01: /*
02: * Copyright 2002,2004 The Apache Software Foundation.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
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 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: } catch (Throwable t) {
46: if (var != null) {
47: context.setVariable(var, t);
48: }
49: }
50: }
51:
52: // Properties
53: //-------------------------------------------------------------------------
54:
55: /**
56: * Sets the name of the variable which is exposed with the Exception that gets
57: * thrown by evaluating the body of this tag or which is set to null if there is
58: * no exception thrown.
59: */
60: public void setVar(String var) {
61: this.var = var;
62: }
63: }
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