Package jakarta.servlet

Interface ServletContext

public interface ServletContext
Defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the MIME type of a file, dispatch requests, or write to a log file.

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.

Author:
Various
See Also:

  • Field Details

    • TEMPDIR

      static final 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
      See Also:

    • ORDERED_LIBS

      static final 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
      Since:
      Servlet 3.0
      See Also:

  • Method Details

    • 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:

    • getContext

      ServletContext getContext(String uripath)
      Returns a 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 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 - a String 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:

    • 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

    • 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

    • 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

    • 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

    • getMimeType

      String getMimeType(String file)
      Returns the MIME type of the specified file, or 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.
      Parameters:
      file - a String specifying the name of a file
      Returns:
      a String specifying the file's MIME type

    • getResourcePaths

      Set<String> 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.

      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/"}.

      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

    • getResource

      URL getResource(String path) throws MalformedURLException
      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 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.

      The provided path parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.

      Parameters:
      path - a String 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

    • getResourceAsStream

      InputStream getResourceAsStream(String path)
      Returns the resource located at the named path as an 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.

      The provided path parameter is canonicalized as per Servlet 6.0, 3.5.2 before being used to match resources.

      Parameters:
      path - a String specifying the path to the resource
      Returns:
      the InputStream returned to the servlet, or null if no resource exists at the specified path

    • getRequestDispatcher

      RequestDispatcher getRequestDispatcher(String path)
      Returns a 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.

      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 - a String specifying the pathname to the resource
      Returns:
      a RequestDispatcher object that acts as a wrapper for the resource at the specified path, or null if the ServletContext cannot return a RequestDispatcher
      See Also:

    • getNamedDispatcher

      RequestDispatcher getNamedDispatcher(String name)
      Returns a 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.

      Parameters:
      name - a String specifying the name of a servlet to wrap
      Returns:
      a RequestDispatcher object that acts as a wrapper for the named servlet, or null if the ServletContext cannot return a RequestDispatcher
      See Also:

    • log

      void log(String msg)
      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 - a String specifying the message to be written to the log file

    • log

      void log(String message, Throwable throwable)
      Writes an explanatory message and a stack trace for a given 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.
      Parameters:
      message - a String that describes the error or exception
      throwable - the Throwable error or exception

    • getRealPath

      String getRealPath(String path)
      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

    • 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

    • getInitParameter

      String getInitParameter(String name)
      Returns a 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.

      Parameters:
      name - a String containing the name of the parameter whose value is requested
      Returns:
      a String containing the value of the context's initialization parameter, or null if the context's initialization parameter does not exist.
      Throws:
      NullPointerException - if the argument name is null
      See Also:

    • getInitParameterNames

      Enumeration<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.
      Returns:
      an Enumeration of String objects containing the names of the context's initialization parameters
      See Also:

    • setInitParameter

      boolean setInitParameter(String name, String value)
      Sets the context initialization parameter with the given name and value on this ServletContext.
      Parameters:
      name - the name of the context initialization parameter to set
      value - 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 initialized
      NullPointerException - if the name parameter is null
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • getAttribute

      Object getAttribute(String name)
      Returns the servlet container attribute with the given name, or 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 jakarta.*.

      Parameters:
      name - a String specifying the name of the attribute
      Returns:
      an Object containing the value of the attribute, or null if no attribute exists matching the given name.
      Throws:
      NullPointerException - if the argument name is null
      See Also:

    • getAttributeNames

      Enumeration<String> getAttributeNames()
      Returns an 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.

      Returns:
      an Enumeration of attribute names
      See Also:

    • setAttribute

      void setAttribute(String name, Object object)
      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 - a String specifying the name of the attribute
      object - an Object representing the attribute to be bound
      Throws:
      NullPointerException - if the name parameter is null

    • removeAttribute

      void removeAttribute(String name)
      Removes the attribute with the given name from this ServletContext. After removal, subsequent calls to 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.

