JDK Tutorials - Herong's Tutorial Examples - v6.32, by Herong Yang
DOMToXML.java - Converting DOM Documents to XML Files
This section provides a tutorial example on how to write a program to convert a DOM document object into an XML file using the default XML transformer, org.apache.xalan.transformer, provided in the JDK.
Once you have a DOM document in memory, for sure you want to know how to write it out into an XML file. One way to do this is to use the XML transform package offered in J2SDK.
The main class in the XML transform package is called Transformer, which can be used process XML from a variety of sources and write the transformation output to a variety of sinks.
Here is a program to illustrate how to use Transformer to convert a DOM document into a XML file:
/* DOMToXML.java * Copyright (c) HerongYang.com. All Rights Reserved. */ import java.io.*; import javax.xml.parsers.*; import org.w3c.dom.*; import javax.xml.transform.*; import javax.xml.transform.dom.*; import javax.xml.transform.stream.*; class DOMToXML { public static void main(String[] args) { try { File x = new File(args[0]); DocumentBuilderFactory f = DocumentBuilderFactory.newInstance(); DocumentBuilder b = f.newDocumentBuilder(); Document d = b.newDocument(); Element r = d.createElement("dictionary"); d.appendChild(r); Element w = d.createElement("word"); r.appendChild(w); Element e = d.createElement("update"); w.appendChild(e); e.setAttribute("date","2002-12-24"); e = d.createElement("name"); w.appendChild(e); e.setAttribute("is_acronym","true"); e.appendChild(d.createTextNode("DTD")); e = d.createElement("definition"); w.appendChild(e); e.appendChild(d.createTextNode("Document Type Definition")); TransformerFactory tf = TransformerFactory.newInstance(); Transformer m = tf.newTransformer(); System.out.println(m.toString()); DOMSource source = new DOMSource(d); StreamResult result = new StreamResult(x); m.transform(source, result); } catch (ParserConfigurationException e) { System.out.println(e.toString()); } catch (TransformerConfigurationException e) { System.out.println(e.toString()); } catch (TransformerException e) { System.out.println(e.toString()); } } }
Run this program with "java DOMToXML word.xml, you will get the following on the Java console window:
com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl@52e922
This tells us that the factory pickup an implementation of Transformer from the com.sun.org.apache.xalan.internal.xsltc.trax package.
word.xml, the XML file generated by the program, looks very good:
<?xml version="1.0" encoding="UTF-8"?> <dictionary><word><update date="2002-12-24"/> <name is_acronym="true">DTD</name> <definition>Document Type Definition</definition></word> </dictionary>
Note that entire root element is stored in a single line. It was split into multiple lines manually to be able to fit the format of this book.
Table of Contents
Date, Time and Calendar Classes
Date and Time Object and String Conversion
Number Object and Numeric String Conversion
Locales, Localization Methods and Resource Bundles
Calling and Importing Classes Defined in Unnamed Packages
HashSet, Vector, HashMap and Collection Classes
Character Set Encoding Classes and Methods
Encoding Conversion Programs for Encoded Text Files
Datagram Network Communication
►DOM (Document Object Model) - API for XML Files
DOMParser.java - Parsing XML Files with DOM
DOMBrowser.java - Browsing DOM Tree Structure
DOMNewDoc.java - Building a New DOM Document
►DOMToXML.java - Converting DOM Documents to XML Files
DTD (Document Type Definition) - XML Validation
XSD (XML Schema Definition) - XML Validation
XSL (Extensible Stylesheet Language)
Message Digest Algorithm Implementations in JDK
Private key and Public Key Pair Generation
PKCS#8/X.509 Private/Public Encoding Standards
Digital Signature Algorithm and Sample Program
"keytool" Commands and "keystore" Files
KeyStore and Certificate Classes
Secret Key Generation and Management
Cipher - Encryption and Decryption
The SSL (Secure Socket Layer) Protocol
SSL Socket Communication Testing Programs