spring各xml配置文件及映射文件的xml头约束

<?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_2_5.xsd"
         id="WebApp_ID" version="2.5">
    <!-- 配置 spring mvc 的核心控制器 -->
    <servlet>
        <servlet-name>SpringMVCDispatcherServlet</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <!-- 配置初始化参数，用于读取 SpringMVC 的配置文件 -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:SpringMVC.xml</param-value>
        </init-param>
        <!-- 配置 servlet 的对象的创建时间点：应用加载时创建。
        取值只能是非 0 正整数，表示启动顺序 -->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>SpringMVCDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/mvc
         http://www.springframework.org/schema/mvc/spring-mvc.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 配置创建 spring 容器要扫描的包 -->
    <context:component-scan base-package="com.itheima"></context:component-scan>

    <!-- 配置视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name="prefix" value="/WEB-INF/pages/"></property>
      <property name="suffix" value=".jsp"></property>
    </bean>
</beans>