org.codehaus.groovy.classgen.asm.MethodCaller Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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*/
package org.codehaus.groovy.classgen.asm;
import org.codehaus.groovy.classgen.ClassGeneratorException;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import java.lang.reflect.Method;
/**
* A helper class to invoke methods more easily in ASM
*
* @author James Strachan
*/
public class MethodCaller implements Opcodes {
private int opcode;
private String internalName;
private String name;
private Class theClass;
private String methodDescriptor;
public static MethodCaller newStatic(Class theClass, String name) {
return new MethodCaller(INVOKESTATIC, theClass, name);
}
public static MethodCaller newInterface(Class theClass, String name) {
return new MethodCaller(INVOKEINTERFACE, theClass, name);
}
public static MethodCaller newVirtual(Class theClass, String name) {
return new MethodCaller(INVOKEVIRTUAL, theClass, name);
}
public MethodCaller(int opcode, Class theClass, String name) {
this.opcode = opcode;
this.internalName = Type.getInternalName(theClass);
this.theClass = theClass;
this.name = name;
}
public void call(MethodVisitor methodVisitor) {
methodVisitor.visitMethodInsn(opcode, internalName, name, getMethodDescriptor(), opcode == Opcodes.INVOKEINTERFACE);
}
public String getMethodDescriptor() {
if (methodDescriptor == null) {
Method method = getMethod();
methodDescriptor = Type.getMethodDescriptor(method);
}
return methodDescriptor;
}
protected Method getMethod() {
Method[] methods = theClass.getMethods();
for (int i = 0; i < methods.length; i++) {
Method method = methods[i];
if (method.getName().equals(name)) {
return method;
}
}
throw new ClassGeneratorException("Could not find method: " + name + " on class: " + theClass);
}
}