      Parameters:
      name - a String specifying the name of the attribute to be removed

    • 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

    • addServlet

      ServletRegistration.Dynamic addServlet(String servletName, String className)
      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 servlet
      className - 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 initialized
      IllegalArgumentException - if servletName is null or an empty String
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addServlet

      ServletRegistration.Dynamic addServlet(String servletName, Servlet servlet)
      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 servlet
      servlet - 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 initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      IllegalArgumentException - if servletName is null or an empty String
      Since:
      Servlet 3.0

    • addServlet

      ServletRegistration.Dynamic addServlet(String servletName, Class<? extends Servlet> servletClass)
      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 servlet
      servletClass - 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 initialized
      IllegalArgumentException - if servletName is null or an empty String
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addJspFile

      ServletRegistration.Dynamic addJspFile(String servletName, String jspFile)
      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 servlet
      jspFile - 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 initialized
      IllegalArgumentException - if servletName is null or an empty String
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 4.0

    • createServlet

      <T extends Servlet> T createServlet(Class<T> clazz) throws ServletException
      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 instantiated
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • getServletRegistration

      ServletRegistration getServletRegistration(String servletName)
      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 the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      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 the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addFilter

      FilterRegistration.Dynamic addFilter(String filterName, String className)
      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 filter
      className - 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 initialized
      IllegalArgumentException - if filterName is null or an empty String
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addFilter

      FilterRegistration.Dynamic addFilter(String filterName, Filter filter)
      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 filter
      filter - 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 initialized
      IllegalArgumentException - if filterName is null or an empty String
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addFilter

      FilterRegistration.Dynamic addFilter(String filterName, Class<? extends Filter> filterClass)
      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 filter
      filterClass - 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 initialized
      IllegalArgumentException - if filterName is null or an empty String
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • createFilter

      <T extends Filter> T createFilter(Class<T> clazz) throws ServletException
      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 instantiated
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • getFilterRegistration

      FilterRegistration getFilterRegistration(String filterName)
      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 the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      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 the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • getSessionCookieConfig

      SessionCookieConfig getSessionCookieConfig()
      Gets the 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.

      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 the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • setSessionTrackingModes

      void setSessionTrackingModes(Set<SessionTrackingMode> sessionTrackingModes)
      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 initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      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 the ServletContext 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 the ServletContext object, and vice-versa.

      Returns:
      set of the session tracking modes in effect for this ServletContext
      Since:
      Servlet 3.0

    • addListener

      void addListener(String className)
      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:

      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 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.

      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 implements ServletContextListener and this ServletContext was not passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.servlet.ServletContext)
      IllegalStateException - if this ServletContext has already been initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addListener

      <T extends EventListener> void addListener(T t)
      Adds the given listener to this ServletContext.

      The given listener must be an instance of one or more of the following interfaces:

      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 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.

      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 of ServletContextListener and this ServletContext was not passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.servlet.ServletContext)
      IllegalStateException - if this ServletContext has already been initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • addListener

      void addListener(Class<? extends EventListener> listenerClass)
      Adds a listener of the given class type to this ServletContext.

      The given listenerClass must implement one or more of the following interfaces:

      If this ServletContext was passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.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.

      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 implements ServletContextListener and this ServletContext was not passed to ServletContainerInitializer.onStartup(java.util.Set<java.lang.Class<?>>, jakarta.servlet.ServletContext)
      IllegalStateException - if this ServletContext has already been initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 3.0

    • createListener

      <T extends EventListener> T createListener(Class<T> clazz) throws ServletException
      Instantiates the given EventListener class.

      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.

      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 instantiated
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      IllegalArgumentException - if the specified EventListener class does not implement any of the ServletContextListener, ServletContextAttributeListener, ServletRequestListener, ServletRequestAttributeListener, HttpSessionAttributeListener, HttpSessionIdListener, or HttpSessionListener interfaces.
      Since:
      Servlet 3.0

    • getJspConfigDescriptor

      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.
      Returns:
      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, 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 a RuntimePermission("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

      void declareRoles(String... roleNames)
      Declares role names that are tested using 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.

      Parameters:
      roleNames - the role names being declared
      Throws:
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      IllegalArgumentException - if any of the argument roleNames is null or the empty string
      IllegalStateException - 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 initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      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

      void setRequestCharacterEncoding(String encoding)
      Sets the request character encoding for this ServletContext.
      Parameters:
      encoding - request character encoding
      Throws:
      IllegalStateException - if this ServletContext has already been initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 4.0

    • setRequestCharacterEncoding

      default void setRequestCharacterEncoding(Charset encoding)
      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 initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      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

      void setResponseCharacterEncoding(String encoding)
      Sets the response character encoding for this ServletContext.
      Parameters:
      encoding - response character encoding
      Throws:
      IllegalStateException - if this ServletContext has already been initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 4.0

    • setResponseCharacterEncoding

      default void setResponseCharacterEncoding(Charset encoding)
      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 initialized
      UnsupportedOperationException - if this ServletContext was passed to the ServletContextListener.contextInitialized(jakarta.servlet.ServletContextEvent) method of a ServletContextListener that was neither declared in web.xml or web-fragment.xml, nor annotated with WebListener
      Since:
      Servlet 6.1