jakarta.servlet.ServletContext Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2023 Oracle and/or its affiliates and others.
* All rights reserved.
* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jakarta.servlet;
import jakarta.servlet.descriptor.JspConfigDescriptor;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Enumeration;
import java.util.EventListener;
import java.util.Map;
import java.util.Set;
/**
* 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 {@link ServletConfig} object, which the Web server
* provides the servlet when the servlet is initialized.
*
* @author Various
*
* @see Servlet#getServletConfig
* @see ServletConfig#getServletContext
*/
public interface ServletContext {
/**
* 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
*/
String TEMPDIR = "jakarta.servlet.context.tempdir";
/**
* 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
*/
String ORDERED_LIBS = "jakarta.servlet.context.orderedLibs";
/**
* 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
* {@link jakarta.servlet.http.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.
*
* @return The context path of the web application, or "" for the root context
*
* @see jakarta.servlet.http.HttpServletRequest#getContextPath()
*
* @since Servlet 2.5
*/
String getContextPath();
/**
* 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
* {@link 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.
*
* @param uripath a String specifying the context path of another web application in the container.
* @return the ServletContext object that corresponds to the named URL, or null if either none exists or
* the container wishes to restrict this access.
*
* @see RequestDispatcher
*/
ServletContext getContext(String uripath);
/**
* 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.
*
* @return The major version of Jakarta Servlet specification that this container supports
*/
int getMajorVersion();
/**
* 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.
*
* @return The minor version of Jakarta Servlet specification that this container supports
*/
int getMinorVersion();
/**
* 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 {@link #getMajorVersion}, which returns the major version of the Servlet
* specification supported by the Servlet container.
*
* @return the major version of the Servlet specification that the application represented by this ServletContext is
* based on
*
* @since Servlet 3.0
*/
int getEffectiveMajorVersion();
/**
* 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 {@link #getMinorVersion}, which returns the minor version of the Servlet
* specification supported by the Servlet container.
*
* @return the minor version of the Servlet specification that the application represented by this ServletContext is
* based on
*
* @since Servlet 3.0
*/
int getEffectiveMinorVersion();
/**
* 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.
*
* @param file a String specifying the name of a file
*
* @return a String specifying the file's MIME type
*/
String getMimeType(String file);
/**
* 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 {@code ServletContext} object, so changes in the returned set are not reflected
* in the {@code ServletContext} object, and vice-versa.
*
*
*
* For example, for a web application containing:
*
*
* {@code
* /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 {@code path} parameter is canonicalized as per Servlet 6.0,
* 3.5.2 before being used to match resources.
*
* @param path the partial path used to match the resources, which must start with a /
* @return 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
*/
Set getResourcePaths(String path);
/**
* 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 {@code path} parameter is canonicalized as per Servlet 6.0,
* 3.5.2 before being used to match resources.
*
* @param path a String specifying the path to the resource
*
* @return the resource located at the named path, or null if there is no resource at that path
*
* @exception MalformedURLException if the pathname is not given in the correct form
*/
URL getResource(String path) throws MalformedURLException;
/**
* 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 {@code path} parameter is canonicalized as per Servlet 6.0,
* 3.5.2 before being used to match resources.
*
* @param path a String specifying the path to the resource
*
* @return the InputStream returned to the servlet, or null if no resource exists at the
* specified path
*/
InputStream getResourceAsStream(String path);
/**
*
* Returns a {@link 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 {@code path} parameter is canonicalized as per Servlet 6.0,
* 3.5.2 before being used to match resources.
*
* @param path a String specifying the pathname to the resource
*
* @return 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 RequestDispatcher
* @see ServletContext#getContext
*/
RequestDispatcher getRequestDispatcher(String path);
/**
* Returns a {@link 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 {@link ServletConfig#getServletName}.
*
*
* This method returns null if the ServletContext cannot return a
* RequestDispatcher for any reason.
