Spring 3 mvc hello world例子

本篇文章中，我会使用maven构建一个基于Spring MVC的入门例子，前端标签库使用的是jstl。

在开始之前，请确保你已经安装maven、eclipse以及tomcat。

1.创建maven工程

在eclipse的工作区中使用maven命令行创建一个空白工程，当然你也可以用eclipse的m2eclipse插件来创建。

mvn archetype:generate -DgroupId=com.wanmei.mvc -DartifactId=SpringTest 
-DarchetypepartifactId=maven-archetype-webapp -DinteractiveMode=false

紧接着，将工程转换为eclipse工程，执行命令：

cd SpringTest
mvn eclipse:eclipse -Dwtpversion=2.0

2.修改POM文件

<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.wanmei.mvc</groupId>
	<artifactId>SpringTest</artifactId>
	<packaging>jar</packaging>
	<version>1.0-SNAPSHOT</version>
	<name>SpringTest</name>
	<url>http://maven.apache.org</url>
	<properties>
		<spring.version>3.2.3.RELEASE</spring.version>
	</properties>
	<dependencies>
		<!-- Spring 3 dependencies -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-web</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
		</dependency>

		<dependency>
			<groupId>taglibs</groupId>
			<artifactId>standard</artifactId>
			<version>1.1.2</version>
		</dependency>
		<dependency>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-resources-plugin</artifactId>
			<version>2.5</version>
		</dependency>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>3.8.1</version>
			<scope>test</scope>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>2.3.2</version>
				<configuration>
					<source>1.6</source>
					<target>1.6</target>
				</configuration>
			</plugin>
		</plugins>
	</build>
</project>

3.spring配置

在WEB-INF目录下添加spring-mvc-servlet.xml，如下：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
 
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
    <context:component-scan base-package="com.wanmei" />
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"></property>
        <property name="prefix">
            <value>/WEB-INF/jsp/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>
 
</beans>

4.修改web.xml配置问卷，添加分发器配置

<?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_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>www.wanmei.com</display-name>
  <servlet>
		<servlet-name>spring-mvc</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
 
	<servlet-mapping>
		<servlet-name>spring-mvc</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
 
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/spring-mvc-servlet.xml</param-value>
	</context-param>
 
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
</web-app>

5.编写请求处理类

package com.wanmei.mvc;
import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
 
@Controller
public class DemoController
{
    @RequestMapping(value = "/",method = RequestMethod.GET)
    public String printWelcome(ModelMap model)
    {
        model.addAttribute("message", "Spring 3 MVC Hello World !");
        return "helloWorld";
    }
}

6.创建视图

在WEB-INF/jsp目录下创建helloWorld.jsp文件，如下：

<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
<%@ taglib prefix="x" uri="http://java.sun.com/jstl/xml" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %>
<%@ taglib prefix="sql" uri="http://java.sun.com/jstl/sql" %>
 
<html>
    <head>
        <title>My first example using Spring 3 MVC</title>
    </head>
    <body>
        <h1>${message}</h1>
    </body>
</html>

7.运行

在tomcat中运行此工程，当然你可以用jetty等容器，我是用tomcat的maven插件运行的，配置如下：

<plugin>
		<groupId>org.apache.tomcat.maven</groupId>
		<artifactId>tomcat7-maven-plugin</artifactId>
		<version>2.1</version>
		<configuration>
			<path>/</path>
		</configuration>
</plugin>

然后运行命令：

mvn clean install tomcat7:run

访问： http://localhost:8080/ 即可看到运行结果。