spring中aop不生效的几种解决办法

时间：2020-04-06 23:34:12 阅读：263 评论：0 收藏：0 [点我收藏+]

标签：etc lan object contex rac 上下文记录 exception signature

先看下这个问题的背景：假设有一个spring应用，开发人员希望自定义一个注解@Log，可以加到指定的方法上，实现自动记录日志(入参、出参、响应耗时这些)

package com.cnblogs.yjmyzz.springbootdemo.aspect;

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 {

}

然后再写一个Aspect来解析这个注解，对打了Log注解的方法进行增强处理　

package com.cnblogs.yjmyzz.springbootdemo.aspect;

import org.aspectj.lang.JoinPoint;
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.springframework.stereotype.Component;

import java.lang.reflect.Method;

@Component
@Aspect
public class LogAspect {

    @Pointcut("execution (* com.cnblogs.yjmyzz.springbootdemo.service..*.*(..))")
    public void logPointcut() {

    }

    @Around("logPointcut()")
    public void around(JoinPoint point) {
        String methodName = point.getSignature().getName();
        Object[] args = point.getArgs();
        Class<?>[] argTypes = new Class[point.getArgs().length];
        for (int i = 0; i < args.length; i++) {
            argTypes[i] = args[i].getClass();
        }
        Method method = null;
        try {
            method = point.getTarget().getClass().getMethod(methodName, argTypes);
        } catch (Exception e) {
            e.printStackTrace();
        }
        //获取方法上的注解
        Log log = method.getAnnotation(Log.class);
        if (log != null) {
            //演示方法执行前，记录一行日志
            System.out.println("before:" + methodName);
        }
        try {
            //执行方法
            ((ProceedingJoinPoint) point).proceed();
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        } finally {
            if (log != null) {
                //演示方法执行后，记录一行日志
                System.out.println("after:" + methodName);
            }
        }
    }
}

写一个测试Service类：

package com.cnblogs.yjmyzz.springbootdemo.service;

import com.cnblogs.yjmyzz.springbootdemo.aspect.Log;
import org.springframework.stereotype.Component;

@Component
public class HelloService {
    
    @Log
    public void sayHi(String msg) {
        System.out.println("\tsayHi:" + msg);
    }

    public void anotherSayHi(String msg) {
        this.sayHi(msg);
    }

}

最后来跑一把：

package com.cnblogs.yjmyzz.springbootdemo;

import com.cnblogs.yjmyzz.springbootdemo.service.HelloService;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

/**
 * @author 菩提树下的杨过
 */
@ComponentScan("com.cnblogs.yjmyzz")
@Configuration
@EnableAspectJAutoProxy
public class SampleApplication {

    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SampleApplication.class);
        HelloService helloService = context.getBean(HelloService.class);
        helloService.sayHi("hi-1");
        System.out.println("\n");
        helloService.anotherSayHi("hi-2");
    }
}

输出如下：

技术图片