MetaInfo (Javadocs [I2P+ 2.13.0+] - API Version 0.9.70+)

java.lang.Object
- org.klomp.snark.MetaInfo

```
public class MetaInfo
extends Object
```
Holds all information extracted from a torrent file.
This class parses and stores the metadata from .torrent files, including:
- Tracker announce URLs
- Info hash for torrent identification
- File names, sizes, and structure
- Piece length and piece hashes for integrity verification
Note: This class has a known limitation where it doesn't propagate custom meta fields into the bencoded info data, and from there to the info_hash. However, it currently works with torrents created by I2P-BT, I2PRufus and Azureus.

Constructor Summary

Constructors
Constructor and Description
`MetaInfo(InputStream in)` Creates a new MetaInfo from the given InputStream.
`MetaInfo(Map<String,BEValue> m)` Creates a new MetaInfo from a Map of BEValues and the SHA1 over the original bencoded info dictionary (this is a hack, we could reconstruct the bencoded stream and recalculate the hash).
`MetaInfo(MetaInfo old, String new_announce, List<List<String>> new_announce_list, String new_comment, String new_created_by, List<String> new_url_list)` Will not change infohash.
`MetaInfo(String announce, String name, String name_utf8, List<List<String>> files, List<Long> lengths, int piece_length, byte[] piece_hashes, long length, boolean privateTorrent, List<List<String>> announce_list, String created_by, List<String> url_list, String comment)` Called by Storage when creating a new torrent from local data.
`MetaInfo(String announce, String name, String name_utf8, List<List<String>> files, List<Long> lengths, int piece_length, byte[] piece_hashes, long length, int privateTorrent, List<List<String>> announce_list, String created_by, List<String> url_list, String comment)` Preserves privateTorrent int value, for use by main().

