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.
- See Also:
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Field Summary
Modifier and TypeFieldDescriptionstatic final String
The name of theServletContext
attribute whose value (of typejava.util.List<java.lang.String>
) contains the list of names of JAR files inWEB-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 specifiedstatic final String
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 -
Method Summary
Modifier and TypeMethodDescriptionRegisters the given filter instance with this ServletContext under the given filterName.Adds the filter with the given name and class type to this servlet context.Adds the filter with the given name and class name to this servlet context.addJspFile
(String servletName, String jspFile) Adds the servlet with the given jsp file to this servlet context.void
addListener
(Class<? extends EventListener> listenerClass) Adds a listener of the given class type to this ServletContext.void
addListener
(String className) Adds the listener with the given class name to this ServletContext.<T extends EventListener>
voidaddListener
(T t) Adds the given listener to this ServletContext.addServlet
(String servletName, Servlet servlet) Registers the given servlet instance with this ServletContext under the given servletName.addServlet
(String servletName, Class<? extends Servlet> servletClass) Adds the servlet with the given name and class type to this servlet context.addServlet
(String servletName, String className) Adds the servlet with the given name and class name to this servlet context.<T extends Filter>
TcreateFilter
(Class<T> clazz) Instantiates the given Filter class.<T extends EventListener>
TcreateListener
(Class<T> clazz) Instantiates the given EventListener class.<T extends Servlet>
TcreateServlet
(Class<T> clazz) Instantiates the given Servlet class.void
declareRoles
(String... roleNames) Declares role names that are tested usingisUserInRole
.getAttribute
(String name) Returns the servlet container attribute with the given name, ornull
if there is no attribute by that name.Returns anEnumeration
containing the attribute names available within this ServletContext.Gets the class loader of the web application represented by this ServletContext.getContext
(String uripath) Returns aServletContext
object that corresponds to a specified URL on the server.Returns the context path of the web application.Gets the session tracking modes that are supported by default for this ServletContext.int
Gets the major version of the Servlet specification that the application represented by this ServletContext is based on.int
Gets the minor version of the Servlet specification that the application represented by this ServletContext is based on.Gets the session tracking modes that are in effect for this ServletContext.getFilterRegistration
(String filterName) Gets the FilterRegistration corresponding to the filter with the given filterName.Map
<String, ? extends FilterRegistration> Gets a (possibly empty) Map of the FilterRegistration objects (keyed by filter name) corresponding to all filters registered with this ServletContext.getInitParameter
(String name) Returns aString
containing the value of the named context-wide initialization parameter, ornull
if the parameter does not exist.Returns the names of the context's initialization parameters as anEnumeration
ofString
objects, or an emptyEnumeration
if the context has no initialization parameters.Gets the<jsp-config>
related configuration that was aggregated from theweb.xml
andweb-fragment.xml
descriptor files of the web application represented by this ServletContext.int
Returns the major version of Jakarta Servlet specification that this container supports.getMimeType
(String file) Returns the MIME type of the specified file, ornull
if the MIME type is not known.int
Returns the minor version of Jakarta Servlet specification that this container supports.getNamedDispatcher
(String name) Returns aRequestDispatcher
object that acts as a wrapper for the named servlet.getRealPath
(String path) Gets the real path corresponding to the given virtual path.Gets the request character encoding that are supported by default for this ServletContext.getRequestDispatcher
(String path) Returns aRequestDispatcher
object that acts as a wrapper for the resource located at the given path.getResource
(String path) Returns a URL to the resource that is mapped to the given path.getResourceAsStream
(String path) Returns the resource located at the named path as anInputStream
object.getResourcePaths
(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.Gets the response character encoding that are supported by default for this ServletContext.Returns the name and version of the servlet container on which the servlet is running.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.getServletRegistration
(String servletName) Gets the ServletRegistration corresponding to the servlet with the given servletName.Map
<String, ? extends ServletRegistration> Gets a (possibly empty) Map of the ServletRegistration objects (keyed by servlet name) corresponding to all servlets registered with this ServletContext.Gets theSessionCookieConfig
object through which various properties of the session tracking cookies created on behalf of this ServletContext may be configured.int
Gets the session timeout in minutes that are supported by default for this ServletContext.Returns the configuration name of the logical host on which the ServletContext is deployed.void
Writes the specified message to a servlet log file, usually an event log.void
Writes an explanatory message and a stack trace for a givenThrowable
exception to the servlet log file.void
removeAttribute
(String name) Removes the attribute with the given name from this ServletContext.void
setAttribute
(String name, Object object) Binds an object to a given attribute name in this ServletContext.boolean
setInitParameter
(String name, String value) Sets the context initialization parameter with the given name and value on this ServletContext.void
setRequestCharacterEncoding
(String encoding) Sets the request character encoding for this ServletContext.default void
setRequestCharacterEncoding
(Charset encoding) Sets the request character encoding for this ServletContext.void
setResponseCharacterEncoding
(String encoding) Sets the response character encoding for this ServletContext.default void
setResponseCharacterEncoding
(Charset encoding) Sets the response character encoding for this ServletContext.void
setSessionTimeout
(int sessionTimeout) Sets the session timeout in minutes for this ServletContext.void
setSessionTrackingModes
(Set<SessionTrackingMode> sessionTrackingModes) Sets the session tracking modes that are to become effective for this ServletContext.
