springmvc之HelloWorld

首先来看看springmvc工程的项目结构，采用maven构建。



POM配置：

<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/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.ztz.springmvc</groupId>
<artifactId>springmvc</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1-b08</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.16</version>
</dependency>

<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.5.2</version>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>

</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

然后看下web工成的web.xml配置

<display-name>springmvc</display-name>
<!-- 加载spring配置文件 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<!-- 字符集过滤器 -->
<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>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- spring监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 防止spring内存溢出监听器 -->
<listener>
<listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
</listener>
<!-- spring mvc servlet -->
<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>
<servlet-mapping>
<servlet-name>springMvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

web.xml里面配置我就不多说了，注释写的很清楚了。不过说下Spring mvc拦截的URL，其实常见的写法是*.do、/*、/app，但是这些模式都不是很好。

<servlet-mapping>
<servlet-name>springMvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

通过将DispatcherServlet映射到 / ，声明了它会作为默认的servlet并且会处理所有的请求，包括对静态资源的请求。但是一般来说，我们无需去拦截静态资源（比如：css、js、图片），Spring提供了一个很方便的配置，使得我们不必过于担心细节。

<!-- 处理对静态资源的请求 -->
<mvc:resources location="/static/" mapping="/static/**" />

接下来配置控制器跟视图解析器(spring-mvc.xml)

	<!--默认的mvc注解映射的支持 -->
<mvc:annotation-driven/>
<!-- 处理对静态资源的请求 -->
<mvc:resources location="/static/" mapping="/static/**" />
<!-- 扫描注解 -->
<context:component-scan base-package="com.ztz.springmvc.controller"/>
<!-- 视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<!-- 前缀 -->
<property name="prefix" value="/WEB-INF/jsp/"/>
<!-- 后缀 -->
<property name="suffix" value=".jsp"/>
</bean>

 Controller层：

package com.ztz.springmvc.controller;

import javax.servlet.http.HttpServletRequest;

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

@Controller
@RequestMapping("/user")
public class UsersController {
@RequestMapping(value="/findAll")
private String findAll(HttpServletRequest request){
request.setAttribute("hello", "spring mvc Helloworld");
return "index";
}
}

JSP页面：

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jstl/core_rt" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
request.setAttribute("basePath", basePath);
%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>springmvc</title>
</head>
<body>
${hello}
<br/>
<img alt="logo" src="${basePath}static/images/java_logo.jpg">
</body>
</html>

启动服务，浏览器访问：http://127.0.0.1:8080/springmvc/user/findAll