java代码中动态添加程序执行时间日志

在写java代码的过程中经常会遇到需要打印一个方法的执行时间，如果在代码中直接写开始和结束时间,然后计算运行时间，这样感觉不太好，代码的耦合性太高，可以通过java的动态代理或者cglib 加上annotation(标注)来实现。

1.通过cglib代理打印当前方法的执行时间.

代码如下：

代理类：

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.Method;

/**
* User: weichun.zhan
* Date: 12-10-25
* Time: 下午3:09
*/
public class ServiceProxy implements MethodInterceptor {

    @Override
    public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
        Logger logger = LoggerFactory.getLogger(method.getDeclaringClass().getName());
        Object result = null;

        MethodRunTimeLog methodRunTimeLog = method.getAnnotation(MethodRunTimeLog.class);
        if (methodRunTimeLog !=null && methodRunTimeLog.debug()) {
            long start = System.currentTimeMillis();
            result = methodProxy.invokeSuper(o, objects); //因为cglib是通过继承类来实现代理，so需调用invokesuper
            long end = System.currentTimeMillis();
            logger.info("Excute  [{}] method took time [{}]ms.", method.getName(), (end - start));

        } else {
            result = methodProxy.invokeSuper(o, objects);
        }
        return result;
    }

    public Object createProxy(Class targetClass) {
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(targetClass);
        enhancer.setCallback(new ServiceProxy());
        return enhancer.create();
    }
}

 

调用类：

ServiceProxy test = new ServiceProxy();
MovieInfoServiceServiceImpl proxyTarget = (MovieInfoServiceServiceImpl)test.createProxy(MovieInfoServiceServiceImpl.class);

 

2.当然也可以通过jdk的动态代理来做，代码如下：

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

/**
* User: weichun.zhan
* Date: 12-10-25
* Time: 下午6:03
*/
public class MovieInfoServiceProxy implements InvocationHandler {

    private MovieInfoService impl;

    public MovieInfoServiceProxy(MovieInfoService impl){
        this.impl = impl;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        Logger logger = LoggerFactory.getLogger(method.getDeclaringClass().getName());

        Object result = null;
       //获取调用方法的method对象，不能直接调用method，不知为什么还没仔细研究
        MethodRunTimeLog methodRunTimeLog = impl.getClass().getMethod(method.getName(),method.getParameterTypes()).getAnnotation(MethodRunTimeLog.class);
        if (methodRunTimeLog !=null && methodRunTimeLog.debug()) {
            long start = System.currentTimeMillis();
            result = method.invoke(impl, args);
            long end = System.currentTimeMillis();
            logger.info("Excute  [{}] method took time [{}]ms.", method.getName(), (end - start));

        } else {
            result = method.invoke(impl, args);
        }
        return result;
    }
}

 

调用代码：

 MovieInfoService proxyTarget = (MovieInfoService) Proxy.newProxyInstance(MovieInfoService.class.getClassLoader(),
                MovieInfoServiceImpl.class.getInterfaces(),new MovieInfoServiceProxy(new MovieInfoServiceImpl()));
        return proxyTarget;

 

标注类：

import java.lang.annotation.*;

/**
 * User: weichun.zhan
 * Date: 12-10-25
 * Time: 下午4:09
 */

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface MethodRunTimeLog {

    boolean debug() default false;

}

 ServiceImpl:

 

@MethodRunTimeLog(debug = true)
    public List<MovieInfo> queryMovieInfos(Collection<String> cids) throws SQLException {
  //具体的实现省略。。。。
}