java读取和写XML文档

最新推荐文章于 2025-07-14 13:29:19 发布

lanzhengwu

最新推荐文章于 2025-07-14 13:29:19 发布

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CC 4.0 BY-SA版权

文章标签： xml java import 文档 dwr null

本文链接：https://blog.youkuaiyun.com/lanzhengwu/article/details/1899342

本文介绍了一个简易聊天室的实现方案，利用DWR和Prototype技术，并采用XML存储数据，提供了完整的JavaBean和Servlet代码示例。

上次因为觉的DWR好用，就写了个简易的聊天室，分别用DWR和prototype
来实现，因为为了方便移植，数据存放在XML文档中，读取和写入XML文档
的代码见下面........................

java bean:

package com.lan.Forum;

public class Forumbean {

private String username="";

private String content="";

private String datetime=null;

public String getContent() {

return content;

}

public void setContent(String content) {

this.content = content;

}

public String getDatetime() {

return datetime;

}

public void setDatetime(String datetime) {

this.datetime = datetime;

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

package com.lan.Forum;

import java.io.File;

import java.io.FileInputStream;

import java.text.DateFormat;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Date;

import javax.servlet.Servlet;

import javax.servlet.ServletConfig;

import javax.servlet.ServletContext;

import javax.servlet.ServletRequest;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.jsp.PageContext;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.NodeList;

public class Forum {

DocumentBuilderFactory dbf=null;

DocumentBuilder db=null;

Document doc=null;

String file="d://Forum.xml";//XML文档的位置

public Forum(){

dbf=DocumentBuilderFactory.newInstance();

try {

db=dbf.newDocumentBuilder();

doc=db.parse(new FileInputStream(file));

} catch (Exception e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

public void writexml(String username,String content){//写进XML

Element forums;

Element forum;

Element name;

Element con;

Element date;

forums=(Element) doc.getElementsByTagName("Forums").item(0);//获得根接点

forum=doc.createElement("Forum");//创建一个子接点元素

name=doc.createElement("UserName");//创建一个元素

name.appendChild(doc.createTextNode(username));//给元素赋值

con=doc.createElement("Content");

con.appendChild(doc.createTextNode(content));

date=doc.createElement("DateTime");

date.appendChild(doc.createTextNode(new Date().toString()));

forum.appendChild(name);//把元素附加给子接点

forum.appendChild(con);

forum.appendChild(date);

forums.appendChild(forum);//把字节点附加给根接点

TransformerFactory tf=TransformerFactory.newInstance();

try {

Transformer trans=tf.newTransformer();

trans.transform(new DOMSource(doc),new StreamResult(new File(file)));

//经过转换工厂类来实现流的转换...

} catch (Exception e) {

// TODO 自动生成 catch 块

e.printStackTrace();

}

public ArrayList<Forumbean> getxml(){//从XML文档读值

ArrayList<Forumbean> list=new ArrayList<Forumbean>();

NodeList n1=doc.getElementsByTagName("Forum");//获得字节点

for(int i=0;i<n1.getLength();i++){

Element n=(Element) n1.item(i);

NodeList u=n.getElementsByTagName("UserName");//获得元素集合

NodeList c=n.getElementsByTagName("Content");

NodeList d=n.getElementsByTagName("DateTime");

String username=u.item(0).getFirstChild().getNodeValue();

String content=c.item(0).getFirstChild().getNodeValue();

String datetime=d.item(0).getFirstChild().getNodeValue();

Forumbean bean=new Forumbean();

bean.setUsername(username);

bean.setContent(content);

bean.setDatetime(datetime);

list.add(bean);

}

return list;

}

XML文档

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<Forum>

<UserName>lanzhengwu</UserName>

<Content>Hello world</Content>

</Forum>

</Forums>