SpringMVC（十八）拦截器

SpringMVC中拦截器的配置和使用

一.配置单个拦截器

先定义一个类，让他实现一个接口  HandlerInterceptor 

package demo20interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

/**
 * Created by mycom on 2018/4/2.
 */
public class MyInteceptor implements HandlerInterceptor {
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        System.out.println("preHandle======");
        return true;
    }

    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle=======");
    }

    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("afterCompletion========");
    }
}

定义一个控制器类

package demo20interceptor;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * Created by mycom on 2018/4/2.
 */
@Controller
public class FirstController {
    @RequestMapping("/first")
    public String doFirst(){
        System.out.println("Handle Model");
        return "success";
    }
}

配置文件中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="demo20interceptor"></context:component-scan>

    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/fileupload/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"></bean>

    <!--拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**/"/>
            <bean class="demo20interceptor.MyInteceptor"></bean>
        </mvc:interceptor>
        
    </mvc:interceptors>
    <!--注解驱动-->
    <mvc:annotation-driven></mvc:annotation-driven>



</beans>

测试的时候直接在地址栏中输入first就可以了

运行的结果是：

preHandle======

Handle Model

postHandle=======

afterCompletion========

二.配置多个拦截器

配置多个拦截器，就要在多定义一个拦截器

package demo20interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

/**
 * Created by mycom on 2018/4/2.
 */
public class MyInterceptor2 implements HandlerInterceptor {
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        System.out.println("second   preHandle");
        return true;
    }

    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("second   postHandle");
    }

    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("second   afterCompletion");
    }
}

在配置文件中，也同样要多配置一个节点