Spring AOP笔记

首先，web.xml配置一个listener

<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

其实，使用默认的springListener配置文件路径:WEB-INF/applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd  http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd  http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
	<aop:aspectj-autoproxy/>
	<bean id="logAspect" class="com.amhuman.comm.LogAspect"></bean>
	<bean id="userService" class="com.amhuman.service.UserServiceImpl" />
	<bean class="com.amhuman.comm.SpringHelper"></bean>
</beans>

接下来就是编写切面了（这里还用到了自定义的注解，下面会补上代码）

package com.amhuman.comm;

import java.lang.reflect.Method;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MethodSignature;

@Aspect
public class LogAspect {
	
	@After("execution(public * *(..))")
	public void afterSayHello(){
		System.out.println("After : ");
	}
	
	@Before("execution(public * *(..))")
	public void beforeSayHello(){
		System.out.println("Before : ");
	}
	
	@Around("execution(public * *(..)) && @annotation(com.amhuman.comm.Log)")
	public Object doLog(ProceedingJoinPoint pjp) throws Throwable{
		String param = ""; 
		Log logAnno = getAnno(pjp);
		if(logAnno.id() != -1){
			Object obj = pjp.getArgs()[logAnno.id()];
			if(logAnno.fieldName() == ""){
				param = obj.toString();
			}else{
				String fieldName = logAnno.fieldName();
				Method getMethod = obj.getClass().getMethod("getUserName", null);
				System.out.println(obj.getClass().toString());
				System.out.println(getMethod.toString());
				Object objddd = getMethod.invoke(obj, null);
				System.out.println(objddd);
//				param = getMethod.invoke(obj, null).toString();
			}
		}
		System.out.println("#before asp : "+ param);
		Object ret = pjp.proceed();
		System.out.println("#aftor asp");
		return ret;
	}
	
	private Log getAnno(ProceedingJoinPoint pjp) throws SecurityException, NoSuchMethodException{
		Class<?> currClass = pjp.getTarget().getClass();
		Method method = ((MethodSignature) pjp.getSignature()).getMethod();
		String shortMethodName = method.getName();
		Method realMethod = currClass.getMethod(shortMethodName, method.getParameterTypes());
		Log logAnnotation = realMethod.getAnnotation(Log.class);
		return logAnnotation;
	} 
}

注解的代码：

package com.amhuman.comm;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)  
@Target({ ElementType.METHOD })
public @interface Log {
	public int id() default -1;
	public String fieldName() default "";
}

写个单元测试跑下：

package com.amhuman.test;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.amhuman.entity.User;
import com.amhuman.service.IUserService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:applicationContext-test.xml" })
public class SpringTest {
	
	@Resource
	IUserService userService;
	
	public IUserService getUserService() {
		return userService;
	}

	public void setUserService(IUserService userService) {
		this.userService = userService;
	}

	@Test
	public void testUser(){
		System.out.println(userService.getDefaultUser().getUserName());
		System.out.println("================================");
		System.out.println(userService.findById(100).getUserName());
		System.out.println("================================");
		System.out.println(userService.find(new User()).getUserName());
	}
	
}

对应的service代码

package com.amhuman.service;

import org.springframework.util.StringUtils;

import com.amhuman.comm.Log;
import com.amhuman.entity.User;

public class UserServiceImpl implements IUserService {
	private String userName;
	
	public String getUserName() {
		return userName;
	}

	public void setUserName(String userName) {
		this.userName = userName;
	}

	/* (non-Javadoc)
	 * @see com.amhuman.service.IUserService#getDefaultUser()
	 */
	@Override
	public User getDefaultUser(){
		System.out.println("###");
		User user = new User();
		user.setUserId(1001);
		if(StringUtils.hasLength(this.userName)){
			user.setUserName(this.userName);
		}else{
			user.setUserName("WUYC-TEST");	
		}
		return user;
	}

	@Override
	@Log(id = 0,fieldName="userId")
	public User find(User user) {
		if(user == null){
			return getDefaultUser();
		}
		user.setUserName("WUTIANYU");
		return user;
	}

	@Override
	@Log(id = 0)
	public User findById(Integer id) {
		if(id == null){
			return getDefaultUser();
		}
		User user = new User();
		user.setUserId(id);
		user.setUserName("UserName["+id+"]");
		return user;
	}
}

搞定！