Servlet配置中改变 <url-pattern> Tomcat报错

Web.xml文件如下：

<?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">
  <display-name>TradeServer</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>TestServlet</servlet-name>
    <servlet-class>com.wechat.TestServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>TestServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

将

<url-pattern>/</url-pattern>改成<url-pattern>/TestServlet</url-pattern>

就会出现错误

我想配置多个Servlet该怎么做？

你这个错，和配置文件没关系吧。不修改

<url-pattern>/</url-pattern>改成<url-pattern>/TestServlet</url-pattern>

还会报？

配置多个servlet：

 <servlet>
    <servlet-name>TestServletA</servlet-name>
    <servlet-class>com.wechat.TestServletA</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>TestServletA</servlet-name>
    <url-pattern>/TestServletA</url-pattern>
  </servlet-mapping>

     <servlet>
    <servlet-name>TestServletB</servlet-name>
    <servlet-class>com.wechat.TestServletB</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>TestServletB</servlet-name>
    <url-pattern>/TestServletB</url-pattern>
  </servlet-mapping>