Using the DOM Parser to Build a Document Tree
A Class That Walks through a DOM Parse Tree
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
public class DOMDump {
static public void main(String[] arg) {
boolean validate = true;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setValidating(validate);
dbf.setNamespaceAware(true);
dbf.setIgnoringElementContentWhitespace(true);
// Parse the input to produce a parse tree with its root
// in the form of a Document object
Document doc = null;
try {
DocumentBuilder builder = dbf.newDocumentBuilder();
builder.setErrorHandler(new MyErrorHandler());
InputSource is = new InputSource("personWithDTD.xml");
doc = builder.parse(is);
} catch (SAXException e) {
System.exit(1);
} catch (ParserConfigurationException e) {
System.err.println(e);
System.exit(1);
} catch (IOException e) {
System.err.println(e);
System.exit(1);
}
dump(doc);
}
private static void dump(Document doc) {
dumpLoop((Node) doc, "");
}
private static void dumpLoop(Node node, String indent) {
switch (node.getNodeType()) {
case Node.CDATA_SECTION_NODE:
System.out.println(indent + "CDATA_SECTION_NODE");
break;
case Node.COMMENT_NODE:
System.out.println(indent + "COMMENT_NODE");
break;
case Node.DOCUMENT_FRAGMENT_NODE:
System.out.println(indent + "DOCUMENT_FRAGMENT_NODE");
break;
case Node.DOCUMENT_NODE:
System.out.println(indent + "DOCUMENT_NODE");
break;
case Node.DOCUMENT_TYPE_NODE:
System.out.println(indent + "DOCUMENT_TYPE_NODE");
break;
case Node.ELEMENT_NODE:
System.out.println(indent + "ELEMENT_NODE");
break;
case Node.ENTITY_NODE:
System.out.println(indent + "ENTITY_NODE");
break;
case Node.ENTITY_REFERENCE_NODE:
System.out.println(indent + "ENTITY_REFERENCE_NODE");
break;
case Node.NOTATION_NODE:
System.out.println(indent + "NOTATION_NODE");
break;
case Node.PROCESSING_INSTRUCTION_NODE:
System.out.println(indent + "PROCESSING_INSTRUCTION_NODE");
break;
case Node.TEXT_NODE:
System.out.print(indent + "TEXT_NODE");
System.out.println(" : "+node.getTextContent());
break;
default:
System.out.println(indent + "Unknown node");
break;
}
NodeList list = node.getChildNodes();
for (int i = 0; i < list.getLength(); i++){
dumpLoop(list.item(i), indent + " ");
}
}
}
class MyErrorHandler implements ErrorHandler {
public void warning(SAXParseException e) throws SAXException {
show("Warning", e);
throw (e);
}
public void error(SAXParseException e) throws SAXException {
show("Error", e);
throw (e);
}
public void fatalError(SAXParseException e) throws SAXException {
show("Fatal Error", e);
throw (e);
}
private void show(String type, SAXParseException e) {
System.out.println(type + ": " + e.getMessage());
System.out.println("Line " + e.getLineNumber() + " Column " + e.getColumnNumber());
System.out.println("System ID: " + e.getSystemId());
}
}
//File: personWithDTD.xml
]>
B D
999 555-8888
b@xyz.net
DOCUMENT_NODE
COMMENT_NODE
DOCUMENT_TYPE_NODE
ELEMENT_NODE
ELEMENT_NODE
ELEMENT_NODE
TEXT_NODE : B D
ELEMENT_NODE
TEXT_NODE : 999 555-8888
ELEMENT_NODE
TEXT_NODE : b@xyz.net