日期:2014-05-16  浏览次数:20403 次

jquery+ json--省市二级联动
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
        <title>Untitled Document</title>
        <script type="text/javascript" src="jquery-1.6.1.js">
        </script>
        <script language="JavaScript">
            $(function(){
                $("#s1").change(function(){
                    var obj = $("#s1");//取得下拉列表框对象 s1
                    //					alert(obj);
                    
                    //2. 取得Options 的长度 
                    len = $('#s1 option').length
                    //					alert(len);
                    
             
                    //3. 取得所选值  注意,如果option没有value属性,则默认取的是text属性值
                    obj_value = $('#s1').val();
                    
                    //					alert("$('#s1').val()"+obj_value);
                    //					alert($('#s2').val());
                    
                    //4. 取得所选中的option
                    var opt = $("#s1 option:selected");
                    ;
                    //					alert("opt:"+opt);
                    //					alert(opt.text());
                    //					alert(opt.val());
                    
                    
                    var url = "../jsonServlet";
                    var param = "name=" + $("#s1 option:selected").text();
                    alert(param);
                    $.ajax({
                        type: "POST",
                        url: url,
                        data: param,
                        cache: false,
                        dataType: "json",
                        success: function(msg){
                            //jsonServlet 返回的是一个JSONArray
                            alert(msg);
                            
                            //清空下拉列表框
                            $("#s2").empty();
                            
                            //遍历数组
                       
                            $.each(msg, function(i, text){
                                alert("数组的索引:" + i);
                                alert("数组的值:" + text);
                                //增加option
							    $("#s2").append("<option>" + text + "</option>")
                                
                                
                            });
                        }
                    })
                    
                });
            })
            
            
            
        </script>
    </head>
    <body>
        <p align="center">
         jquery+ json--省市二级联动
        </p>
        <table align="center">
            <tr>
                <td>
                    省份
                </td>
                <td>
                    <select id="s1">
                        <option value="1">省份</option>
                        <option value="2">湖北</option>
                        <option value="3">浙江</option>
                    </select>
                </td>
                <td>
                    <select id="s2">
                        <option>城市</option>
                    </select>
                </td>
            </tr>
        </table>
    </body>
</html>

后台:JsonServlet.java

package com.wepull.servlet;

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;

public class JsonServlet extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletExcep