AOP的基本使用

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestLog {

}
@Slf4j
@Aspect
@Component
public class RequestLogAspect {
@Around(“@within(org.springframework.stereotype.Controller) || @within(org.springframework.web.bind.annotation.RestController))”)
public Object aroundApi(ProceedingJoinPoint joinPoint) throws Throwable {
Signature signature = joinPoint.getSignature();
MethodSignature methodSignature = (MethodSignature)signature;
Method targetMethod = methodSignature.getMethod();
if(!targetMethod.isAnnotationPresent(RequestLog.class)) {
return joinPoint.proceed();
}
HttpServletRequest request = WebUtil.getRequest();
log.info(“{} : {}”, request.getRequestURI(), JSON.toJSONString(parseArgs(targetMethod, joinPoint.getArgs())));
return joinPoint.proceed();
}
public List parseArgs(Method method, Object[] args) {
Map<String, Object> paraMap = new HashMap<>(16);
Object requestBodyValue = null;
List reqArgs = Lists.newArrayList();
if (!paraMap.isEmpty()) {
reqArgs.add(paraMap);
}
if (requestBodyValue != null) {
reqArgs.add(requestBodyValue);
}
return reqArgs;
}
}
@Aspect
@Component
public class LogAspect {
/**

• 定义切入点，切入点为 spring.aop.ProductController 类下的所有方法
  /
  @Pointcut("execution(public * spring.aop.ProductController.(…))“)
  public void log() {
  }
  /**
• 前置通知：在连接点方法执行之前执行
  /
  @Before(“log()”)
  public void doBefore(JoinPoint joinPoint) {
  System.out.println((“-------------------- 前置通知逻辑 --------------------”));
  }
  /*
• 后置通知：在连接点方法执行之后执行，即使连接点方法发生异常也会执行
  /
  //@After(“log()”)
  public void doAfter() {
  System.out.println(“-------------------- 后置通知逻辑 --------------------”);
  }
  /*
• 返回通知：在连接点方法返回结果后执行，即连接点方法若发生异常则不会执行
• str为方法返回值的引用，参数名称可以自定义
  /
  //@AfterReturning(pointcut = “log()”, returning = “str”)
  public void doAfterReturning(Object str) {
  System.out.println(“返回通知逻辑…” + str);
  }
  /*
• 异常通知：在连接点方法发生异常之后执行
  /
  //@AfterThrowing(“log()”)
  public void doAfterThrowing() {
  System.out.println(“异常通知逻辑…”);
  }
  /*
• 环绕通知：在连接点方法执行之前和执行之后执行
  */
  //@Around(value = “log()”)
  public Object doAround(ProceedingJoinPoint proceedingJoinPoint) { // 其它通知类型的方法也可以加上形参 ProceedingJoinPoint proceedingJoinPoint
  System.out.println(”-------------------- 环绕通知执行开始 --------------------“);
  Object result = null;
  //获取方法所需参数
  Object[] args = proceedingJoinPoint.getArgs();
  System.out.println(“aaa…”);
  try {
  result = proceedingJoinPoint.proceed(args);
  System.out.println(“bbb…”);
  } catch (Throwable throwable) {
  throwable.printStackTrace();
  System.out.println(“ccc…”);
  }finally {
  System.out.println(“result : {} " + result);
  System.out.println(“ddd…”);
  }
  System.out.println(”-------------------- 环绕通知执行结束 --------------------”);
  // 返回结果，此处可改变方法的返回结果
  //return result;
  return null;
  }
  }
  @Component
  public class ProductController {
  public String save() {
  System.out.println(“保存产品信息”);
  //int i = 1/0;
  return “hello”;
  }
  }