springboot实现aop

news2024/9/29 9:29:07

AOP(术语)

连接点
类里面哪些方法可以增强，这些点被称为连接点
切入点
实际被真正增强的方法
通知（增强）
实际增强的逻辑部分称为通知（增强）
通知（增强）有多种类型

前置通知–@Before
后置通知–@After
环绕通知–@Around
异常通知–@AfterThrowing
最终通知–@AfterReturning
切面（是动作）–
把通知（增强）应用到切入点过程

引入依赖

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

实现步骤

新建一个注解类，用于后面做切入点

@Retention(value = RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Authorization {

}

建一个切面类

@Aspect
@Component
public class AuthAspect {
    /**
     * 定义了一个切点
     * 这里的路径填自定义注解的全路径
     */
    @Pointcut("@annotation(com.zhuyh.studytest.spring5.aop.Authorization)")
    public void authornizeCut() {

    }

    @Before("authornizeCut()")
    public void cutProcess(JoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        System.out.println("AOP开始拦截, 当前拦截的方法名: " + method.getName());
    }

    @After("authornizeCut()")
    public void after(JoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        System.out.println("AOP执行的方法 :" + method.getName() + " 执行完了");
    }


    @Around("authornizeCut()")
    public Object testCutAround(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("AOP拦截开始进入环绕通知.......");
        Object proceed = joinPoint.proceed();
        System.out.println("准备退出环绕......");
        return proceed;
    }

    /**
     * returning属性指定连接点方法返回的结果放置在result变量中
     *
     * @param joinPoint 连接点
     * @param result    返回结果
     */
    @AfterReturning(value = "authornizeCut()", returning = "result")
    public void afterReturn(JoinPoint joinPoint, Object result) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        System.out.println("AOP拦截的方法执行成功, 进入返回通知拦截, 方法名为: " + method.getName() + ", 返回结果为: " + result.toString());
    }

    @AfterThrowing(value = "authornizeCut()", throwing = "e")
    public void afterThrow(JoinPoint joinPoint, Exception e) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        System.out.println("AOP进入方法异常拦截, 方法名为: " + method.getName() + ", 异常信息为: " + e.getMessage());
    }
}

来一个Controller作为请求被代理的对象

@RestController
@RequestMapping("/company")
public class CompanyController {
    @GetMapping("/aopTest")
    @Authorization
    public Object aopTest(@RequestParam String name){
        //远程调用
        System.out.println("执行接口name:" + name);
        // int n = 1/0;
        return "成功了-----" + name;
    }
}

启动类启动项目

@SpringBootApplication
public class StudyTestApplication {
    public static void main(String[] args) {
        SpringApplication.run(StudyTestApplication.class, args);
    }
}

测试验证

浏览器或者api调用工具调接口
控制台打印

AOP拦截开始进入环绕通知.......
AOP开始拦截, 当前拦截的方法名: aopTest
执行接口name:zhuyh
AOP拦截的方法执行成功, 进入返回通知拦截, 方法名为: aopTest, 返回结果为: 成功了-----zhuyh
AOP执行的方法 :aopTest 执行完了
准备退出环绕......

Controller加入一个异常 int i=1/0; 重启项目再次调用
异常通知打印了 / by zero

AOP拦截开始进入环绕通知.......
AOP开始拦截, 当前拦截的方法名: aopTest
执行接口name:zhuyh
AOP进入方法异常拦截, 方法名为: aopTest, 异常信息为: / by zero
AOP执行的方法 :aopTest 执行完了
2024-01-24 16:50:10.477 ERROR 4888 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.ArithmeticException: / by zero] with root cause

java.lang.ArithmeticException: / by zero
	at com.zhuyh.studytest.spring5.aop.CompanyController.aopTest(CompanyController.java:16) ~[classes/:na]