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Field Details
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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- See Also:
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ORDERED_LIBS
The name of theServletContext
attribute whose value (of typejava.util.List<java.lang.String>
) contains the list of names of JAR files inWEB-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- Since:
- Servlet 3.0
- See Also:
-
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Method Details
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getContextPath
String getContextPath()Returns the context path of the web application.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.- Returns:
- The context path of the web application, or "" for the root context
- Since:
- Servlet 2.5
- See Also:
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getContext
Returns aServletContext
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 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.- Parameters:
uripath
- aString
specifying the context path of another web application in the container.- Returns:
- the
ServletContext
object that corresponds to the named URL, or null if either none exists or the container wishes to restrict this access. - See Also:
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getMajorVersion
int getMajorVersion()Returns the major version of Jakarta Servlet specification that this container supports. All implementations that comply with version X.Y of the specification, must return the integer X.- Returns:
- The major version of Jakarta Servlet specification that this container supports
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getMinorVersion
int getMinorVersion()Returns the minor version of Jakarta Servlet specification that this container supports. All implementations that comply with version X.Y of the specification, must return the integer Y.- Returns:
- The minor version of Jakarta Servlet specification that this container supports
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getEffectiveMajorVersion
int getEffectiveMajorVersion()Gets the major version of the Servlet specification that the application represented by this ServletContext is based on.The value returned may be different from
getMajorVersion()
, which returns the major version of the Servlet specification supported by the Servlet container.- Returns:
- the major version of the Servlet specification that the application represented by this ServletContext is based on
- Since:
- Servlet 3.0
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getEffectiveMinorVersion
int getEffectiveMinorVersion()Gets the minor version of the Servlet specification that the application represented by this ServletContext is based on.The value returned may be different from
getMinorVersion()
, which returns the minor version of the Servlet specification supported by the Servlet container.- Returns:
- the minor version of the Servlet specification that the application represented by this ServletContext is based on
- Since:
- Servlet 3.0
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getMimeType
Returns the MIME type of the specified file, ornull
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 includetext/html
andimage/gif
.- Parameters:
file
- aString
specifying the name of a file- Returns:
- a
String
specifying the file's MIME type
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getResourcePaths
Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path matches the supplied path argument.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 theServletContext
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
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.
The provided
path
parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.- Parameters:
path
- the partial path used to match the resources, which must start with a /- Returns:
- a Set containing the directory listing, or null if there are no resources in the web application whose path begins with the supplied path.
- Since:
- Servlet 2.3
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getResource
Returns a URL to the resource that is mapped to the given path.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 aRequestDispatcher
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.
The provided
path
parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.- Parameters:
path
- aString
specifying the path to the resource- Returns:
- the resource located at the named path, or
null
if there is no resource at that path - Throws:
MalformedURLException
- if the pathname is not given in the correct form
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getResourceAsStream
Returns the resource located at the named path as anInputStream
object.The data in the
InputStream
can be of any type or length. The path must be specified according to the rules given ingetResource
. This method returnsnull
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.
