KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > turbine > modules > screens > VelocitySecureScreen


1 package org.apache.turbine.modules.screens;
2
3 /*
4  * Copyright 2001-2004 The Apache Software Foundation.
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License")
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import org.apache.turbine.services.velocity.TurbineVelocity;
20 import org.apache.turbine.util.RunData;
21
22 import org.apache.velocity.context.Context;
23
24 /**
25  * VelocitySecureScreen
26  *
27  * Always performs a Security Check that you've defined before
28  * executing the doBuildtemplate(). You should extend this class and
29  * add the specific security check needed. If you have a number of
30  * screens that need to perform the same check, you could make a base
31  * screen by extending this class and implementing the isAuthorized().
32  * Then each screen that needs to perform the same check could extend
33  * your base screen.
34  *
35  * @author <a HREF="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
36  * @version $Id: VelocitySecureScreen.java,v 1.4.2.2 2004/05/20 03:03:54 seade Exp $
37  */
38 public abstract class VelocitySecureScreen
39         extends VelocityScreen
40 {
41     /**
42      * Implement this to add information to the context.
43      *
44      * @param data Turbine information.
45      * @param context Context for web pages.
46      * @exception Exception, a generic exception.
47      */
48     protected abstract void doBuildTemplate(RunData data,
49                                             Context context)
50             throws Exception JavaDoc;
51
52     /**
53      * This method overrides the method in VelocityScreen to
54      * perform a security check first.
55      *
56      * @param data Turbine information.
57      * @exception Exception, a generic exception.
58      */
59     protected void doBuildTemplate(RunData data)
60         throws Exception JavaDoc
61     {
62         if (isAuthorized(data))
63         {
64             doBuildTemplate(data, TurbineVelocity.getContext(data));
65         }
66     }
67
68     /**
69      * Implement this method to perform the security check needed.
70      * You should set the template in this method that you want the
71      * user to be sent to if they're unauthorized. See the
72      * VelocitySecurityCheck utility.
73      *
74      * @param data Turbine information.
75      * @return True if the user is authorized to access the screen.
76      * @exception Exception, a generic exception.
77      */
78     protected abstract boolean isAuthorized(RunData data)
79             throws Exception JavaDoc;
80 }
81
Popular Tags