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>