001 /*
002 $Id: MethodCaller.java,v 1.3 2005/05/27 10:13:09 russel 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
008 that the following conditions are met:
009
010 1. Redistributions of source code must retain copyright
011 statements and notices. Redistributions must also contain a
012 copy of this document.
013
014 2. Redistributions in binary form must reproduce the
015 above copyright notice, this list of conditions and the
016 following disclaimer in the documentation and/or other
017 materials provided with the distribution.
018
019 3. The name "groovy" must not be used to endorse or promote
020 products derived from this Software without prior written
021 permission of The Codehaus. For written permission,
022 please contact info@codehaus.org.
023
024 4. Products derived from this Software may not be called "groovy"
025 nor may "groovy" appear in their names without prior written
026 permission of The Codehaus. "groovy" is a registered
027 trademark of The Codehaus.
028
029 5. Due credit should be given to The Codehaus -
030 http://groovy.codehaus.org/
031
032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043 OF THE POSSIBILITY OF SUCH DAMAGE.
044
045 */
046 package org.codehaus.groovy.classgen;
047
048 import java.lang.reflect.Method;
049
050 import org.objectweb.asm.MethodVisitor;
051 import org.objectweb.asm.Opcodes;
052 import org.objectweb.asm.Type;
053
054 /**
055 * A helper class to invoke methods more easily in ASM
056 *
057 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
058 * @version $Revision: 1.3 $
059 */
060 public class MethodCaller implements Opcodes {
061
062 private int opcode;
063 private String internalName;
064 private String name;
065 private Class theClass;
066 private String methodDescriptor;
067
068 public static MethodCaller newStatic(Class theClass, String name) {
069 return new MethodCaller(INVOKESTATIC, theClass, name);
070 }
071
072 public static MethodCaller newInterface(Class theClass, String name) {
073 return new MethodCaller(INVOKEINTERFACE, theClass, name);
074 }
075
076 public static MethodCaller newVirtual(Class theClass, String name) {
077 return new MethodCaller(INVOKEVIRTUAL, theClass, name);
078 }
079
080 public MethodCaller(int opcode, Class theClass, String name) {
081 this.opcode = opcode;
082 this.internalName = Type.getInternalName(theClass);
083 this.theClass = theClass;
084 this.name = name;
085
086 }
087
088 public void call(MethodVisitor methodVisitor) {
089 methodVisitor.visitMethodInsn(opcode, internalName, name, getMethodDescriptor());
090 }
091
092 public String getMethodDescriptor() {
093 if (methodDescriptor == null) {
094 Method method = getMethod();
095 methodDescriptor = Type.getMethodDescriptor(method);
096 }
097 return methodDescriptor;
098 }
099
100 protected Method getMethod() {
101 Method[] methods = theClass.getMethods();
102 for (int i = 0; i < methods.length; i++) {
103 Method method = methods[i];
104 if (method.getName().equals(name)) {
105 return method;
106 }
107 }
108 throw new ClassGeneratorException("Could not find method: " + name + " on class: " + theClass);
109 }
110 }