java下拉链表

_wangtao 2011-12-13 06:52:10

java程序如何在下拉链表内获取数据库的某一列的值?比如年龄有20、22、19。

然后生成链表值，求源代码。望各位帮忙解答一下，初学！谢谢..

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li1037 2011-12-13

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好像是<select>
<option> <%=jsp%></option>

</select>

chabale 2011-12-13

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ajax省市联动的效果
代码：根据你的需求自己改改：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'province.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">

<script type="text/javascript">
function loadXMLDoc()
{
xmlhttp = null;
var country = document.getElementById("country");
country.length = 1;
country.selectedIndex = 0;
var province = document.getElementById("province");
if(province.value == ""){
return ;
}
var url="http://localhost:8080/Ajax_Province/GetProvince?&province="+encodeURIComponent(province.value);
if (window.XMLHttpRequest) {// code for Firefox, Mozilla, IE7, etc.
xmlhttp = new XMLHttpRequest();
} else if (window.ActiveXObject) {// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
if (xmlhttp != null) {
xmlhttp.onreadystatechange = state_Change;
xmlhttp.open("post", url, true);
xmlhttp.send(null);
} else {
alert("Your browser does not support XMLHTTP.");
}
}

function state_Change() {
var province = document.getElementById("province");
var country = document.getElementById("country");
if (xmlhttp.readyState == 4&&xmlhttp.status == 200) {// 4 = "loaded"
var serviceData = xmlhttp.responseText;
if(serviceData == null||serviceData == ""){
return;
}
var s = serviceData.split(",");
for(var i=0;i<s.length-1;i++){
country.options[i+1] = new Option(s[i],s[i]);
}
}
}

</script>
</head>

<body>
出生地:<select id="province" onchange="loadXMLDoc()">
<option value="">------请选择省-----</option>
<option value="江西省">江西省</option>
<option value="江苏省">江苏省</option>
<option value="浙江省">浙江省</option>
<option value="山东省">山东省</option>
<option value="辽宁省">辽宁省</option>
<option value="福建省">福建省</option>

</select>

<select id="country"><option value="">-----请选择市-----</option></select>
</body>
</html>
servlet：
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.neusoft.zjl.service.ProvinceService;

public class GetProvince extends HttpServlet {

/**
* Constructor of the object.
*/
public GetProvince() {
super();
}

/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

doPost(request, response);
}

/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
List list = null;
ProvinceService provinceService = new ProvinceService();
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
String strprovince = request.getParameter("province");
if(strprovince == null||"".equals(strprovince)){
return ;
}
String province = new String(strprovince.getBytes("ISO-8859-1"),"UTF-8");
list = provinceService.getCountry(province);//这个是查询数据库的你可以换你的对数据库的操作
if(list ==null){
return;
}
StringBuffer sb = new StringBuffer();
for(int i=0;i<list.size();i++){
String s = (String)list.get(i);
sb.append(s+",");
}
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.print(sb);
out.flush();
out.close();
}

/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}

}