View Javadoc

1   /*
2    * $Id: Proxy.java,v 1.5 2005/10/03 18:07:36 tug Exp $
3    * 
4    * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5    * 
6    * Redistribution and use of this software and associated documentation
7    * ("Software"), with or without modification, are permitted provided that the
8    * following conditions are met: 1. Redistributions of source code must retain
9    * copyright statements and notices. Redistributions must also contain a copy
10   * of this document. 2. Redistributions in binary form must reproduce the above
11   * copyright notice, this list of conditions and the following disclaimer in
12   * the documentation and/or other materials provided with the distribution. 3.
13   * The name "groovy" must not be used to endorse or promote products derived
14   * from this Software without prior written permission of The Codehaus. For
15   * written permission, please contact info@codehaus.org. 4. Products derived
16   * from this Software may not be called "groovy" nor may "groovy" appear in
17   * their names without prior written permission of The Codehaus. "groovy" is a
18   * registered trademark of The Codehaus. 5. Due credit should be given to The
19   * Codehaus - http://groovy.codehaus.org/
20   * 
21   * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
22   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24   * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
25   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
28   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
31   * DAMAGE.
32   *  
33   */
34  package groovy.util;
35  
36  import groovy.lang.GroovyObjectSupport;
37  import groovy.lang.MissingMethodException;
38  import org.codehaus.groovy.runtime.InvokerHelper;
39  
40  /***
41   * Dynamic groovy proxy for another object.  All method
42   * invocations get forwarded to actual object, unless the proxy overrides it.
43   * See groovy/util/ProxyTest.groovy for usage details.
44   *
45   * @author Troy Heninger
46   * @author Dierk Koenig
47   */
48  public class Proxy extends GroovyObjectSupport {
49  
50      private Object adaptee = null;
51  
52      /***
53       * This method is for convenience.
54       * It allows to get around the need for defining dump ctors is subclasses.
55       * See unit tests for details.
56       */
57      public Proxy wrap(Object adaptee){
58          setAdaptee(adaptee);
59          return this;
60      }
61  
62      public Object getAdaptee() {
63          return adaptee;
64      }
65  
66      public void setAdaptee(Object adaptee) {
67          this.adaptee = adaptee;
68      }
69  
70      public Object invokeMethod(String name, Object args) {
71          try {
72              return super.invokeMethod(name, args);
73          }
74          catch (MissingMethodException e) {
75              return InvokerHelper.getMetaClass(adaptee).invokeMethod(adaptee, name, args);
76          }
77      }
78  
79  }