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xmlhttp初体验

[ 来源:www.it55.com | 作者: | 时间:2007-07-14 | 收藏 | 推荐 ] 【大中小】

太久没有研究过新技术了.作为一个程序员,我觉得很惭愧.老早就想看看关于xmlhttp的技术了,今天总算有点时间,做个一个最初的体验.马上就爱上了它.
如果你想不刷新页面就可以与后台进行数据交互,或者在异构系统之间交换数据,xmlhttp技术是个不错的选择.
下面是我的一个很小的体验程序,参考了csdn网友s_phoenix()给人的回贴.
首先建一个tomcat的web项目.

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1:-------index.htm文件内容如下: 45398 www.it55.com it55学习IT知识，享受IT生活 4dfkjn

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
</HEAD>

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<BODY>
<script language="javascript">
var XML="<root><test>李春雷</test><test>毛泽东</test></root>"
var xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
var xmlDoc=new ActiveXObject("Msxml2.DOMDocument");
function test(){//客户端xml的解析
xmlDoc.loadXML(XML);
if(xmlDoc.parseError.line>0){
throw xmlDoc.parseError.reason;
}
var nodes= xmlDoc.selectNodes("/root/test");
for(var i=0;i<nodes.length;i++){
alert(nodes.item(i).text);
}
}

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function action(){//客户端和服务端的通讯
xmlHttp.open("post","http://127.0.0.1:8888/xmlhttpTest/UrlTestServlet",false);
xmlHttp.setRequestHeader("context-type","text/xml;charset=utf-8");
xmlHttp.send(XML);
var showstr=xmlHttp.responseText;
alert(showstr);
}

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</script>
<button onclick="test();">查看将要传输的xml</button><br/>
<button onclick="action();">朝服务器传送xml，并接收服务器回应</button>
</BODY>
</HTML>

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2:------------写一个servlet: UrlTestServlet.java

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/*
* 创建日期 2005-4-7
*
* TODO 要更改此生成的文件的模板，请转至
* 窗口－首选项－ Java －代码样式－代码模板
*/
package com.lcl; vd;k;l www.it55.com rdfg

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import org.dom4j.io.*;
import org.dom4j.*;

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/**
* @author lcl
*
* TODO 要更改此生成的类型注释的模板，请转至
* 窗口－首选项－ Java －代码样式－代码模板
*/

45398 www.it55.com it55学习IT知识，享受IT生活 4dfkjn

public class UrlTestServlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/xml;charset=utf-8";
//Initialize global variables
public void init() throws ServletException {
}
//Process the HTTP Get request

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public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType(CONTENT_TYPE);
request.setCharacterEncoding("utf-8");
PrintWriter out = response.getWriter();
InputStream is=request.getInputStream(); IT资讯之家 www.it55.com

SAXReader reader=new SAXReader();
Document doc=null;
try{
doc=reader.read(is);
} catch(Exception ex){
System.out.println(ex);
}
String[] s= getElementTexts(doc,"test");
out.println("数据交换成功:返回" + s[0] + s[1]);
} vd;k;l www.it55.com rdfg

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
} IT资讯之家 www.it55.com

private String getElementText(Document doc,String name){
return doc.getRootElement().element(name).getText();
}

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private String[] getElementTexts(Document doc,String name){
List l=doc.getRootElement().elements(name);
Iterator it=l.iterator();
List l1=new LinkedList();
while(it.hasNext()){
Element e=(Element)it.next();
l1.add(e.getText());
}
return (String[])l1.toArray(new String[]{});
}

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//Clean up resources
public void destroy() {
}
}

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3:--------web.xml更改如下(加servlet映射):

http://www.it55.com/

<?xml version="1.0" encoding="ISO-8859-1"?> www.it55.com在线教程

<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd"> www.it55.com在线教程

<web-app>
<display-name>Welcome to Tomcat</display-name>
<description>
Welcome to Tomcat
</description> www.it55.com

45398 www.it55.com it55学习IT知识，享受IT生活 4dfkjn

    <servlet>
        <servlet-name>UrlTestServlet</servlet-name>
        <servlet-class>com.lcl.UrlTestServlet</servlet-class>
    </servlet>

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    <servlet-mapping>
        <servlet-name>UrlTestServlet</servlet-name>
        <url-pattern>/UrlTestServlet</url-pattern>
    </servlet-mapping> www.it55.com

<welcome-file-list>
<welcome-file>index.htm</welcome-file>

（编辑：IT资讯之家 www.it55.com）