1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. 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 package javax.servlet.jsp;
18
19 import javax.servlet;
20
21 /**
22 * The JspPage interface describes the generic interaction that a JSP Page
23 * Implementation class must satisfy; pages that use the HTTP protocol
24 * are described by the HttpJspPage interface.
25 *
26 * <p><B>Two plus One Methods</B>
27 * <p>
28 * The interface defines a protocol with 3 methods; only two of
29 * them: jspInit() and jspDestroy() are part of this interface as
30 * the signature of the third method: _jspService() depends on
31 * the specific protocol used and cannot be expressed in a generic
32 * way in Java.
33 * <p>
34 * A class implementing this interface is responsible for invoking
35 * the above methods at the appropriate time based on the
36 * corresponding Servlet-based method invocations.
37 * <p>
38 * The jspInit() and jspDestroy() methods can be defined by a JSP
39 * author, but the _jspService() method is defined automatically
40 * by the JSP processor based on the contents of the JSP page.
41 *
42 * <p><B>_jspService()</B>
43 * <p>
44 * The _jspService()method corresponds to the body of the JSP page. This
45 * method is defined automatically by the JSP container and should never
46 * be defined by the JSP page author.
47 * <p>
48 * If a superclass is specified using the extends attribute, that
49 * superclass may choose to perform some actions in its service() method
50 * before or after calling the _jspService() method. See using the extends
51 * attribute in the JSP_Engine chapter of the JSP specification.
52 * <p>
53 * The specific signature depends on the protocol supported by the JSP page.
54 *
55 * <pre>
56 * public void _jspService(<em>ServletRequestSubtype</em> request,
57 * <em>ServletResponseSubtype</em> response)
58 * throws ServletException, IOException;
59 * </pre>
60 */
61
62
63 public interface JspPage extends Servlet {
64
65 /**
66 * The jspInit() method is invoked when the JSP page is initialized. It
67 * is the responsibility of the JSP implementation (and of the class
68 * mentioned by the extends attribute, if present) that at this point
69 * invocations to the getServletConfig() method will return the desired
70 * value.
71 *
72 * A JSP page can override this method by including a definition for it
73 * in a declaration element.
74 *
75 * A JSP page should redefine the init() method from Servlet.
76 */
77 public void jspInit();
78
79 /**
80 * The jspDestroy() method is invoked when the JSP page is about to be
81 * destroyed.
82 *
83 * A JSP page can override this method by including a definition for it
84 * in a declaration element.
85 *
86 * A JSP page should redefine the destroy() method from Servlet.
87 */
88 public void jspDestroy();
89
90 }