
A02: All State Insurance (Insurance: Regression)
GitHub
README
a01 Exploratory Data Analysis
a02 Data Processing
b01 Modelling
b02 Modelling Pyspark
Section B: Classification
BX.01: Fraud Detection (Binary Classification)
GitHub
README
Deploy End to End Machine Learning Model (Fraud Detection) on Heroku
a01 Classification EDA
a02 Classification Statistics
b01a Classification Modelling (Boosting): XGBboost
b01b Classification Modelling (Boosting): XGBboost (HPO)
b01c Classification Modelling (Boosting): XGBboost Custom Loss
b02 Classification Modelling (Boosting): LightGBM
b03 Classification Modelling (Boosting): Catboost
b03b Classification Modelling (Boosting): Catboost Custom Loss
e01 Classification Modelling (Ensemble): Stacking
m01 Classification Modelling (sklearn): Undersampling
m02 Classification Modelling (sklearn): Logistic Regression SMOTE
m03 Classification Modelling (sklearn): Decision Tree
m04 Classification Modelling (sklearn): Calibrated Classification
b05 Classification Modelling (sklearn): Isolation Forest and LOF
s01 Classification Modelling (Special): pycaret (lda)
s02 Classification Modelling (Special): evalML
x01 Classification Modelling (Big Data): dask
x02 Classification Modelling (Big Data): vaex
x03 Classification Modelling (Big Data): pySpark
y01 Classification Modelling (Deep Learning): keras simple model
y02 Classification Modelling (Deep Learning): keras large model
y03 Classification Modelling (Deep Learning): keras oversampling
y04 Classification Modelling (Deep Learning): keras classifier sklearn api
y05 Classification Modelling (Deep Learning): keras classifier (Keras tuner)
BX.02: Customer Churn (Binary Classification)
GitHub
README
a01 Exploratory Data Analysis
a01 Exploratory Data Analysis (Plolty)
a02 Customer Churn: Data Processing
bx01 Modelling (Boosting): XGBoost with HyperbandCV
bx02 Modelling (Boosting): XGBoost with Bayes Optimization
bl01 Modelling (Boosting): LightGBM Classifier with sklearn pipeline and HyperbandCV
bl02 Modelling (Boosting): LightGBM Classifier with Optuna HPO
bl03 Modelling (Boosting): LightGBM Classifier with Hyperopt HPO
bc01 Modelling (Boosting): CatBoostClassifier with optuna hyperparameter tuning
ml01 Modelling (Sklearn): LogisticRegression
ml02 Modelling (Sklearn): LogisticRegressionCV
splr01 Modelling (Special): (Pycaret) Logistic Regression
spn01 Modelling (Special): (Pycaret) Naive Bayes
spx01 Modelling (Special): (Pycaret) Xgboost
spdla01 Modelling (Special): (Pycaret) Linear Discriminant Analysis
sflr01 Modelling (Special): (featuretools) Logistic Regression
se01 Modelling (Special): (evalml) Built-in Algorithm
w01 Model Interpretation: (What If Tool) Logistic Regression
wbl Model Interpretation: (LOFO) Logistic Regression
w01 Model Interpretation: (Interpret) Builtin Estimators Logistic Regression and Boosting
y01 Deep Learning: (Keras) Sequential Simple Model
BX.03: Porto Seguro Auto Insurance (Binary Classification)
GitHub
README
a01 Exploratory Data Analysis
a02 Modelling: LightGBM
a03 Modelling: XGBoost
a04 Modelling: Keras Entity Embedding
a05 Modelling: Stacking different Models
a06 Feature Selection: Boruta and Target Permutation
BX.04: Breast Cancer Wisconsin (Binary Classification)
GitHub
README
a01 Exploratory Data Analysis
b01 Modlling: (Boosting) XGBoost
y01 Deep Learning: Keras Sequential with class_weight
y02 Deep Learning: Keras Sequential
BY.01: Prudential Insurance (Multiclass Classification)
GitHub
README
a01 Exploratory Data Analysis
a02 Multiclass Classification Statistics
a03 Data Preprocessing
a04 Data Preprocessing Script
b01 Modelling: Linear Regression
b02 Modelling: RF Classifier
