AOP 实现自定义注解

1.自定义注解
2.编写 AOP
3.测试

1.自定义注解

package com.base.yun.spring.aop;

import java.lang.annotation.Documented;

import java.lang.annotation.ElementType;

import java.lang.annotation.Retention;

import java.lang.annotation.RetentionPolicy;

import java.lang.annotation.Target;

/**

* 说明：

* 定义日志注解

*/

@Target(ElementType.METHOD)

@Retention(RetentionPolicy.RUNTIME)

@Documented

public @interface FileLog {

  String value() default "记录日志";

}  

2.编写 AOP

package com.base.yun.spring.aop;

import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.ProceedingJoinPoint;

import org.aspectj.lang.annotation.After;

import org.aspectj.lang.annotation.AfterReturning;

import org.aspectj.lang.annotation.AfterThrowing;

import org.aspectj.lang.annotation.Around;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.Before;

import org.springframework.stereotype.Component;

/**

 * 说明： 日志的切面处理程序

 */

@Aspect

@Component

public class LogAspect {

    @Before("within(com.base.yun.spring.service.*) && @annotation(fileLog)")

    public void doAccessCheck(JoinPoint jp, FileLog fileLog) {

        System.out.println("前置通知-->>");

    }

    @After("within(com.base.yun.spring.service.*) && @annotation(fileLog)")

    public void doAfterReturning(JoinPoint jp, FileLog fileLog) {

        System.out.println("后置通知-->>");

    }

    @Around("within(com.base.yun.spring.service.*) && @annotation(fileLog)")

    public Object doAround(ProceedingJoinPoint pJoinPoint, FileLog fileLog) throws Throwable {

        System.out.println("环绕通知开始");

        // 这里如果pJoinPoint.proceed()不执行，后面拦截到的方法都不会执行，非常适用于权限管理

        Object result = pJoinPoint.proceed();

        System.out.println("环绕通知结束");

        return result;

    }

    @AfterReturning("within(com.base.yun.spring.service.*) && @annotation(fileLog)")

    public void addSuccessLog(JoinPoint jp, FileLog fileLog) {

        Object[] parames = jp.getArgs();

        // 获取目标方法体参数

        String className = jp.getTarget().getClass().toString();

        // 获取目标类名

        String signature = jp.getSignature().toString();

        // 获取目标方法签名

        String methodName = signature.substring(signature.lastIndexOf(".") + 1,

                signature.indexOf("("));

        // 获取注解值

        String desc = fileLog.value();

        // 把调用的信息写到日常记录信息里面去...

        System.out.println("最终通知注解值："+desc);

    }

    // 标注该方法体为异常通知，当目标方法出现异常时，执行该方法体

    @AfterThrowing(pointcut = "within(com.base.yun.spring.service.*) && @annotation(fileLog)", throwing = "e")

    public void addExceptionLog(JoinPoint jp, FileLog fileLog, Exception e) {

        System.out.println("异常通知-->");

        // 把错误信息写到错误日志文件里面去...

    }

}

3.测试

<aop:aspectj-autoproxy/>

     <bean class="com.base.yun.spring.aop.LogAspect"/>

     <bean id="purchaseService" class="com.base.yun.spring.service.PurchaseService" />

package spring;

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.base.yun.spring.service.PurchaseService;

public class AopTest {

    @Test

    public void testAop() {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("user.xml");

        PurchaseService service = ctx.getBean("purchaseService",PurchaseService.class);

        service.purchaseProduct("电风扇", 98, "日用品");

    }

}

测试结果：

环绕通知开始

前置通知-->>

购买商品。。。

环绕通知结束

后置通知-->>

最终通知注解值：记录日志