springmvc之HelloWorld

首先来看看springmvcproject的项目结构，採用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>
	<!-- 载入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。凝视写的非常清楚了。只是说下Spring mvc拦截的URL，事实上常见的写法是*.do、/*、/app，可是这些模式都不是非常好。

	<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而且会处理全部的请求，包含对静态资源的请求。

可是一般来说。我们无需去拦截静态资源（比方：css、js、图片）。Spring提供了一个非常方便的配置，使得我们不必过于操心细节。

<!-- 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，浏览器訪问：http://127.0.0.1:8080/springmvc/user/findAll