b03 Modelling: RF Classifier AUC ROC
b04 Modelling: XGBoost Multiclass Classification
b05 Modelling: XGBoost Linear Regression and Poisson Regression with Offset
c01 Multiclass Model Interpretation: eli5, shap and pdpbox
Section C: Timeseries Analysis
C01: Timeseries Analysis for Web Traffic Data
GitHub
README
a01 Data Processing
b01 Timeseries visualization and eda
c01 Timeseries statistics
d01 Timeseries modelling: ARIMA
d02 Timeseries modelling: VAR
e01 Timeseries modelling: sklearn
f01 Timeseries modelling: tsfresh and xgboost
g01 Timeseries modelling: fbprophet
g02 Timeseries modelling: fbprophet holidays
h01 Timeseries modelling: deep learning
Section D: Natural Language Processing (NLP)
D01: Twitter Sentiment Analysis (Analytics Vidhya Hackathon: Identify the Sentiment)
GitHub
a00 README
a01 Text Data Processing
a02 Text Data EDA
a03 Scattertext for positive and negative sentiments
a03b Result: Twitter Sentiment Html
b01 Text Data Modelling: BoW + Word2Vec + TF-IDF
b02 Text Data Modelling: TF-IDF + Logistic Regression
c01 Sentiment Analysis: ktrain
c01 Sentiment Analysis: ktrain, neptune
c01 Sentiment Analysis: ktrain, neptune HPO
c02 Sentiment Analysis: simpletransformers + Roberta
d01 Sentiment Analysis: (keras) LSTM
d02 Sentiment Analysis: (keras) GRU, CNN, LSTM
e01 Sentiment Analysis: (transformers) Small data with torch and distilbert
e02 Sentiment Analysis: (transformers): Full data with keras and distilbert
e03 Sentiment Analysis: BERT and Tensorflow
e03 Sentiment Analysis: BERT, Tensorflow, and Neptune
D02: Toxic Comments (Multiclass Text Classification)
GitHub
README
a01 Text Data Processing
a02 Text Data EDA
a03 Text Data EDA: Plotly
m01 Text Data Binary Classification (Toxic or not)
s01 Named Entity Recognition and Dependency Parsing: spacy2
s01 Named Entity Recognition and Dependency Parsing: spacy3
y01 Deep Learning: GRU and Fasttext
y01b Deep Learning: GRU, Fasttext, Badwords
y02 Deep Learning: Transformers PyTorch BERT
y02b Deep Learning: Transformers PyTorch XLNET
y02c Deep Learning: Transformers PyTorch DisltilBert
y03 Bert Client: XGBoost
y03b Bert Client: Keras Sequential
D03: Consumer Complaints (Multiclass Text Classification)
GitHub
README
a01 Text Processing
a02 EDA for Text Data
b01 Text Data Modelling: Tf-idf and Sklearn Classifiers
b02 Text Data Modelling: LinearSVC
c01 Model Evaluation: Yellowbrick
c02 Model Evaluation: scikit-plot
d01 Text Data Modelling: PySpark
e01 Text Data Modelling: simpletransformers
Section E: Insurance Data Modelling
E01: French Motor Claims (Pure Premium Modelling)
GitHub
README
a01 Data Cleaning
b01 Frequency Modelling (Poisson Regressor)
b02 Severity Modelling (Gamma Regressor)
b03 Pure Premium Modelling (Tweedie Regressor)
b04 Tweedie Model vs FrequencySeverity Model
b05 Lorentz Curves Comparison
c01 Xgboost with Tweedie Regression
d01 GAM Linearized Modelling using Pygam
Section F: Financial Data Analysis
F01: Credit Risk (Banking: Financial Modelling (Scorecard))
GitHub
README
a01 EDA for Credit Risk Data
a02 Data Processing
b01 Risk Modelling: PDModel Gini KS CreditScore Scorecard
Chapter 2: SQL
2A: SQLITE Queries for Northwind Database (Book: SQL Practice Problems by Vasilik)
a01 Beginner Level Problems (1-19)
a02 Intermediate Level Problems (20-31)
a03 Advanced Level Problems (32-57)
2B.01: SQL Queries for Hospital Management Database
a01 SQL Queries using postgres
a02 SQL Queries using postgres, sqlalachemy and pandas
a03 SQL Queries using sqlite3
2B.02: SQL Queries for Computer Store Database
a01 SQL Queries using postgres
a02 SQL Queries using sqlite
2B.03: SQL Queries for Employee Management Database
a01 SQL Queries using postgres and pyspark
