001 /*
002 * $Id: NewInstanceMetaMethod.java,v 1.1 2004/03/25 00:35:19 glaforge Exp $
003 *
004 * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005 *
006 * Redistribution and use of this software and associated documentation
007 * ("Software"), with or without modification, are permitted provided that the
008 * following conditions are met:
009 * 1. Redistributions of source code must retain copyright statements and
010 * notices. Redistributions must also contain a copy of this document.
011 * 2. Redistributions in binary form must reproduce the above copyright
012 * notice, this list of conditions and the following disclaimer in the
013 * documentation and/or other materials provided with the distribution.
014 * 3. The name "groovy" must not be used to endorse or promote products
015 * derived from this Software without prior written permission of The Codehaus.
016 * For written permission, please contact info@codehaus.org.
017 * 4. Products derived from this Software may not be called "groovy" nor may
018 * "groovy" appear in their names without prior written permission of The
019 * Codehaus. "groovy" is a registered trademark of The Codehaus.
020 * 5. Due credit should be given to The Codehaus - http://groovy.codehaus.org/
021 *
022 * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
023 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
024 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
025 * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
026 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
027 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
028 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
029 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
030 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
031 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
032 * DAMAGE.
033 *
034 */
035 package org.codehaus.groovy.runtime;
036
037 import groovy.lang.MetaMethod;
038
039 import java.lang.reflect.Modifier;
040
041 /**
042 * A MetaMethod implementation where the underlying method is really a static
043 * helper method on some class but it appears to be an instance method on a class.
044 *
045 * This implementation is used to add new methods to the JDK writing them as normal
046 * static methods with the first parameter being the class on which the method is added.
047 *
048 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
049 * @version $Revision: 1.1 $
050 */
051 public class NewInstanceMetaMethod extends MetaMethod {
052
053 private static final Class[] EMPTY_TYPE_ARRAY = {};
054
055 private MetaMethod metaMethod;
056 private Class[] logicalParameterTypes;
057
058 public NewInstanceMetaMethod(MetaMethod metaMethod) {
059 super(metaMethod);
060 this.metaMethod = metaMethod;
061 Class[] realParameterTypes = metaMethod.getParameterTypes();
062 int size = realParameterTypes.length;
063 if (size <= 1) {
064 logicalParameterTypes = EMPTY_TYPE_ARRAY;
065 }
066 else {
067 logicalParameterTypes = new Class[--size];
068 System.arraycopy(realParameterTypes, 1, logicalParameterTypes, 0, size);
069 }
070 }
071
072 public Class getDeclaringClass() {
073 return getBytecodeParameterTypes()[0];
074 }
075
076 public boolean isStatic() {
077 return false;
078 }
079
080 public int getModifiers() {
081 // lets clear the static bit
082 return super.getModifiers() ^ Modifier.STATIC;
083 }
084
085 public Class[] getParameterTypes() {
086 return logicalParameterTypes;
087 }
088
089 public Class[] getBytecodeParameterTypes() {
090 return super.getParameterTypes();
091 }
092
093 public Object invoke(Object object, Object[] arguments) throws Exception {
094 // we need to cheat using the type
095 int size = arguments.length;
096 Object[] newArguments = new Object[size + 1];
097 newArguments[0] = object;
098 System.arraycopy(arguments, 0, newArguments, 1, size);
099 return metaMethod.invoke(null, newArguments);
100 }
101 }