javax.servlet.ServletContext Maven / Gradle / Ivy
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/*
* Copyright (c) 1998-2018 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package javax.servlet;
import javax.servlet.descriptor.JspConfigDescriptor;
import java.io.InputStream;
import java.util.*;
/**
* ServletContexts encapsulate applications. Applications are generalized
* virtual hosts; a URL prefix defines a distinct application.
* So /myapp and /yourapp could define different applications. As a
* degenerate case, each virtual host has its own ServletContext.
*
* Each application is entirely distinct. Each has its own:
*
* - Class loader -- each application gets its own beans and servlets.
*
- ServletContext attributes
*
- Servlets and servlet mappings (e.g. *.jsp could map to different
* servlets in different applications.)
*
- File root
*
- Mime mapping
*
- Real-path mapping (aliases)
*
*
* URIs are relative to the application root (e.g. /myapp) for
* most ServletContext methods. So you can define user workspaces with
* identical JSP files and servlets in different applications.
*
*
Including and forwarding
*
* Forwarding and including files, the Servlet equivalent of SSI are
* handled by the RequestDispatcher methods.
*
*
Global initialization
*
* There is no direct equivalent of a global.jsa. To initialize
* and cleanup shared classes on start and stop, use a load-on-startup
* servlet. The init() method will be called when the application starts
* and the destroy() method will be called when the application finishes.
*
*
* <servlet servlet-name='global'
* servlet-class='test.InitServlet'
* load-on-startup/>
*
*
* Basic configuration
*
* In the resin.conf, to define the /myapp application with a document
* root in /www/myweb, add the following to the resin.conf.
*
*
* <web-app id='/myapp' app-dir='/www/myweb'/>
*
*
* Servlet and Bean locations (class loaders)
*
* Each application has its own directories to load application servlets
* and beans. By default these are WEB-APP/classes and WEB-APP/lib.
* To add a servlet test.MyServlet, create the java file:
* /www/myweb/WEB-APP/classes/test/MyServlet.java
*
* Load balancing
*
* When using load balancing with a web server, each JVM will have its own
* application object. The attributes are not shared. In contrast,
* sessions are always sent to the same JVM.
*
* So the application object is best used as a cache rather than
* as a way for servlets to communicate.
*/
public interface ServletContext {
public static final String ORDERED_LIBS = "javax.servlet.context.orderedLibs";
public static final String TEMPDIR = "javax.servlet.context.tempdir";
/**
* Returns the URL prefix for the ServletContext.
*/
public String getServletContextName();
/**
* Returns a server-specific string identifying the servlet engine.
*/
public String getServerInfo();
/**
* Returns the major version of the servlet API.
*/
public int getMajorVersion();
/**
*
* @return major version of the spec the app is based on
* @Since Servlet 3.0
*/
public int getEffectiveMajorVersion();
/**
* Returns the minor version of the servlet API.
*/
public int getMinorVersion();
/**
* @return minor version of the spec the app is based on
* @Since Servlet 3.0
*/
public int getEffectiveMinorVersion();
/**
* Returns the value of an initialization parameter from the configuration
* file.
*
* The Resin configuration looks something like:
*
* <web-app id='/myapp' app-dir='/www/myapp'>
* <context-param name1='value1'/>
* <context-param name2='value2'/>
* </web-app>
*
*
* @param name init parameter name
* @return init parameter value
*/
public String getInitParameter(String name);
/**
* Returns an enumeration of all init parameter names.
*/
public Enumeration getInitParameterNames();
/**
* Returns the ServletContext for the uri.
* Note: the uri is not relative to the application.T
*
* @param uri path relative to the root
* @return the ServletContext responsible for the given uri.
*/
public ServletContext getContext(String uri);
/**
* Returns the context-path for the web-application.
*/
public String getContextPath();
/**
* Returns the real file path for the given uri. The file path will
* be in native path format (with native path separators.)
*
* See ServletRequest to return the real path relative to the
* request uri.
*
* @param uri path relative to the application root to be translated.
* @return native file path for the uri.
*/
public String getRealPath(String uri);
/**
* Returns a request dispatcher for later inclusion or forwarding. This
* is the servlet API equivalent to SSI includes. The uri is relative
* to the application root.
*
*
The following example includes the result of executing inc.jsp
* into the output stream. If the context path is /myapp, the equivalent
* uri is /myapp/inc.jsp
*
*
* RequestDispatcher disp;
* disp = getRequestDispatcher("/inc.jsp?a=b");
* disp.include(request, response);
*
See ServletRequest to return a request dispatcher relative to the
* request uri.
