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 }