2B.04: SQL Queries for the Warehouse Database
a01 SQL Queries using postgres
a02 SQL Queries using pyspark and postgres
2B.05: SQL Queries for Movie Theaters Database
a01 SQL Queries using pyspark and postgres
a02 SQL Queries using pyspark and sqlite
2B.06: SQL Queries for Pieces and Providers Database
a01 SQL Queries using postgresql
a02 SQL Queries using pyspark, sqlite and sqlalchemy
Chapter 3: Business Projects
3.01: Spanish Translation A/B Testing
GitHub
README
a01 Spanish Translation A/B Testing with Extensive EDA and Statistical Tests
3.02: Customer Lifetime Value
GitHub
README
a01 Data Cleaning
b01 Modelling: BG/NBD and Gamma-Gamma Distribution
b02 Modelling: Keras Modelling and XGBoost
NOTE:
If we are using Safari, we can expand the collapsible links in above section. But for other browers, such as Google Chrome, the links may not be expanded. In that case, I have included all the expanded version of the links in the below section.
My Personal Module: bp
If we are using Safari, we can expand the collapsible links in above section. But for other browers, such as Google Chrome, the links may not be expanded. In that case, I have included all the expanded version of the links in the below section.
Data Description
Data Visualization
Data Visualization using Plotly
EDA using Plotly
Miscellaneous Plots
Matplotib Styles
Deal with Colors
Statistics
Timeseries Analysis
Model Evaluation
A01: King County Seattle House Price Prediction (Regression)
GitHub
README
Statistics Report
a01 Data Processing
a02 Data processing Script
a03 Regression Statistics
a04 Regression EDA
a05 Regression EDA: bokeh
a06 Regression EDA: plotly
a07 Regression EDA: pixiedust
a08 Regression EDA: pandas profiling
b01 Regression Modelling (Boosting): Hist Gradient Boosting
b02 Regression Modelling (Boosting): XGBoost
b03 Regression Modelling (Boosting): LightGBM
b04 Regression Modelling (Boosting): CatBoost
e01 Regression Modelling (Ensemble): Stacking and Blending
m01 Regression Modelling (sklearn): linear and polynomial regression
m02 Regression Modelling (sklearn): sklearn methods
m03 Regression Modelling (sklearn): Random Forest
m04 Regression Modelling (statsmodels): linear OLS
s01 Regression Modelling (Special): pycaret
s02 Feature Engineering (Featuretools): XGBoost
s03 Feature Engineering (Featuretools): LightGBM
s04 Feature Engineering (Featuretools): CatBoost
w01 Model Interpretation: Yellowbrick, Lime, Eli5
w02 Model Interpretation: What If Tool (WIT)
w03 Model Interpretation: Dalex
w04 Model Interpretation: Dtreeviz
x01 Big Data Analysis: PySpark
x02 Big Data Analysis: PySpark Random Forest Tuning
y01 Deep Learning: Keras
z01 Best Model: CatBoost
z02 Best Model: XGBoost
z03 Best Model: Overall
A02: All State Insurance (Insurance: Regression)GitHub
README
a01 Exploratory Data Analysis
a02 Data Processing
b01 Modelling
b02 Modelling Pyspark
Section B: Classification
BX.01: Fraud Detection (Binary Classification)GitHub
README
Deploy End to End Machine Learning Model (Fraud Detection) on Heroku
a01 Classification EDA
a02 Classification Statistics
b01a Classification Modelling (Boosting): XGBboost
b01b Classification Modelling (Boosting): XGBboost (HPO)
b01c Classification Modelling (Boosting): XGBboost
b02 Classification Modelling (Boosting): LightGBM
b03 Classification Modelling (Boosting): Catboost
b03b Classification Modelling (Boosting): Catboost Custom Loss
e01 Classification Modelling (Ensemble): Stacking
m01 Classification Modelling (sklearn): Undersampling
m02 Classification Modelling (sklearn): Logistic Regression SMOTE
m03 Classification Modelling (sklearn): Decision Tree
m04 Classification Modelling (sklearn): Calibrated Classification
