/**************************************************************************************
* Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package org.codehaus.aspectwerkz.transform;
import java.util.Iterator;
import java.util.List;
import javassist.CannotCompileException;
import javassist.CtBehavior;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtField;
import javassist.Modifier;
import javassist.NotFoundException;
import javassist.expr.ExprEditor;
import javassist.expr.NewExpr;
import org.codehaus.aspectwerkz.definition.DefinitionLoader;
import org.codehaus.aspectwerkz.definition.SystemDefinition;
import org.codehaus.aspectwerkz.exception.WrappedRuntimeException;
import org.codehaus.aspectwerkz.metadata.ClassMetaData;
import org.codehaus.aspectwerkz.metadata.ConstructorMetaData;
import org.codehaus.aspectwerkz.metadata.JavassistMetaDataMaker;
/**
* Advises constructor CALL join points.
*
* @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur</a>
* @author <a href="mailto:jboner@codehaus.org">Jonas Bon�r</a>
*/
public class ConstructorCallTransformer implements Transformer {
/**
* List with the definitions.
*/
private List m_definitions;
/**
* The join point index.
*/
private int m_joinPointIndex;
/**
* Creates a new instance of the transformer.
*/
public ConstructorCallTransformer() {
m_definitions = DefinitionLoader.getDefinitions();
}
/**
* Transforms the call side pointcuts.
*
* @param context the transformation context
* @param klass the class set.
*/
public void transform(final Context context, final Klass klass) throws NotFoundException, CannotCompileException {
m_joinPointIndex = TransformationUtil.getJoinPointIndex(klass.getCtClass());
for (Iterator it = m_definitions.iterator(); it.hasNext();) {
final SystemDefinition definition = (SystemDefinition)it.next();
final CtClass ctClass = klass.getCtClass();
ClassMetaData classMetaData = JavassistMetaDataMaker.createClassMetaData(ctClass);
if (classFilter(definition, classMetaData, ctClass)) {
return;
}
ctClass.instrument(
new ExprEditor() {
public void edit(NewExpr newExpr) throws CannotCompileException {
try {
CtBehavior where = null;
try {
where = newExpr.where();
}
catch (RuntimeException e) {
// <clinit> access leads to a bug in Javassist
where = ctClass.getClassInitializer();
}
// filter caller methods
if (methodFilterCaller(where)) {
return;
}
CtConstructor ctConstructor = newExpr.getConstructor();
String calleeClassName = newExpr.getClassName();
// filter callee classes
if (!definition.inIncludePackage(calleeClassName)) {
return;
}
// filter the constructors
if (constructorFilter(ctConstructor)) {
return;
}
// create the class meta-data
ClassMetaData calleeSideClassMetaData;
try {
calleeSideClassMetaData =
JavassistMetaDataMaker.createClassMetaData(
context.getClassPool().get(calleeClassName)
);
}
catch (NotFoundException e) {
throw new WrappedRuntimeException(e);
}
// create the method meta-data
ConstructorMetaData constructorMetaData =
JavassistMetaDataMaker.createConstructorMetaData(newExpr.getConstructor());
// is this a caller side method pointcut?
if (definition.isPickedOutByCallPointcut(calleeSideClassMetaData, constructorMetaData)) {
// check the callee class is not the same as target class, if that is the case
// then we have have class loaded and set in the ___AW_clazz already
String declaringClassMethodName = TransformationUtil.STATIC_CLASS_FIELD;
CtClass declaringClass = ctConstructor.getDeclaringClass();
if (!declaringClass.getName().replace('/', '.').equals(where.getDeclaringClass().getName().replace('/', '.'))) {
declaringClassMethodName =
addCalleeMethodDeclaringClassField(ctClass, ctConstructor);
}
// call the wrapper method instead of the callee method
StringBuffer body = new StringBuffer();
body.append('{');
if (ctConstructor.getParameterTypes().length > 0) {
body.append("Object[] args = $args; ");
}
else {
body.append("Object[] args = null; ");
}
body.append("Class declaringClassMethodName = ");
body.append(declaringClassMethodName);
body.append("; ");
if (Modifier.isStatic(where.getModifiers())) {
body.append("Object nullObject = null;");
}
body.append("$_ = ($r)");
body.append(TransformationUtil.JOIN_POINT_MANAGER_FIELD);
body.append('.');
body.append(TransformationUtil.PROCEED_WITH_CALL_JOIN_POINT_METHOD);
body.append('(');
body.append(TransformationUtil.calculateHash(ctConstructor));
body.append(',');
body.append(m_joinPointIndex);
body.append(", args, ");
if (Modifier.isStatic(where.getModifiers())) {
body.append("nullObject");
}
else {
body.append("this");
}
body.append(", declaringClassMethodName, ");
body.append(TransformationUtil.JOIN_POINT_TYPE_CONSTRUCTOR_CALL);
body.append("); }");
newExpr.replace(body.toString());
context.markAsAdvised();
m_joinPointIndex++;
}
}
catch (NotFoundException nfe) {
nfe.printStackTrace();
// TODO: should we swallow this exception?
