二级联动菜单代码(AJAX+JAVA)珍藏

[java]

pageEncoding="UTF-8"%>

二级菜单联动演示

var req;

window.οnlοad=function(){//版面加载时的函数

}

function Change_Select(){//当第一个下拉框的选项发生改换时调用该函数

var zhi = document.getElementByIdx_x('hero').value;

var url = "servlet/select?id="+ escape(zhi);

if(window.XMLHttpRequest){

req = new XMLHttpRequest();

}else if(window.ActiveXObject){

req = new ActiveXObject("Microsoft.XMLHTTP");

}

if(req){

req.open("GET",url,true);

req.onreadystatechange = callback; //指定回调函数为callback

req.send(null);

}

}

function callback(){

if(req.readyState ==4){

if(req.status ==200){

parseMessage();//解析XML文档

}else{

alert("Not able to retrieve description" + req.statusText);

}

}

}

function parseMessage(){

var xmlDoc = req.responseXML.documentElement;//获得归来的XML文档

var xSel = xmlDoc.getElementsByTagName_r('select');

//获得XML文档中的所有符号

var select_root = document.getElementByIdx_x('skill');

//获得网页中的第二个下拉框

select_root.options.length=0;

//每次获得新的数据的时候先把每二个下拉框架的长度清0

for(var i=0;i

var xValue = xSel[i].childNodes[0].firstChild.nodeValue;

//获得每个符号中的第一个符号的值,也即便符号的值

var xText = xSel[i].childNodes[1].firstChild.nodeValue;

//获得每个符号中的第二个符号的值,也即便符号的值

var option = new Option(xText, xValue);

//依据每组value和text符号的值创立一个option对象

try{

select_root.add(option);//将option对象增加到第二个下拉框中

}catch(e){

}

}

}

[java]

package onlinetest.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class SelectServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse

response)

throws ServletException, IOException {

response.setContentType("text/xml");

response.setHeader("Cache-Control", "no-cache");

String targetId = request.getParameter("id").toString();

// 获得哀求中参数为idio.iochirly.com的值

String xml_start = "";

String xml_end = "";

String xml = "";

if (targetId.equalsIgnoreCase("0")) {

xml =

"0Unbounded";

} else if (targetId.equalsIgnoreCase("1")) {

xml =

"1Mana

Burn";

xml +=

"2Death

Coil";

xml +=

"3Unhkly

Aura";

xml +=

"4Unholy

Fire";

} else if (targetId.equalsIgnoreCase("2")) {

xml =

"1Corpexplode";

xml +=

"2Raise

Dead";

xml +=

"3Brilliance

Aura";

xml +=

"4Aim

Aura";

} else {// 万一是3,则归来下面的字符

xml =

"1Rain

of

Chaos";

xml +=

"2Finger

of

Death";

xml +=

"3Bash";

xml +=

"4Summon

Doom";

}

String last_xml = xml_start + xml + xml_end;

response.getWriter().write(last_xml);

}

public void doPost(HttpServletRequest request, HttpServletResponse

response)

throws ServletException, IOException {

doGet(request, response);// 对于post的哀求措施和get哀求措施一样处理

}

}在这篇文章中，我列出了11个 Java编程中常见的讹谬。