Jdom操作、創建和解析XML

 需要導入Jdom的一個jar包；

1、Jdom創建XML
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
 {
        //創建文檔
  Document document = new Document();
        //創建文檔根元素
  Element root = new Element("root");
        //向文檔呢添加根元素
  document.addContent(root);
  //添加注釋
  Comment comment = new Comment("This is my comments");
        //在根元素下添加注釋
  root.addContent(comment);
        //創建一個元素
  Element e = new Element("hello");
        //給元素添加屬性的第一種方式,它有返回值，返回一個Element對象
  e.setAttribute("sohu", "www.sohu.com");
        //給根元素添加屬性
  root.addContent(e);
Element e2 = new Element("world");
        //創建元素屬性的第二種方式
  Attribute attr = new Attribute("test", "hehe");
        //給元素添加屬性
  e2.setAttribute(attr);
        //將元素添加到根元素下
  e.addContent(e2);
        //添加元素屬性和文本內容，屬于方法鏈的編程風格
  e2.addContent(new Element("aaa").setAttribute("a", "b")
    .setAttribute("x", "y").setAttribute("gg", "hh").setText("text content"));
//設置其格式,一般還有一個沒有縮進與空格的格式getRawFormat，主要用于XML的網絡傳輸，因為它沒有空格，減少網絡傳輸的數據量。
  Format format = Format.getPrettyFormat();
//設置元素前面空格
  format.setIndent("    ");
  //設置編碼方式
//  format.setEncoding("gbk");
  //將XML文檔輸出
  XMLOutputter out = new XMLOutputter(format);
  out.output(document, new FileWriter("jdom.xml"));
}
}
2、Jdom解析XML
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從XML中解析
  SAXBuilder builder = new SAXBuilder();
  //獲得XML文檔對象
  Document doc = builder.build(new File("jdom.xml"));
  //得到文檔根元素
  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子元素下的屬性
  List list = hello.getAttributes();
//得到hello元素下屬性的名字和值
  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);
  }
  //刪除hello下的world子元素
  hello.removeChild("world");
//將文檔保存到另一個文件
  XMLOutputter out = new XMLOutputter(Format.getPrettyFormat().setIndent("    "));
out.output(doc, new FileOutputStream("jdom2.xml"));
}
}
3、綜合實例
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("學生信息");
  Element stu1 = new Element("學生");
  Element stu2 = new Element("學生");
  Element name1 = new Element("姓名");
  Element sex1 = new Element("性別");
  Element age1 = new Element("年齡");
  Element name2 = new Element("姓名");
  Element sex2 = new Element("性別");
  Element age2 = new Element("年齡");
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("性別").getName() + ":"
  + ele.getChild("性別").getText());
System.out.println(ele.getChild("年齡").getName() + ":"
  + ele.getChild("年齡").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("學生");
   Element cla=new Element("班級");
   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("學生");
   Element age=stu.getChild("年齡2");
      age.setName("年齡");
   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();
  }
 }
}</pre>