模拟jQueryajax服务器端与客户端通信的代码_jquery

package com.ljq.test;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLDecoder;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@SuppressWarnings("serial")
public class AjaxServer extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
try {
//设置页面utf-8编码
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
Integer total = (Integer) request.getSession().getAttribute("total");
int temp = 0;
if (total == null) {
temp = 1;
} else {
temp = total.intValue() + 1;
}
request.getSession().setAttribute("total", temp);
// 1.取参数
String param = request.getParameter("name");
String name = URLDecoder.decode(param, "UTF-8");
// 2、检查参数是否有效
if (param == null || param.length() == 0) {
out.println("用户名不能为空");
} else {
// 3、校验操作
if (name.equals("linjiqin")) {
// 4、返回结果数据
out.println("用户名[" + name + "]已经存在，请使用其他用户名, " + temp);
} else {
out.println("用户名[" + name + "]尚未存在，可以使用该用户名注册, " + temp);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

AjaxServer
com.ljq.test.AjaxServer


AjaxServer
/servlet/ajaxServer


index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>