Ajax经典入门案例详解（入门中的经典，经典中的入门，适合初学者）

package com.xushouwei.check; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class CheckUser extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); //为了方便起见，假设数据库中有这些学号,在实际应用中应该是从数据库中获取的 String[] xhs={"081110","081111","081112","081113"}; //取得用户填写的学号 String xh=request.getParameter("xh"); //设置响应内容 String responseContext="true"; for(int i=0;i<xhs.length;i++) { //如果有该学号，修改响应内容 if(xh.equals(xhs[i])) { responseContext="false"; } } //将处理结果返回给客户端 out.println(responseContext); out.flush(); out.close(); } }