通过Dom4j读写XML文档

[原]通过Dom4j读写XML文档

package com.yy.xml.dom4j;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class User {
private String xmlDocName = "users.xml";

public User() {
super();
// TODO Auto-generated constructor stub
}

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
User user = new User();
//user.newXML();
user.readXML();
}

public void newXML(){
/**
* users.xml
*/
Document doc = DocumentHelper.createDocument(); //users.xml

/**
* 根元素 users
*/
Element users = doc.addElement("users"

screen.width/2)this.style.width=screen.width/2;" border=0>; //根元素 users
doc.setRootElement(users);
users.addComment("the xml document about some login system information of users"

screen.width/2)this.style.width=screen.width/2;" border=0>;

/**
* 根元素 users 下的子元素 user
*/
Element user = users.addElement("user"

screen.width/2)this.style.width=screen.width/2;" border=0>; // 新增 users 的一个子元素 user
user.addAttribute("id","1"

screen.width/2)this.style.width=screen.width/2;" border=0>; //增加user的一个属性，并设置此属性值
Element username = user.addElement("username"

screen.width/2)this.style.width=screen.width/2;" border=0>; // 新增 user 元素的子元素 username
username.setText("yy"

screen.width/2)this.style.width=screen.width/2;" border=0>; //设置 username 的值
Element password = user.addElement("password"

screen.width/2)this.style.width=screen.width/2;" border=0>; // 新增 user 元素的子元素 password
password.setText("12345678"

screen.width/2)this.style.width=screen.width/2;" border=0>; //设置 password 的值

Element user2 = user.createCopy(); //通过对已有元素的拷贝，产生同一元素的不同实体
user2.attribute("id"

screen.width/2)this.style.width=screen.width/2;" border=0>.setValue("2"

screen.width/2)this.style.width=screen.width/2;" border=0>;
user2.element("username"

screen.width/2)this.style.width=screen.width/2;" border=0>.setText("liyun"

screen.width/2)this.style.width=screen.width/2;" border=0>;
user2.element("password"

screen.width/2)this.style.width=screen.width/2;" border=0>.setText("87654321"

screen.width/2)this.style.width=screen.width/2;" border=0>;
users.add(user2); //根元素增加已有的子元素

/**
* 通过 org.dom4j.io.OutputFormat 来设置XML文档输出格式
*/
OutputFormat format = OutputFormat.createPrettyPrint(); //设置XML文档输出格式
format.setEncoding("GB2312"

screen.width/2)this.style.width=screen.width/2;" border=0>; //设置XML文档的编码类型
format.setSuppressDeclaration(true);
format.setIndent(true); //设置是否缩进
format.setIndent(" "

screen.width/2)this.style.width=screen.width/2;" border=0>; //以空格方式实现缩进
format.setNewlines(true); //设置是否换行

/**
* 通过 org.dom4j.io.XMLWriter 创建XML文档（写）
*/
try {
XMLWriter xmlWriter = new XMLWriter(new FileOutputStream(new File(xmlDocName)),format);
xmlWriter.write(users);
xmlWriter.close();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

public void readXML(){
SAXReader saxReader = new SAXReader();
try {
/**
* 先通过 org.dom4j.io.SAXReader 读入整份XML文档
*/
Document usersXMLDoc = saxReader.read(new FileInputStream(new File(xmlDocName)));

/**
* 取得XML文档的各元素及其值
*/
Element users = usersXMLDoc.getRootElement(); //取得XML文档的根元素
Iterator users_subElements = users.elementIterator(); //以Iterator集合得到根元素下的所有子元素
//Iterator users_subElements = users.elementIterator("user"

screen.width/2)this.style.width=screen.width/2;" border=0>; //可以指定所要得到的子元素的名称
while(users_subElements.hasNext()){
Element user = (Element)users_subElements.next();
List user_subElements = user.elements(); //以List集合得到 user 下的所有子元素
//List user_subElements = user.elements("username"

screen.width/2)this.style.width=screen.width/2;" border=0>; //可以指定名称取得所要取的元素
for(int i=0;i<user_subElements.size();i++){
Element ele = (Element)user_subElements.get(i);
System.out.print(ele.getName()+" : "+ele.getText()+" "

screen.width/2)this.style.width=screen.width/2;" border=0>;
}
System.out.println();
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}