The provided
path
parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.- Parameters:
path
- aString
specifying the path to the resource- Returns:
- the
InputStream
returned to the servlet, ornull
if no resource exists at the specified path
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getRequestDispatcher
Returns aRequestDispatcher
object that acts as a wrapper for the resource located at the given path. ARequestDispatcher
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 aRequestDispatcher
for resources in foreign contexts.This method returns
null
if theServletContext
cannot return aRequestDispatcher
.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.
The provided
path
parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.- Parameters:
path
- aString
specifying the pathname to the resource- Returns:
- a
RequestDispatcher
object that acts as a wrapper for the resource at the specified path, ornull
if theServletContext
cannot return aRequestDispatcher
- See Also:
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getNamedDispatcher
Returns aRequestDispatcher
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 theServletContext
cannot return aRequestDispatcher
for any reason.- Parameters:
name
- aString
specifying the name of a servlet to wrap- Returns:
- a
RequestDispatcher
object that acts as a wrapper for the named servlet, ornull
if theServletContext
cannot return aRequestDispatcher
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log
Writes the specified message to a servlet log file, usually an event log. The name and type of the servlet log file is specific to the servlet container.- Parameters:
msg
- aString
specifying the message to be written to the log file
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log
Writes an explanatory message and a stack trace for a givenThrowable
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.- Parameters:
message
- aString
that describes the error or exceptionthrowable
- theThrowable
error or exception
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getRealPath
Gets the real path corresponding to the given virtual path.The path should begin with a / and is interpreted as relative to the current context root. If the path does not begin with a /, the container will behave as if the method was called with / appended to the beginning of the provided 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.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.
The provided
path
parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.- Parameters:
path
- the virtual path to be translated to a real path- Returns:
- the real path, or null if the translation cannot be performed
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getServerInfo
String getServerInfo()Returns the name and version of the servlet container on which the servlet is running.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)
.- Returns:
- a
String
containing at least the servlet container name and version number
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getInitParameter
Returns aString
containing the value of the named context-wide initialization parameter, ornull
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.
- Parameters:
name
- aString
containing the name of the parameter whose value is requested- Returns:
- a
String
containing the value of the context's initialization parameter, ornull
if the context's initialization parameter does not exist. - Throws:
NullPointerException
- if the argumentname
isnull
- See Also:
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getInitParameterNames
Enumeration<String> getInitParameterNames()Returns the names of the context's initialization parameters as anEnumeration
ofString
objects, or an emptyEnumeration
if the context has no initialization parameters.- Returns:
- an
Enumeration
ofString
objects containing the names of the context's initialization parameters - See Also:
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setInitParameter
Sets the context initialization parameter with the given name and value on this ServletContext.- Parameters:
name
- the name of the context initialization parameter to setvalue
- the value of the context initialization parameter to set- Returns:
- true if the context initialization parameter with the given name and value was set successfully on this ServletContext, and false if it was not set because this ServletContext already contains a context initialization parameter with a matching name
- Throws:
IllegalStateException
- if this ServletContext has already been initializedNullPointerException
- if the name parameter isnull
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
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getAttribute
Returns the servlet container attribute with the given name, ornull
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
jakarta.*
.- Parameters:
name
- aString
specifying the name of the attribute- Returns:
- an
Object
containing the value of the attribute, ornull
if no attribute exists matching the given name. - Throws:
NullPointerException
- if the argumentname
isnull
- See Also:
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getAttributeNames
Enumeration<String> getAttributeNames()Returns anEnumeration
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.- Returns:
- an
Enumeration
of attribute names - See Also:
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setAttribute
Binds an object to a given attribute name in this ServletContext. If the name specified is already used for an attribute, this method will replace the attribute with the new to the new attribute.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
jakarta.*
.- Parameters:
name
- aString
specifying the name of the attributeobject
- anObject
representing the attribute to be bound- Throws:
NullPointerException
- if the name parameter isnull
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removeAttribute
Removes the attribute with the given name from this ServletContext. After removal, subsequent calls togetAttribute(java.lang.String)
to retrieve the attribute's value will returnnull
.If listeners are configured on the
ServletContext
the container notifies them accordingly.- Parameters:
name
- aString
specifying the name of the attribute to be removed
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getServletContextName
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.- Returns:
- The name of the web application or null if no name has been declared in the deployment descriptor.
