KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > jelly > tags > core > CatchTag


1 /*
2  * Copyright 2002,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */

16 package org.apache.commons.jelly.tags.core;
17
18 import org.apache.commons.jelly.JellyTagException;
19 import org.apache.commons.jelly.TagSupport;
20 import org.apache.commons.jelly.XMLOutput;
21
22 /**
23  * A tag which catches exceptions thrown by its body.
24  * This allows conditional logic to be performed based on if exceptions
25  * are thrown or to do some kind of custom exception logging logic.
26  *
27  * @author <a HREF="mailto:jstrachan@apache.org">James Strachan</a>
28  * @version $Revision: 155420 $
29  */

30 public class CatchTag extends TagSupport {
31
32     private String JavaDoc var;
33
34     public CatchTag() {
35     }
36
37     // Tag interface
38
//-------------------------------------------------------------------------
39
public void doTag(XMLOutput output) throws JellyTagException {
40         if (var != null) {
41             context.removeVariable(var);
42         }
43         try {
44             invokeBody(output);
45         }
46         catch (Throwable JavaDoc t) {
47             if (var != null) {
48                 context.setVariable(var, t);
49             }
50         }
51     }
52
53     // Properties
54
//-------------------------------------------------------------------------
55

56     /**
57      * Sets the name of the variable which is exposed with the Exception that gets
58      * thrown by evaluating the body of this tag or which is set to null if there is
59      * no exception thrown.
60      */

61     public void setVar(String JavaDoc var) {
62         this.var = var;
63     }
64 }
65
Popular Tags