*
* @param name a String specifying the name of a servlet to wrap
*
* @return a RequestDispatcher object that acts as a wrapper for the named servlet, or null if
* the ServletContext cannot return a RequestDispatcher
*
* @see RequestDispatcher
* @see ServletContext#getContext
* @see ServletConfig#getServletName
*/
RequestDispatcher getNamedDispatcher(String name);
/**
*
* 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.
*
* @param msg a String specifying the message to be written to the log file
*/
void log(String msg);
/**
* 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.
*
* @param message a String that describes the error or exception
*
* @param throwable the Throwable error or exception
*/
void log(String message, Throwable throwable);
/**
* 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 {@code path} parameter is canonicalized as per Servlet 6.0,
* 3.5.2 before being used to match resources.
*
* @param path the virtual path to be translated to a real path
*
* @return the real path, or null if the translation cannot be performed
*/
String getRealPath(String path);
/**
* 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).
*
*
* @return a String containing at least the servlet container name and version number
*/
String getServerInfo();
/**
* 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.
*
* @param name a String containing the name of the parameter whose value is requested
*
* @return 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 {@code name} is {@code null}
*
* @see ServletConfig#getInitParameter
*/
String getInitParameter(String name);
/**
* 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.
*
* @return an Enumeration of String objects containing the names of the context's
* initialization parameters
*
* @see ServletConfig#getInitParameter
*/
Enumeration getInitParameterNames();
/**
* Sets the context initialization parameter with the given name and value on this ServletContext.
*
* @param name the name of the context initialization parameter to set
* @param value the value of the context initialization parameter to set
*
* @return 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
*
* @throws NullPointerException if the name parameter is {@code null}
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
boolean setInitParameter(String name, String value);
/**
* 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.*.
*
* @param name a String specifying the name of the attribute
*
* @return an Object containing the value of the attribute, or null if no attribute exists
* matching the given name.
*
* @see ServletContext#getAttributeNames
*
* @throws NullPointerException if the argument {@code name} is {@code null}
*
*/
Object getAttribute(String name);
/**
* Returns an Enumeration containing the attribute names available within this ServletContext.
*
*
* Use the {@link #getAttribute} method with an attribute name to get the value of an attribute.
*
* @return an Enumeration of attribute names
*
* @see #getAttribute
*/
Enumeration getAttributeNames();
/**
* 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.*.
*
* @param name a String specifying the name of the attribute
*
* @param object an Object representing the attribute to be bound
*
* @throws NullPointerException if the name parameter is {@code null}
*
*/
void setAttribute(String name, Object object);
/**
* Removes the attribute with the given name from this ServletContext. After removal, subsequent calls to
* {@link #getAttribute} to retrieve the attribute's value will return null.
*
*
* If listeners are configured on the ServletContext the container notifies them accordingly.
*
* @param name a String specifying the name of the attribute to be removed
*/
void removeAttribute(String name);
/**
* 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.
*
* @return The name of the web application or null if no name has been declared in the deployment descriptor.
*
* @since Servlet 2.3
*/
String getServletContextName();
/**
* Adds the servlet with the given name and class name to this servlet context.
*
*
* The registered servlet may be further configured via the returned {@link 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
* {@link jakarta.servlet.annotation.ServletSecurity}, {@link jakarta.servlet.annotation.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.
*
* @param servletName the name of the servlet
* @param className the fully qualified class name of the servlet
*
* @return 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
*
* @throws IllegalArgumentException if servletName is null or an empty String
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
ServletRegistration.Dynamic addServlet(String servletName, String className);
/**
* Registers the given servlet instance with this ServletContext under the given servletName.
*
*
* The registered servlet may be further configured via the returned {@link 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.
*
* @param servletName the name of the servlet
* @param servlet the servlet instance to register
*
* @return 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
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @throws IllegalArgumentException if servletName is null or an empty String
*
* @since Servlet 3.0
*/
ServletRegistration.Dynamic addServlet(String servletName, Servlet servlet);
/**
* Adds the servlet with the given name and class type to this servlet context.
