Spring MVC 入门--Hello World

Bertha 。 2021-09-14 05:26 457阅读 0赞

# Spring MVC 学习 #

## Hello world ##

--------------------

### 步骤 ###

>  *  添加jar包
>  *  在web.xml文件中配置DispatcherServlet
>  *  添加Spring MVC的配饰文件
>  *  编写处理请求的处理器，并且标识为处理器
>  *  编写视图

### 实践 ###

#### 添加jar包 ####

maven 添加jar包

<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.chen</groupId>
        <artifactId>springmvc</artifactId>
        <packaging>war</packaging>
        <version>1.0-SNAPSHOT</version>
        <name>springMVC Maven Webapp</name>
        <url>http://maven.apache.org</url>
        <dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
    
            
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
                <scope>provided</scope>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>4.3.9.RELEASE</version>
                <type>jar</type>
            </dependency>
    
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>
                <version>4.3.9.RELEASE</version>
                <type>jar</type>
            </dependency>
    
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-beans</artifactId>
                <version>4.3.9.RELEASE</version>
                <type>jar</type>
            </dependency>
    
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>4.3.9.RELEASE</version>
                <type>jar</type>
            </dependency>
    
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-orm</artifactId>
                <version>4.3.9.RELEASE</version>
                <type>jar</type>
            </dependency>
            
    
    
        </dependencies>
        <build>
            <finalName>springMVC</finalName>
        </build>
    </project>

手动添加jar包(需要添加的jar包)

- commons-logging-1.2.jar - spring-aop-4.3.9.RELEASE.jar - spring-beans-4.3.9.RELEASE.jar - spring-context-4.3.9.RELEASE.jar - spring-core-4.3.9.RELEASE.jar - spring-expression-4.3.9.RELEASE.jar - spring-web-4.3.9.RELEASE.jar - spring-webmvc-4.3.9.RELEASE.jar

#### 在web.xml文件中配置DispatcherServlet ####

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
        
        <servlet>
            <servlet-name>springDispatcherServlet </servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            
            <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>

#### 添加spring MVC配置文件 ####

配置文件放在src根目录，maven工程放在resources目录

<?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" 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">
        
        <context:component-scan base-package="com.chen"/>
        
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="./WEB-INF/views/"/>
            <property name="suffix" value=".jsp"/>
        </bean>
    </beans>

#### 编写处理请求的处理器 ####

在代码目录下新建包 handler，在其下面新建控制器 HelloWorld.java

package com.chen.handler;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    @Controller
    public class Helloworld { 
        @RequestMapping(value = "/helloWorld")
        public String hello(){
            System.out.println("Hello ,World");
            return "success";
        }
    }

#### 标识为处理器 ####

见上面java文件里的@Controller以及@RequestMapping(value = “/helloWorld”)  
两个注解一个将该java类标识为处理器，另一个将访问url为“/helloWorld”的请求到此处进行处理

#### 编写视图界面 ####

在index.jsp页面中加入一个超链接

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %>
    <!DOCTYPE html>
    <html lang="zh">
    <head>
        <meta charset="UTF-8">
        <title>Test</title>
    </head>
    <body>
        <a href="helloWorld">Hello World</a>
    </body>
    </html>

在WEB-INF下新建views文件夹，添加success.jsp文件

<%-- Created by IntelliJ IDEA. User: chen Date: 2017/9/12 Time: 22:13 To change this template use File | Settings | File Templates. --%>
    <%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>成功</title>
        <meta charset="UTF-8">
    </head>
    <body>
    <h2>成功</h2>
    </body>
    </html>

### 启动项目 ###

启动项目，自动进入index.jsp页面  
![这里写图片描述][SouthEast]

点击Hello World 超链接进入success.jsp页面  
![这里写图片描述][SouthEast 1]

同时控制台输出Hello，World  
![这里写图片描述][SouthEast 2]

到此，Spring MVC入门的Hello World完成。

[SouthEast]: /images/20210911/1748d93d7a7c471087b8d1e5fd68b871.png
[SouthEast 1]: /images/20210911/08b93aabffdc4d6c9783fac70732fdf4.png
[SouthEast 2]: /images/20210911/50d101d95279435881a0ecb7e0f44096.png