SpringMVC——HelloWorld

廢話不說。

首先，用IDEA新建一個maven專案。

如果是第一次用maven-archetype新建專案，可能需要等一段時間。我第一次就等了很久，睡了一覺以後，目錄結構如下圖：

新建了必要的資料夾後，目錄結構如下：

接下來就是用maven新增必要的jar包了，我的pom.xml檔案如下：（這個地方我參考了GW_Cheng的部落格http://blog.csdn.net/frankcheng5143/article/details/50512340）

<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>jc_yoky</groupId>
  <artifactId>springmvc</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>springmvc Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <properties>
    <!-- basic settings -->
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.build.locales>zh_CN</project.build.locales>
    <project.build.jdk>1.8</project.build.jdk>

    <!-- lib versions -->
    <junit.version>3.8.1</junit.version>
    <spring.version>4.3.7.RELEASE</spring.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>${junit.version}</version>
      <scope>test</scope>
    </dependency>
    <!-- spring start -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${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>

  </dependencies>
  <build>
    <finalName>springmvc</finalName>
  </build>
</project>

這樣，我們需要的jar包也匯入完畢了。

---

接下來，先部署到tomcat上看下是否報錯：
按照步驟來，不會有問題的！

啟動一下，應該是不會報錯，因為我們還什麼都沒幹……^ - ^

---

接下來就是springMVC的配置了，這才是重頭戲。

首先是web.xml檔案的配置

<?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"
         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>springmvctest</display-name>
  <!-- 統一編碼 -->
  <filter>
    <filter-name>charsetEncoding</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>charsetEncoding</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!-- 配置DispatchcerServlet -->
  <servlet>
    <servlet-name>springDispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!-- 配置Spring mvc下的配置檔案的位置和名稱 -->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>springDispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

然後在resources下新建springmvc.xml:

<?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:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.2.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
        http://www.springframework.org/schema/task
        http://www.springframework.org/schema/task/spring-task-4.2.xsd">

    <!-- 掃描路徑 -->
    <context:component-scan base-package="com.hjc.springmvc" >
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>

    <!-- 配置根檢視 -->
    <mvc:view-controller path="/" view-name="index"/>

    <!-- 啟用基於註解的配置 @RequestMapping, @ExceptionHandler,資料繫結 ,@NumberFormat ,
    @DateTimeFormat ,@Controller ,@Valid ,@RequestBody ,@ResponseBody等  -->
    <mvc:annotation-driven />

    <!-- 靜態資源配置 -->
    <mvc:resources location="/static/" mapping="/static/**"></mvc:resources>

    <!-- 檢視層配置 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

這樣配置檔案也基本寫好了。此時的目錄結構如下：

---

接下來就是寫測試用的Java類了。在java/com/springmvc/controller下新建HelloWorld.java類：

package com.hjc.springmvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
 * Created by hjc on 2017/3/4.
 */
@Controller
@RequestMapping(value="/hello")
public class HelloWorld {
    @RequestMapping(value="/world",method= RequestMethod.GET)
    public String hello(Model model){
        System.out.println("進入了hello方法");
        model.addAttribute("msg","hello springmvc！");
        return "index";
    }
}

接下來是展示層index.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
<h2>Hello Spring!</h2>
${msg}
<a href="/hello/world">顯示message</a>
</body>
</html>

執行tomcat，訪問localhost:8080，點選顯示message，“hello springmvc”就顯示出來了！

---

到這，springMVC框架的bootstrap就告一段落了。這其實就是一個非常簡單的檢視層到控制層，再返回檢視層的MVC架構了。

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希望這個簡單的部落格能夠幫助到初學者，這裡也感謝【傑鍋鍋（Jackie）】、【GW_Cheng】兩位博主的賜教。
http://www.cnblogs.com/bigdataZJ/p/springmvc1.html
http://blog.csdn.net/frankcheng5143/article/details/50512340
有什麼問題歡迎留言，有錯誤的地方歡迎指正。