建立AOP

• 建立package命名為com.learn.aop（根據實際情況修改）

• 配置AOP，新建ExecutionAOP，內容如下

  @Aspect
  @Component
  public class ExecutionAop {
  
      // 切點範圍
      @Pointcut("execution(* com.learn.service..*(..))")
      public void pointcut(){ }
  
      @Before("pointcut()")
      public void before() {
          System.out.println("[email protected]
   
  ");
      }
  
      @AfterReturning("pointcut()")
      public void afterReturning() {
          System.out.println("[email protected]");
      }
  
      @After("pointcut()")
      public void after() {
          System.out.println("[email protected]");
      }
  
      @AfterThrowing("pointcut()")
      public void afterThrowing
   
  () {
          System.out.println("[email protected]");
      }
  
      @Around("pointcut()")
      public Object around(ProceedingJoinPoint pjp) throws Throwable {
          Object result;
          System.out.println("[email protected]前----------------");
          try {
              result = pjp.proceed();
          } catch
   
   (Throwable throwable) {
              System.out.println("[email protected]異常----------------");
              // 監聽引數為true則丟擲異常，為false則捕獲並不丟擲異常
              if (pjp.getArgs().length > 0 && !(Boolean) pjp.getArgs()[0]) {
                  result = null;
              } else {
                  throw throwable;
              }
          }
          System.out.println("[email protected]後----------------");
          return result;
      }
  
      // Around簡單示例
  //    @Around("pointcut()")
  //    public Object around(ProceedingJoinPoint pjp) throws Throwable {
  //        Object result;
  //        System.out.println("[email protected]前----------------");
  //        result = pjp.proceed();
  //        System.out.println("[email protected]後----------------");
  //        return result;
  //    }
  
  }