XUrlResourceStorageService.java :  » XML-UI » xui32 » com » xoetrope » deploy » Java Open Source

package com.xoetrope.deploy;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.net.URL;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import net.xoetrope.xui.build.BuildProperties;

/**
 * A utility to download a file and store it in the local files system. It is 
 * required that the application is signed for this to work
 *
 * <p> Copyright (c) Xoetrope Ltd., 2001-2007, This software is licensed under
 * the GNU Public License (GPL), please see license.txt for more details. If
 * you make commercial use of this software you must purchase a commercial
 * license from Xoetrope.</p>
 */
public class XUrlResourceStorageService
{
  public static boolean storeFile( URL src, File dest )
  {
    byte[] fileBytes = new byte[ 0 ];

    try {
      dest.getParentFile().mkdirs();
      
      // Check the file date
      // See http://www.w3.org/Protocols/HTTP/1.0/draft-ietf-http-spec.html#DateFormats 
      // for a description of the date formats
      String lm = src.openConnection().getHeaderField( "Last-Modified" );
      Date lmd = null;
      if ( lm != null ) {
        String[] formats = { "EEE, d MMM yyyy HH:mm:ss Z", "EEEE, d-MMM-yyyy HH:mm:ss Z", "EEE MMM d HH:mm:ss yyyy" };
        for ( int i = 0; i < formats.length; i++ ) {
          SimpleDateFormat sdf = new SimpleDateFormat( formats[ i ], Locale.ENGLISH );
          try {
            lmd = sdf.parse( lm );
            break;
          } 
          catch ( ParseException ex )
          {          
          }
        }
      }
      else
        return true;

      if (( lmd != null ) && dest.exists()) {
        if ( dest.lastModified() >= lmd.getTime())
          return true;
      }
      
      BufferedInputStream is = new BufferedInputStream( src.openStream());
      byte[] b = new byte[ 1024 ];
      
      if ( is != null ) {
        OutputStream fos = new BufferedOutputStream( new FileOutputStream( dest ));
        int i = is.read( b );
        while ( i != -1 ) {
          fileBytes = new byte[ i ];
          System.arraycopy( b, 0, fileBytes, 0, i );
          fos.write( fileBytes );
          b = new byte[ 1024 ];
          i = is.read( b );
        }
        fos.flush();
        fos.close();
      }
      else
        return false;
    }
    catch ( Exception ex ) {
      if ( BuildProperties.DEBUG )
        ex.printStackTrace();
      return false;
    }
    
    return true;
  }
}