com.torrentMech.codec
Class Torrent

java.lang.Object
  com.torrentMech.codec.Torrent

public class Torrent
extends java.lang.Object

Torrent represents a decoded Torrent file. Dictionaries are stored internally as Hashtable objects while lists are stored as LinkedList objects. Values from the decoded torrent can be called from various class methods. Malformed torrent files will throw a com.torrentMech.codec.CorruptTorrentException.

Version:

.01 alpha

Author:

Will Bailey

Field Summary

private int	pos Used internally to keep the current position withing the bencoded torrent string during decoding.
private java.lang.String	torrent Internally represents the original bencoded torrent.
private static int	TORRENT_E Used within the decoder methods to keep track of current stage of decoding.
private static int	TORRENT_KEY Used within the decoder methods to keep track of current stage of decoding.
private static int	TORRENT_LIST_ELEMENT Used within the decoder methods to keep track of current stage of decoding.
private static int	TORRENT_VALUE Used within the decoder methods to keep track of current stage of decoding.
private java.util.Hashtable	torrentTree Internally represents the top level dictionary of the torrent.

Constructor Summary

Torrent(java.io.BufferedReader br)
Populates the Torrent instance with torrent details read from a java.io.BufferedReader.

Torrent(java.lang.String torrent)
Populates the Torrent instance with torrent details read from a java.lang.String.

Method Summary

private java.lang.String	checkOptionalKey(java.lang.String key) Internal utility method for the Torrent class to assist in retrieving requests for optional keys within the torrent.
private java.util.Hashtable	decodeDict() Decode a bencoded torrent's dictionary into it's key/value pairs.
private java.lang.String	decodeInt() Decodes integer values of a torrent.
private java.util.LinkedList	decodeList() Decodes list sections of the torrent.
private java.lang.String	decodeString() Decodes String sections of the torrent.
java.lang.String	getComment()
java.lang.String	getCreatedBy()
long	getCreationDate()
java.lang.String[][]	getFiles() Returns a two-dimensional java.lang.String array of the files contained in the torrent.
java.lang.String	getTorrent()
java.lang.String[]	getTrackers() Returns all unique trackers for this torrent.
boolean	isMultiFile()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TORRENT_KEY

private static final int TORRENT_KEY

Used within the decoder methods to keep track of current stage of decoding. Currently on a key.

See Also:

Constant Field Values

TORRENT_VALUE

private static final int TORRENT_VALUE

Used within the decoder methods to keep track of current stage of decoding. Currently on a value.

See Also:

Constant Field Values

TORRENT_E

private static final int TORRENT_E

Used within the decoder methods to keep track of current stage of decoding. End of list or dictionary.

See Also:

Constant Field Values

TORRENT_LIST_ELEMENT

private static final int TORRENT_LIST_ELEMENT

Used within the decoder methods to keep track of current stage of decoding. List element.

See Also:

Constant Field Values

pos

private int pos

Used internally to keep the current position withing the bencoded torrent string during decoding.

torrentTree

private java.util.Hashtable torrentTree

Internally represents the top level dictionary of the torrent.

torrent

private java.lang.String torrent

Internally represents the original bencoded torrent.

Constructor Detail

Torrent

public Torrent(java.io.BufferedReader br)
        throws CorruptTorrentException

Populates the Torrent instance with torrent details read from a java.io.BufferedReader.

Throws:

CorruptTorrentException

Torrent

public Torrent(java.lang.String torrent)
        throws CorruptTorrentException

Populates the Torrent instance with torrent details read from a java.lang.String. This String is not a path or URL to a torrent, but the actual Bencoded torrent.

Throws:

CorruptTorrentException

Method Detail

getTorrent

public java.lang.String getTorrent()

Returns:

The torrent in Bencoded form that this Torrent instance represents.

getTrackers

public java.lang.String[] getTrackers()

Returns all unique trackers for this torrent. The trackers are drawn from the announce key and the announce-list key. The annouce key is compared to the announce-list key to see if the tracker shows up twice (most torrents seem to repeat the announce tracker within the announce-list key).

Returns:

Returns a java.lang.String array of all the unique trackers for this torrent.

getFiles

public java.lang.String[][] getFiles()

Returns a two-dimensional java.lang.String array of the files contained in the torrent. Each of the first dimensions of the array is the file name including path and each of the second dimensions of the array is the corresponding file length in bytes. The array is initialized in the form [n][2] where n is the # of files in the torrent.
i.e. A [2][2] array would be as follows:

[MyFolder\File1.txt]	[MyFolder\File2.txt]
[1024]	[2436]

Returns:

Returns a two-dimensional java.lang.String array of the torrent files including their path and length.

isMultiFile

public boolean isMultiFile()

Returns:

Returns true if the torrent contains multiple files, false if it is a single file torrent.

getCreationDate

public long getCreationDate()

Returns:

Returns the creation date of the torrent is milliseconds since 1970 or 0 if none exists.

getCreatedBy

public java.lang.String getCreatedBy()

Returns:

Returns the value of the optional created by key or Null if none exists.

getComment

public java.lang.String getComment()

Returns:

Returns the value of the optional comment key or Null if none exists.

checkOptionalKey

private java.lang.String checkOptionalKey(java.lang.String key)

Internal utility method for the Torrent class to assist in retrieving requests for optional keys within the torrent. Simply to reduce redundant code. The argument is the key being queried.

Returns:

Returns the java.lang.String value of the requested key or null if the key doesn't exist.

decodeDict

private java.util.Hashtable decodeDict()
                                throws CorruptTorrentException

Decode a bencoded torrent's dictionary into it's key/value pairs. Recursive method.

Returns:

Hashtable representing a bencoded torrent dictionary.

Throws:

CorruptTorrentException

decodeString

private java.lang.String decodeString()
                               throws CorruptTorrentException

Decodes String sections of the torrent.

Throws:

CorruptTorrentException

decodeInt

private java.lang.String decodeInt()
                            throws CorruptTorrentException

Decodes integer values of a torrent. Returned as a String for storage in the Hashtable.

Throws:

CorruptTorrentException

decodeList

private java.util.LinkedList decodeList()
                                 throws CorruptTorrentException

Decodes list sections of the torrent.

Throws:

CorruptTorrentException