java拦截器（interceptor）

1.声明式

（1）注解，使用Aspect的@Aspect

（2）实现HandlerInterceptor

 /**
  * 拦截请求
  *
  * @author Administrator
  *
  */
 @Component
 public class RequestHandlerInterceptor implements HandlerInterceptor {
     @Resource
     private RedisUtil redisUtil;

     @Override
     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
             throws Exception {
         String address = request.getParameter("address");
         if (redisUtil.get(address) != null && StringUtils.isNotBlank(String.valueOf(address))) {
             response.setCharacterEncoding("gbk");
             ResultObject ro = ResultObject.fail().add("result", "水肥机器正在执行中，该命令不能同步执行");
             PrintWriter pw = response.getWriter();
             pw.write(JSONObject.toJSONString(ro));
             return false;
         } else {
             System.out.println("下发地址---------------" + address);
         }

         return HandlerInterceptor.super.preHandle(request, response, handler);
     }

     @Override
     public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
             ModelAndView modelAndView) throws Exception {
         // TODO Auto-generated method stub
         HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
     }

     @Override
     public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
             throws Exception {
         // TODO Auto-generated method stub
         HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
     }

 }

添加拦截器，实现WebMvcConfigurer

/**
 * @author Administrator
 *
 */
@Configuration
public class RequestConfigurerAdapter implements WebMvcConfigurer {
    @Autowired
    private RequestHandlerInterceptor requestHandlerInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // TODO Auto-generated method stub
        WebMvcConfigurer.super.addInterceptors(registry);
        registry.addInterceptor(this.requestHandlerInterceptor).addPathPatterns("/**");
    }

}

（3）配置

使用aop空间中的相关标签