001 /**
002 *
003 * Copyright 2003-2004 The Apache Software Foundation
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 //
019 // This source code implements specifications defined by the Java
020 // Community Process. In order to remain compliant with the specification
021 // DO NOT add / change / or delete method signatures!
022 //
023
024 package javax.servlet.jsp;
025
026 import javax.servlet.*;
027
028 /**
029 * The JspPage interface describes the generic interaction that a JSP Page
030 * Implementation class must satisfy; pages that use the HTTP protocol
031 * are described by the HttpJspPage interface.
032 *
033 * <p><B>Two plus One Methods</B>
034 * <p>
035 * The interface defines a protocol with 3 methods; only two of
036 * them: jspInit() and jspDestroy() are part of this interface as
037 * the signature of the third method: _jspService() depends on
038 * the specific protocol used and cannot be expressed in a generic
039 * way in Java.
040 * <p>
041 * A class implementing this interface is responsible for invoking
042 * the above methods at the appropriate time based on the
043 * corresponding Servlet-based method invocations.
044 * <p>
045 * The jspInit() and jspDestroy() methods can be defined by a JSP
046 * author, but the _jspService() method is defined automatically
047 * by the JSP processor based on the contents of the JSP page.
048 *
049 * <p><B>_jspService()</B>
050 * <p>
051 * The _jspService()method corresponds to the body of the JSP page. This
052 * method is defined automatically by the JSP container and should never
053 * be defined by the JSP page author.
054 * <p>
055 * If a superclass is specified using the extends attribute, that
056 * superclass may choose to perform some actions in its service() method
057 * before or after calling the _jspService() method. See using the extends
058 * attribute in the JSP_Engine chapter of the JSP specification.
059 * <p>
060 * The specific signature depends on the protocol supported by the JSP page.
061 *
062 * <pre>
063 * public void _jspService(<em>ServletRequestSubtype</em> request,
064 * <em>ServletResponseSubtype</em> response)
065 * throws ServletException, IOException;
066 * </pre>
067 */
068
069
070 public interface JspPage extends Servlet {
071
072 /**
073 * The jspInit() method is invoked when the JSP page is initialized. It
074 * is the responsibility of the JSP implementation (and of the class
075 * mentioned by the extends attribute, if present) that at this point
076 * invocations to the getServletConfig() method will return the desired
077 * value.
078 *
079 * A JSP page can override this method by including a definition for it
080 * in a declaration element.
081 *
082 * A JSP page should redefine the init() method from Servlet.
083 */
084 public void jspInit();
085
086 /**
087 * The jspDestroy() method is invoked when the JSP page is about to be
088 * destroyed.
089 *
090 * A JSP page can override this method by including a definition for it
091 * in a declaration element.
092 *
093 * A JSP page should redefine the destroy() method from Servlet.
094 */
095 public void jspDestroy();
096
097 }