一、實(shí)驗(yàn)介紹

1.1 實(shí)驗(yàn)內(nèi)容

本節(jié)課程主要利用 Spring MVC 框架實(shí)現(xiàn)攔截器以及 Spring MVC 框架的整合。

1.2 實(shí)驗(yàn)知識點(diǎn)

• Spring MVC 框架
• 攔截器

1.3 實(shí)驗(yàn)環(huán)境

• JDK1.8
• Eclipse JavaEE

二、實(shí)驗(yàn)步驟

2.1 攔截器實(shí)現(xiàn)

在項目 hrms 的目錄 src/main/java 下新建包 com.shiyanlou.interceptor，并在該包下新建類 LoginInterceptor，來驗(yàn)證用戶是否登錄，代碼如下：

package com.shiyanlou.interceptor;import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; public class LoginInterceptor implements HandlerInterceptor { // 不攔截 "/login" 請求 private static final String[] IGNORE_URI = { "/login" }; @Override public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3) throws Exception { } @Override public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3) throws Exception { } // 該方法將在 Controller 處理前進(jìn)行調(diào)用 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { // flag 表示是否登錄 boolean flag = false; // 獲取請求的 URL String url = request.getServletPath(); for (String s : IGNORE_URI) { if (url.contains(s)) { flag = true; break; } } if (!flag) { // 獲取 Session 并判斷是否登錄 String username = (String) request.getSession().getAttribute( "username"); if (username == null) { request.setAttribute("message", "Please log in first!"); // 如果未登錄，進(jìn)行攔截，跳轉(zhuǎn)到登錄頁面 request.getRequestDispatcher("/login.jsp") .forward(request, response); } else { flag = true; } } return flag; } }

2.2 spring-mvc.xml 配置文件

在目錄 src/main/resources 下新建 Spring MVC 配置文件 spring-mvc.xml，添加如下代碼：

<?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/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd"> <!-- 自動掃描該包，Spring MVC 會將包下用 @Controller 注解的類注冊為 Spring 的 controller --> <context:component-scan base-package="com.shiyanlou.controller" /> <!-- 設(shè)置默認(rèn)配置方案 --> <mvc:annotation-driven /> <!-- 靜態(tài)資源訪問 --> <mvc:resources location="/" mapping="/**" /> <!-- 視圖解析器 --> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/" /> <property name="suffix" value=".jsp" /> </bean> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="maxUploadSize" value="3500000" /> <property name="defaultEncoding" value="UTF-8" /> </bean> <!-- 配置攔截器 --> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/*" /> <bean class="com.shiyanlou.interceptor.LoginInterceptor" /> </mvc:interceptor> </mvc:interceptors> </beans>

2.3 配置 web.xml

修改項目 hrms 的 src->main->webapp->WEB-INF 目錄下的 web.xml 內(nèi)容如下：

<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 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>hrms</display-name> <!-- 配置 Spring 核心監(jiān)聽器 --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- 指定 Spring 的配置文件 --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mybatis.xml</param-value> </context-param> <!-- 定義 Spring MVC 前端控制器 --> <servlet> <servlet-name>springMVC</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <!-- 為 DispatcherServlet 建立映射 --> <servlet-mapping> <servlet-name>springMVC</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <listener> <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class> </listener> <!-- 編碼過濾器 --> <filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- 設(shè)置首頁 --> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> </web-app>

三、實(shí)驗(yàn)總結(jié)

到這里我們就實(shí)現(xiàn)了攔截器和 Spring MVC 的整合，項目的代碼全部完成，下一節(jié)我們將對實(shí)現(xiàn)的系統(tǒng)進(jìn)行運(yùn)行測試。

轉(zhuǎn)載于:https://www.cnblogs.com/wanghuaijun/p/7076772.html

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