Spring之AOP系列--将类上的注解作为切点(用@Pointcut)

小灰灰 2023-09-23 13:12 86阅读 0赞

原文网址：[Spring之AOP系列--将类上的注解作为切点(用@Pointcut)\_IT利刃出鞘的博客-CSDN博客][Spring_AOP_--_Pointcut_IT_-CSDN]

## 简介 ##

**说明**

本文介绍Spring（SpringBoot）的AOP的用法：自定义注解，在Controller的类上使用此注解，然后在AOP中获得注解和方法的相关信息，并获取返回值信息。

本文使用@Pointcut+@Before+@AfterReturning。

**方案介绍**

AOP可将切点设为注解类，例如，若想控制Controller，只需切@RestController，方法有：

法1：@Pointcut结合@within（推荐）

@Pointcut("@within(org.springframework.web.bind.annotation.RestController)")

法2：@Before或@Around，结合@within

@Before("@within(restController)")
    public void before(JoinPoint joinPoint, RestController restController)

**基础代码**

项目结构、pom.xml、公共代码等与此文一样：[Spring之AOP系列--将方法上的注解做为切点(用@Before)\_IT利刃出鞘的博客-CSDN博客][Spring_AOP_--_Before_IT_-CSDN]

## 切面代码 ##

### 写法1：不带参数 ###

package com.example.demo.aspect;
    
    import com.example.demo.annotation.ApiLog;
    import com.example.demo.entity.User;
    import com.example.demo.util.JsonUtil;
    import io.swagger.annotations.Api;
    import io.swagger.annotations.ApiOperation;
    import org.aspectj.lang.JoinPoint;
    import org.aspectj.lang.annotation.*;
    import org.aspectj.lang.reflect.MethodSignature;
    import org.springframework.stereotype.Component;
    
    import java.lang.reflect.Method;
    
    /**
     * Before结合类上的注解获得操作日志
     */
    @Aspect
    @Component
    public class ApiLogAspectByPointcutWithoutArg {
        @Pointcut("@within(com.example.demo.annotation.ApiLog)")
        public void pointcut() {
        }
    
        @Before("pointcut()")
        public void before(JoinPoint joinPoint) {
            System.out.println("++++++++++++++++++++++++ before ++++++++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
            MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
            Method method = methodSignature.getMethod();
            System.out.println("------------------ 方法信息 ------------------");
            System.out.println("joinPoint.getTarget().toString()  : " + joinPoint.getTarget().toString());
            System.out.println("methodSignature.getName()         : " + methodSignature.getName());
            System.out.println("method.getName()                  : " + method.getName());
            System.out.println("method.getReturnType().getName()  : " + method.getReturnType().getName());
    
            System.out.println("------------------ 类的ApiLog注解数据 ------------------");
            Class<?> declaringClass = method.getDeclaringClass();
            ApiLog apiLog = declaringClass.getAnnotation(ApiLog.class);
            System.out.println("tag: " + apiLog.tag());
    
            System.out.println("------------------ 类的Api注解数据 ------------------");
            Class<?> aClass = method.getDeclaringClass();
            if (aClass.isAnnotationPresent(Api.class)) {
                String[] tags = aClass.getAnnotation(Api.class).tags();
                String value = aClass.getAnnotation(Api.class).value();
    
                String tagJoin = String.join("+", tags);
                System.out.println("tags：" + tagJoin + "; value:" + value);
            }
    
            System.out.println("------------------ 方法注解数据 ----------------");
            if (method.isAnnotationPresent(ApiOperation.class)) {
                System.out.println("操作为：" + method.getAnnotation(ApiOperation.class).value());
            }
    
            System.out.println("------------------ 入参数据 ------------------");
            Object[] objects = joinPoint.getArgs();
            for (Object o : objects) {
                System.out.println(o);
                if (o instanceof User) {
                    System.out.println("id是：" + ((User) (o)).getId() +
                            "; 名字是：" + ((User) (o)).getUserName() +
                            "; 备注是：" + ((User) (o)).getNote());
                }
            }
            System.out.println("#################################################");
        }
    
        @After("pointcut()")
        public void after(JoinPoint joinPoint) {
            System.out.println("++++++++++++++++++++++++ after ++++++++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
        }
    
        @AfterReturning(value = "pointcut()", returning = "returnValue")
        public void afterReturning(JoinPoint joinPoint, Object returnValue) {
            System.out.println("+++++++++++++++++++++ afterReturning +++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
            System.out.println("------------------ 返回值 --------------------");
            System.out.println(JsonUtil.toJson(returnValue));
        }
    
