学习笔记，仅供参考

一、AOP

AOP为Aspect Oriented Programming的缩写，意为：面向切面编程，通过预编译方式和运行期动态代理实现程序功能的统一维护的一种技术。 AOP是OOP的延续，是软件开发中的一个热点，也是Spring框架中的一个重要内容，是函数式编程的一种衍生范型。

二、实现

引入依赖

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

新建SysLog类

package com.example.aop.annotation;

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 SysLog {
    String value() default " ";
}

新建SysLogAspect类

package com.example.aop.annotation;

import com.example.aop.service.LogService;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

@Aspect
@Component
public class SysLogAspect {
    @Autowired
    private LogService logService;

    @Pointcut("@annotation(com.example.aop.annotation.SysLog)")
    public void logPointCut() {}

    @Before("logPointCut()")
    public void before(JoinPoint joinPoint) {
        long beginTime = System.currentTimeMillis();
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        SysLog annotation = method.getAnnotation(SysLog.class);
        String value = annotation.value();
        Object[] args = joinPoint.getArgs();
        try {
            logService.log(beginTime, "before " + method.getName());
        } catch (Exception e) {
        }
    }

    @Around("logPointCut()")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        long beginTime = System.currentTimeMillis();
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        SysLog annotation = method.getAnnotation(SysLog.class);
        String value = annotation.value();
        Object[] args = joinPoint.getArgs();
        Object object = joinPoint.proceed(args);
        try {
            logService.log(beginTime, "around " + method.getName());
        } catch (Exception e) {
        }
        return object;
    }

    @After("logPointCut()")
    public void after(JoinPoint joinPoint) {
        long beginTime = System.currentTimeMillis();
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        SysLog annotation = method.getAnnotation(SysLog.class);
        String value = annotation.value();
        Object[] args = joinPoint.getArgs();
        try {
            logService.log(beginTime, "after " + method.getName());
        } catch (Exception e) {
        }
    }

    @AfterReturning("logPointCut()")
    public void afterReturning(JoinPoint joinPoint) {
        long beginTime = System.currentTimeMillis();
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        SysLog annotation = method.getAnnotation(SysLog.class);
        String value = annotation.value();
        Object[] args = joinPoint.getArgs();
        try {
            logService.log(beginTime, "after returning " + method.getName());
        } catch (Exception e) {
        }
    }

    @AfterThrowing("logPointCut()")
    public void afterThrowing(JoinPoint joinPoint) {
        long beginTime = System.currentTimeMillis();
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        SysLog annotation = method.getAnnotation(SysLog.class);
        String value = annotation.value();
        Object[] args = joinPoint.getArgs();
        try {
            logService.log(beginTime, "after throwing " + method.getName());
        } catch (Exception e) {
        }
    }
}

新建TestService类

package com.example.aop.service;

import com.example.aop.dto.TestDomain;
import com.example.aop.annotation.SysLog;
import org.springframework.stereotype.Service;

@Service
public class TestService {
    @SysLog("log-1")
    public void log1(String name, TestDomain testDomain) {
        System.out.println("print log 1" + name + " " + testDomain.toString());
    }

    @SysLog("log-2")
    public void log2(String name, TestDomain testDomain) {
        System.out.println("print log 2" + name + " " + testDomain.toString());
    }


    @SysLog("throw-exception")
    public void throwException() {
        System.out.println("throw exception");
        int i = 3/0;
    }
}

新建TestController

package com.example.aop.controller;

import com.example.aop.dto.TestDomain;
import com.example.aop.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @Autowired
    private TestService testService;

    @GetMapping("test")
    public String test(@RequestParam("p1") String p1) {
        TestDomain testDomain = new TestDomain();
        testDomain.setId("1");
        testDomain.setTitle("t1");
        testService.log1(p1, testDomain);
        testService.log2(p1, testDomain);
        testService.throwException();
        return "hello aop";
    }
}

三、测试

运行AopApplication, 然后访问http://localhost:8080/test?p1=123,可以看到控制台有以下输出：

before log1 at: 1554903984403
print log 1123 com.example.aop.dto.TestDomain@2a7a4cd5
around log1 at: 1554903984402
after log1 at: 1554903984409
after returning log1 at: 1554903984409
before log2 at: 1554903984409
print log 2123 com.example.aop.dto.TestDomain@2a7a4cd5
around log2 at: 1554903984409
after log2 at: 1554903984410
after returning log2 at: 1554903984410
before throwException at: 1554903984410
throw exception
after throwException at: 1554903984410
after throwing throwException at: 1554903984410

github地址:https://github.com/lijun003/SpringBoot-AOP-log)https://github.com/lijun003/SpringBoot-AOP-log