Hell to Spring AOP : performance Jamon

前言

公司一项目为web型项目，其中一个页面打开花上8-9seconds。要优化，必须的。

首先要找到优化的点所在。在方法开始和结尾处分别使用System.currentTimeMillis()，然后相减固然能得到函数的调用时间。

或者使用cassandra中的latency tracker,都可以。

大哥，你是知道的，我喜欢玩点花活，刚好项目中使用了Spring，所以考虑到了AOP

Action

JamonPerformanceMonitorInterceptor

spring中已经有tracer和monitor：JamonPerformanceMonitorInterceptor

似乎直接用即可,但我不熟悉Jamon，一眼看去，似乎只要简单的start, stop即可.由于我想在eclipse中控制台直接查看结果，

又没有配置Log4j，所以写了简单的wrapper类

 

import org.aopalliance.intercept.MethodInvocation; import org.apache.commons.logging.Log; import org.springframework.aop.interceptor.JamonPerformanceMonitorInterceptor;import com.jamonapi.Monitor; import com.jamonapi.MonitorFactory;@SuppressWarnings("serial") public class OurJamonPerformanceMonitorInterceptor extends JamonPerformanceMonitorInterceptor { public OurJamonPerformanceMonitorInterceptor() { super.setTrackAllInvocations(true); } @Override protected Object invokeUnderTrace(MethodInvocation invocation, Log logger) throws Throwable { String monitorName = createInvocationTraceName(invocation); Monitor monitor = MonitorFactory.start(monitorName); try { return invocation.proceed(); } finally { monitor.stop(); System.out.println(monitor); if (isLogEnabled(logger)) { logger.trace("Performance stats for method " + monitorName + ":" + monitor); } } } } 

配置文件 applicationContext.xml

 

 

<bean id="performanceMonitorInterceptor" class="org.leef.spring.OurJamonPerformanceMonitorInterceptor">

<aop:config proxy-target-class="false">
    <aop:pointcut id="operationPointCut" expression="execution(* org.leef.dao.EventDAO.*(..))" />
    <aop:advisor advice-ref="performanceMonitorInterceptor" pointcut-ref="operationPointCut" order="1"/>
</aop:config>

 

问题1 只有public private 方法能被代理，监控

在网络上搜索一番后，AspectJ Load-time Weaving in Spring, AspectJ可以代理任何public, protected, private方法，于是乎仿照例子，写了个Advice

import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.util.StopWatch;@Aspect public class PerformanceAdvice { @Pointcut("execution(protected * org.leef.dao.EventDAO.*(..))") public void eventPointCut() { } @Around("eventPointCut()") public Object profile(ProceedingJoinPoint pjp) throws Throwable { final Logger logger = LoggerFactory.getLogger(pjp.getSignature() .getDeclaringType()); StopWatch sw = new StopWatch(getClass().getSimpleName()); try { sw.start(pjp.getSignature().getName()); return pjp.proceed(); } finally { sw.stop(); logger.debug(sw.prettyPrint()); } } } 

配置文件

applicationContext.xml

<context:load-time-weaver aspectj-weaving="on" />

 

aop.xml

放在meta-inf目录下

 <!DOCTYPE aspectj PUBLIC "-//AspectJ//DTD//EN" "http://www.eclipse.org/aspectj/dtd/aspectj.dtd"> <aspectj> <weaver> <!-- only weave classes in this package --> <include within="org.leef.dao.*" /> <include within="org.leef.common.*" /> </weaver> <aspects> <!-- use only this aspect for weaving --> <aspect name="org.leef.common.PerformanceAdvice" /> </aspects> </aspectj>

注意在

• weaver中将advice本身所在的包也要包含进去，否则

java.lang.NoSuchMethodError: org.leef.common.PerformanceAdvice.aspectOf()

• 启动包含有aspectj-weaving时，必须要加入vm 参数 -javaagent:/path/to/jar/spring-agent.jar

spring3.0中是-javaagent:/path/to/jar/spring-instrument.jar

 

java.lang.IllegalStateException: ClassLoader [sun.misc.Launcher$AppClassLoader] does NOT provide an 'addTransformer(ClassFileTransformer)' method. Specify a custom LoadTimeWeaver or start your Java virtual machine with Spring's agent: -javaagent:org.springframework.instrument.jar

 

好了，这就是我的第一个AOP。

同样的，关于AOP的故事，还有很多。。。