        @AfterThrowing(pointcut = "pointcut()", throwing = "e")
        public void afterThrowing(JoinPoint joinPoint, Throwable e) {
            System.out.println("+++++++++++++++++++++ afterThrowing +++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
            System.out.println("------------------ 异常信息 --------------------");
            e.printStackTrace();
        }
    }

### 写法2：带参数 ###

package com.example.demo.aspect;
    
    import com.example.demo.annotation.ApiLog;
    import com.example.demo.entity.User;
    import com.example.demo.util.JsonUtil;
    import io.swagger.annotations.Api;
    import io.swagger.annotations.ApiOperation;
    import org.aspectj.lang.JoinPoint;
    import org.aspectj.lang.annotation.*;
    import org.aspectj.lang.reflect.MethodSignature;
    import org.springframework.stereotype.Component;
    
    import java.lang.reflect.Method;
    
    /**
     * Before结合类上的注解获得操作日志
     */
    @Aspect
    @Component
    public class ApiLogAspectByPointcutWithArg {
        @Pointcut("@within(apiLog)")
        public void pointcut(ApiLog apiLog) {
    
        }
    
        @Before("pointcut(apiLog)")
        // 会报警告：argNames attribute isn't defined。
        // 解决方法：@Before(value = "pointcut(apiLog)", argNames = "joinPoint,apiLog")
        public void before(JoinPoint joinPoint, ApiLog apiLog) {
            System.out.println("++++++++++++++++++++++++ before ++++++++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
    
            MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
            Method method = methodSignature.getMethod();
            System.out.println("------------------- 方法信息 ------------------");
            System.out.println("joinPoint.getTarget().toString()  : " + joinPoint.getTarget().toString());
            System.out.println("methodSignature.getName()         : " + methodSignature.getName());
            System.out.println("method.getName()                  : " + method.getName());
            System.out.println("method.getReturnType().getName()  : " + method.getReturnType().getName());
    
            System.out.println("------------------ 类的ApiLog注解数据 ------------------");
            System.out.println("tag: " + apiLog.tag());
    
            System.out.println("------------------ 类的Api注解数据 ------------------");
            Class<?> aClass = method.getDeclaringClass();
            if (aClass.isAnnotationPresent(Api.class)) {
                String[] tags = aClass.getAnnotation(Api.class).tags();
                String value = aClass.getAnnotation(Api.class).value();
    
                String tagJoin = String.join("+", tags);
                System.out.println("tags：" + tagJoin + "; value:" + value);
            }
    
            System.out.println("------------------ 方法注解数据 ----------------");
            if (method.isAnnotationPresent(ApiOperation.class)) {
                System.out.println("操作为：" + method.getAnnotation(ApiOperation.class).value());
            }
    
            System.out.println("------------------ 入参数据 ------------------");
            Object[] objects = joinPoint.getArgs();
            for (Object o : objects) {
                System.out.println(o);
                if (o instanceof User) {
                    System.out.println("id是：" + ((User) (o)).getId() +
                            "; 名字是：" + ((User) (o)).getUserName() +
                            "; 备注是：" + ((User) (o)).getNote());
                }
            }
            System.out.println("#################################################");
        }
    
        @After("pointcut(apiLog)")
        // 会报警告：argNames attribute isn't defined。
        // 解决方法：@After(value = "pointcut(apiLog)", argNames = "joinPoint,apiLog")
        public void after(JoinPoint joinPoint, ApiLog apiLog) {
            System.out.println("++++++++++++++++++++++++ after ++++++++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
        }
    
        @AfterReturning(value = "pointcut(apiLog)", returning = "returnValue")
        // 会报警告：argNames attribute isn't defined。
        // 解决方法@AfterReturning(value = "pointcut(apiLog)", returning = "returnValue")
        public void afterReturning(JoinPoint joinPoint, ApiLog apiLog, Object returnValue) {
            System.out.println("+++++++++++++++++++++ afterReturning +++++++++++++++++++++++++");
            System.out.println("------------------ joinPoint ------------------");
            System.out.println(joinPoint);
            System.out.println("-------------------- 返回值 -------------------");
            System.out.println(JsonUtil.toJson(returnValue));
        }
    }

