/*
* 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.core.injection;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.List;
import org.apache.tuscany.spi.ObjectCreationException;
import org.apache.tuscany.spi.ObjectFactory;
/**
* Creates new instances of a Java class
*
* @version $Rev: 430937 $ $Date: 2006-08-11 18:17:56 -0700 (Fri, 11 Aug 2006) $
* @see org.apache.tuscany.core.injection.Injector
*/
public class PojoObjectFactory<T> implements ObjectFactory<T> {
private final Constructor<T> ctr;
private ObjectFactory[] initializerFactories;
/**
* Creates the object factory
*
* @param ctr the constructor to use when instantiating a new object
*/
public PojoObjectFactory(Constructor<T> ctr) {
assert ctr != null;
this.ctr = ctr;
initializerFactories = new ObjectFactory[ctr.getParameterTypes().length];
}
/**
* Creates the object factory
*
* @param ctr the constructor to use when instantiating a new object
* @param factories an ordered list of <code>ObjectFactory</code>s to use for returning constructor parameters
*/
public PojoObjectFactory(Constructor<T> ctr, List<ObjectFactory> factories) {
assert ctr != null;
int params = ctr.getParameterTypes().length;
assert params == factories.size();
this.ctr = ctr;
initializerFactories = new ObjectFactory[params];
int i = 0;
for (ObjectFactory factory : factories) {
initializerFactories[i] = factory;
i++;
}
}
/**
* Returns the ordered array of <code>ObjectFactory</code>s use in creating constructor parameters
*/
public ObjectFactory[] getInitializerFactories() {
return initializerFactories;
}
/**
* Sets an <code>ObjectFactory</code>s to use in creating constructor parameter
*
* @param pos the constructor parameter position
* @param factory the object factory
*/
public void setInitializerFactory(int pos, ObjectFactory factory) {
assert pos < initializerFactories.length;
initializerFactories[pos] = factory;
}
/**
* Creates a new instance of an object
*/
public T getInstance() throws ObjectCreationException {
int size = initializerFactories.length;
Object[] initargs = new Object[size];
// create the constructor arg array
for (int i = 0; i < size; i++) {
ObjectFactory<?> objectFactory = initializerFactories[i];
initargs[i] = objectFactory.getInstance();
}
try {
ctr.setAccessible(true);
return ctr.newInstance(initargs);
} catch (InstantiationException e) {
throw new AssertionError("Class is not instantiable [" + ctr.getDeclaringClass().getName() + "]");
} catch (IllegalAccessException e) {
throw new AssertionError("Constructor is not accessible [" + ctr + "]");
} catch (InvocationTargetException e) {
throw new ObjectCreationException("Exception thrown by constructor [" + ctr + "]", e);
}
}
}