/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Axis" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.axis.utils.bytecode;
import org.apache.bcel.classfile.ClassParser;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.Method;
import java.io.IOException;
import java.io.InputStream;
import java.util.Hashtable;
import java.util.Vector;
/**
* This class implements an Extractor using BCEL
*
* @author <a href="mailto:dims@yahoo.com">Davanum Srinivas</a>
* @version $Revision: 1.1 $ $Date: 2002/06/12 15:02:59 $
*/
public class BCEL implements Extractor {
/**
* Cache of BCEL JavaClass objects which correspond to particular
* Java classes.
*
* !!! NOTE : AT PRESENT WE DO NOT CLEAN UP THIS CACHE.
*/
private static Hashtable clazzCache = new Hashtable();
/**
* Get Parameter Names using BCEL
*
* @param method the Java method we're interested in
* @return list of names or null
*/
public String[] getParameterNamesFromDebugInfo(java.lang.reflect.Method m) {
Class c = m.getDeclaringClass();
int numParams = m.getParameterTypes().length;
Vector temp = new Vector();
// Don't worry about it if there are no params.
if (numParams == 0)
return null;
// Try to obtain a tt-bytecode class object
JavaClass bclass = (JavaClass) clazzCache.get(c);
if (bclass == null) {
try {
String className = c.getName();
String classFile = className.replace('.', '/');
InputStream is =
c.getClassLoader().getResourceAsStream(classFile + ".class");
ClassParser parser = new ClassParser(is, className);
bclass = parser.parse();
clazzCache.put(c, bclass);
} catch (IOException e) {
// what now?
}
}
Method[] methods = bclass.getMethods();
Method method = null;
// Get the BCEL Method corresponding to the
// ava.lang.reflect.Method
for (int i = 0; i < methods.length; i++) {
if (m.getName().equals(methods[i].getName()) &&
getSignature(m).equals(methods[i].getSignature())) {
method = methods[i];
break;
}
}
// Obtain the exact method we're interested in.
if (method == null)
return null;
// Get the Code object, which contains the local variable table.
Code code = method.getCode();
if (code == null)
return null;
LocalVariableTable attr = method.getLocalVariableTable();
if (attr == null)
return null;
// OK, found it. Now scan through the local variables and record
// the names in the right indices.
LocalVariable[] vars = attr.getLocalVariableTable();
String[] argNames = new String[numParams + 1];
argNames[0] = null; // don't know return name
// NOTE: we scan through all the variables here, because I have been
// told that jikes sometimes produces unpredictable ordering of the
// local variable table.
for (int j = 0; j < vars.length; j++) {
LocalVariable var = vars[j];
if (!var.getName().equals("this")) {
if (temp.size() < var.getIndex() + 1)
temp.setSize(var.getIndex() + 1);
temp.setElementAt(var.getName(), var.getIndex());
}
}
int k = 0;
for (int j = 0; j < temp.size(); j++) {
if (temp.elementAt(j) != null) {
k++;
argNames[k] = (String) temp.elementAt(j);
if (k + 1 == argNames.length)
break;
}
}
return argNames;
}
/**
* Compute the JVM signature for the class.
*/
String getSignature(Class clazz) {
String type = null;
if (clazz.isArray()) {
Class cl = clazz;
int dimensions = 0;
while (cl.isArray()) {
dimensions++;
cl = cl.getComponentType();
}
StringBuffer sb = new StringBuffer();
for (int i = 0; i < dimensions; i++) {
sb.append("[");
}
sb.append(getSignature(cl));
type = sb.toString();
} else if (clazz.isPrimitive()) {
if (clazz == Integer.TYPE) {
type = "I";
} else if (clazz == Byte.TYPE) {
type = "B";
} else if (clazz == Long.TYPE) {
type = "J";
} else if (clazz == Float.TYPE) {
type = "F";
} else if (clazz == Double.TYPE) {
type = "D";
} else if (clazz == Short.TYPE) {
type = "S";
} else if (clazz == Character.TYPE) {
type = "C";
} else if (clazz == Boolean.TYPE) {
type = "Z";
} else if (clazz == Void.TYPE) {
type = "V";
}
} else {
type = "L" + clazz.getName().replace('.', '/') + ";";
}
return type;
}
/*
* Compute the JVM method descriptor for the method.
*/
String getSignature(java.lang.reflect.Method meth) {
StringBuffer sb = new StringBuffer();
sb.append("(");
Class[] params = meth.getParameterTypes(); // avoid clone
for (int j = 0; j < params.length; j++) {
sb.append(getSignature(params[j]));
}
sb.append(")");
sb.append(getSignature(meth.getReturnType()));
return sb.toString();
}
}