###  ###

## 测试代码 ##

package com.example.demo.controller;
    
    import com.example.demo.annotation.ApiLog;
    import com.example.demo.annotation.OperationLog;
    import com.example.demo.entity.User;
    import com.example.demo.service.UserService;
    import io.swagger.annotations.Api;
    import io.swagger.annotations.ApiOperation;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.*;
    
    @ApiLog(tag = "用户接口")
    @Api(tags = "用户")
    @RequestMapping("/user")
    @RestController
    public class UserController {
        @Autowired
        private UserService userService;
    
        @ApiOperation("打印数据")
        @GetMapping("print")
        public User testPrint(User user) {
            userService.printUser(user);
            return user;
        }
    
        @ApiOperation("添加数据")
        @PostMapping("add")
        @OperationLog(type = "添加", desc = "添加数据")
        public User testAdd(User user) {
            return user;
        }
    
        @ApiOperation("更新数据")
        @PostMapping("update")
        @OperationLog(type = "更新", desc = "更新数据")
        public User testUpdate(User user) {
            userService.printUser(user);
            return user;
        }
    
        @ApiOperation("删除数据")
        @PostMapping("delete")
        public void delete(User user) {
        }
    }

## 测试 ##

### 测试1：添加数据（有返回值） ###

![c46804d6edc84ed7b2f57066cebf808f.png][]

后端结果

++++++++++++++++++++++++ before ++++++++++++++++++++++++++++++
    ------------------ joinPoint ------------------
    execution(User com.example.demo.controller.UserController.testAdd(User))
    ------------------ 方法信息 ------------------
    joinPoint.getTarget().toString()  : com.example.demo.controller.UserController@1bc3bb5
    methodSignature.getName()         : testAdd
    method.getName()                  : testAdd
    method.getReturnType().getName()  : com.example.demo.entity.User
    ------------------ 类的ApiLog注解数据 ------------------
    tag: 用户接口
    ------------------ 类的Api注解数据 ------------------
    tags：用户; value:
    ------------------ 方法注解数据 ----------------
    操作为：添加数据
    ------------------ 入参数据 ------------------
    User(id=12, userName=Tony, note=abc)
    id是：12; 名字是：Tony; 备注是：abc
    #################################################
    +++++++++++++++++++++ afterReturning +++++++++++++++++++++++++
    ------------------ joinPoint ------------------
    execution(User com.example.demo.controller.UserController.testAdd(User))
    ------------------ 返回值 --------------------
    {"id":12,"userName":"Tony","note":"abc"}
    ++++++++++++++++++++++++ after ++++++++++++++++++++++++++++++
    ------------------ joinPoint ------------------
    execution(User com.example.demo.controller.UserController.testAdd(User))

### 测试2：删除数据（无返回值） ###

![8a6f334bc885434298105bb74effa646.png][]

后端结果：

++++++++++++++++++++++++ before ++++++++++++++++++++++++++++++
    ------------------ joinPoint ------------------
    execution(void com.example.demo.controller.UserController.delete(User))
    ------------------ 方法信息 ------------------
    joinPoint.getTarget().toString()  : com.example.demo.controller.UserController@1bc3bb5
    methodSignature.getName()         : delete
    method.getName()                  : delete
    method.getReturnType().getName()  : void
    ------------------ 类的ApiLog注解数据 ------------------
    tag: 用户接口
    ------------------ 类的Api注解数据 ------------------
    tags：用户; value:
    ------------------ 方法注解数据 ----------------
    操作为：删除数据
    ------------------ 入参数据 ------------------
    User(id=1212, userName=Peter, note=abc)
    id是：1212; 名字是：Peter; 备注是：abc
    #################################################
    +++++++++++++++++++++ afterReturning +++++++++++++++++++++++++
    ------------------ joinPoint ------------------
    execution(void com.example.demo.controller.UserController.delete(User))
    ------------------ 返回值 --------------------
    null
    ++++++++++++++++++++++++ after ++++++++++++++++++++++++++++++
    ------------------ joinPoint ------------------
    execution(void com.example.demo.controller.UserController.delete(User))

[Spring_AOP_--_Pointcut_IT_-CSDN]: https://knife.blog.csdn.net/article/details/127627108
[Spring_AOP_--_Before_IT_-CSDN]: https://knife.blog.csdn.net/article/details/125768072
[c46804d6edc84ed7b2f57066cebf808f.png]: https://img-blog.csdnimg.cn/c46804d6edc84ed7b2f57066cebf808f.png
[8a6f334bc885434298105bb74effa646.png]: https://img-blog.csdnimg.cn/8a6f334bc885434298105bb74effa646.png