b05 Classification Modelling (sklearn): Isolation Forest and LOF
s01 Classification Modelling (Special): pycaret (lda)
s02 Classification Modelling (Special): evalML
x01 Classification Modelling (Big Data): dask
x02 Classification Modelling (Big Data): vaex
x03 Classification Modelling (Big Data): pySpark
y01 Classification Modelling (Deep Learning): keras simple model
y02 Classification Modelling (Deep Learning): keras large model
y03 Classification Modelling (Deep Learning): keras oversampling
y04 Classification Modelling (Deep Learning): keras classifier sklearn api
y05 Classification Modelling (Deep Learning): keras classifier (Hyperparameter tuning)
BX.02: Customer Churn (Binary Classification)GitHub
README
a01 Exploratory Data Analysis
a01 Exploratory Data Analysis (Plolty)
a02 Customer Churn: Data Processing
bx01 Modelling (Boosting): XGBoost with HyperbandCV
bx02 Modelling (Boosting): XGBoost with Bayes Optimization
bl01 Modelling (Boosting): LightGBM Classifier with sklearn pipeline and HyperbandCV
bl02 Modelling (Boosting): LightGBM Classifier with Optuna HPO
bl03 Modelling (Boosting): LightGBM Classifier with Hyperopt HPO
bc01 Modelling (Boosting): CatBoostClassifier with optuna hyperparameter tuning
ml01 Modelling (Sklearn): LogisticRegression
ml02 Modelling (Sklearn): LogisticRegressionCV
splr01 Modelling (Special): (Pycaret) Logistic Regression
spn01 Modelling (Special): (Pycaret) Naive Bayes
spx01 Modelling (Special): (Pycaret) Xgboost
spdla01 Modelling (Special): (Pycaret) Linear Discriminant Analysis
sflr01 Modelling (Special): (featuretools) Logistic Regression
se01 Modelling (Special): (evalml) Built-in Algorithm
w01 Model Interpretation: (What If Tool) Logistic Regression
wbl Model Interpretation: (LOFO) Logistic Regression
w01 Model Interpretation: (Interpret) Builtin Estimators Logistic Regression and Boosting
y01 Deep Learning: (Keras) Sequential Simple Model
BX.03: Porto Seguro Auto Insurance (Binary Classification)GitHub
README
a01 Exploratory Data Analysis
a02 Modelling: LightGBM
a03 Modelling: XGBoost
a04 Modelling: Keras Entity Embedding
a05 Modelling: Stacking different Models
a06 Feature Selection: Boruta and Target Permutation
BX.04: Breast Cancer Wisconsin (Binary Classification)GitHub
README
a01 Exploratory Data Analysis
b01 Modlling: (Boosting) XGBoost
y01 Deep Learning: Keras Sequential with class_weight
y02 Deep Learning: Keras Sequential
BY.01: Prudential Insurance (Multiclass Classification)GitHub
README
a01 Exploratory Data Analysis
a02 Multiclass Classification Statistics
a03 Data Preprocessing
a04 Data Preprocessing Script
b01 Modelling: Linear Regression
b02 Modelling: RF Classifier
b03 Modelling: RF Classifier AUC ROC
b04 Modelling: XGBoost Multiclass Classification
b05 Modelling: XGBoost Linear Regression and Poisson Regression with Offset
c01 Multiclass Model Interpretation: eli5, shap and pdpbox
Section C: Timeseries Analysis
C01: Timeseries Analysis for Web Traffic DataGitHub
README
a01 Data Processing
b01 Timeseries visualization and eda
c01 Timeseries statistics
d01 Timeseries modelling: ARIMA
d02 Timeseries modelling: VAR
e01 Timeseries modelling: sklearn
f01 Timeseries modelling: tsfresh and xgboost
g01 Timeseries modelling: fbprophet
g02 Timeseries modelling: fbprophet holidays
h01 Timeseries modelling: deep learning
Section D: Natural Language Processing (NLP)
D01: Twitter Sentiment Analysis (Analytics Vidhya Hackathon: Identify the Sentiment)GitHub
a00 README
a01 Text Data Processing
a02 Text Data EDA
a03 Scattertext for positive and negative sentiments
a03b Result: Twitter Sentiment Html
