Android调用Servlet与MySQL交互

web.xml文件

<?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"
  metadata-complete="true">
  <display-name>testweb</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名称 -->
<servlet-name>Servlet_Sql</servlet-name>    
<!-- servlet指向的类文件 -->
<servlet-class>Servlet_Sql</servlet-class>   
</servlet>
<servlet-mapping>
<servlet-name>Servlet_Sql</servlet-name>
<!-- 这个是定义web访问时servlet的相对路径 -->
<url-pattern>/Servlet_Sql</url-pattern>           
</servlet-mapping>
</web-app>