- Since:
- Servlet 2.3
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addServlet
Adds the servlet with the given name and class name to this servlet context.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
, jakarta.annotation.security.RunAs, and jakarta.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.- Parameters:
servletName
- the name of the servletclassName
- the fully qualified class name of the servlet- Returns:
- a ServletRegistration object that may be used to further configure the registered servlet, or null if this ServletContext already contains a complete ServletRegistration for a servlet with the given servletName
- Throws:
IllegalStateException
- if this ServletContext has already been initializedIllegalArgumentException
- ifservletName
is null or an empty StringUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addServlet
Registers the given servlet instance with this ServletContext under the given servletName.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.
- Parameters:
servletName
- the name of the servletservlet
- the servlet instance to register- Returns:
- a ServletRegistration object that may be used to further configure the given servlet, or null if this ServletContext already contains a complete ServletRegistration for a servlet with the given servletName or if the same servlet instance has already been registered with this or another ServletContext in the same container
- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
IllegalArgumentException
- ifservletName
is null or an empty String- Since:
- Servlet 3.0
-
addServlet
Adds the servlet with the given name and class type to this servlet context.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
, jakarta.annotation.security.RunAs, and jakarta.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.- Parameters:
servletName
- the name of the servletservletClass
- the class object from which the servlet will be instantiated- Returns:
- a ServletRegistration object that may be used to further configure the registered servlet, or null if this ServletContext already contains a complete ServletRegistration for the given servletName
- Throws:
IllegalStateException
- if this ServletContext has already been initializedIllegalArgumentException
- ifservletName
is null or an empty StringUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addJspFile
Adds the servlet with the given jsp file to this servlet context.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.
- Parameters:
servletName
- the name of the servletjspFile
- the full path to a JSP file within the web application beginning with a `/'.- Returns:
- a ServletRegistration object that may be used to further configure the registered servlet, or null if this ServletContext already contains a complete ServletRegistration for a servlet with the given servletName
- Throws:
IllegalStateException
- if this ServletContext has already been initializedIllegalArgumentException
- ifservletName
is null or an empty StringUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 4.0
-
createServlet
Instantiates the given Servlet class.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
, jakarta.annotation.security.RunAs, and jakarta.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.- Type Parameters:
T
- the class of the Servlet to create- Parameters:
clazz
- the Servlet class to instantiate- Returns:
- the new Servlet instance
- Throws:
ServletException
- if the given clazz fails to be instantiatedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
getServletRegistration
Gets the ServletRegistration corresponding to the servlet with the given servletName.- Parameters:
servletName
- the name of a servlet- Returns:
- the (complete or preliminary) ServletRegistration for the servlet with the given servletName, or null if no ServletRegistration exists under that name
- Throws:
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
getServletRegistrations
Map<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.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.
- Returns:
- Map of the (complete and preliminary) ServletRegistration objects corresponding to all servlets currently registered with this ServletContext
- Throws:
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addFilter
Adds the filter with the given name and class name to this servlet context.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.
- Parameters:
filterName
- the name of the filterclassName
- the fully qualified class name of the filter- Returns:
- a FilterRegistration object that may be used to further configure the registered filter, or null if this ServletContext already contains a complete FilterRegistration for a filter with the given filterName
- Throws:
IllegalStateException
- if this ServletContext has already been initializedIllegalArgumentException
- iffilterName
is null or an empty StringUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addFilter
Registers the given filter instance with this ServletContext under the given filterName.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.
- Parameters:
filterName
- the name of the filterfilter
- the filter instance to register- Returns:
- a FilterRegistration object that may be used to further configure the given filter, or null if this ServletContext already contains a complete FilterRegistration for a filter with the given filterName or if the same filter instance has already been registered with this or another ServletContext in the same container
- Throws:
IllegalStateException
- if this ServletContext has already been initializedIllegalArgumentException
- iffilterName
is null or an empty StringUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addFilter
Adds the filter with the given name and class type to this servlet context.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 Jakarta EE platform and CDI specifications for additional details about Managed Beans and resource injection.
- Parameters:
filterName
- the name of the filterfilterClass
- the class object from which the filter will be instantiated- Returns:
- a FilterRegistration object that may be used to further configure the registered filter, or null if this ServletContext already contains a complete FilterRegistration for a filter with the given filterName
- Throws:
IllegalStateException
- if this ServletContext has already been initializedIllegalArgumentException
- iffilterName
is null or an empty StringUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
createFilter
Instantiates the given Filter class.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.