b01 Text Data Modelling: BoW + Word2Vec + TF-IDF
b02 Text Data Modelling: TF-IDF + Logistic Regression
c01 Sentiment Analysis: ktrain
c01 Sentiment Analysis: ktrain, neptune
c01 Sentiment Analysis: ktrain, neptune HPO
c02 Sentiment Analysis: simpletransformers + Roberta
d01 Sentiment Analysis: (keras) LSTM
d02 Sentiment Analysis: (keras) GRU, CNN, LSTM
e01 Sentiment Analysis: (transformers) Small data with torch and distilbert
e02 Sentiment Analysis: (transformers): Full data with keras and distilbert
e03 Sentiment Analysis: BERT and Tensorflow
e03 Sentiment Analysis: BERT, Tensorflow, and Neptune
D02: Toxic Comments (Multiclass Text Classification)GitHub
README
a01 Text Data Processing
a02 Text Data EDA
a03 Text Data EDA: Plotly
m01 Text Data Binary Classification (Toxic or not)
s01 Named Entity Recognition and Dependency Parsing: spacy2
s01 Named Entity Recognition and Dependency Parsing: spacy3
y01 Deep Learning: GRU and Fasttext
y01b Deep Learning: GRU, Fasttext, Badwords
y02 Deep Learning: Transformers PyTorch BERT
y02b Deep Learning: Transformers PyTorch XLNET
y02c Deep Learning: Transformers PyTorch DisltilBert
y03 Bert Client: XGBoost
y03b Bert Client: Keras Sequential
D03: Consumer Complaints (Multiclass Text Classification)GitHub
README
a01 Text Processing
a02 EDA for Text Data
b01 Text Data Modelling: Tf-idf and Sklearn Classifiers
b02 Text Data Modelling: LinearSVC
c01 Model Evaluation: Yellowbrick
c02 Model Evaluation: scikit-plot
d01 Text Data Modelling: PySpark
e01 Text Data Modelling: simpletransformers
Section E: Insurance Data Modelling
E01: French Motor Claims (Pure Premium Modelling)GitHub
README
a01 Data Cleaning
b01 Frequency Modelling (Poisson Regressor)
b02 Severity Modelling (Gamma Regressor)
b03 Pure Premium Modelling (Tweedie Regressor)
b04 Tweedie Model vs FrequencySeverity Model
b05 Lorentz Curves Comparison
c01 Xgboost with Tweedie Regression
d01 GAM Linearized Modelling using Pygam
Section F: Financial Data Analysis
F01: Credit Risk (Banking: Financial Modelling (Scorecard))GitHub
README
a01 EDA for Credit Risk Data
a02 Data Processing
b01 Risk Modelling: PDModel Gini KS CreditScore Scorecard
Chapter 2: SQL
2A: SQLITE Queries for Northwind Database (Book: SQL Practice Problems by Vasilik)a01 Beginner Level Problems (1-19)
a02 Intermediate Level Problems (20-31)
a03 Advanced Level Problems (32-57)
2B.01: SQL Queries for Hospital Management Databasea01 SQL Queries using postgres
a02 SQL Queries using postgres, sqlalachemy and pandas
a03 SQL Queries using sqlite3
2B.02: SQL Queries for Computer Store Databasea01 SQL Queries using postgres
a02 SQL Queries using sqlite
2B.03: SQL Queries for Employee Management Databasea01 SQL Queries using postgres and pyspark
2B.04: SQL Queries for the Warehouse Databasea01 SQL Queries using postgres
a02 SQL Queries using pyspark and postgres
2B.05: SQL Queries for Movie Theaters Databasea01 SQL Queries using pyspark and postgres
a02 SQL Queries using pyspark and sqlite
2B.06: SQL Queries for Pieces and Providers Databasea01 SQL Queries using postgresql
a02 SQL Queries using pyspark, sqlite and sqlalchemy
Chapter 3: Business Projects
3.01: Spanish Translation A/B TestingGitHub
README
a01 Spanish Translation A/B Testing with Extensive EDA and Statistical Tests
3.02: Customer Lifetime ValueGitHub
README
a01 Data Cleaning
b01 Modelling: BG/NBD and Gamma-Gamma Distribution
b02 Modelling: Keras Sequential and XGBoost
Chapter 4: Personal Module "bp"
The module "bp" expands pandas DataFrame API and adds various visualization and data analysis functionalities. For example, we can get a plot of a numeric column using the method "df.bp.plot_num("my_numeric_variable")".
