trouble creating javax.xml.validation.Validator from locally cached version of XMLSchema.xsd

Hi

I need to write a code generation tool that takes in XSD files as input. The first thing I want to do is make sure the XSD input file is valid. My code works fine if create the javax.xml.transform.Source using the URL http://www.w3.org/2001/XMLSchema.xsd .  Some times the tool must be used offline. In this case I want to load XMLSchema.xsd from the local file system. For unknown reason I can not get this to work. I keep getting a SAXParseException

[ERROR] Parse error line:-1 col:-1schema_reference.4: Failed to read schema document './cache/www.w3.org/2001/XMLSchema.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.

I checked the current working and directory and know that the file it is complaining about exists.

Any idea what I am doing wrong?

thanks

Andy

import static java.lang.System.err;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

import java.net.HttpURLConnection;
import java.net.URL;

import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;

import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

import pojo2pooco.Settings;

public class ValidateSchema {
	static Validator validator;

	static {
		//
		// 1. Lookup a factory for the W3C XML Schema language
		SchemaFactory factory = SchemaFactory.newInstance("http://www.w3.org/2001/XMLSchema");

		Source sources[] = ValidateSchema.getSources();

		// 2. Compile the schema.
		Schema schema = null;
		try {
			schema = factory.newSchema(sources);

		} catch (SAXParseException spe) {
[ERROR] Parse error line:-1 col:-1schema_reference.4: Failed to read schema document 'http://www.w3.org/2001/XMLSchema.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.

			ValidateSchema.printSAXParseError(spe);
			System.exit(1);

		} catch (SAXException e) {
			err.println( "[ERROR] " + e);
			e.printStackTrace();
			System.exit(1);
		}

		// 3. Get a validator from the schema.
		validator = schema.newValidator();
	}

private static Source[] getSources() {
		Source ret[] = null;
		// try to use version from w3.org
		String schemaLocation = new String("http://www.w3.org/2001/XMLSchema.xsd");

		/**
		 * <xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/xml.xsd">
		 */

		String namespaceLocation = new String("http://www.w3.org/2001/xml.xsd");

		if (isURLContentAvalibleFromServer(schemaLocation) && isURLContentAvalibleFromServer(namespaceLocation)) {
			ret = new Source[1];
			ret[0] = getSourceFromServerForURL(schemaLocation);
			// we do not need namespaceLocation

		} else {
			err.println("[INFO] could not get files from www.w3.org");
			err.println("[INFO] will try to use cache versions from " + Settings.localCachePath);
			ret = new Source[2];
			err.println( "******* AEDWIP pwd = " + System.getProperty("user.dir"));
			String fileName = Settings.localCachePath + "/www.w3.org/2001/XMLSchema.xsd";
			// I tried different systemID values
			ret[0] = getSourceFromLocalCacheFor(fileName, fileName); //null //"XMLSchema.xsd" //schemaLocation
			fileName = Settings.localCachePath + "/www.w3.org/2001/xml.xsd";
			ret[1] = getSourceFromLocalCacheFor(fileName, fileName); //null // "xml.xsd" //namespaceLocation
		}

		return ret;
	}


	private static Source getSourceFromLocalCacheFor(String fileNameStr, String systemID) {

		Source ret = null;
        	File file = new java.io.File(fileNameStr);
		InputStream input = null;
		try {
			input = new FileInputStream(file);
		} catch (FileNotFoundException e) {
			err.println("[ERROR] getSourceFromLocalCacheFor()"  + e.getLocalizedMessage());
			System.exit(1);
		}
		ret = new StreamSource(input);
		ret.setSystemId(systemID);
		return ret;
	}

	private static Source getSourceFromServerForURL(String urlStr) {
		Source ret = null;
		try {
			URL url = new URL(urlStr);
			InputStream input = url.openStream();
			ret = new StreamSource(input);
			ret.setSystemId(urlStr);
		} catch (Exception ex) {
			err.println( "[ERROR] could not create source for "
						+ urlStr
						+ " " + ex.getLocalizedMessage());
		}

		return ret;
	}

	private static boolean isURLContentAvalibleFromServer(String testURLStr) {
		boolean ret = false;
		HttpURLConnection connection = null;

		try {
			connection = (HttpURLConnection) new URL(testURLStr)
					.openConnection();
			connection.setRequestMethod("HEAD");
			int responseCode = connection.getResponseCode();

			if (responseCode == 200) {
				ret = true;
			}
		} catch (Exception ex) {
			// content is not available
			ret = false;
		} finally {
			if (connection != null) {
				connection.disconnect();
			}
		}

		return ret;
	}