Spring MVC 之拦截器（八）

 在springMVC中实现拦截器有两种方式

1、实现HandlerInterceptor接口

2、继承HandlerInterceptorAdaptor类

编写拦截器：

package com.cy.springannotation.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
/**
 * 拦截器
 * @author acer
 *
 */
public class MyIntercetor implements HandlerInterceptor{
    private Logger log=Logger.getLogger(this.getClass());

    @Override
    public void afterCompletion(HttpServletRequest arg0,
            HttpServletResponse arg1, Object arg2, Exception arg3)
            throws Exception {
        log.info("1---afterCompletion方法-----DispatcherServlet完全处理完请求后被调用，往往执行一些资源清理动作");
    }

    @Override
    public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
            Object arg2, ModelAndView arg3) throws Exception {
        log.info("1---postHandle方法----------Controller方法后");
    }

    @Override
    public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1,
            Object arg2) throws Exception {
        log.info("1---preHandle方法-----------Controller方法前");
        //如返回为false的时候，拦截器可阻止方法的调用 ，默认返回false
//        return false;
        return true;
    }

}

在springAnnotation-servlet.xml里配置：

 <!-- 配置拦截器 -->
      <mvc:interceptors>
        <mvc:interceptor>
          <mvc:mapping path="/login.do"/>
          <bean class="com.cy.springannotation.interceptor.MyIntercetor"></bean>
        </mvc:interceptor>
     </mvc:interceptors> 

 配置多个拦截器的时候：

<!-- 配置拦截器 -->
      <mvc:interceptors>
        <mvc:interceptor>
          <mvc:mapping path="/login.do"/>  <!-- 如果不配置mapping则默认所有请求均被该拦截器拦截 -->
          <bean class="com.cy.springannotation.interceptor.MyIntercetor"></bean>
        </mvc:interceptor>
        <mvc:interceptor>
          <mvc:mapping path="/*"/>
          <bean class="com.cy.springannotation.interceptor.SecondIntercetor"></bean>
        </mvc:interceptor>
     </mvc:interceptors> 

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