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拦截器interceptor

作者:互联网

拦截器interceptor

  1. 配置

    <mvc:interceptors>
        <mvc:interceptor>
            <!--/**回处理/后面的所有请求-->
            <mvc:mapping path="/**"/>
            <bean class="cn.pinked.config.MyInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>
  2. 拦截器

    public class MyInterceptor implements HandlerInterceptor {
    
        //return true; 执行下一个拦截器
        //return false; 不执行下一个拦截器
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
            System.out.println("==========preHandle==========");
            return true;
        }
    
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
            System.out.println("==========postHandle==========");
        }
    
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
            System.out.println("==========afterCompletion==========");
        }
    }
  3. 输出

    ==========preHandle==========
    controller===test()执行
    ==========postHandle==========
    ==========afterCompletion==========
  4. 总结

    preHandle
    调用时间:Controller方法处理之前
    若返回false,则中断执行,注意:不会进入afterCompletion

    postHandle
    调用前提:preHandle返回true
    调用时间:Controller方法处理完之后,DispatcherServlet进行视图的渲染之前,也就是说在这个方法中你可以对ModelAndView进行操作
    备注:postHandle虽然post打头,但post、get方法都能处理

    afterCompletion
    调用前提:preHandle返回true
    调用时间:DispatcherServlet进行视图的渲染之后
    多用于清理资源

标签:Exception,拦截器,preHandle,postHandle,interceptor,public,afterCompletion
来源: https://www.cnblogs.com/pinked/p/12234515.html