SpringMVC 学习-入门篇

一、都需要哪些 Jar 包

<properties>
    <spring.version>4.2.3.RELEASE</spring.version>
</properties>

<dependencies>
    <!-- SpringMVC start -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <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>
    <!-- SpringMVC end -->
</dependencies>

二、web.xml 配置文件

<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"
    version="3.0" metadata-complete="true">
    
    <servlet>
    　　<servlet-name>springmvc</servlet-name>
    　　<!-- 负责分发 -->
    　　<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    　　<init-param>
    　　　　<param-name>contextConfigLocation</param-name>
    　　　　<param-value>/WEB-INF/*-servlet.xml</param-value>
    　　</init-param>
    　　<!-- 启动服务时加载 -->
    　　<load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

三、在默认路径 WEB-INF 下创建配置文件 springmvc-servlet.xml

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:task="http://www.springframework.org/schema/task"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
           http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
           http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd
    ">
    <!-- 注解驱动 -->
    <mvc:annotation-driven/>
    <!-- 注解扫描包 -->
    <context:component-scan base-package="com.erim.web" />
    <!-- 对加载页面的路径解析 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    　　<!-- 前缀 -->
    　　<property name="prefix" value="/"></property>
    　　<!-- 后缀 -->
    　　<property name="suffix" value=".html"></property>
    </bean>
</beans>

四、我们创建一个 Controller 层 Java 类

package com.erim.web;

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

@Controller
public class HelloWorldController {

    /**
     * @Description: 测试SpringMVC
     * @Author: Libra
     * @CreateTime: 2017年11月30日 下午3:49:09
     * @return
     */
    @ResponseBody
    @RequestMapping("/getHelloWorld")
    public String getHelloWorld() {
        return "Hello World!";
    }
}

五、SpringMVC 访问静态文件

在过滤所有请求的前提下，访问静态文件也是一种请求，那我们如何配置才可以访问静态文件呢。

如下：还是 springmvc-servlet.xml 配置文件

<!-- 静态资源访问 -->
<mvc:resources location="/img/" mapping="/img/**"/>  
<mvc:resources location="/js/" mapping="/js/**"/>  

六、跳转页面且传递参数

@RequestMapping("/helloWorld")
public String openPage(HttpServletRequest request) {
    request.setAttribute("name", "LiMing");
    return "hello";
}

html 页面无法接受参数，JSP 页面通过 EL 表达式可以接收参数，如下：

${name}