如今就從 SpringMVC 的網站開發開始。固然,最早是用 Mavan 下載所需的 jar。下面是 pom.xml 配置:html
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.kay</groupId> <artifactId>SpringMVCDome</artifactId> <packaging>war</packaging> <version>1.0-SNAPSHOT</version> <name>SpringMVCDome Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <!-- Compile dependencies --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>4.2.5.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>4.2.5.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.2.5.RELEASE</version> </dependency> <!-- test dependencies --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>4.2.5.RELEASE</version> <scope>test</scope> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> </dependencies> <build> <finalName>SpringMVCDome</finalName> </build> </project>
下面是代碼結構
java
注:開發環境:web
編碼:UTF-8
spring
工具:IDEA 15.0.3apache
JDK:JDK 1.八、Java EE 5
api
開發環境:Maven 3瀏覽器
Web 容器:Tomcat 9spring-mvc
開發技術選型:mvc
MVC 框架:Spring MVC 4.2.5
app
表現層:JSP
打開src\main\webapp\WEB-INF\下的 web.xml 文件,對 web.xml 進行配置,以下:
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <display-name>SpringMVCDemo Web Application</display-name> <!-- 設置一個 servlet --> <servlet> <servlet-name>mvc-dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mvc-dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- 配置一個 encodingFilter ,以免 post 請求中文出現亂碼 --> <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> </web-app>
在model包中新建javabean類 IndexController(名稱並不固定,可任意取),並修改以下:
package org.spring.model; /** * JavaBean UserBean 模板 * * @Author kay * @version 1.0 */ public class UserBean { private String name; private int age; public void setName(String name){ this.name = name; } public String getName() { return this.name; } public void setAge(int age){ this.age = age; } public int getAge() { return this.age; } }
在controller包中新建java類 IndexController(名稱並不固定,可任意取),並修改以下:
package org.spring.controller; import org.spring.model.UserBean; import org.springframework.stereotype.Controller; import org.springframework.ui.ModelMap; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import java.util.ArrayList; import java.util.List; /** * index 頁面的控制器,用於處理網站默認頁面的請求 * * @Author kay * @version 1.0 */ @Controller public class IndexController { @RequestMapping(value = "/",method = RequestMethod.GET) public String defaultIndex(ModelMap modelMap){ List<UserBean> userBeans = new ArrayList<UserBean>(); UserBean userBeanA = new UserBean(); UserBean userBeanB = new UserBean(); userBeanA.setName("zhang"); userBeanA.setAge(27); userBeanB.setName("li"); userBeanB.setAge(35); userBeans.add(userBeanA); userBeans.add(userBeanB); modelMap.addAttribute("users", userBeans); return "index"; } }
新建該xml文件後,在配置完web.xml後,需在web.xml同級目錄下新建 mvc-dispatcher-servlet.xml(-servlet前面是在servlet裏面定義的servlet名),以下:
<?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.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <!-- 指明 controller 所在包,並掃描其中的註解 --> <context:component-scan base-package="org.spring.controller"/> <!-- 靜態資源(js、image等)的訪問 --> <mvc:default-servlet-handler/> <!-- 開啓註解 --> <mvc:annotation-driven/> <!-- ViewResolver 視圖解析器 --> <!-- 用於支持Servlet、JSP視圖解析 --> <bean id="jspViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/WEB-INF/pages/"/> <property name="suffix" value=".jsp"/> </bean> </beans>
咱們刪除 webapp 目錄下的 index.jsp 文件,在WEB-INF目錄下新建文件夾pages,再在pages目錄下新建 index.jsp,並修改成以下所示:
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>SpringMVC Demo Home</title> </head> <body> <h3>This is SpringMVC Demo Home</h3> <c:forEach items="${users}" var="user"> <c:out value="${user.name}"/><br/> <c:out value="${user.age}"/><br/> </c:forEach> </body> </html>
這樣,說明配置完成。這裏總結一下其相關機制:首先,瀏覽器訪問 localhost:8080,後臺controller攔截該請求,進行相應的處理(此處無),在跳轉到視圖 index.jsp進行顯示。此後,將會進行詳細的介紹。
對於 Spring MVC 功能實現的分析,咱們首先從 web.xml 開始,在 web.xml 文件中咱們配置的是從 DispatcherServlet 開始的。
<servlet> <servlet-name>mvc-dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mvc-dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
接下來,咱們的分析就從 DispatcherServlet 開始。
——水門(2016年3月寫於武漢)