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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.beanshell;
17  
18  import org.apache.commons.jelly.JellyContext;
19  import org.apache.commons.jelly.expression.ExpressionSupport;
20  
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  
25  /*** Represents a <a href="http://www.beanshell.org" target="alexandria_uri">http://www.beanshell.org">beanshell</a> expression
26    *
27    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
28    * @version $Revision: 155420 $
29    */
30  public class BeanShellExpression extends ExpressionSupport {
31  
32      /*** The Log to which logging calls will be made. */
33      private static final Log log = LogFactory.getLog( BeanShellExpression.class );
34  
35      /*** The expression */
36      private String text;
37  
38      public BeanShellExpression(String text) {
39          this.text = text;
40      }
41  
42      // Expression interface
43      //-------------------------------------------------------------------------
44      public String getExpressionText() {
45          return "${" + text + "}";
46      }
47  
48      public Object evaluate(JellyContext context) {
49          try {
50              JellyInterpreter interpreter = new JellyInterpreter();
51              interpreter.setJellyContext(context);
52  
53              if ( log.isDebugEnabled() ) {
54                  log.debug( "Evaluating beanshell: " + text );
55              }
56  
57              return interpreter.eval( text );
58          }
59          catch (Exception e) {
60              log.warn( "Caught exception evaluating: " + text + ". Reason: " + e, e );
61              return null;
62          }
63      }
64  }