一、在數(shù)據(jù)庫數(shù)據(jù)庫中建立三個(gè)表
1.city
字段：
districtname，locationid，districtid
2.province
字段：
locationid，locationname
3.village
字段：
villageid,villagename,districtid
二、代碼如下：
<%@ page language="java" contentType="text/html; charset=gb2312"
??? pageEncoding="gb2312"%>
<%@ page import="java.sql.* "%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>jsp實(shí)現(xiàn)三級(jí)聯(lián)動(dòng)的下拉列表框效果</title>
<%
?? Connection conn=null;
?? Statement stmt=null;
?? ResultSet rs=null,rs1=null,rs2=null;
?? String sql;
?? int count;
?? int count2;
?? String drivername="com.microsoft.jdbc.sqlserver.SQLServerDriver";
?? String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=SJLD";
?? try{
??? Class.forName(drivername);
??? conn=DriverManager.getConnection(url,"sa","");
??? stmt=conn.createStatement（）;
??? sql="select * from city order by locationid asc";
??? rs=stmt.executeQuery(sql);
?? }catch(SQLException e){
??? System.out.println(e.getMessage());
?? }
??
%>
<script language="javascript">
var onecount;
onecount=0;
subcat=new Array();
<%
count=0;
while(rs.next()){
?%>
?subcat[<%=count%>]=new Array("<%=rs.getString("districtname")%>","<%=rs.getInt("locationid")%>","<%=rs.getInt("districtid")%>");
?<%
?count = count + 1 ;
}
rs.close();
rs=null;
%>
onecount=<%=count%>;
function changelocation(locationid){
document.myform.smalllocation.length=0;
var locationid=locationid;
var i;
document.myform.smalllocation.options[0]=new Option('==所選城市的地區(qū)==','');
for(i=0;i<onecount;i++){
if (subcat[i][1] == locationid)
{
document.myform.smalllocation.options[document.myform.smalllocation.length] = new Option(subcat[i][0], subcat[i][2]);
}
}
??
}
</script>
<%
?sql="select * from village order by districtid asc";
?rs2=stmt.executeQuery(sql);
%>
<script language="javascript">
var onecount2;
onecount2=0;
subcat2=new Array();
<%
count2=0;
while(rs2.next()){
?%>
?subcat2[<%=count2%>]=new Array("<%=rs2.getString("villagename")%>","<%=rs2.getInt("districtid")%>","<%=rs2.getInt("villageid")%>");
?<%
?count2 = count2 + 1 ;
}
rs2.close();
rs2=null;
%>
onecount2=<%=count2%>;
function changelocation2(districtid)
{
document.myform.village.length = 0;
var districtid=districtid;
var j;
document.myform.village.options[0] = new Option('==所選地區(qū)的縣區(qū)==','');
for (j=0;j < onecount2; j++)
{
? if (subcat2[j][1] == districtid)
?{
? document.myform.village.options[document.myform.village.length] = new Option(subcat2[j][0], subcat2[j][2]);
? }
}
}
</script>
</head>
<body>
<form name="myform" method="post">
分類：<select name="biglocation" onChange="changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value)" size="1">
<option selected>請(qǐng)選擇你所在的省份</option>
<%
? sql ="select * from province order by locationname asc";
?rs1 = stmt.executeQuery(sql);
?while(rs1.next()){
?%>
?<option value="<%=rs1.getInt("locationid")%>"><%=rs1.getString("locationname")%></option>
?<% }
?
?
?rs1.close();
?rs1 = null;
?conn.close();
?conn =null;
%>
</select><select name="smalllocation" onChange="changelocation2(document.myform.smalllocation.options[document.myform.smalllocation.selectedIndex].value)">
<option selected value="">==所有地區(qū)==</option>
</select><select name="village" size="1">
<option selected>==所有縣區(qū)==</option>
</select>
</form>
</body>
</html>