*
*
* The registered servlet may be further configured via the returned {@link 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 {@link jakarta.servlet.annotation.ServletSecurity},
* {@link jakarta.servlet.annotation.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.
*
* @param servletName the name of the servlet
* @param servletClass the class object from which the servlet will be instantiated
*
* @return 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
*
* @throws IllegalArgumentException if servletName is null or an empty String
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
ServletRegistration.Dynamic addServlet(String servletName, Class servletClass);
/**
* Adds the servlet with the given jsp file to this servlet context.
*
*
* The registered servlet may be further configured via the returned {@link 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.
*
* @param servletName the name of the servlet
* @param jspFile the full path to a JSP file within the web application beginning with a `/'.
*
* @return 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
*
* @throws IllegalArgumentException if servletName is null or an empty String
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 4.0
*/
ServletRegistration.Dynamic addJspFile(String servletName, String jspFile);
/**
* Instantiates the given Servlet class.
*
*
* The returned Servlet instance may be further customized before it is registered with this ServletContext via a call
* to {@link #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:
* {@link jakarta.servlet.annotation.ServletSecurity}, {@link jakarta.servlet.annotation.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.
*
* @param the class of the Servlet to create
* @param clazz the Servlet class to instantiate
*
* @return the new Servlet instance
*
* @throws ServletException if the given clazz fails to be instantiated
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
T createServlet(Class clazz) throws ServletException;
/**
* Gets the ServletRegistration corresponding to the servlet with the given servletName.
*
* @param servletName the name of a servlet
*
* @return 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
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
ServletRegistration getServletRegistration(String servletName);
/**
* 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.
*
* @return 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
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
Map getServletRegistrations();
/**
* Adds the filter with the given name and class name to this servlet context.
*
*
* The registered filter may be further configured via the returned {@link 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.
*
* @param filterName the name of the filter
* @param className the fully qualified class name of the filter
*
* @return 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
*
* @throws IllegalArgumentException if filterName is null or an empty String
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
FilterRegistration.Dynamic addFilter(String filterName, String className);
/**
* Registers the given filter instance with this ServletContext under the given filterName.
*
*
* The registered filter may be further configured via the returned {@link 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.
*
* @param filterName the name of the filter
* @param filter the filter instance to register
*
* @return 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
*
* @throws IllegalArgumentException if filterName is null or an empty String
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
FilterRegistration.Dynamic addFilter(String filterName, Filter filter);
/**
* Adds the filter with the given name and class type to this servlet context.
*
*
* The registered filter may be further configured via the returned {@link 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.
*
* @param filterName the name of the filter
* @param filterClass the class object from which the filter will be instantiated
*
* @return 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
*
* @throws IllegalArgumentException if filterName is null or an empty String
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
FilterRegistration.Dynamic addFilter(String filterName, Class filterClass);
/**
* Instantiates the given Filter class.
*
*
* The returned Filter instance may be further customized before it is registered with this ServletContext via a call to
* {@link #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.
*
* @param the class of the Filter to create
* @param clazz the Filter class to instantiate
*
* @return the new Filter instance
*
* @throws ServletException if the given clazz fails to be instantiated
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
T createFilter(Class clazz) throws ServletException;
/**
* Gets the FilterRegistration corresponding to the filter with the given filterName.
*
* @param filterName the name of a filter
* @return 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
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
FilterRegistration getFilterRegistration(String filterName);
/**
* 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.
*
* @return 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
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
Map getFilterRegistrations();
/**
* Gets the {@link 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.
*
* @return 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
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
SessionCookieConfig getSessionCookieConfig();
/**
* 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.
*
* @param sessionTrackingModes the set of session tracking modes to become effective for this ServletContext
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @throws 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
*/
void setSessionTrackingModes(Set sessionTrackingModes);
/**
* Gets the session tracking modes that are supported by default for this ServletContext.
*
*
* The returned set is not backed by the {@code ServletContext} object, so changes in the returned set are not reflected
* in the {@code ServletContext} object, and vice-versa.
*
*
* @return set of the session tracking modes supported by default for this ServletContext
*
* @since Servlet 3.0
*/
Set getDefaultSessionTrackingModes();
/**
* Gets the session tracking modes that are in effect for this ServletContext.
*
*
* The session tracking modes in effect are those provided to {@link #setSessionTrackingModes setSessionTrackingModes}.
*
*
* The returned set is not backed by the {@code ServletContext} object, so changes in the returned set are not reflected
* in the {@code ServletContext} object, and vice-versa.
*
*
* @return set of the session tracking modes in effect for this ServletContext
*
* @since Servlet 3.0
*/
Set getEffectiveSessionTrackingModes();
/**
* 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:
*
* - {@link ServletContextAttributeListener}
*
- {@link ServletRequestListener}
*
- {@link ServletRequestAttributeListener}
*
- {@link jakarta.servlet.http.HttpSessionAttributeListener}
*
- {@link jakarta.servlet.http.HttpSessionIdListener}
*
- {@link jakarta.servlet.http.HttpSessionListener}
*
*
*
* If this ServletContext was passed to {@link ServletContainerInitializer#onStartup}, then the class with the given
* name may also implement {@link 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 {@link ServletRequestListener}, {@link ServletContextListener}, or
* {@link jakarta.servlet.http.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.
*
* @param 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 {@link ServletContextListener} and this ServletContext was not passed to
* {@link ServletContainerInitializer#onStartup}
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
void addListener(String className);
/**
* Adds the given listener to this ServletContext.
*
*
* The given listener must be an instance of one or more of the following interfaces:
*
* - {@link ServletContextAttributeListener}
*
- {@link ServletRequestListener}
*
- {@link ServletRequestAttributeListener}
*
- {@link jakarta.servlet.http.HttpSessionAttributeListener}
*
- {@link jakarta.servlet.http.HttpSessionIdListener}
*
- {@link jakarta.servlet.http.HttpSessionListener}
*
*
*
* If this ServletContext was passed to {@link ServletContainerInitializer#onStartup}, then the given listener may also
* be an instance of {@link 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 {@link ServletRequestListener}, {@link ServletContextListener}, or
* {@link jakarta.servlet.http.HttpSessionListener}), then the listener will be added to the end of the ordered list of
* listeners of that interface.
*
* @param the class of the EventListener to add
* @param 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 {@link ServletContextListener} and this ServletContext was not passed to
* {@link ServletContainerInitializer#onStartup}
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
void addListener(T t);
/**
* Adds a listener of the given class type to this ServletContext.
*
*
* The given listenerClass must implement one or more of the following interfaces:
*
* - {@link ServletContextAttributeListener}
*
- {@link ServletRequestListener}
*
- {@link ServletRequestAttributeListener}
*
- {@link jakarta.servlet.http.HttpSessionAttributeListener}
*
- {@link jakarta.servlet.http.HttpSessionIdListener}
*
- {@link jakarta.servlet.http.HttpSessionListener}
*
*
*
* If this ServletContext was passed to {@link ServletContainerInitializer#onStartup}, then the given
* listenerClass may also implement {@link 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 {@link ServletRequestListener}, {@link ServletContextListener}, or
* {@link jakarta.servlet.http.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.
*
* @param 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 {@link ServletContextListener} and this ServletContext was not passed to
* {@link ServletContainerInitializer#onStartup}
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 3.0
*/
void addListener(Class listenerClass);
/**
* Instantiates the given EventListener class.
*
*
* The specified EventListener class must implement at least one of the {@link ServletContextListener},
* {@link ServletContextAttributeListener}, {@link ServletRequestListener}, {@link ServletRequestAttributeListener},
* {@link jakarta.servlet.http.HttpSessionAttributeListener}, {@link jakarta.servlet.http.HttpSessionIdListener}, or
* {@link jakarta.servlet.http.HttpSessionListener} interfaces.
*
*
* The returned EventListener instance may be further customized before it is registered with this ServletContext via a
* call to {@link #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.