- Type Parameters:
T
- the class of the Filter to create- Parameters:
clazz
- the Filter class to instantiate- Returns:
- the new Filter instance
- Throws:
ServletException
- if the given clazz fails to be instantiatedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
getFilterRegistration
Gets the FilterRegistration corresponding to the filter with the given filterName.- Parameters:
filterName
- the name of a filter- Returns:
- the (complete or preliminary) FilterRegistration for the filter with the given filterName, or null if no FilterRegistration exists under that name
- Throws:
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
getFilterRegistrations
Map<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.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.
- Returns:
- Map of the (complete and preliminary) FilterRegistration objects corresponding to all filters currently registered with this ServletContext
- Throws:
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
getSessionCookieConfig
SessionCookieConfig getSessionCookieConfig()Gets theSessionCookieConfig
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.
- Returns:
- the SessionCookieConfig object through which various properties of the session tracking cookies created on behalf of this ServletContext may be configured
- Throws:
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
setSessionTrackingModes
Sets the session tracking modes that are to become effective for this ServletContext.The given sessionTrackingModes replaces any session tracking modes set by a previous invocation of this method on this ServletContext.
- Parameters:
sessionTrackingModes
- the set of session tracking modes to become effective for this ServletContext- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
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 container- Since:
- Servlet 3.0
-
getDefaultSessionTrackingModes
Set<SessionTrackingMode> getDefaultSessionTrackingModes()Gets the session tracking modes that are supported by default for this ServletContext.The returned set is not backed by the
ServletContext
object, so changes in the returned set are not reflected in theServletContext
object, and vice-versa.- Returns:
- set of the session tracking modes supported by default for this ServletContext
- Since:
- Servlet 3.0
-
getEffectiveSessionTrackingModes
Set<SessionTrackingMode> getEffectiveSessionTrackingModes()Gets the session tracking modes that are in effect for this ServletContext.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 theServletContext
object, and vice-versa.- Returns:
- set of the session tracking modes in effect for this ServletContext
- Since:
- Servlet 3.0
-
addListener
Adds the listener with the given class name to this ServletContext.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<?>>, jakarta.servlet.ServletContext)
, then the class with the given name may also implementServletContextListener
, 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
, orHttpSessionListener
), 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.
- Parameters:
className
- the fully qualified class name of the listener- Throws:
IllegalArgumentException
- if the class with the given name does not implement any of the above interfaces, or if it implementsServletContextListener
and this ServletContext was not passed toServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.servlet.ServletContext)
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addListener
Adds the given listener to this ServletContext.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<?>>, jakarta.servlet.ServletContext)
, then the given listener may also be an instance ofServletContextListener
, 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
, orHttpSessionListener
), then the listener will be added to the end of the ordered list of listeners of that interface.- Type Parameters:
T
- the class of the EventListener to add- Parameters:
t
- the listener to be added- Throws:
IllegalArgumentException
- if the given listener is not an instance of any of the above interfaces, or if it is an instance ofServletContextListener
and this ServletContext was not passed toServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.servlet.ServletContext)
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
addListener
Adds a listener of the given class type to this ServletContext.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<?>>, jakarta.servlet.ServletContext)
, then the given listenerClass may also implementServletContextListener
, 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
, orHttpSessionListener
), 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.
- Parameters:
listenerClass
- the listener class to be instantiated- Throws:
IllegalArgumentException
- if the given listenerClass does not implement any of the above interfaces, or if it implementsServletContextListener
and this ServletContext was not passed toServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.servlet.ServletContext)
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 3.0
-
createListener
Instantiates the given EventListener class.The specified EventListener class must implement at least one of the
ServletContextListener
,ServletContextAttributeListener
,ServletRequestListener
,ServletRequestAttributeListener
,HttpSessionAttributeListener
,HttpSessionIdListener
, orHttpSessionListener
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.
