/*
 * Copyright 2005 the original author or authors.
 * 
 * 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.wamblee.concurrency.spring;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.wamblee.concurrency.Lock;

/**
 * Locking advice. This automatically synchronized an object using a given lock.  
 *
 * @author Erik Brakkee
 */
public class LockAdvice implements MethodInterceptor {
    
    /**
     * Lock to use. 
     */
    private Lock lock; 
    
    /**
     * Constructs lock advice.  
     * @param aLock Lock to use. 
     */
    public LockAdvice(Lock aLock) { 
        lock = aLock; 
    }
    
    /* (non-Javadoc)
     * @see org.aopalliance.intercept.MethodInterceptor#invoke(org.aopalliance.intercept.MethodInvocation)
     */
    public Object invoke(MethodInvocation aInvocation) throws Throwable {
        lock.acquire();
        try {  
            return aInvocation.proceed(); 
        } finally { 
            lock.release();
        }
    }

}