*
* @param the class of the EventListener to create
* @param clazz the EventListener class to instantiate
*
* @return the new EventListener instance
*
* @throws ServletException if the given clazz fails to be instantiated
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @throws IllegalArgumentException if the specified EventListener class does not implement any of the
* {@link ServletContextListener}, {@link ServletContextAttributeListener}, {@link ServletRequestListener},
* {@link ServletRequestAttributeListener}, {@link jakarta.servlet.http.HttpSessionAttributeListener},
* {@link jakarta.servlet.http.HttpSessionIdListener}, or {@link jakarta.servlet.http.HttpSessionListener} interfaces.
*
* @since Servlet 3.0
*/
T createListener(Class clazz) throws ServletException;
/**
* 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.
*
* @return 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
*
* @see jakarta.servlet.descriptor.JspConfigDescriptor
*
* @since Servlet 3.0
*/
JspConfigDescriptor getJspConfigDescriptor();
/**
* 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.
*
* @return the class loader of the web application represented by this ServletContext
*
* @since Servlet 3.0
*/
ClassLoader getClassLoader();
/**
* Declares role names that are tested using isUserInRole.
*
*
* Roles that are implicitly declared as a result of their use within the
* {@link ServletRegistration.Dynamic#setServletSecurity setServletSecurity} or
* {@link ServletRegistration.Dynamic#setRunAsRole setRunAsRole} methods of the {@link ServletRegistration} interface
* need not be declared.
*
* @param roleNames the role names being declared
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @throws IllegalArgumentException if any of the argument roleNames is null or the empty string
*
* @throws IllegalStateException if the ServletContext has already been initialized
*
* @since Servlet 3.0
*/
void declareRoles(String... roleNames);
/**
* 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.
*
* @return a String containing the configuration name of the logical host on which the servlet context is
* deployed.
*
* @since Servlet 3.1
*/
String getVirtualServerName();
/**
* Gets the session timeout in minutes that are supported by default for this ServletContext.
*
* @return the session timeout in minutes that are supported by default for this ServletContext
*
* @since Servlet 4.0
*/
int getSessionTimeout();
/**
* Sets the session timeout in minutes for this ServletContext.
*
* @param sessionTimeout session timeout in minutes
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 4.0
*/
void setSessionTimeout(int sessionTimeout);
/**
* 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).
*
* @return the request character encoding that are supported by default for this ServletContext
*
* @since Servlet 4.0
*/
String getRequestCharacterEncoding();
/**
* Sets the request character encoding for this ServletContext.
*
* @param encoding request character encoding
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 4.0
*/
void setRequestCharacterEncoding(String encoding);
/**
* Sets the request character encoding for this ServletContext.
*
* Implementations are strongly encouraged to override this default method and provide a more efficient implementation.
*
* @param encoding request character encoding
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 6.1
*/
default void setRequestCharacterEncoding(Charset encoding) {
setRequestCharacterEncoding(encoding.name());
}
/**
* 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).
*
* @return the request character encoding that are supported by default for this ServletContext
*
* @since Servlet 4.0
*/
String getResponseCharacterEncoding();
/**
* Sets the response character encoding for this ServletContext.
*
* @param encoding response character encoding
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 4.0
*/
void setResponseCharacterEncoding(String encoding);
/**
* Sets the response character encoding for this ServletContext.
*
* Implementations are strongly encouraged to override this default method and provide a more efficient implementation.
*
* @param encoding response character encoding
*
* @throws IllegalStateException if this ServletContext has already been initialized
*
* @throws UnsupportedOperationException if this ServletContext was passed to the
* {@link ServletContextListener#contextInitialized} method of a {@link ServletContextListener} that was neither
* declared in web.xml or web-fragment.xml, nor annotated with
* {@link jakarta.servlet.annotation.WebListener}
*
* @since Servlet 6.1
*/
default void setResponseCharacterEncoding(Charset encoding) {
setResponseCharacterEncoding(encoding.name());
}
}