共用的Servlet
GetAjaxInfoServlet.java
package com.ruanku.web;
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;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
public class GetAjaxInfoServlet extends HttpServlet{
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException {
this.doPost(request,response);
}
/**
* 判断使用哪种Servlet
*/
@Override
protected void doPost(HttpServletRequest request,IOException {
response.setContentType("text/html;charset=utf-8");
String action=request.getParameter("action");
if("checkUserName".equals(action)){
this.checkUserName(request,response);
}else if("ejld".equals(action)){
this.ejld(request,response);
}
}
/**
* 验证用户名
*/
private void checkUserName(HttpServletRequest request,IOException {
PrintWriter out=response.getWriter();
String userName=request.getParameter("userName");
JSONObject resultJson=new JSONObject();
if("jack".equals(userName)){
resultJson.put("exist",true);
}else{
resultJson.put("exist",false);
}
out.println(resultJson);
out.flush();
out.close();
}
/*
* 二级联动
*/
private void ejld(HttpServletRequest request,IOException {
PrintWriter out=response.getWriter();
String shengId=request.getParameter("shengId");
JSONObject resultJson=new JSONObject();
JSONArray jsonArray=new JSONArray();
JSONObject temp=null;
switch(Integer.parseInt(shengId)){
case 1:{
temp=new JSONObject();temp.put("id",1);temp.put("text","南京");jsonArray.add(temp);
temp=new JSONObject();temp.put("id",2);temp.put("text","南通");jsonArray.add(temp);
temp=new JSONObject();temp.put("id",3);temp.put("text","泰兴");jsonArray.add(temp);
break;
}
case 2:{
temp=new JSONObject();temp.put("id",4);temp.put("text","济南");jsonArray.add(temp);
temp=new JSONObject();temp.put("id",5);temp.put("text","烟台");jsonArray.add(temp);
temp=new JSONObject();temp.put("id",6);temp.put("text","蓬莱");jsonArray.add(temp);
break;
}
case 3:{
temp=new JSONObject();temp.put("id",7);temp.put("text","杭州");jsonArray.add(temp);
temp=new JSONObject();temp.put("id",8);temp.put("text","宁波");jsonArray.add(temp);
temp=new JSONObject();temp.put("id",9);temp.put("text","温州");jsonArray.add(temp);
break;
}
}
resultJson.put("rows",jsonArray);
out.println(resultJson);
out.flush();
out.close();
}
}
配置的xml信息
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>AjaxJsonchap01</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-name>getAjaxInfoServlet</servlet-name>
<servlet-class>com.ruanku.web.GetAjaxInfoServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>getAjaxInfoServlet</servlet-name>
<url-pattern>/getAjaxInfo</url-pattern>
</servlet-mapping>
</web-app>
<1>判断登录名是否相同
checkUserName.jsp
@H_404_14@<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <Meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <script type="text/javascript"> function checkUserName(){ var userName=document.getElementById("userName").value; var xmlHttp; if(window.XMLHttpRequest){ xmlHttp=new XMLHttpRequest(); }else{ xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlHttp.onreadystatechange=function(){ if(xmlHttp.readyState==4 && xmlHttp.status==200){ alert(xmlHttp.responseText); var dataObj=eval("("+xmlHttp.responseText+")"); if(dataObj.exist){ document.getElementById("tip").innerHTML="<img src='no.png'/>该用户名已经存在"; }else{ document.getElementById("tip").innerHTML="<img src='ok.png'/>该用户名可用"; } } }; xmlHttp.open("get","getAjaxInfo?action=checkUserName&userName="+userName,true); xmlHttp.send(); } </script> </head> <body> <table> <tr> <th>用户注册</th> </tr> <tr> <td>用户名：</td> <td><input type="text" id="userName" name="userName" onblur="checkUserName()"/><font id="tip"></font></td> </tr> <tr> <td>密码：</td> <td><input type="text" id="password" name="password"/></td> </tr> <tr> <td>确认密码：</td> <td><input type="text" id="password2" name="password2"/></td> </tr> <tr> <td><input type="submit" value="注册"/></td> <td><input type="button" value="重置"/></td> </tr> </table> </body> </html>二级联动
ejld.jsp
@H_404_14@<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <Meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <script type="text/javascript"> function loadInfo(){ var shengId=document.getElementById("sheng").value; shi.options.length=0; // 删除所有市下拉框的选项 var xmlHttp; if(window.XMLHttpRequest){ xmlHttp=new XMLHttpRequest(); }else{ xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlHttp.onreadystatechange=function(){ if(xmlHttp.readyState==4 && xmlHttp.status==200){ alert(xmlHttp.responseText); var dataObj=eval("("+xmlHttp.responseText+")"); for(var i=0;i<dataObj.rows.length;i++){ var o=dataObj.rows[i]; shi.options.add(new Option(o.text,o.id)); } } }; xmlHttp.open("get","getAjaxInfo?action=ejld&shengId="+shengId,true); xmlHttp.send(); } </script> </head> <body> 省： <select id="sheng" onchange="loadInfo()"> <option value="1">江苏省</option> <option value="2">山东省</option> <option value="3">浙江省</option> </select> 市 <select id="shi"> </select> </body> </html>