Currently my module contains following methods:
| 1 | 2 | 3 | 4 | |||
|---|---|---|---|---|---|---|
| BPAccessor | hlp | plot_daily_cat | plotly_corr_heatmap | |||
| Plotly_Charts | json | plot_date_cat | plotly_countplot | |||
| RandomColor | light_axis | plot_ecdf | plotly_country_plot | |||
| add_interactions | lm_plot | plot_gini | plotly_distplot | |||
| add_text_barplot | lm_residual_corr_plot | plot_ks | plotly_histogram | |||
| adjustedR2 | lm_stats | plot_multiple_jointplots_with_pearsonr | plotly_mapbox | |||
| hex_to_rgb | magnify | plot_num | plotly_radar_plot | |||
| discrete_cmap | multiple_linear_regression | plot_num_cat | plotly_scattergl_plot | |||
| display_calendar | no_axis | plot_num_cat2 | plotly_scattergl_plot_colorcol | |||
| plot_plot_binn | optimize_memory | plot_num_num | plotly_scattergl_plot_subplots | |||
| find_corr | parallelize_dataframe | plot_pareto | plotly_usa_bubble_map | |||
| freq_count | parse_json_col | plot_roc_auc | plotly_usa_map | |||
| get_binary_classification_report | partial_corr | plot_roc_skf | plotly_usa_map2 | |||
| get_binary_classification_scalar_metrics | plot_boxplot_cats_num | plot_simple_linear_regression | point_biserial_correlation | |||
| get_binary_classification_scalar_metrics2 | plot_cat | plot_statistics | print_calendar | |||
| get_column_descriptions | plot_cat_binn | plot_stem | print_confusion_matrix | |||
| get_distinct_colors | plot_cat_cat | plot_two_clusters | print_df_eval | |||
| get_false_negative_frauds | plot_cat_cat2 | plotly_agg_country_plot | print_statsmodels_summary | |||
| get_high_correlated_features_df | plot_cat_cat_pct | plotly_agg_usa_plot | random | |||
| get_mpl_style | plot_cat_num | plotly_binary_clf_evaluation | regression_residual_plots | |||
| get_outliers | plot_confusion_matrix_plotly | plotly_boxplot | remove_outliers | |||
| get_outliers_kde | plot_corr | plotly_boxplot_allpoints_with_outliers | rgb2hex | |||
| get_plotly_colorscale | plot_corr_style | plotly_boxplot_categorical_column | select_kbest_features | |||
| get_yprobs_sorted_proportions | plot_corrplot_with_pearsonr | plotly_bubbleplot | show_methods |
Chapter 5: Overview of My Projects (GIF Videos)
- Click on the box to show the GIF video. (The box moves down and GIF video plays above it.)
- Go to the buttom of the gif and click the same button again to hide the video.


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NYCAASC 2018: Emergence Workshops
NYCAASC 2018 > Workshops: Track 3
Interconnected Global Struggles: Socialism in Vietnam post-Revolution
GC 269, 4:00 - 5:20
U.S. women organizers and activists participated in a women's delegation to Vietnam hosted by the Vietnam Women's Union. Our delegates shared our women's movements in the U.S. while the delegation took this time as an opportunity to learn about the successes of VWU's organizing, where they have 16 million members and are organized at the national, provincial, and communal levels. This workshop will cover the work of VWU including domestic violence, microcredit loans, supporting the political leadership of women, and also lessons learned on Vietnam's recovery post-war and building towards socialism. Hear about the reflections from U.S. women's movement and Vietnam's women's movement.
