javax.servlet.RequestDispatcher 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 SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package javax.servlet;
import java.io.IOException;
/**
* The RequestDispatcher gives servlets the capabilities of SSI includes.
* The forwarded or included page is handled as a normal page request.
*
*
* RequestDispatcher disp;
* disp = request.getRequestDispatcher("inc.jsp?a=b");
* disp.include(request, response);
*
*
* Servlets typically use ServletRequest.setAttribute()
* to communicate between included pages.
*
*
A popular architecture uses servlets to process the initial request
* and JSP files to format the results. That template architecture uses
* request attributes to communicate data from the servlet to the JSP page.
* disp.forward() transfers the request to the JSP file.
*/
public interface RequestDispatcher {
public static final String ERROR_MESSAGE = "javax.servlet.error.message";
public static final String ERROR_EXCEPTION = "javax.servlet.error.exception";
public static final String ERROR_EXCEPTION_TYPE
= "javax.servlet.error.exception_type";
public static final String ERROR_REQUEST_URI
= "javax.servlet.error.request_uri";
public static final String ERROR_SERVLET_NAME
= "javax.servlet.error.servlet_name";
public static final String ERROR_STATUS_CODE
= "javax.servlet.error.status_code";
public static final String FORWARD_CONTEXT_PATH
= "javax.servlet.forward.context_path";
public static final String FORWARD_PATH_INFO
= "javax.servlet.forward.path_info";
public static final String FORWARD_QUERY_STRING
= "javax.servlet.forward.query_string";
public static final String FORWARD_REQUEST_URI
= "javax.servlet.forward.request_uri";
public static final String FORWARD_SERVLET_PATH
= "javax.servlet.forward.servlet_path";
public static final String INCLUDE_CONTEXT_PATH
= "javax.servlet.include.context_path";
public static final String INCLUDE_PATH_INFO
= "javax.servlet.include.path_info";
public static final String INCLUDE_QUERY_STRING
= "javax.servlet.include.query_string";
public static final String INCLUDE_REQUEST_URI
= "javax.servlet.include.request_uri";
public static final String INCLUDE_SERVLET_PATH
= "javax.servlet.include.servlet_path";
/**
* Forwards the request to another page. Forward may not be called
* if data has been sent to the client. Specifically,
* forward calls the response.reset() method to clear
* the output buffer.
*
*
Query parameters are added to the original query parameters.
*
*
The new URI values are based on the RequestDispatcher URI.
* So getRequestURI(), getServletPath(), and getPathInfo() will reflect
* the request dispatcher URI.
*
* @param request the original request
* @param response the original response
*/
public void forward(ServletRequest request, ServletResponse response)
throws ServletException, IOException;
/**
* Includes the result of another page.
*
*
Query parameters are added to the original query parameters.
*
*
The included request's URI methods reflect the original
* URI data. So getRequestURI() will return the URI sent by
* the browser.
*
*
Included pages should use request.getAttribute() to get the
* new URI values:
*
* getRequestURI javax.servlet.include.request_uri
* getContextPath javax.servlet.include.context_path
* getServletPath javax.servlet.include.servlet_path
* getPathInfo javax.servlet.include.path_info
* getQueryString javax.servlet.include.query_string
*
*
* @param request the original request
* @param response the original response
*/
public void include(ServletRequest request, ServletResponse response)
throws ServletException, IOException;
}