/* * Copyright (c) 2000 David Flanagan.  All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */package com.davidflanagan.examples.xml;import org.w3c.dom.*;         // W3C DOM classes for traversing the documentimport java.io.*;/** * Output a DOM Level 1 Document object to a java.io.PrintWriter as a simple * XML document.  This class does not handle every type of DOM node, and it * doesn't deal with all the details of XML like DTDs, character encodings and * preserved and ignored whitespace.  However, it does output basic * well-formed XML that can be parsed by a non-validating parser. **/public class XMLDocumentWriter {    PrintWriter out;  // the stream to send output to    /** Initialize the output stream */    public XMLDocumentWriter(PrintWriter out) {	this.out = out; }    /** Close the output stream. */    public void close() { out.close(); }    /** Output a DOM Node (such as a Document) to the output stream */    public void write(Node node) { write(node, ""); }    /**     * Output the specified DOM Node object, printing it using the specified     * indentation string     **/    public void write(Node node, String indent) {	// The output depends on the type of the node	switch(node.getNodeType()) {	case Node.DOCUMENT_NODE: {       // If its a Document node	    Document doc = (Document)node;	    out.println(indent + "<?xml version='1.0'?>");  // Output header	    Node child = doc.getFirstChild();   // Get the first node	    while(child != null) {              // Loop 'till no more nodes		write(child, indent);           // Output node		child = child.getNextSibling(); // Get next node	    }	    break;	} 	case Node.DOCUMENT_TYPE_NODE: {  // It is a <!DOCTYPE> tag	    DocumentType doctype = (DocumentType) node;	    // Note that the DOM Level 1 does not give us information about	    // the the public or system ids of the doctype, so we can't output	    // a complete <!DOCTYPE> tag here.  We can do better with Level 2.	    out.println("<!DOCTYPE " + doctype.getName() + ">");	    break;	}	case Node.ELEMENT_NODE: {        // Most nodes are Elements	    Element elt = (Element) node;	    out.print(indent + "<" + elt.getTagName());   // Begin start tag	    NamedNodeMap attrs = elt.getAttributes();     // Get attributes	    for(int i = 0; i < attrs.getLength(); i++) {  // Loop through them		Node a = attrs.item(i);		out.print(" " + a.getNodeName() + "='" +  // Print attr. name			  fixup(a.getNodeValue()) + "'"); // Print attr. value	    }	    out.println(">");                             // Finish start tag	    String newindent = indent + "    ";           // Increase indent	    Node child = elt.getFirstChild();             // Get child	    while(child != null) {                        // Loop 		write(child, newindent);                  // Output child		child = child.getNextSibling();           // Get next child	    }	    out.println(indent + "</" +                   // Output end tag			elt.getTagName() + ">");	    break;	}	case Node.TEXT_NODE: {                   // Plain text node	    Text textNode = (Text)node;	    String text = textNode.getData().trim();   // Strip off space	    if ((text != null) && text.length() > 0)   // If non-empty		out.println(indent + fixup(text));     // print text	    break;	}	case Node.PROCESSING_INSTRUCTION_NODE: {  // Handle PI nodes	    ProcessingInstruction pi = (ProcessingInstruction)node;	    out.println(indent + "<?" + pi.getTarget() +			       " " + pi.getData() + "?>");	    break;	}	case Node.ENTITY_REFERENCE_NODE: {        // Handle entities	    out.println(indent + "&" + node.getNodeName() + ";");	    break;	}	case Node.CDATA_SECTION_NODE: {           // Output CDATA sections	    CDATASection cdata = (CDATASection)node;	    // Careful! Don't put a CDATA section in the program itself!	    out.println(indent + "<" + "![CDATA[" + cdata.getData() +			"]]" + ">");	    break;	}	case Node.COMMENT_NODE: {                 // Comments	    Comment c = (Comment)node;	    out.println(indent + "<!--" + c.getData() + "-->");	    break;	}	default:   // Hopefully, this won't happen too much!	    System.err.println("Ignoring node: " + node.getClass().getName());	    break;	}    }    // This method replaces reserved characters with entities.    String fixup(String s) {	StringBuffer sb = new StringBuffer();	int len = s.length();	for(int i = 0; i < len; i++) {	    char c = s.charAt(i);	    switch(c) {	    default: sb.append(c); break;	    case '<': sb.append("&lt;"); break;	    case '>': sb.append("&gt;"); break;	    case '&': sb.append("&amp;"); break;	    case '"': sb.append("&quot;"); break;	    case '\'': sb.append("&apos;"); break;	    }	}	return sb.toString();    }}