Cathy Dang
Cathy Dang is the Executive Director of CAAAV and has organized in labor and community-led planning for over a decade with Restaurant Opportunities Centers United, the Retail Action Project and other grassroots organizations including the fight to keep Wal-Mart out of Los Angeles' Chinatown. In her time with the Retail Action Project, she helped win the first wage increase in the Victoria's Secret flagship store of 700+ employees and organized workers to win a racial discrimination case affecting Black women workers across several VS locations. At CAAAV, she has helped lead campaigns winning victories securing dozens of Chinatown tenants' homes and started the first project to organize NYC's public housing Asian-immigrant tenants. She is originally from Ridgewood, Queens and Los Angeles, California, and a daughter of Chinese-Vietnamese refugee parents who raised her in their nail salon in Downtown Brooklyn.


This command allows you to see any indices (or snapshots) matching
index selection or
snapshot selection.
Starting in v3.1.0, the term (CLOSED)
will appear next to indices which are
in a closed state.
$ curator show [OPTIONS] COMMAND [ARGS]... Show indices or snapshots Options: --help Show this message and exit. Commands: indices Index selection. snapshots Snapshot selection.
This command requires either the indices subcommand for index selection, or the snapshots subcommand for snapshot selection.
Display a list of indices matching the selection parameters:
curator show indices <<index selection parameters>>
Display a list of snapshots in the named repository matching the selection parameters:
curator show snapshots <<snapshot selection parameters>>


Apache Flume Tutorial
Flume is a standard, simple, robust, flexible, and extensible tool for data ingestion from various data producers (webservers) into Hadoop. In this tutorial, we will be using simple and illustrative example to explain the basics of Apache Flume and how to use it in practice.
Audience
This tutorial is meant for all those professionals who would like to learn the process of transferring log and streaming data from various webservers to HDFS or HBase using Apache Flume.
Prerequisites
To make the most of this tutorial, you should have a good understanding of the basics of Hadoop and HDFS commands.
Introduction
Flume is a standard, simple, robust, flexible, and extensible tool for data ingestion from various data producers (webservers) into Hadoop. In this tutorial, we will be using simple and illustrative example to explain the basics of Apache Flume and how to use it in practice.
This tutorial is meant for all those professionals who would like to learn the process of transferring log and streaming data from various webservers to HDFS or HBase using Apache Flume.
Prerequisites
To make the most of this tutorial, you should have a good understanding of the basics of Hadoop and HDFS commands.
Flume is a standard, simple, robust, flexible, and extensible tool for data ingestion from various data producers (webservers) into Hadoop. In this tutorial, we will be using simple and illustrative example to explain the basics of Apache Flume and how to use it in practice.
Audience
This tutorial is meant for all those professionals who would like to learn the process of transferring log and streaming data from various webservers to HDFS or HBase using Apache Flume.
Prerequisites
To make the most of this tutorial, you should have a good understanding of the basics of Hadoop and HDFS commands.
Flume is a standard, simple, robust, flexible, and extensible tool for data ingestion from various data producers (webservers) into Hadoop. In this tutorial, we will be using simple and illustrative example to explain the basics of Apache Flume and how to use it in practice.
Audience
This tutorial is meant for all those professionals who would like to learn the process of transferring log and streaming data from various webservers to HDFS or HBase using Apache Flume.
Prerequisites
To make the most of this tutorial, you should have a good understanding of the basics of Hadoop and HDFS commands.
Flume is a standard, simple, robust, flexible, and extensible tool for data ingestion from various data producers (webservers) into Hadoop. In this tutorial, we will be using simple and illustrative example to explain the basics of Apache Flume and how to use it in practice.
Audience
This tutorial is meant for all those professionals who would like to learn the process of transferring log and streaming data from various webservers to HDFS or HBase using Apache Flume.
Prerequisites
To make the most of this tutorial, you should have a good understanding of the basics of Hadoop and HDFS commands.
Flume is a standard, simple, robust, flexible, and extensible tool for data ingestion from various data producers (webservers) into Hadoop. In this tutorial, we will be using simple and illustrative example to explain the basics of Apache Flume and how to use it in practice.
Audience
This tutorial is meant for all those professionals who would like to learn the process of transferring log and streaming data from various webservers to HDFS or HBase using Apache Flume.
Prerequisites
To make the most of this tutorial, you should have a good understanding of the basics of Hadoop and HDFS commands.