純JSP+DWR實(shí)現(xiàn)三級(jí)聯(lián)動(dòng)下拉選擇菜單實(shí)現(xiàn)技巧_JSP教程

推薦：JSP中實(shí)現(xiàn)系統(tǒng)登錄后的退出原理及代碼
首先要在你登錄的頁(yè)面的某個(gè)地方，寫上一個(gè)超級(jí)鏈接,讓它鏈接到exit.jsp頁(yè)面去，然后新建一個(gè)exit.jsp頁(yè)面在其body中寫上如下代碼,即可以實(shí)現(xiàn)登錄后的退出,感興趣的朋友可以了解下啊，或許對(duì)你有所幫助

網(wǎng)上看到一些例子，對(duì)于一個(gè)簡(jiǎn)單的三級(jí)聯(lián)動(dòng)，都加上什么Struts, Hibernate諸如此類的框架。這個(gè)Ajax聯(lián)動(dòng)殊不知和這些框架有什么關(guān)系，一個(gè)小Demo干嘛整得那么大。

今天我做了一個(gè)dwr+jsp做的例子。
web.xml:

復(fù)制代碼代碼如下:hl5o.cn

 
<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> 
<servlet> 
<servlet-name>dwr-invoker</servlet-name> 
<servlet-class> 
org.directwebremoting.servlet.DwrServlet 
</servlet-class> 
<init-param> 
<param-name>debug</param-name> 
<param-value>true</param-value> 
</init-param> 
</servlet> 
<servlet> 
<servlet-name>SelectServlet</servlet-name> 
<servlet-class>com.action.SelectServlet</servlet-class> 
</servlet> 
<servlet-mapping> 
<servlet-name>dwr-invoker</servlet-name> 
<url-pattern>/dwr/*</url-pattern> 
</servlet-mapping> 
<servlet-mapping> 
<servlet-name>SelectServlet</servlet-name> 
<url-pattern>/select</url-pattern> 
</servlet-mapping> 
<welcome-file-list> 
<welcome-file>index.jsp</welcome-file> 
</welcome-file-list> 
</web-app> 

dwr.xml:

復(fù)制代碼代碼如下:hl5o.cn

 
<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 
2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd"> 
<dwr> 
<!-- 沒有它DWR什么也做不了 --> 
<allow> 
<create creator="new" javascript="menu"> 
<param name="class" value="com.dao.CountryDAO" /> 
</create> 
<!-- 要轉(zhuǎn)換的Bean --> 
<convert converter="bean" match="com.vo.Country" /> 
<convert converter="bean" match="com.vo.Province" /> 
<convert converter="bean" match="com.vo.City" /> 
</allow> 
</dwr> 

test.jsp:

復(fù)制代碼代碼如下:hl5o.cn

<%@ page language="java" import="java.util.*,com.vo.*"
pageEncoding="GBK"%>
<%@ taglib uri="http://java.sun.com/jstl/core" <html>
<head>
<title>DWR三級(jí)聯(lián)動(dòng)</title>
<script type='text/javascript'
src='/mutiplyMenu/dwr/interface/menu.js'></script>
<script type='text/javascript' src='/mutiplyMenu/dwr/engine.js'></script>
<script type='text/javascript' src='/mutiplyMenu/dwr/util.js'></script>
</head>
<body>
<script type="text/javascript">
//根據(jù)國(guó)家id查詢所屬省或州
function queryProvince()
{
var countryId = $("country").value;
//默認(rèn)為不選擇
if(countryId == 0)
{
${"province"}.options.length=0;
${"city"}.options.length=0;
}
else
{
menu.queryProvinceById(countryId,provinceCallback);
}
}
//根據(jù)國(guó)家id查詢所屬省或州的回調(diào)函數(shù)
function provinceCallback(provinces)
{
${"province"}.options.length=0;
//每次獲得新的數(shù)據(jù)的時(shí)候先把每二個(gè)下拉框架的長(zhǎng)度清0
for(var i=0;i< provinces.length;i ++){
var value = provinces[i].id;
var text = provinces[i].provinceName;
var option = new Option(text, value);
//根據(jù)每組value和text標(biāo)記的值創(chuàng)建一個(gè)option對(duì)象
try{
$("province").add(option);//將option對(duì)象添加到第二個(gè)下拉框中
}catch(e){
}
}
//同時(shí)關(guān)聯(lián)第三級(jí)
var provinceId = ${"province"}.value;
menu.queryCityById(provinceId,cityCallback);
}
//查詢所屬城市
function queryCity()
{
var provinceId = $("province").value;
menu.queryCityById(provinceId,cityCallback);
}
//查詢所屬城市回調(diào)函數(shù)
function cityCallback(citys)
{
//每次獲得新的數(shù)據(jù)的時(shí)候先把每三個(gè)下拉框架的長(zhǎng)度清0
${"city"}.options.length=0;
for(var i=0;i< citys.length;i ++){
var value = citys[i].id;
var text = citys[i].cityName;
var option = new Option(text, value);
//根據(jù)每組value和text標(biāo)記的值創(chuàng)建一個(gè)option對(duì)象
try{
$("city").add(option);//將option對(duì)象添加到第三個(gè)下拉框中
}catch(e){
}
}
}
function change1()
{
queryProvince();
}
function change2()
{
queryCity();
}
</script>
<div align="center">
<h3>
<br>
</h3>
<h3>
DWR三級(jí)聯(lián)動(dòng)演示
</h3>

<select id="country" onchange="change1();">
<option selected="selected" value="0">
請(qǐng)選擇
</option>
<%
@SuppressWarnings("unchecked")
List list = (List) request.getAttribute("countrys");
for (int i = 0; i < list.size(); i++)
{
Country temp = (Country) list.get(i);
%>
<option value="<%=temp.getId()%>"><%=temp.getCountryName()%></option>
<%
}
%>
</select>
<select id="province" onchange="change2();">
</select>
<select id="city">
</select>
</div>
</body>
</html>

servlet,dao就不帖了，想了解的可以去下載源碼

分享：jsp+ajax實(shí)現(xiàn)無(wú)刷新(鼠標(biāo)離開文本框即驗(yàn)證用戶名)實(shí)現(xiàn)思路
jsp+ajax實(shí)現(xiàn)無(wú)刷新,鼠標(biāo)離開文本框即驗(yàn)證用戶名,很方便的功能，感興趣的朋友可以了解下，或許對(duì)你學(xué)習(xí)ajax無(wú)刷新有所幫助