SpringMVC基础-10-拦截器

代码示例：

InterceptorTestController:

package com.atguigu.controller;

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

/**
 * @Title: InterceptorTestController
 * @Description:
 * @Author:
 * @Version: 1.0
 * @create 2020/6/22 11:08
 */
@Controller
public class InterceptorTestController {

    @RequestMapping("/test01")
    public String test01(){
        System.out.println("test01...");
        //int i =  10/0;
        return "success";
    }
}

MyFirstInterceptor:

package com.atguigu.controller;

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

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

/**
 * 1.实现 HandlerInterceptor接口
 * 2.在SpringMVC配置文件中注册注册这个拦截器
 *      配置这个拦截器拦截哪些请求的目标方法
 */
public class MyFirstInterceptor implements HandlerInterceptor {

    /**
     * 目标方法之前运行
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("MyFirstInterceptor...preHandle...");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("MyFirstInterceptor...postHandle...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("MyFirstInterceptor...afterCompletion...");
    }
}

MySecondInterceptor:

package com.atguigu.controller;

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

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

/**
 * @Title: MySecondInterceptor
 * @Description:
 * @Author:
 * @Version: 1.0
 * @create 2020/6/22 12:58
 */
public class MySecondInterceptor implements HandlerInterceptor {

    /**
     * 目标方法之前运行
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("MySecondInterceptor...preHandle...");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("MySecondInterceptor...postHandle...");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("MySecondInterceptor...afterCompletion...");
    }
}

springmvc.xml:

<?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:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <context:component-scan base-package="com.atguigu"></context:component-scan>
    
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <!-- 静态资源能访问，动态映射的请求就不行 -->
    <mvc:default-servlet-handler/>
    <!-- springmvc可以保证动态请求和静态请求都能访问 -->
    <mvc:annotation-driven/>

    <!--拦截器配置-->
    <mvc:interceptors>
        <!--配置某个拦截器：默认是拦截所有请求的-->
        <bean class="com.atguigu.controller.MyFirstInterceptor"></bean>

        <!--配置某个拦截器更详细的信息-->
        <mvc:interceptor>
            <!--只拦截test01请求-->
            <mvc:mapping path="/test01"/>
            <bean class="com.atguigu.controller.MySecondInterceptor"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

</beans>

web.xml:

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         id="WebApp_ID" version="3.0">
    <display-name>10.SpringMVC_interceptor</display-name>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

    <!-- The front controller of this Spring Web application,
    responsible for handling all application requests -->
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <!-- contextConfigLocation:指定SpringMVC配置文件位置 -->
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <!-- Map all requests to the DispatcherServlet for handling -->
    <servlet-mapping>
        <servlet-name>springDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- 配置一个字符编码的Filter；一定注意：字符编码filter一般都在其他Filter之前； -->
    <!--配置字符集编码的Filter-->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <!-- encoding：指定解决POST请求乱码 -->
        <init-param>
            <param-name>encoding</param-name>
            <!--不区分大小写-->
            <param-value>utf-8</param-value>
        </init-param>
        <init-param>
            <!-- forceEncoding:顺手解决响应乱码；response.setCharacterEncoding(this.encoding); -->
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!--支持Rest风格的Filter（开启PUT、DELETE请求）-->
    <filter>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>HiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <!-- 使用SpringMVC前端控制器写完就直接写字符编码过滤器；
        Tomcat一装上，上手就是server.xml的8080处添加URIEncoding="UTF-8"
     -->

</web-app>

index.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    <%
        pageContext.setAttribute("ctp", request.getContextPath());
    %>
</head>
<body>
    <a href="${ctp}/test01">test01</a>
</body>
</html>

success.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
System.out.println("success.jsp....");
%>
<h1>成功！</h1>
</body>
</html>