/*
* Copyright 2000-2004 The Apache Software Foundation
*
* Licensed 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 "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.bcel5_2_0.classfile;
import java.io.DataInputStream;
import java.io.IOException;
import org.apache.bcel5_2_0.Constants;
import org.apache.bcel5_2_0.generic.Type;
import org.apache.bcel5_2_0.util.BCELComparator;
/**
* This class represents the method info structure, i.e., the representation
* for a method in the class. See JVM specification for details.
* A method has access flags, a name, a signature and a number of attributes.
*
* @version $Id: Method.java 386056 2006-03-15 11:31:56Z tcurdt $
* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
*/
public final class Method extends FieldOrMethod {
private static BCELComparator _cmp = new BCELComparator() {
public boolean equals( Object o1, Object o2 ) {
Method THIS = (Method) o1;
Method THAT = (Method) o2;
return THIS.getName().equals(THAT.getName())
&& THIS.getSignature().equals(THAT.getSignature());
}
public int hashCode( Object o ) {
Method THIS = (Method) o;
return THIS.getSignature().hashCode() ^ THIS.getName().hashCode();
}
};
/**
* Empty constructor, all attributes have to be defined via `setXXX'
* methods. Use at your own risk.
*/
public Method() {
}
/**
* Initialize from another object. Note that both objects use the same
* references (shallow copy). Use clone() for a physical copy.
*/
public Method(Method c) {
super(c);
}
/**
* Construct object from file stream.
* @param file Input stream
* @throws IOException
* @throws ClassFormatException
*/
Method(DataInputStream file, ConstantPool constant_pool) throws IOException,
ClassFormatException {
super(file, constant_pool);
}
/**
* @param access_flags Access rights of method
* @param name_index Points to field name in constant pool
* @param signature_index Points to encoded signature
* @param attributes Collection of attributes
* @param constant_pool Array of constants
*/
public Method(int access_flags, int name_index, int signature_index, Attribute[] attributes,
ConstantPool constant_pool) {
super(access_flags, name_index, signature_index, attributes, constant_pool);
}
/**
* Called by objects that are traversing the nodes of the tree implicitely
* defined by the contents of a Java class. I.e., the hierarchy of methods,
* fields, attributes, etc. spawns a tree of objects.
*
* @param v Visitor object
*/
public void accept( Visitor v ) {
v.visitMethod(this);
}
/**
* @return Code attribute of method, if any
*/
public final Code getCode() {
for (int i = 0; i < attributes_count; i++) {
if (attributes[i] instanceof Code) {
return (Code) attributes[i];
}
}
return null;
}
/**
* @return ExceptionTable attribute of method, if any, i.e., list all
* exceptions the method may throw not exception handlers!
*/
public final ExceptionTable getExceptionTable() {
for (int i = 0; i < attributes_count; i++) {
if (attributes[i] instanceof ExceptionTable) {
return (ExceptionTable) attributes[i];
}
}
return null;
}
/** @return LocalVariableTable of code attribute if any, i.e. the call is forwarded
* to the Code atribute.
*/
public final LocalVariableTable getLocalVariableTable() {
Code code = getCode();
if (code == null) {
return null;
}
return code.getLocalVariableTable();
}
/** @return LineNumberTable of code attribute if any, i.e. the call is forwarded
* to the Code atribute.
*/
public final LineNumberTable getLineNumberTable() {
Code code = getCode();
if (code == null) {
return null;
}
return code.getLineNumberTable();
}
/**
* Return string representation close to declaration format,
* `public static void main(String[] args) throws IOException', e.g.
*
* @return String representation of the method.
*/
public final String toString() {
ConstantUtf8 c;
String name, signature, access; // Short cuts to constant pool
StringBuilder buf;
access = Utility.accessToString(access_flags);
// Get name and signature from constant pool
c = (ConstantUtf8) constant_pool.getConstant(signature_index, Constants.CONSTANT_Utf8);
signature = c.getBytes();
c = (ConstantUtf8) constant_pool.getConstant(name_index, Constants.CONSTANT_Utf8);
name = c.getBytes();
signature = Utility.methodSignatureToString(signature, name, access, true,
getLocalVariableTable());
buf = new StringBuilder(signature);
for (int i = 0; i < attributes_count; i++) {
Attribute a = attributes[i];
if (!((a instanceof Code) || (a instanceof ExceptionTable))) {
buf.append(" [").append(a.toString()).append("]");
}
}
ExceptionTable e = getExceptionTable();
if (e != null) {
String str = e.toString();
if (!str.equals("")) {
buf.append("\n\t\tthrows ").append(str);
}
}
return buf.toString();
}
/**
* @return deep copy of this method
*/
public final Method copy( ConstantPool _constant_pool ) {
return (Method) copy_(_constant_pool);
}
/**
* @return return type of method
*/
public Type getReturnType() {
return Type.getReturnType(getSignature());
}
/**
* @return array of method argument types
*/
public Type[] getArgumentTypes() {
return Type.getArgumentTypes(getSignature());
}
/**
* @return Comparison strategy object
*/
public static BCELComparator getComparator() {
return _cmp;
}
/**
* @param comparator Comparison strategy object
*/
public static void setComparator( BCELComparator comparator ) {
_cmp = comparator;
}
/**
* Return value as defined by given BCELComparator strategy.
* By default two method objects are said to be equal when
* their names and signatures are equal.
*
* @see java.lang.Object#equals(java.lang.Object)
*/
public boolean equals( Object obj ) {
return _cmp.equals(this, obj);
}
/**
* Return value as defined by given BCELComparator strategy.
* By default return the hashcode of the method's name XOR signature.
*
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return _cmp.hashCode(this);
}
}