/*
 * Copyright 2002-2004 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.springframework.aop.interceptor;

import java.io.Serializable;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Simple AOP Alliance MethodInterceptor that can be introduced in a chain
 * to display verbose trace information about intercepted method invocations
 * with method entry and method exit info using Commons Logging at DEBUG level.
 * @author Dmitriy Kopylenko
 * @author Juergen Hoeller
 */
public class TraceInterceptor implements MethodInterceptor, Serializable {

	/** Static to avoid serializing the logger */
	protected static final Log logger = LogFactory.getLog(TraceInterceptor.class);

	public Object invoke(MethodInvocation invocation) throws Throwable {
		if (logger.isDebugEnabled()) {
			logger.debug("Entering method '" + invocation.getMethod().getName() +
			    "' in class [" + invocation.getThis().getClass().getName() + "]");
		}
		try {
			return invocation.proceed();
		}
		finally {
			logger.debug("Exiting method '" + invocation.getMethod().getName() +
			    "' in class [" + invocation.getThis().getClass().getName() + "]");
		}
	}

}
