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JWAT-Tools uses the available JWAT libraries to make high level tasks available either from command-line or programmatically. Common tasks include: Test, Compress, Decompress, CDX, Arc2Warc. More specialised tasks include: Changed, ContainerMD, Delete, Extract, Interval, PathIndex, Unpack, Headers2CDX.

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package org.jwat.tools.validators;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;

import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class XmlEntityResolver implements EntityResolver {

	protected File cache_dir;

	public XmlEntityResolver(File cache_dir) {
		this.cache_dir = cache_dir;
		if (!cache_dir.exists()) {
			cache_dir.mkdirs();
		}
	}

	@Override
	public synchronized InputSource resolveEntity(String publicId, String systemId)
			throws SAXException, IOException {
		// debug
		System.out.println( "Resolving: " + systemId + " (\"" + publicId + "\")" );
		if ( systemId != null ) {
			int pos = systemId.lastIndexOf( "/" );
			if ( pos != -1) {
				String res = systemId.substring( pos + 1 );
				File file = new File( cache_dir, res );

				if ( file.exists() && file.isFile() ) {
					/*
					 * Load cached dtd.
					 */
					try {
						// debug
						System.out.println( " Loading cached: " + file.getAbsolutePath() );
						return new InputSource( new BufferedReader( new InputStreamReader( new FileInputStream( file ) ) ) );
					}
					catch (FileNotFoundException e) {
						return null;
					}
				}
				else {
					/*
					 * Attempt to cache dtd.
					 */
					URL url;
					InputStream in = null;
					FileOutputStream out = null;

					try {
						byte[] buffer = new byte[ 1024 ];
						int len;
						url = new URL( systemId );
						in = url.openStream();
						out = new FileOutputStream( file );

						while ( ( len = in.read( buffer, 0, 1024 ) ) != -1 ) {
							out.write( buffer, 0, len );
						}
						out.close();
						in.close();

						// debug
						System.out.println( " Saving cached: " + file.getAbsolutePath() );
						return new InputSource( new BufferedReader( new InputStreamReader( new FileInputStream( file ) ) ) );
					}
					catch (MalformedURLException e) {
						return null;
					}
					catch (IOException e) {
						return null;
					}
					finally {
						try {
							if ( out != null ) {
								out.close();
							}
						}
						catch (IOException e) {}
						try {
							if ( in != null ) {
								in.close();
							}
						}
						catch (IOException e) {}
					}
				}
			}
		}
		return null;
	}

}