Jdom操作、创建和解析XML

需要导入Jdom的一个jar包；

1、Jdom创建XML

package com.shengsiyuan.jdom;

import java.io.FileWriter;

import org.jdom.Attribute;
import org.jdom.Comment;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

public class JDomTest1
{
public static void main(String[] args) throws Exception
{
//创建文档
Document document = new Document();
//创建文档根元素
Element root = new Element("root");
//向文档呢添加根元素
document.addContent(root);
//添加注释
Comment comment = new Comment("This is my comments");
//在根元素下添加注释
root.addContent(comment);
//创建一个元素
Element e = new Element("hello");
//给元素添加属性的第一种方式,它有返回值，返回一个Element对象
e.setAttribute("sohu", "www.sohu.com");
//给根元素添加属性
root.addContent(e);

Element e2 = new Element("world");
//创建元素属性的第二种方式
Attribute attr = new Attribute("test", "hehe");
//给元素添加属性
e2.setAttribute(attr);
//将元素添加到根元素下
e.addContent(e2);
//添加元素属性和文本内容，属于方法链的编程风格
e2.addContent(new Element("aaa").setAttribute("a", "b")
.setAttribute("x", "y").setAttribute("gg", "hh").setText("text content"));

//设置其格式,一般还有一个没有缩进与空格的格式getRawFormat，主要用于XML的网络传输，因为它没有空格，减少网络传输的数据量。
Format format = Format.getPrettyFormat();

//设置元素前面空格
format.setIndent(" ");
//设置编码方式
//format.setEncoding("gbk");
//将XML文档输出
XMLOutputter out = new XMLOutputter(format);
out.output(document, new FileWriter("jdom.xml"));

}
}

2、Jdom解析XML

package com.shengsiyuan.jdom;

import java.io.File;
import java.io.FileOutputStream;
import java.util.List;

import org.jdom.Attribute;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

public class JDomTest2
{
public static void main(String[] args) throws Exception
{
//JDOM从XML中解析
SAXBuilder builder = new SAXBuilder();
//获得XML文档对象
Document doc = builder.build(new File("jdom.xml"));
//得到文档根元素
Element element = doc.getRootElement();

System.out.println(element.getName());
//得到根元素下的hello元素
Element hello = element.getChild("hello");

System.out.println(hello.getText());
//得到hello子元素下的属性
List list = hello.getAttributes();

//得到hello元素下属性的名字和值
for(int i = 0 ;i < list.size(); i++)
{
Attribute attr = (Attribute)list.get(i);

String attrName = attr.getName();
String attrValue = attr.getValue();

System.out.println(attrName + "=" + attrValue);
}
//删除hello下的world子元素
hello.removeChild("world");

//将文档保存到另一个文件
XMLOutputter out = new XMLOutputter(Format.getPrettyFormat().setIndent(" "));

out.output(doc, new FileOutputStream("jdom2.xml"));

}
}

3、综合实例

package cn.com.xmltest;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

public class XMLTest
{
public static void main(String[] args)
{
modifyXML();
}

public static void createXML()
{
Element root = new Element("学生信息");
Element stu1 = new Element("学生");
Element stu2 = new Element("学生");
Element name1 = new Element("姓名");
Element sex1 = new Element("性别");
Element age1 = new Element("年龄");
Element name2 = new Element("姓名");
Element sex2 = new Element("性别");
Element age2 = new Element("年龄");

name1.setText("小明");
sex1.setText("男");
age1.setText("19");

name2.setText("小花");
sex2.setText("女");
age2.setText("20");

root.addContent(stu1);
root.addContent(stu2);
stu1.addContent(name1);
stu1.addContent(sex1);
stu1.addContent(age1);
stu2.addContent(name2);
stu2.addContent(sex2);
stu2.addContent(age2);

Document doc = new Document(root);
Format f = Format.getPrettyFormat();
f.setEncoding("gb2312");
XMLOutputter out = new XMLOutputter(f);

try
{
out.output(doc, new FileOutputStream(new File("c:/myxml.xml")));
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}

}

public static void searchXML()
{
SAXBuilder build = new SAXBuilder();
try
{
Document doc = build.build("c:/myxml.xml");
Element e = doc.getRootElement();

List<Element> list = e.getChildren();
for (Element ele : list)
{
System.out.println(ele.getChild("姓名").getName() + ":"
+ ele.getChild("姓名").getText());
System.out.println(ele.getChild("性别").getName() + ":"
+ ele.getChild("性别").getText());
System.out.println(ele.getChild("年龄").getName() + ":"
+ ele.getChild("年龄").getText());
}
}
catch (JDOMException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
}

public static void addElement()
{
SAXBuilder build=new SAXBuilder();
try
{
Document doc=build.build("c:/myxml.xml");
Element root=doc.getRootElement();
Element stu=root.getChild("学生");
Element cla=new Element("班级");
cla.addContent("2班");
stu.addContent(cla);
XMLOutputter out=new XMLOutputter();
out.output(doc,new FileOutputStream(new File("c:/myxml.xml")));


}
catch (JDOMException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}

}

public static void modifyXML()
{
SAXBuilder build=new SAXBuilder();
Document doc;
try
{
doc = build.build("c:/myxml.xml");
Element root=doc.getRootElement();
Element stu=root.getChild("学生");
Element age=stu.getChild("年龄2");
age.setName("年龄");
age.setText("10");
List<Element> list=stu.getChildren();

for(Element e:list)
{
if(e.getName().equals(""));
//{
////Element height=new Element("身高");
////height.setText("175厘米");
////root.addContent(height);
// stu.removeChild(str);
//}
}
XMLOutputter out=new XMLOutputter();
out.output(doc,new FileOutputStream(new File("c:/myxml.xml")));
}
catch (JDOMException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
}

}