Metacat

/**

 *    Purpose: A Class that validates XML documents

 *             This class is designed to be 'parser independent

 *             i.e. it uses only org.xml.sax classes

 *             It is tied to SAX 2.0 methods

 *  Copyright: 2000 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Dan Higgins, Matt Jones

 *     '$Date$'

 * '$Revision$'

import java.net.MalformedURLException;

import java.util.*;

import java.io.*;

import java.lang.reflect.*;

import org.w3c.dom.*;

import org.xml.sax.*;

import org.xml.sax.helpers.XMLReaderFactory;

import com.arbortext.catalog.*;

/**

 *                National Center for Ecological Analysis and Synthesis

 *                April 28, 2000

  static int ERROR=1;

  static int FATAL_ERROR=2;

  XMLReader parser;

  ErrorStorer ef;

  String xml_doc; // document to be parsed

  public DBValidate(String parserName) {

    try {

      // Get an instance of the parser

      parser = XMLReaderFactory.createXMLReader(parserName);

      parser.setFeature("http://xml.org/sax/features/validation",true);

      //parser.setValidationMode(true);     // Oracle

    } catch (Exception e) {

      System.err.println("Could not create parser!!!");

    CatalogEntityResolver cer = new CatalogEntityResolver();

    try {

      Catalog myCatalog = new Catalog();

      myCatalog.loadSystemCatalogs();

      myCatalog.parseCatalog(xmlcatalogfile);

      cer.setCatalog(myCatalog);

    } catch (Exception e) {System.out.println("Problem creating Catalog!");}

    parser.setEntityResolver(cer);

  }

  public DBValidate(String parserName, Connection conn) {

    this(parserName);

    DBEntityResolver dbresolver = new DBEntityResolver(conn);

    parser.setEntityResolver(dbresolver);

  }

   * validate an xml document against its DTD

   *

   * @param doc the filename of the document to validate

   */

  public boolean validate(String doc) {

    xml_doc = doc;

    ef = new ErrorStorer();

    ef.resetErrors();

    parser.setErrorHandler(ef);

    try {

      parser.parse((createURL(xml_doc)).toString());

    } catch (IOException e) {

      System.out.println("IOException:Could not parse :"+xml_doc);

      ParseError eip = null;

      if (ef.errorNodes == null)  ef.errorNodes = new Vector();

      ef.errorNodes.addElement(eip);

      // {System.out.println("Exception parsing:Could not parse :"+xml_doc);}

      ef.getErrorNodes().size() > 0 ) {

      return false;

    } else {

      return true;

   * validate an xml document against its DTD

   *

   * @param xmldoc the String containing the xml document to validate

   */

  public boolean validateString(String xmldoc) {

    ef.resetErrors();

    parser.setErrorHandler(ef);

    InputSource is = new InputSource(new StringReader(xmldoc));

    try {

      parser.parse(is);

    }

    catch (Exception e) {System.out.println("Error in parsing!");}

      ef.getErrorNodes().size() > 0 ) {

      return false;

    } else {

      return true;

    errorstring.append("<?xml version=\"1.0\" ?>\n");

        ef.getErrorNodes().size() > 0 ) {

      Vector errors = ef.getErrorNodes();

                      ((ParseError)(e.nextElement())).toXML());

  private URL createURL(String name) throws Exception {

    try {

      URL u = new URL(name);

      return u;

    } catch (MalformedURLException ex) {

    }

    URL u = new URL("file:" + new File(name).getAbsolutePath());

    return u;

  }

  /**

   * main method for testing

   * <p>

   * Usage: java DBValidate <xmlfile or URL>

   */

  public static void main(String[] args) {

    if (args.length != 1) {

      System.out.println("Usage: java DBValidate <xmlfile or URL>");

      System.exit(0);

    }

    String doc = args[0];

      Connection conn = util.openDBConnection();

      DBValidate gxv = new DBValidate(util.getOption("saxparser"), conn);

      if (gxv.validate(doc)) {

        System.out.print(gxv.returnErrors());

      } else {

        System.out.print(gxv.returnErrors());

      }

    } catch (SQLException e) {

      System.out.println("<error>Couldn't open database connection.</error>");

    } catch (ClassNotFoundException e) {

      System.out.println("<error>Couldn't open database connection.</error>");

  }

  /**

   * ErrorStorer has been revised here to simply create a Vector of

   * ParseError objects

   *

   */

  class ErrorStorer implements ErrorHandler {

    }

     * The client is is allowed to get a reference to the Hashtable,

     * and so could corrupt it, or add to it...

     */

    public Vector getErrorNodes() {

        return errorNodes;

    }

     * The ParseError object for the node key is returned.

     * If the node doesn't have errors, null is returned.

     */

    public Object getError() {

        if (errorNodes == null)

            return null;

        return errorNodes;

    }

     * Reset the error storage.

     */

    public void resetErrors() {

        if (errorNodes != null)

        errorNodes.removeAllElements();

    }

    /***/

    public void warning(SAXParseException ex) {

        handleError(ex, WARNING);

    }

        handleError(ex, ERROR);

    }

        handleError(ex, FATAL_ERROR);

    }

      // System.out.println("!!! handleError: "+ex.getMessage());

        errorNodes = new Vector();

      }

                           ex.getColumnNumber(), ex.getMessage());

      errorNodes.addElement(eip);

    }

   * The ParseError class wraps up all the error info from

   * the ErrorStorer's error method.

   *

   * @see ErrorStorer

   */

  class ParseError extends Object {

    // Data

    //

    int lineNo;

    int charOffset;

    String msg;

     * Constructor

     */

      this.fileName=fileName;

      this.lineNo=lineNo;

      this.charOffset=charOffset;

      this.msg=msg;

    // Getters...

    //

    public String getFileName() { return fileName; }

    public int getLineNo() { return lineNo; }

    public int getCharOffset() { return charOffset;}

    public String getMsg() { return msg; }

    public void setMsg(String s) { msg = s; }

    /** Return the error message as an xml fragment */

    public String toXML() {

      StringBuffer err = new StringBuffer();

      err.append("<error>\n");

      err.append("<filename>").append(getFileName()).append("</filename>\n");

      err.append("<line>").append(getLineNo()).append("</line>\n");

      err.append("<offset>").append(getCharOffset()).append("</offset>\n");

      err.append("<message>").append(getMsg()).append("</message>\n");

      err.append("</error>\n");

      return err.toString();

    }

/**

 * '$Log$

 * 'Fixed bug in DBEntityResolver so that it now properly delegates to

 * 'the system id found inthe database.

 * 'Changed DBValidate to use DBEntityResolver, rather than the OASIS

 * 'catalog, and to return validation results in XML format.

 * '

 * 'Merged in substantial changes to DBWriter and associated classes and to

 * 'the MetaCatServlet in order to accomodate the new UPDATE and DELETE

 * 'functions.  The command line tools and the parameters for the

 * 'servlet have changed substantially.

 * '

 * 'Added RCSfile keyword

 * '

 * 'Revision 1.6.2.2  2000/06/25 23:34:18  jones

 * 'Changed documentation formatting, added log entries at bottom of source files

 * ''

 */