/*
* JBoss, Home of Professional Open Source
* Copyright 2006, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.kernel.plugins.lazy;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Set;
import javassist.util.proxy.MethodFilter;
import javassist.util.proxy.MethodHandler;
import javassist.util.proxy.ProxyFactory;
import javassist.util.proxy.ProxyObject;
import org.jboss.beans.metadata.spi.BeanMetaData;
import org.jboss.kernel.Kernel;
import org.jboss.kernel.plugins.config.Configurator;
import org.jboss.kernel.spi.config.KernelConfigurator;
import org.jboss.kernel.spi.dependency.KernelControllerContext;
import org.jboss.kernel.spi.registry.KernelBus;
/**
* Javassist lazy initializer.
*
* @author <a href="mailto:ales.justin@jboss.com">Ales Justin</a>
*/
public class JavassistLazyInitializer extends AbstractLazyInitializer
{
@SuppressWarnings("deprecation")
public Object initializeProxy(Kernel kernel, String bean, boolean exposeClass, Set<String> interfaces) throws Throwable
{
KernelControllerContext context = getKernelControllerContext(kernel, bean);
BeanMetaData bmd = context.getBeanMetaData();
KernelConfigurator configurator = kernel.getConfigurator();
ClassLoader cl = Configurator.getClassLoader(bmd);
Class<?> beanClass = getBeanClass(context, configurator, cl);
ProxyFactory factory = new ProxyFactory();
factory.setFilter(FINALIZE_FILTER);
if (exposeClass)
{
factory.setSuperclass(beanClass);
}
if (interfaces != null && interfaces.size() > 0)
{
factory.setInterfaces(getClasses(configurator, interfaces, cl));
}
Class<?> proxyClass = getProxyClass(factory);
ProxyObject proxy = (ProxyObject)proxyClass.newInstance();
proxy.setHandler(new LazyHandler(bean, kernel.getBus(), beanClass));
return proxy;
}
protected Class<?> getProxyClass(ProxyFactory factory)
{
SecurityManager sm = System.getSecurityManager();
if (sm == null)
return factory.createClass();
else
return AccessController.doPrivileged(new ClassCreator(factory));
}
private static final MethodFilter FINALIZE_FILTER = new MethodFilter()
{
public boolean isHandled(Method m)
{
// skip finalize methods
return !("finalize".equals(m.getName()) && m.getParameterTypes().length == 0);
}
};
/**
* Lazy method handler.
*/
public class LazyHandler extends AbstractInvokeHandler implements MethodHandler
{
public LazyHandler(String bean, KernelBus bus, Class<?> proxyClass)
{
super(bean, bus, proxyClass);
}
public Object invoke(Object self, Method thisMethod, Method proceed, Object[] args) throws Throwable
{
return executeInvoke(self, thisMethod, args);
}
}
/**
* Privileged class creator.
*/
protected class ClassCreator implements PrivilegedAction<Class<?>>
{
private ProxyFactory factory;
public ClassCreator(ProxyFactory factory)
{
this.factory = factory;
}
public Class<?> run()
{
return factory.createClass();
}
}
}