DOM 文档操作和 XML 文件互相转换的 Java 实现

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Test.java
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import javax.xml.parsers.*; 
import org.w3c.dom.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;

public class Test{
	public static void main(String argv[])
	{
		Document document;
		ManageDomAndXml manageDX = new ManageDomAndXml();
		document = manageDX.transformXmlToDom("test.xml");
		manageDX.ParseDom(document);
		manageDX.AddRecordToDom(document);
		manageDX.transformDomToXml(document,"test.xml");
	}
}
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ManageDomAndXml.java 
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import java.io.*;
import javax.xml.parsers.*; 
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;

public class ManageDomAndXml{
  static Document document;
  public ManageDomAndXml(){};
	
	//用递归方法遍历DOM树	
  public void GetElement(NodeList nodelist){
		
    Node		cnode;
    int		i;
    String	str;
    int		len;
	
    if(nodelist.getLength() == 0){
		return;
    }
    for(i=0;i<nodelist.getLength();i++) {
      cnode = nodelist.item(i);
      if(cnode.getNodeType() == 1) {
        System.out.println(cnode.getNodeName());
        GetElement(cnode.getChildNodes());
      }
      else if(cnode.getNodeType() == 3) {
        str = cnode.getNodeValue();
        len = str.length();
        if(len > 1)
          System.out.println("      "+str+" "+len);
      }
    }
  }
	
	// 遍历所提供的DOM文档.
  public void ParseDom(Document document)
  {
    NodeList nodelist;

    Element element = document.getDocumentElement();
    System.out.println("----"+element.getNodeName());
		
    nodelist = element.getChildNodes();
    GetElement(nodelist);
  }
	
	// 将提供的XML文件解析成DOM文档
	public Document transformXmlToDom(String FileName)
	{
   DocumentBuilderFactory factory = 
		            DocumentBuilderFactory.newInstance();
		
   try {
	   DocumentBuilder builder = factory.newDocumentBuilder();
     document = builder.parse( new File(FileName) );
   } catch (SAXException sxe) {
     Exception  exc = sxe;
     if (sxe.getException() != null)
       exc = sxe.getException();
     exc.printStackTrace();
   }
   catch (ParserConfigurationException pce) {
     System.out.println(pce.getMessage() );
   } catch (IOException ioe) {
     System.out.println(ioe.getMessage() );
   }
   return document;
  }
	
  // 在指定的文档中增加对象，注意：只是针对所提供的test.xml
  public void AddRecordToDom(Document document)
  {
	Element root = document.getDocumentElement();
	Element books = document.createElement("COMPUTES");
	root.appendChild(books);
	Element infor = document.createElement("Title");
	books.appendChild(infor);
	Text text = document.createTextNode("understand XML");
	infor.appendChild(text);
	infor = document.createElement("Writer");
	books.appendChild(infor);
	text = document.createTextNode("IBM");
	infor.appendChild(text);
	infor = document.createElement("Date");
	books.appendChild(infor);
	text = document.createTextNode("2001.8.12");
	books.appendChild(infor);

  }
   // 将DOM文档转化成指定的XML文件 
   public void transformDomToXml(Document document,String FileName)
   {
     try{
      TransformerFactory tFactory = TransformerFactory.newInstance();
      Transformer transformer = tFactory.newTransformer();
			
      DOMSource source = new DOMSource(document);
      StreamResult result = new StreamResult(new File(FileName));
      transformer.transform(source,result);
     }catch (TransformerConfigurationException tce) {
        System.out.println("   " + tce.getMessage() );  
     }catch (TransformerException te) {
          System.out.println("   " + te.getMessage() );
     }
  }

}

=====================================================================
test.xml (ansi 格式)
=====================================================================
<?xml version="1.0"?>
<BOOKS>
<COMPUTER>
<Title>C language</Title>
<Writer>Bob Dylan</Writer>
<Date>2000.11.13</Date>
</COMPUTER>
<COMPUTER>
<Title>C++ language</Title>
<Writer>W.Richard</Writer>
<Date>2001</Date>
</COMPUTER>
</BOOKS>