totorrentdeserialiseimpl.java

这是一个基于java编写的torrent的P2P源码

/*
 * File    : TOTorrentDeserialiseImpl.java
 * Created : 5 Oct. 2003
 * By      : Parg 
 * 
 * Azureus - a Java Bittorrent client
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details ( see the LICENSE file ).
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.gudy.azureus2.core3.torrent.impl;


import java.io.*;
import java.net.*;
import java.util.*;

import org.gudy.azureus2.core3.html.HTMLUtils;
import org.gudy.azureus2.core3.torrent.*;
import org.gudy.azureus2.core3.util.*;

public class 
TOTorrentDeserialiseImpl
	extends TOTorrentImpl
{
	public
	TOTorrentDeserialiseImpl(
		File		file )
		
		throws TOTorrentException
	{	
		if ( !file.exists()){
			throw( new TOTorrentException( 	"Torrent file '" + file.toString() + "' does not exist",
					TOTorrentException.RT_FILE_NOT_FOUND ));

		}
		
		if(!file.isFile()) {
			
			throw( new TOTorrentException( 	"Torrent must be a file ('" + file.toString() + "')",
											TOTorrentException.RT_FILE_NOT_FOUND ));
		}

		if ( file.length() == 0 ){
		
			throw( new TOTorrentException( 	"Torrent is zero length ('" + file.toString() + "')",
											TOTorrentException.RT_ZERO_LENGTH ));
			
		}
			// parg: there used to be a check made that the torrent file wasn't larger than 1MB.
			// However, this as been exceeded! (see bug 826617)
			// As there is no technical reason for this limit I have removed it
		
		FileInputStream fis = null;
		
		try{
				
			fis = new FileInputStream(file);
	
			construct( fis );
	
		}catch( Throwable e ){
			
			throw( new TOTorrentException( "Error reading torrent file '" + file.toString() + " - " + Debug.getNestedExceptionMessage(e),
											TOTorrentException.RT_READ_FAILS ));
			
		}finally{
			
			if ( fis != null ){
				
				try{
					
					fis.close();
					
				}catch( IOException e ){
					
					Debug.printStackTrace( e );
				}
			}
		}
	}
	
	public
	TOTorrentDeserialiseImpl(
		InputStream		is )
		
		throws TOTorrentException
	{		
		construct( is );
	}
	
	public
	TOTorrentDeserialiseImpl(
		byte[]		bytes )
		
		throws TOTorrentException
	{
		construct( bytes );
	}
	public
	TOTorrentDeserialiseImpl(
		Map			map )
		
		throws TOTorrentException
	{
		construct( map );
	}

	protected void
	construct(
		InputStream		is )
	
		throws TOTorrentException
	{
		ByteArrayOutputStream metaInfo = new ByteArrayOutputStream();
		
		try{
			byte[] buf = new byte[32*1024];	// raised this limit as 2k was rather too small
			
			// do a check to see if it's a BEncode file.
			int iFirstByte = is.read();
			
			if (	iFirstByte != 'd' &&
					iFirstByte != 'e' &&
					iFirstByte != 'i' &&
					!(iFirstByte >= '0' && iFirstByte <= '9')){
				
					// often people download an HTML file by accident - if it looks like HTML
					// then produce a more informative error
				
				try{
					metaInfo.write(iFirstByte);
					
					int nbRead;
							
					while ((nbRead = is.read(buf)) > 0 && metaInfo.size() < 32000 ){
						
						metaInfo.write(buf, 0, nbRead);
					}
					
					String	char_data = new String( metaInfo.toByteArray());
					
					if ( char_data.toLowerCase().indexOf( "html") != -1 ){
						
						char_data = HTMLUtils.convertHTMLToText2( char_data );
						
						char_data = HTMLUtils.splitWithLineLength( char_data, 80 );
						
						if ( char_data.length() > 400 ){
							
							char_data = char_data.substring(0,400) + "...";
						}
						
						throw( 	new TOTorrentException( 
									"Contents maybe HTML:\n" + char_data,
									TOTorrentException.RT_DECODE_FAILS ));
					}
				}catch( Throwable e ){
				
					if ( e instanceof TOTorrentException ){
						
						throw((TOTorrentException)e);
					}
					
						// ignore this
				}
				
				throw( new TOTorrentException( "Contents invalid - bad header",
						TOTorrentException.RT_DECODE_FAILS ));
      