}
}
}
);
}
TransformationUtil.setJoinPointIndex(klass.getCtClass(), m_joinPointIndex);
}
/**
* Creates a new static class field, for the declaring class of the constructor.
*
* @param ctClass the class
* @param ctConstructor the constructor
* @return the name of the field
*/
private String addCalleeMethodDeclaringClassField(final CtClass ctClass, final CtConstructor ctConstructor)
throws NotFoundException, CannotCompileException {
String fieldName = TransformationUtil.STATIC_CLASS_FIELD +
TransformationUtil.DELIMITER + "init" +
TransformationUtil.DELIMITER +
ctConstructor.getDeclaringClass().getName().replace('.', '_');
boolean hasField = false;
CtField[] fields = ctClass.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
CtField field = fields[i];
if (field.getName().equals(fieldName)) {
hasField = true;
break;
}
}
if (!hasField) {
CtField field = new CtField(
ctClass.getClassPool().get("java.lang.Class"),
fieldName,
ctClass
);
field.setModifiers(Modifier.STATIC | Modifier.PRIVATE | Modifier.FINAL);
ctClass.addField(
field, "java.lang.Class#forName(\"" + ctConstructor.getDeclaringClass().getName().replace('/', '.') + "\")"
);
}
return fieldName;
}
/**
* Filters the classes to be transformed.
*
* @param definition
* @param classMetaData the meta-data for the class
* @param cg the class to filter
* @return boolean true if the method should be filtered away
*/
private boolean classFilter(
final SystemDefinition definition,
final ClassMetaData classMetaData,
final CtClass cg) {
if (cg.isInterface()) {
return true;
}
String className = cg.getName().replace('/', '.');
if (definition.inExcludePackage(className)) {
return true;
}
if (!definition.inIncludePackage(className)) {
return true;
}
if (definition.hasCallPointcut(classMetaData)) {
return false;
}
return true;
}
/**
* Filters the caller methods.
*
* @param method the method to filter
* @return boolean true if the method should be filtered away
*/
private boolean methodFilterCaller(final CtBehavior method) {
if (Modifier.isNative(method.getModifiers()) ||
Modifier.isInterface(method.getModifiers()) ||
method.getName().equals(TransformationUtil.GET_META_DATA_METHOD) ||
method.getName().equals(TransformationUtil.SET_META_DATA_METHOD) ||
method.getName().equals(TransformationUtil.CLASS_LOOKUP_METHOD) ||
method.getName().equals(TransformationUtil.GET_UUID_METHOD)) {
return true;
}
else {
return false;
}
}
/**
* Filters the constructor.
*
* @param constructor the name of method to filter
* @return boolean true if the method should be filtered away
* @TODO: create metadata instance and check with the system
*/
private boolean constructorFilter(final CtConstructor constructor) {
if (constructor.equals("<clinit>") ||
constructor.getName().startsWith(TransformationUtil.ORIGINAL_METHOD_PREFIX) ||
constructor.getName().equals(TransformationUtil.GET_META_DATA_METHOD) ||
constructor.getName().equals(TransformationUtil.SET_META_DATA_METHOD) ||
constructor.getName().equals(TransformationUtil.CLASS_LOOKUP_METHOD) ||
constructor.getName().equals(TransformationUtil.GET_UUID_METHOD)) {
return true;
}
else {
return false;
}
}
}