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/*
* 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.
*/
import java.io.PrintWriter;
import org.w3c.dom.CDATASection;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.ProcessingInstruction;
import org.w3c.dom.Text;
/**
* 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("<");
break;
case '>':
sb.append(">");
break;
case '&':
sb.append("&");
break;
case '"':
sb.append(""");
break;
case '\'':
sb.append("'");
break;
}
}
return sb.toString();
}
}
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