Spring MVC 入门

　　首先在maven中添加如下依赖 : 

 <dependencies>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>4.2.4.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.2.4.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.2.4.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.1.1</version>
        </dependency>

    </dependencies>

　　接下来在web.xml文件中配置DispatcherServlet : 

<?xml version="1.0" encoding="UTF-8" ?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
         http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0">

    <!-- 配置DispatcherServlet -->
    <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>
    </servlet>

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

</web-app>

　　这里面需要注意的是url-pattern建议使用"/",因为如果使用"/*"则这个url会匹配*.jsp这种带有后缀的请求,从而派给DispatcherServlet进行转发,如果你的Controller类中没有相应的handler,则会报404错误.

　　web.xml文件配置成功之后接着在classpath路径下编写一个springmvc.xml文件 : 

<?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"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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-4.0.xsd
       http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

    <!-- 配置自动扫描的包 -->
    <context:component-scan base-package="com.czp.springmvc"></context:component-scan>

    <!-- 配置视图解析器,如何把handler方法返回值解析为实际的物理视图 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

</beans>

　　配置完成之后我们就可以写相应的Handler类了,我们在com.czp.springmvc.handlers包下写一个Controller类 : 

package com.czp.springmvc.handlers;

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

/**
 * Created by cpppp on 17-5-19.
 */

@Controller
public class HelloSpring {

    @RequestMapping("/hellospring")
    public String hello() {
        System.out.println("hello world");
        return "success";
    }

}

　　这样我们就成功完成了第一个SpringMVC的例子.