org.jboss.interceptor.proxy.SimpleInterceptionChain Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source
* Copyright 2009, Red Hat, Inc. and/or its affiliates, and individual
* contributors by the @authors tag. See the copyright.txt in the
* distribution for a full listing of individual contributors.
*
* Licensed 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.jboss.interceptor.proxy;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.interceptor.InvocationContext;
import org.jboss.interceptor.spi.context.InterceptionChain;
import org.jboss.interceptor.spi.model.InterceptionType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @author Marius Bogoevici
*/
public class SimpleInterceptionChain implements InterceptionChain
{
private final Logger log = LoggerFactory.getLogger(SimpleInterceptionChain.class);
private Object target;
private Method targetMethod;
private int currentPosition;
private final InterceptionType interceptionType;
private List interceptorMethodInvocations;
public SimpleInterceptionChain(Collection> interceptorInvocations, InterceptionType interceptionType, Object target, Method targetMethod)
{
this.interceptionType = interceptionType;
this.target = target;
this.targetMethod = targetMethod;
this.currentPosition = 0;
interceptorMethodInvocations = new ArrayList();
for (InterceptorInvocation interceptorInvocation : interceptorInvocations)
{
interceptorMethodInvocations.addAll(interceptorInvocation.getInterceptorMethodInvocations());
}
}
public Object invokeNextInterceptor(InvocationContext invocationContext) throws Throwable
{
try
{
if (hasNextInterceptor())
{
int oldCurrentPosition = currentPosition;
try
{
InterceptorInvocation.InterceptorMethodInvocation nextInterceptorMethodInvocation = interceptorMethodInvocations.get(currentPosition++);
if (log.isTraceEnabled())
{
log.trace("Invoking next interceptor in chain:" + nextInterceptorMethodInvocation.method.toString());
}
if (nextInterceptorMethodInvocation.method.getJavaMethod().getParameterTypes().length == 1)
{
validateInterceptor(nextInterceptorMethodInvocation, invocationContext);
return nextInterceptorMethodInvocation.invoke(invocationContext);
}
else if (nextInterceptorMethodInvocation.method.getJavaMethod().getParameterTypes().length == 0)
{
validateInterceptor(nextInterceptorMethodInvocation, null);
nextInterceptorMethodInvocation.invoke(null);
while (hasNextInterceptor())
{
nextInterceptorMethodInvocation = interceptorMethodInvocations.get(currentPosition++);
validateInterceptor(nextInterceptorMethodInvocation, null);
nextInterceptorMethodInvocation.invoke(null);
}
return null;
}
else
{
throw new IllegalStateException("Impossible state: interceptor method has more than one argument:" + nextInterceptorMethodInvocation.getMethod());
}
}
finally
{
currentPosition = oldCurrentPosition;
}
}
else
{
if (targetMethod != null)
{
targetMethod.setAccessible(true);
if (invocationContext.getMethod() != null)
{
return targetMethod.invoke(target, invocationContext.getParameters());
}
else
{
return targetMethod.invoke(target);
}
}
else
{
return null;
}
}
}
catch (InvocationTargetException e)
{
throw e.getCause();
}
}
private void validateInterceptor(InterceptorInvocation.InterceptorMethodInvocation nextInterceptorMethodInvocation, InvocationContext context) {
int expectedParameters = context == null? 0: 1;
if (nextInterceptorMethodInvocation.method.getJavaMethod().getParameterTypes().length != expectedParameters)
{
throw new IllegalStateException(
"Mismatch between number of expected and actual parameters on "
+ nextInterceptorMethodInvocation.getMethod() + ": expected " + expectedParameters
+ ", actual " + nextInterceptorMethodInvocation.getMethod().getJavaMethod().getParameterTypes().length);
}
}
public boolean hasNextInterceptor()
{
return currentPosition < interceptorMethodInvocations.size();
}
}