1 /*
2 * $Id: NewInstanceMetaMethod.java,v 1.1 2004/03/25 00:35:19 glaforge 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:
9 * 1. Redistributions of source code must retain copyright statements and
10 * notices. Redistributions must also contain a copy of this document.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name "groovy" must not be used to endorse or promote products
15 * derived from this Software without prior written permission of The Codehaus.
16 * For written permission, please contact info@codehaus.org.
17 * 4. Products derived from this Software may not be called "groovy" nor may
18 * "groovy" appear in their names without prior written permission of The
19 * Codehaus. "groovy" is a registered trademark of The Codehaus.
20 * 5. Due credit should be given to The Codehaus - http://groovy.codehaus.org/
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
23 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
26 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
28 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
32 * DAMAGE.
33 *
34 */
35 package org.codehaus.groovy.runtime;
36
37 import groovy.lang.MetaMethod;
38
39 import java.lang.reflect.Modifier;
40
41 /***
42 * A MetaMethod implementation where the underlying method is really a static
43 * helper method on some class but it appears to be an instance method on a class.
44 *
45 * This implementation is used to add new methods to the JDK writing them as normal
46 * static methods with the first parameter being the class on which the method is added.
47 *
48 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
49 * @version $Revision: 1.1 $
50 */
51 public class NewInstanceMetaMethod extends MetaMethod {
52
53 private static final Class[] EMPTY_TYPE_ARRAY = {};
54
55 private MetaMethod metaMethod;
56 private Class[] logicalParameterTypes;
57
58 public NewInstanceMetaMethod(MetaMethod metaMethod) {
59 super(metaMethod);
60 this.metaMethod = metaMethod;
61 Class[] realParameterTypes = metaMethod.getParameterTypes();
62 int size = realParameterTypes.length;
63 if (size <= 1) {
64 logicalParameterTypes = EMPTY_TYPE_ARRAY;
65 }
66 else {
67 logicalParameterTypes = new Class[--size];
68 System.arraycopy(realParameterTypes, 1, logicalParameterTypes, 0, size);
69 }
70 }
71
72 public Class getDeclaringClass() {
73 return getBytecodeParameterTypes()[0];
74 }
75
76 public boolean isStatic() {
77 return false;
78 }
79
80 public int getModifiers() {
81 // lets clear the static bit
82 return super.getModifiers() ^ Modifier.STATIC;
83 }
84
85 public Class[] getParameterTypes() {
86 return logicalParameterTypes;
87 }
88
89 public Class[] getBytecodeParameterTypes() {
90 return super.getParameterTypes();
91 }
92
93 public Object invoke(Object object, Object[] arguments) throws Exception {
94 // we need to cheat using the type
95 int size = arguments.length;
96 Object[] newArguments = new Object[size + 1];
97 newArguments[0] = object;
98 System.arraycopy(arguments, 0, newArguments, 1, size);
99 return metaMethod.invoke(null, newArguments);
100 }
101 }