/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* 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
* "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.tuscany.sca.contribution.java.impl;
import java.lang.ref.WeakReference;
import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.Map;
import org.apache.tuscany.sca.contribution.Contribution;
import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
import org.apache.tuscany.sca.contribution.resolver.ClassReference;
import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
/**
* A Model Resolver for ClassReferences.
*
* @version $Rev: 557916 $ $Date: 2007-07-20 01:04:40 -0700 (Fri, 20 Jul 2007) $
*/
public class ClassReferenceModelResolver implements ModelResolver {
private Contribution contribution;
protected WeakReference<ClassLoader> classLoader;
private Map<String, ClassReference> map = new HashMap<String, ClassReference>();
private ModelResolver osgiResolver;
public ClassReferenceModelResolver(Contribution contribution, ModelFactoryExtensionPoint modelFactories) {
this.contribution = contribution;
if (this.contribution != null) {
this.classLoader = new WeakReference<ClassLoader>(this.contribution.getClassLoader());
} else {
// This path should be used only for unit testing.
this.classLoader = new WeakReference<ClassLoader>(this.getClass().getClassLoader());
}
try {
Class osgiResolverClass =
Class.forName("org.apache.tuscany.sca.contribution.osgi.impl.OSGiClassReferenceModelResolver");
if (osgiResolverClass != null) {
Constructor constructor =
osgiResolverClass.getConstructor(Contribution.class, ModelFactoryExtensionPoint.class);
this.osgiResolver = (ModelResolver)constructor.newInstance(contribution, modelFactories);
}
} catch (Exception e) {
}
}
public void addModel(Object resolved) {
ClassReference clazz = (ClassReference)resolved;
map.put(clazz.getClassName(), clazz);
}
public Object removeModel(Object resolved) {
return map.remove(((ClassReference)resolved).getClassName());
}
public <T> T resolveModel(Class<T> modelClass, T unresolved) {
Object resolved = map.get(unresolved);
if (resolved != null) {
return modelClass.cast(resolved);
}
//Load a class on demand
Class clazz = null;
if (osgiResolver != null) {
resolved = osgiResolver.resolveModel(modelClass, unresolved);
clazz = ((ClassReference)resolved).getJavaClass();
}
if (clazz == null) {
try {
// Search contribution classloader (which has visibility of classes in the contribution
// as well as explicitly imported packages from other contributions)
clazz = Class.forName(((ClassReference)unresolved).getClassName(), true, classLoader.get());
} catch (ClassNotFoundException e) {
}
}
if (clazz != null) {
//if we load the class
// Store a new ClassReference wrappering the loaded class
ClassReference classReference = new ClassReference(clazz);
map.put(getPackageName(classReference), classReference);
// Return the resolved ClassReference
return modelClass.cast(classReference);
} else {
return unresolved;
}
}
/***************
* Helper methods
***************/
private String getPackageName(ClassReference clazz) {
int pos = clazz.getClassName().lastIndexOf(".");
return clazz.getClassName().substring(0, pos - 1);
}
}