MethodCallingInterceptor.java

/**
 * Copyright (C) 2010 Daniel Manzke <daniel.manzke@googlemail.com>
 *
 * 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 de.devsurf.injection.guice.aop;

import java.lang.reflect.Method;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.interceptor.Interceptor;

import org.aopalliance.intercept.MethodInvocation;

import com.google.inject.matcher.Matcher;
import com.google.inject.matcher.Matchers;

/**
 * Interceptor Example which monitors all Methods and logs their Signatures.
 * 
 * @author Daniel Manzke
 * 
 */
@Interceptor
public class MethodCallingInterceptor {
	private Logger _logger = Logger.getLogger(MethodCallingInterceptor.class.getName());

	@Invoke
	public Object invoke(MethodInvocation invocation) throws Throwable {
		Object destination = invocation.getThis();
		StringBuilder logMessageBuilder = new StringBuilder(250);

		logMessageBuilder.append("Invoking Method \"");
		logMessageBuilder.append(invocation.getMethod().getName());
		logMessageBuilder.append("\" on ");
		logMessageBuilder.append(destination.getClass().getName());
		logMessageBuilder.append(" with Arguments: ");

		Class<?>[] types = invocation.getMethod().getParameterTypes();
		Object[] parameters = invocation.getArguments();

		for (int i = 0; i < types.length; i++) {
			Object parameter = parameters[i];
			Class<?> type = types[i];

			logMessageBuilder.append(" \"");
			logMessageBuilder.append(type.getSimpleName());
			logMessageBuilder.append("\": ");
			logMessageBuilder.append(parameter);
		}
		_logger.log(Level.SEVERE, logMessageBuilder.toString());

		return invocation.proceed();
	}

	@ClassMatcher
	public Matcher<? super Class<?>> getClassMatcher() {
		return Matchers.any();
	}

	@MethodMatcher
	public Matcher<? super Method> getMethodMatcher() {
		return Matchers.annotatedWith(Intercept.class);
	}

}