1 /** 2 * 3 * Copyright 2003-2004 The Apache Software Foundation 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 // 19 // This source code implements specifications defined by the Java 20 // Community Process. In order to remain compliant with the specification 21 // DO NOT add / change / or delete method signatures! 22 // 23 24 package javax.servlet.jsp; 25 26 import javax.servlet.Servlet; 27 28 /** 29 * The JspPage interface describes the generic interaction that a JSP Page 30 * Implementation class must satisfy; pages that use the HTTP protocol 31 * are described by the HttpJspPage interface. 32 * 33 * <p><B>Two plus One Methods</B> 34 * <p> 35 * The interface defines a protocol with 3 methods; only two of 36 * them: jspInit() and jspDestroy() are part of this interface as 37 * the signature of the third method: _jspService() depends on 38 * the specific protocol used and cannot be expressed in a generic 39 * way in Java. 40 * <p> 41 * A class implementing this interface is responsible for invoking 42 * the above methods at the appropriate time based on the 43 * corresponding Servlet-based method invocations. 44 * <p> 45 * The jspInit() and jspDestroy() methods can be defined by a JSP 46 * author, but the _jspService() method is defined automatically 47 * by the JSP processor based on the contents of the JSP page. 48 * 49 * <p><B>_jspService()</B> 50 * <p> 51 * The _jspService()method corresponds to the body of the JSP page. This 52 * method is defined automatically by the JSP container and should never 53 * be defined by the JSP page author. 54 * <p> 55 * If a superclass is specified using the extends attribute, that 56 * superclass may choose to perform some actions in its service() method 57 * before or after calling the _jspService() method. See using the extends 58 * attribute in the JSP_Engine chapter of the JSP specification. 59 * <p> 60 * The specific signature depends on the protocol supported by the JSP page. 61 * 62 * <pre> 63 * public void _jspService(<em>ServletRequestSubtype</em> request, 64 * <em>ServletResponseSubtype</em> response) 65 * throws ServletException, IOException; 66 * </pre> 67 */ 68 69 70 public interface JspPage extends Servlet { 71 72 /** 73 * The jspInit() method is invoked when the JSP page is initialized. It 74 * is the responsibility of the JSP implementation (and of the class 75 * mentioned by the extends attribute, if present) that at this point 76 * invocations to the getServletConfig() method will return the desired 77 * value. 78 * 79 * A JSP page can override this method by including a definition for it 80 * in a declaration element. 81 * 82 * A JSP page should redefine the init() method from Servlet. 83 */ 84 public void jspInit(); 85 86 /** 87 * The jspDestroy() method is invoked when the JSP page is about to be 88 * destroyed. 89 * 90 * A JSP page can override this method by including a definition for it 91 * in a declaration element. 92 * 93 * A JSP page should redefine the destroy() method from Servlet. 94 */ 95 public void jspDestroy(); 96 97 }