- Type Parameters:
T
- the class of the EventListener to create- Parameters:
clazz
- the EventListener class to instantiate- Returns:
- the new EventListener instance
- Throws:
ServletException
- if the given clazz fails to be instantiatedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
IllegalArgumentException
- if the specified EventListener class does not implement any of theServletContextListener
,ServletContextAttributeListener
,ServletRequestListener
,ServletRequestAttributeListener
,HttpSessionAttributeListener
,HttpSessionIdListener
, orHttpSessionListener
interfaces.- Since:
- Servlet 3.0
-
getJspConfigDescriptor
JspConfigDescriptor getJspConfigDescriptor()Gets the<jsp-config>
related configuration that was aggregated from theweb.xml
andweb-fragment.xml
descriptor files of the web application represented by this ServletContext.- Returns:
- the
<jsp-config>
related configuration that was aggregated from theweb.xml
andweb-fragment.xml
descriptor files of the web application represented by this ServletContext, or null if no such configuration exists - Since:
- Servlet 3.0
- See Also:
-
getClassLoader
ClassLoader getClassLoader()Gets the class loader of the web application represented by this ServletContext.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 aRuntimePermission("getClassLoader")
permission to check whether access to the requested class loader should be granted.- Returns:
- the class loader of the web application represented by this ServletContext
- Since:
- Servlet 3.0
-
declareRoles
Declares role names that are tested usingisUserInRole
.Roles that are implicitly declared as a result of their use within the
setServletSecurity
orsetRunAsRole
methods of theServletRegistration
interface need not be declared.- Parameters:
roleNames
- the role names being declared- Throws:
UnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
IllegalArgumentException
- if any of the argument roleNames is null or the empty stringIllegalStateException
- if the ServletContext has already been initialized- Since:
- Servlet 3.0
-
getVirtualServerName
String getVirtualServerName()Returns the configuration name of the logical host on which the ServletContext is deployed. Servlet containers may support multiple logical hosts. This method must return the same name for all the servlet contexts deployed on a logical host, and the name returned by this method must be distinct, stable per logical host, and suitable for use in associating server configuration information with the logical host. The returned value is NOT expected or required to be equivalent to a network address or hostname of the logical host.- Returns:
- a
String
containing the configuration name of the logical host on which the servlet context is deployed. - Since:
- Servlet 3.1
-
getSessionTimeout
int getSessionTimeout()Gets the session timeout in minutes that are supported by default for this ServletContext.- Returns:
- the session timeout in minutes that are supported by default for this ServletContext
- Since:
- Servlet 4.0
-
setSessionTimeout
void setSessionTimeout(int sessionTimeout) Sets the session timeout in minutes for this ServletContext.- Parameters:
sessionTimeout
- session timeout in minutes- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 4.0
-
getRequestCharacterEncoding
String getRequestCharacterEncoding()Gets the request character encoding that are supported by default for this ServletContext. This method returns null if no request encoding character encoding has been specified in deployment descriptor or container specific configuration (for all web applications in the container).- Returns:
- the request character encoding that are supported by default for this ServletContext
- Since:
- Servlet 4.0
-
setRequestCharacterEncoding
Sets the request character encoding for this ServletContext.- Parameters:
encoding
- request character encoding- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 4.0
-
setRequestCharacterEncoding
Sets the request character encoding for this ServletContext.Implementations are strongly encouraged to override this default method and provide a more efficient implementation.
- Parameters:
encoding
- request character encoding- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 6.1
-
getResponseCharacterEncoding
String getResponseCharacterEncoding()Gets the response character encoding that are supported by default for this ServletContext. This method returns null if no response encoding character encoding has been specified in deployment descriptor or container specific configuration (for all web applications in the container).- Returns:
- the request character encoding that are supported by default for this ServletContext
- Since:
- Servlet 4.0
-
setResponseCharacterEncoding
Sets the response character encoding for this ServletContext.- Parameters:
encoding
- response character encoding- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 4.0
-
setResponseCharacterEncoding
Sets the response character encoding for this ServletContext.Implementations are strongly encouraged to override this default method and provide a more efficient implementation.
- Parameters:
encoding
- response character encoding- Throws:
IllegalStateException
- if this ServletContext has already been initializedUnsupportedOperationException
- if this ServletContext was passed to theServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent)
method of aServletContextListener
that was neither declared inweb.xml
orweb-fragment.xml
, nor annotated withWebListener
- Since:
- Servlet 6.1
-