自定义annotation注解并对其做切面

傷城~ 2023-10-11 14:57 13阅读 0赞

**编写一个注解**

@Target(ElementType.METHOD)
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    @RequestMapping(method = RequestMethod.GET)
    public @interface RequestGet {
        
    
        /**
         * Alias for {@link RequestMapping#name}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String name() default "";
    
        /**
         * Alias for {@link RequestMapping#value}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String[] value() default {
        };
    
        /**
         * Alias for {@link RequestMapping#path}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String[] path() default {
        };
    
        /**
         * Alias for {@link RequestMapping#params}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String[] params() default {
        };
    
        /**
         * Alias for {@link RequestMapping#headers}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String[] headers() default {
        };
    
        /**
         * Alias for {@link RequestMapping#consumes}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String[] consumes() default {
        };
    
        /**
         * Alias for {@link RequestMapping#produces}.
         */
        @AliasFor(annotation = RequestMapping.class)
        String[] produces() default {
        };
    
    }

这个注解的功能和GetMapping注解是一样的。

**编写一个测试controller**

@RestController
    public class TestController {
        
    
        @RequestGet("/hello")
        public String hello(String name){
        
            return "hello" + name;
        }
    
    }

**编写对这个注解的增加类**

@Component
    @Aspect
    public class RequestGetAspect {
        
    
        private static final Logger logger = LoggerFactory.getLogger(RequestGetAspect.class);
    
    
        /**
         * 对这个注解做切面
         */
        @Pointcut("@annotation(com.wk.annation.demo.annation.RequestGet)")
        public void pointCut(){
        
    
        }
    
        @Around("pointCut()")
        public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        
            logger.info("方法开始执行");
            Object[] args = joinPoint.getArgs();
            for (Object arg : args) {
        
                logger.info("方法参数：" + arg);
            }
            logger.info("方法结束执行");
            return joinPoint.proceed();
        }
    
    }

**查看日志**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNzUwNjU2_size_16_color_FFFFFF_t_70_pic_center]  
![在这里插入图片描述][20201027101316422.png_pic_center]

这样我们可以通过自定义注解实现对这个接口的参数校验，或者限流等操作。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNzUwNjU2_size_16_color_FFFFFF_t_70_pic_center]: https://img-blog.csdnimg.cn/20201027101306964.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNzUwNjU2,size_16,color_FFFFFF,t_70#pic_center
[20201027101316422.png_pic_center]: https://img-blog.csdnimg.cn/20201027101316422.png#pic_center