Ajax实例
程序员文章站
2022-03-09 14:51:49
...
1. ajax验证用户名
2. ajax二级联动
2. ajax二级联动
GetAjaxInfoServlet.java
package com.andrew.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);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, 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);
}
}
private void checkUserName(HttpServletRequest request, HttpServletResponse response)
throws ServletException, 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();
}
private void ejld(HttpServletRequest request, HttpServletResponse response)
throws ServletException, 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();
}
}
web.xml
<servlet>
<servlet-name>getAjaxInfoServlet</servlet-name>
<servlet-class>com.andrew.web.GetAjaxInfoServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>getAjaxInfoServlet</servlet-name>
<url-pattern>/getAjaxInfo</url-pattern>
</servlet-mapping>
checkUserName.jsp
<%@ 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>
ejld.jsp
<%@ 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>
http://localhost:8080/HeadFirstAjaxJsonChap04/ejld.jsp
http://localhost:8080/HeadFirstAjaxJsonChap04/checkUserName.jsp
该用户名可用