Java注解+Aop

Java注解+Aop

本文以实际简单需求，来整理 注解+Aop 的搭配步骤

需求：通过自定义注解拿到注解注释的东西，具体逻辑细节可忽略

环境：Springboot 2.4.3

前置准备

依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>

代码实现

1. 定义注解
2. 定义aop

定义注解

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

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface RateLimit {
    int fieldInt() default 10;
    String fieldStr() default "default";
}

定义aop并编写逻辑

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class RateLimitAop {

    @Around("@annotation(rl)")
    public Object around(ProceedingJoinPoint pjp, RateLimit rl){
        System.out.println(pjp.getSignature().getName());
        System.out.println("fieldInt >>> " + rl.fieldInt());
        System.out.println("fieldStr >>> " + rl.fieldStr());
        // 调用目标方法
        Object proceed =null;
        try {
            proceed = pjp.proceed();
            System.out.println("成功执行");
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        }
        return proceed;
    }
}

使用注解

import org.springframework.stereotype.Service;

@Service
public class UseAopService {

    @RateLimit(fieldInt = 8, fieldStr = "自定义")
    public void rate() {
        System.out.println("run in method...");
    }
}

测试类

import cn.saddydire.demo.annotest2.UseAopService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = DemoApplication .class)
public class AopTest {

    @Resource
    private UseAopService aopService;
    @Test
    public void test01() {
        aopService.rate();
    }

}