笔者最近学习一些spring mvc，在复制别人代码的时候报这个错。报错来源web.xml，原因是不符合xsd对xml的约束
源文件
<?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">
<servlet>
<!--名称 -->
<servlet-name>springmvc</servlet-name>
<!-- Servlet类 -->
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 启动顺序，数字越小，启动越早 -->
<load-on-startup>1</load-on-startup>
<init-param>
<!--SpringMVC配置参数文件的位置 -->
<param-name>contextConfigLocation</param-name>
<!--默认名称为ServletName-servlet.xml -->
<param-value>classpath*:springmvc-servlet.xml</param-value>
</init-param>
</servlet>
<!--所有请求都会被springmvc拦截 -->
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
解决方法:
调整<load-on-startup>节点的顺序，放到</servlet>之前，修改后的web.xml如下
<?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">
<servlet>
<!--名称 -->
<servlet-name>springmvc</servlet-name>
<!-- Servlet类 -->
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<!--SpringMVC配置参数文件的位置 -->
<param-name>contextConfigLocation</param-name>
<!--默认名称为ServletName-servlet.xml -->
<param-value>classpath*:springmvc-servlet.xml</param-value>
</init-param>
<!-- 启动顺序，数字越小，启动越早 -->
<load-on-startup>1</load-on-startup>
</servlet>
<!--所有请求都会被springmvc拦截 -->
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
