Ajax用例

package com.servlets; 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 checkServlet extends HttpServlet { /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to * post. * * @param request * the request send by the client to the server * @param response * the response send by the server to the client * @throws ServletException * if an error occurred * @throws IOException * if an error occurred */ public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); // 从数据库中读取名字然后判断是否存在 // 这里简写成规定的几个名字 response.addHeader("pragma", "no-cache"); response.addHeader("cache-control", "no-cache"); response.addHeader("expires", "0"); String name = request.getParameter("name"); if (name.equals("zzx") || name.equals("aaa")) { out.print("true"); } else { out.print("false"); } } }