使用DOM解析器解析XML

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) {
    String filename = null;
    boolean validate = false;

    if (arg.length == 1) {
      filename = arg[0];
    } else if (arg.length == 2) {
      if (!arg[0].equals("-v"))
        usage();
      validate = true;
      filename = arg[1];
    } else {
      usage();
    }

    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(filename);
      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);
    }

    // Use a TreeDumper to list the tree
    TreeDumper td = new TreeDumper();
    td.dump(doc);
  }

  private static void usage() {
    System.err.println("Usage: DOMCheck [-v] <filename>");
    System.exit(1);
  }
}
class TreeDumper {
    public void dump(Document doc) {
        dumpLoop((Node)doc,"");
    }
    private 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.println(indent + "TEXT_NODE");
            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());
  }
}