*
* @param uri path relative to the app root (including query string)
* for the included file.
* @return RequestDispatcher for later inclusion or forwarding.
*/
public RequestDispatcher getRequestDispatcher(String uri);
/**
* Returns a request dispatcher based on a servlet name.
*
* @param servletName the servlet name to include or forward to.
* @return RequestDispatcher for later inclusion or forwarding.
*/
public RequestDispatcher getNamedDispatcher(String servletName);
/**
* Returns the mime type for the given uri.
*
* @param uri path relative to the application root.
*/
public String getMimeType(String uri);
/**
* Returns an attribute value.
*
* @param name of the attribute.
* @return stored value
*/
public Object getAttribute(String name);
/**
* Returns an enumeration of all the attribute names.
*/
public Enumeration getAttributeNames();
/**
* Sets an attribute value. Because servlets are multithreaded,
* setting ServletContext attributes will generally need synchronization.
*
* A typical initialization of an application attribute will look like:
*
* ServletContext app = getServletContext();
* Object value;
* synchronized (app) {
* value = app.getAttribute("cache");
* if (value == null) {
* value = new Cache();
* app.setAttribute("cache", value);
* }
* }
* getResourcePaths(String prefix);
/**
* Returns the resource as a stream. In general, the
* RequestDispatcher routines are more useful.
*
* @param path path relative to the application root.
* @return InputStream to the resource.
*/
public InputStream getResourceAsStream(String path);
/**
* @deprecated
*/
public Servlet getServlet(String name)
throws ServletException;
/**
* @deprecated
*/
public Enumeration getServlets();
/**
* @deprecated
*/
public Enumeration getServletNames();
/**
* @deprecated
*/
public void log(Exception exception, String msg);
/**
* Sets the session cookie configuration
*
* @Since Servlet 3.0
*/
public SessionCookieConfig getSessionCookieConfig();
/**
* The session tracking mode
*
* @Since Servlet 3.0
*/
public void setSessionTrackingModes(Set modes);
/**
* The session tracking mode
*
* @Since Servlet 3.0
*/
public Set getDefaultSessionTrackingModes();
/**
* The session tracking mode
*
* @Since Servlet 3.0
*/
public Set getEffectiveSessionTrackingModes();
/**
* Sets init parameter
* @param name
* @param value
* @return
*/
public boolean setInitParameter(String name, String value);
/**
* Adds a servlet with the given className to context
*/
public ServletRegistration.Dynamic addServlet(String servletName, String className);
/**
* Adds a servlet to context
*/
public ServletRegistration.Dynamic addServlet(String servletName, Servlet servlet);
/**
* Adds a servlet class to the servlet container.
*/
public ServletRegistration.Dynamic addServlet(String servletName,
Class servletClass);
/**
* Creates a servlet instance using the web-apps injection.
*/
public T createServlet(Class c)
throws ServletException;
/** Returs servlet registration using servletName
* @param servletName
* @return a ServletRegistration object
*/
public ServletRegistration getServletRegistration(String servletName);
/**
* Returns servlet registrations
* @return
*/
public Map getServletRegistrations();
/**
* Adds a dynamic filter registration using className
* @param filterName
* @param className
* @return
*/
public FilterRegistration.Dynamic addFilter(String filterName, String className);
/**
* Adds a dynamic filter registration using filter
*
* @param filterName
* @param filter
* @return
*/
public FilterRegistration.Dynamic addFilter(String filterName, Filter filter);
/**
* Adds a filter using filterClass
* @param filterName
* @param filterClass
* @return
*/
public FilterRegistration.Dynamic addFilter(String filterName,
Class filterClass);
/**
* Create a filter using class
* @param c
* @param
* @return
* @throws ServletException
*/
public T createFilter(Class c)
throws ServletException;
/**
* Returns filter registration sing filterName
* @param filterName
* @return
*/
public FilterRegistration getFilterRegistration(String filterName);
/**
* Returns filter registrations
* @return
*/
public Map getFilterRegistrations();
public void addListener(String className);
public void addListener(T t);
public void addListener(Class listenerClass);
public T createListener(Class listenerClass)
throws ServletException;
public JspConfigDescriptor getJspConfigDescriptor();
public ClassLoader getClassLoader();
public void declareRoles(String... roleNames);
}