SpringBoot中使用AOP

• maven依赖
• 示例

1、AOP基于动态代理模式。
2、AOP是 方法级别 的。即,在方法执行的前,后,执行过程中,报错,返回结果等等流程中进行特殊操作

         org.springframework.boot
         spring-boot-starter-aop
   

这里可以不用指定版本号， 在SpringBoot 的 parent 包里面有版本的控制。

1. 可以代理指定包中的方法 通过 execution 表达式
2. 可以代理方法上加了注解的

import java.lang.annotation.*;


@Documented
@Target({ElementType.TYPE,ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface MyAnnotation {

    String value() default "";

    String myValue() default "我是自定义注解";

}

import lombok.extern.slf4j.Slf4j;
import org.aopalliance.intercept.Joinpoint;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import java.util.Arrays;


@Aspect
@Component
@Slf4j
public class MyAop {

    @Pointcut("@annotation(com.intellsite.business.util.MyAnnotation)")
    public void testMyAnnotationAspect() {}

    
    //@Before(value = "testMyAnnotationAspect()") // 注解无参数 写法
    @Before(value = "testMyAnnotationAspect() && @annotation(myAnnotation)") // 注解带参数 写法
    public void before(JoinPoint joinpoint,MyAnnotation myAnnotation) {
        log.info("AOP before 执行 ...: 参数类型 {},name:{}",joinpoint.getArgs(),joinpoint.getSignature().getName());

        log.info("before-value ==" + myAnnotation.value() + ", before-myValue == " + myAnnotation.myValue());

        // 接收到请求，记录请求内容
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attributes.getRequest();

        // 记录请求内容
        System.out.println("URL : " + request.getRequestURL().toString());
        System.out.println("HTTP_METHOD : " + request.getMethod());
        System.out.println("IP : " + request.getRemoteAddr());
        System.out.println("CLASS_METHOD : " + joinpoint.getSignature().getDeclaringTypeName() + "." + joinpoint.getSignature().getName());
        System.out.println("ARGS : " + Arrays.toString(joinpoint.getArgs()));

    }

    
    @Around(value = "testMyAnnotationAspect() && @annotation(myAnnotation))")
    public Object around(ProceedingJoinPoint proceedingJoinPoint, MyAnnotation myAnnotation) {
        try {
            log.info("AOP around 开始... 执行方法 ... : [ {} ], 参数为: [ {} ]",proceedingJoinPoint.getSignature().getName(),proceedingJoinPoint.getArgs());

            log.info("自定义注解值 value: " + myAnnotation.value() + "myValue: " + myAnnotation.myValue());

            Object proceed = proceedingJoinPoint.proceed();

            log.info("AOP around 结束... 执行方法 ... : [ {} ], 参数为: [ {} ]",proceedingJoinPoint.getSignature().getName(),proceedingJoinPoint.getArgs());

            return proceed;

        }catch (Throwable throwable) {
            log.info("AOP around 执行错误... error ：{}", throwable.getMessage());
            throwable.printStackTrace();
            return "执行around出错。。。";
        }


    }

    
    @After(value = "execution(* com.intellsite.business.controller.AnnotationController.*(..))")
    public void after(JoinPoint joinPoint) {
        log.info("AOP after 执行... : {}",joinPoint.toLongString());
    }

    
    @AfterReturning(value = "execution(* com.intellsite.business.controller.AnnotationController.getInfo(..)))",returning = "result")
    public void afterReturning(JoinPoint joinPoint,Object result) {
        log.info("AOP afterReturning 执行...  ：返回结果：{}", result);
    }

    
    @AfterThrowing(value = "testMyAnnotationAspect()",throwing = "exception")
    public void afterThrowing(JoinPoint joinPoint, Throwable exception) {
        log.error("AOP afterThrowing 执行... , msg : {}", exception.getMessage());
        if (exception instanceof NullPointerException) {

            log.info("空指针异常");
        }
    }
}

1. 没抛异常的顺序
   正常： around开始 --》 before 执行–》afterReturning 执行–》after 执行–》around结束
2. 异常时执行顺序
   异常： around开始–》before 执行–》afterThrowing 执行–》after 执行–》around

原文: https://www.cnblogs.com/dw3306/p/9615197.html