			}
			      
			    
			
			metaInfo.write(iFirstByte);
		
			int nbRead;
				
			while ((nbRead = is.read(buf)) > 0){
			
				metaInfo.write(buf, 0, nbRead);
			}
		}catch( Throwable e ){
			
			throw( new TOTorrentException( "Error reading torrent: " + Debug.getNestedExceptionMessage(e),
											TOTorrentException.RT_READ_FAILS ));
		}
		
		construct( metaInfo.toByteArray());
	}
	
	protected void
	construct(
		byte[]		bytes )
		
		throws TOTorrentException
	{
		try{
			Map meta_data = BDecoder.decode(bytes);
	
			// print( "", "", meta_data );
			
			construct( meta_data );
			
		}catch( IOException e ){
			
			throw( new TOTorrentException( 	"Error reading torrent: " + Debug.getNestedExceptionMessage(e),
											TOTorrentException.RT_DECODE_FAILS, e ));
		}
	}
	
	protected void
	construct(
		Map		meta_data )
		
		throws TOTorrentException
	{
		try{
		
			String	announce_url		= null;
			
			boolean	got_announce		= false;
			boolean	got_announce_list	= false;
			
			boolean	bad_announce		= false;
			
				// decode the stuff
			
			Iterator root_it = meta_data.keySet().iterator();
			
			while( root_it.hasNext()){
				
				String	key = (String)root_it.next();
				
				if ( key.equalsIgnoreCase( TK_ANNOUNCE )){
							
					got_announce	= true;
					
					announce_url = readStringFromMetaData( meta_data, TK_ANNOUNCE );
					
					if ( announce_url == null ){
						
						bad_announce = true;
						
					}else{
						
						announce_url = announce_url.replaceAll( " ", "" );
						
						try{
						
							setAnnounceURL( new URL( announce_url ));
							
						}catch( MalformedURLException e ){
							
							if ( announce_url.indexOf( "://" ) == -1 ){
								
								announce_url = "http:/" + (announce_url.startsWith("/")?"":"/") + announce_url;
							}
							
							try{
								
								setAnnounceURL( new URL( announce_url ));
									
							}catch( MalformedURLException f ){
									
								bad_announce	= true;
							}
						}
					}
					
				}else if ( key.equalsIgnoreCase( TK_ANNOUNCE_LIST )){
	
					got_announce_list	= true;
					
					List	announce_list = null;
					
					Object	ann_list = meta_data.get( TK_ANNOUNCE_LIST );
					
					if( ann_list instanceof List ) {   //some malformed torrents have this key as a zero-sized string instead of a zero-sized list
						announce_list = (List)ann_list;
					}
					
					if ( announce_list != null && announce_list.size() > 0 ){
            
			            announce_url = readStringFromMetaData( meta_data, TK_ANNOUNCE );
			            
			            if ( announce_url != null ){
			            	
				            announce_url = announce_url.replaceAll( " ", "" );
			            }
			            
			            boolean announce_url_found = false;
            
						for (int i=0;i<announce_list.size();i++){
							
							List	set = (List)announce_list.get(i);
								
							Vector urls = new Vector();
								
							for (int j=0;j<set.size();j++){
								
								String url_str = readStringFromMetaData((byte[])set.get(j));
									
								url_str=url_str.replaceAll( " ", "" );
                  
					                	//check to see if the announce url is somewhere in the announce-list
																		
					            try{
					            	urls.add( new URL( url_str ));		
						    
					            	if ( url_str.equalsIgnoreCase( announce_url )) {
					                	
					            		announce_url_found = true;
					            	}
						
					            }catch( MalformedURLException e ){
									
					            	if ( url_str.indexOf( "://" ) == -1 ){
											
					            		url_str = "http:/" + (url_str.startsWith("/")?"":"/") + url_str;
									}
							         
									try{
						           		urls.add( new URL( url_str ));		
						          
						           		if ( url_str.equalsIgnoreCase( announce_url )) {
						                	
						            		announce_url_found = true;
						            	}
						       
									}catch( MalformedURLException f ){
				
										Debug.printStackTrace( f );
									} 
								}
							}
							
							if ( urls.size() > 0 ){
							
								URL[]	url_array = new URL[urls.size()];
								
								urls.copyInto( url_array );
								
								addTorrentAnnounceURLSet( url_array );
							}
						}
            
			            	//if the original announce url isn't found, add it to the list
							// watch out for those invalid torrents with announce url missing
						
			            if ( !announce_url_found && announce_url != null && announce_url.length() > 0) {
			              try {
			              	Vector urls = new Vector();