import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Logger;
import java.util.zip.GZIPInputStream;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.transform.stream.StreamSource;

/**
 * $Id: Bla.java 403 2006-06-13 01:48:38Z elkner $ 
 * 
 * Copyright (c) 2005-2006 Jens Elkner.
 * All Rights Reserved.
 *
 * This software is the proprietary information of Jens Elkner.
 * Use is subject to license terms.
 */
/**
 * @author 	Jens Elkner
 * @version	$Revision: 403 $
 */
public class Bla {
	private static final Logger log = 
		Logger.getLogger(Bla.class.getName());
	
	/**
	 * boilerplate
	 * @param path
	 * @param gzip
	 * @return stream src
	 * @throws IOException
	 */
	public static StreamSource getInputSourceByFile(File path, boolean gzip) 
	throws IOException 
	{
		InputStream is = null;
		try {
			is = new FileInputStream(path);
			if (gzip) {
				is = new GZIPInputStream(is);
			}
			return new StreamSource(is, path.getName());
		} catch (IOException e) {
			if (is != null) {
				try { is.close(); } catch (Exception x) { /** ignore */ }
			}
			throw e;
		}
	}

	/**
	 * boilerplate
	 * @param reader
	 * @throws XMLStreamException
	 */
	public static void fastForwardToEndOfElement(XMLStreamReader reader) 
		throws XMLStreamException
	{
		if (reader == null) {
			return;
		}
		int starts = 1;
		while(reader.hasNext()) {
			int e = reader.next();
			if (e == XMLStreamConstants.END_ELEMENT) {
				starts--;
				if (starts == 0) {
					return;
				}
			} else if (e == XMLStreamConstants.START_ELEMENT) {
				starts++;
			}
		}
		log.warning("Missing " + starts + " End Of Element tags");
	}

	/**
	 * boilerplate
	 * @param src
	 * @param root
	 * @param namespaceAware
	 * @return null on error
	 */
	public static final XMLStreamReader getReader(StreamSource src, 
		String root, boolean namespaceAware) 
	{
		if (src == null) {
			return null;
		}
		XMLInputFactory xif = XMLInputFactory.newInstance();
		xif.setProperty(XMLInputFactory.IS_COALESCING, Boolean.TRUE);
		xif.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES, 
			Boolean.TRUE);
		xif.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, 
			Boolean.valueOf(namespaceAware));
		xif.setProperty(XMLInputFactory.IS_VALIDATING, Boolean.FALSE);
//		xif.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES,
//			Boolean.FALSE);
		try {
			XMLStreamReader reader = xif.createXMLStreamReader(src);
			while(reader.hasNext()) {
				int e = reader.next();
				if (e == XMLStreamConstants.START_ELEMENT) {
					if (root == null || reader.getLocalName().equals(root)) {
						return reader;
					}
					fastForwardToEndOfElement(reader);
				}
			}
		} catch (XMLStreamException e) {
			if (e.getNestedException() != null) {
				log.warning(e.getNestedException().getLocalizedMessage());
			} else {
				log.warning(e.getLocalizedMessage());
			}
		} catch (Exception e) {
			log.warning(e.getLocalizedMessage());
		}
		return null;
	}

	/**
	 * exception demo
	 * @param in
	 * @throws Exception
	 */
	public static void parse(XMLStreamReader in) throws Exception {
		int depth = 1;
		String indent = "  ";
		StringBuilder buf = new StringBuilder(indent);
		System.out.println(in.getLocalName());
		while(in.hasNext()) {
			int e = in.next();
			if (e == XMLStreamConstants.END_ELEMENT) {
				depth--;
				buf.setLength(buf.length()-indent.length());
				if (depth == 0) {
					break;
				}
			} else if (e == XMLStreamConstants.START_ELEMENT) {
				depth++;
				buf.append(indent);
				System.out.print(in.getLocalName() + ": ");
				String txt = in.getElementText();
				System.out.println(txt);
				depth--;
				buf.setLength(buf.length()-indent.length());
			} else {
				fastForwardToEndOfElement(in);
			}
		}
	}
	
	/**
	 * @param args	0 .. xml file to read
	 * @throws Exception 
	 */
	public static void main(String[] args) throws Exception {
		File f = null;
		if (args.length == 0) {
			f = new File("/tmp/ebay/attributesCS/US.xml.gz");
		} else {
			f = new File(args[0]);
		}
		if (f.canRead() && f.isFile()) {
			StreamSource src = null;
			XMLStreamReader in = null;
			try {
				src = getInputSourceByFile(f, f.getName().endsWith(".xml.gz"));
				in = getReader(src, "GetAttributesCSResponse", false);
				if (in != null) {
					parse(in);
				} else {
					log.severe("GetAttributesCSResponse tag not found");
				}
			} finally {
				try { in.close(); } catch (Exception x) { /* ignore */ }
				try { src.getInputStream().close(); } catch (Exception x) {/**/}
			}
		} else {
			System.err.println("Usage: java ... file.xml.gz");
		}
	}
}