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`checkPiece(int piece, byte[] bs, int off, int length)` Checks that the given piece has the same SHA1 hash as the given byte array.
`(package private) boolean`	`checkPiece(PartialPiece pp)` Checks a piece against the stored hashes using a PartialPiece.
`String`	`getAnnounce()` Returns the string representing the URL of the tracker for this torrent.
`List<List<String>>`	`getAnnounceList()` Returns a list of lists of urls.
`String`	`getComment()` The comment string or null.
`String`	`getCreatedBy()` The created-by string or null.
`long`	`getCreationDate()` The creation date (ms) or zero.
`List<List<String>>`	`getFiles()` Returns a list of lists of file name hierarchies or null if it is a single name.
`byte[]`	`getInfoBytes()` Side effect: Caches infoBytesLength.
`int`	`getInfoBytesLength()` The size of getInfoBytes().
`byte[]`	`getInfoHash()` Returns the original 20 byte SHA1 hash over the bencoded info map.
`List<Long>`	`getLengths()` Returns a list of Longs indication the size of the individual files, or null if it is a single file.
`String`	`getName()` Returns the requested name for the file or toplevel directory.
`static String`	`getNameAndInfoHash(InputStream in, byte[] infoHashOut)` Efficiently returns the name and the 20 byte SHA1 hash of the info dictionary in a torrent file.
`byte[]`	`getPieceHashes()` Returns the piece hashes.
`int`	`getPieceLength(int piece)` Return the length of a piece.
`int`	`getPieces()` Returns the number of pieces in the torrent.
`int`	`getPrivateTrackerStatus()`
`byte[]`	`getTorrentData()` Returns the bencoded torrent file data.
`long`	`getTotalLength()` Returns the total length of the torrent in bytes.
`List<String>`	`getWebSeedURLs()` Returns the web seed URLs for BEP 19 HTTP seeding.
`boolean`	`isPaddingFile(int filenum)` Is this file a padding file?
`boolean`	`isPrivate()` Is it a private torrent?
`static void`	`main(String[] args)` Command-line utility to inspect and optionally modify torrent file metadata.
`MetaInfo`	`reannounce(String announce)` Creates a copy of this MetaInfo that shares everything except the announce URL.
`String`	`toString()` Returns a human-readable summary of this torrent's metadata.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - MetaInfo
```
public MetaInfo(InputStream in)
         throws IOException
```
    Creates a new MetaInfo from the given InputStream. The InputStream must start with a correctly bencoded dictionary describing the torrent. Caller must close the stream.
    Parameters:
    in - the stream containing the bencoded torrent data
    Throws:
    IOException - if the stream cannot be read or the bencoded data is malformed
  - MetaInfo
```
public MetaInfo(Map<String,BEValue> m)
         throws InvalidBEncodingException
```
    Creates a new MetaInfo from a Map of BEValues and the SHA1 over the original bencoded info dictionary (this is a hack, we could reconstruct the bencoded stream and recalculate the hash). Will NOT throw a InvalidBEncodingException if the given map does not contain a valid announce string. WILL throw a InvalidBEncodingException if the given map does not contain a valid info dictionary.
    Parameters:
    m - the parsed bencoded dictionary as a map of keys to BEValues
    Throws:
    InvalidBEncodingException - if the info dictionary is missing or malformed
  - MetaInfo
```
public MetaInfo(MetaInfo old,
                String new_announce,
                List<List<String>> new_announce_list,
                String new_comment,
                String new_created_by,
                List<String> new_url_list)
```
    Will not change infohash. Retains creation date of old MetaInfo if nonzero.
    Parameters:
    old - the source MetaInfo whose infohash, name, files, and hashes are reused
    new_announce - the replacement announce URL, may be null
    new_announce_list - tiered list of replacement announce URLs, may be null
    new_comment - replacement comment string, may be null
    new_created_by - replacement created-by string, may be null
    new_url_list - replacement web seed URLs, may be null
  - MetaInfo
```
public MetaInfo(String announce,
                String name,
                String name_utf8,
                List<List<String>> files,
                List<Long> lengths,
                int piece_length,
                byte[] piece_hashes,
                long length,
                boolean privateTorrent,
                List<List<String>> announce_list,
                String created_by,
                List<String> url_list,
                String comment)
```
    Called by Storage when creating a new torrent from local data.
    Parameters:
    announce - the tracker announce URL, may be null
    name - the file or top-level directory name
    name_utf8 - unused, retained for API compatibility
    files - list of file path components per file, null for single-file torrent
    lengths - list of file sizes in bytes, null for single-file torrent
    piece_length - the length of each data piece in bytes
    piece_hashes - concatenated 20-byte SHA1 hashes of all pieces
    length - total torrent size in bytes
    privateTorrent - whether the tracker restricts peer sharing to the swarm
    announce_list - tiered list of alternate announce URLs, may be null
    created_by - application name that created the torrent, may be null
    url_list - web seed URLs for BEP 19 HTTP seeding, may be null
    comment - free-form user comment, may be null
  - MetaInfo
```
public MetaInfo(String announce,
                String name,
                String name_utf8,
                List<List<String>> files,
                List<Long> lengths,
                int piece_length,
                byte[] piece_hashes,
                long length,
                int privateTorrent,
                List<List<String>> announce_list,
                String created_by,
                List<String> url_list,
                String comment)
```
    Preserves privateTorrent int value, for use by main().
    Parameters:
    announce - the tracker announce URL, may be null
    name - the file or top-level directory name
    name_utf8 - unused, retained for API compatibility
    files - list of file path components per file, null for single-file torrent
    lengths - list of file sizes in bytes, null for single-file torrent
    piece_length - the length of each data piece in bytes
    piece_hashes - concatenated 20-byte SHA1 hashes of all pieces
    length - total torrent size in bytes
    privateTorrent - 0 = not present, 1 = private, -1 = explicitly not private
    announce_list - tiered list of alternate announce URLs, may be null
    created_by - application name that created the torrent, may be null
    url_list - web seed URLs for BEP 19 HTTP seeding, may be null
    comment - free-form user comment, may be null
- Method Detail
  - checkPiece
```
public boolean checkPiece(int piece,
                          byte[] bs,
                          int off,
                          int length)
```
    Checks that the given piece has the same SHA1 hash as the given byte array. Returns random results or IndexOutOfBoundsExceptions when the piece number is unknown.
    Parameters:
    piece - the piece index
    bs - the byte array containing the piece data
    off - the offset within the byte array where the piece data starts
    length - the number of bytes in the piece
    Returns:
    true if the computed SHA1 hash matches the stored hash for that piece
    Throws:
    IndexOutOfBoundsException - if the piece index is out of range
  - checkPiece
```
boolean checkPiece(PartialPiece pp)
```
    Checks a piece against the stored hashes using a PartialPiece.
    Parameters:
    pp - the PartialPiece containing the piece data and hash
    Returns:
    true if the hash embedded in the PartialPiece matches the stored hash for that piece
  - getAnnounce
```
public String getAnnounce()
```
    Returns the string representing the URL of the tracker for this torrent.
    Returns:
    may be null!
  - getAnnounceList
```
public List<List<String>> getAnnounceList()
```
    Returns a list of lists of urls.
    Returns:
    tiered announce URLs per BEP 12, or null if none were specified
  - getComment
```
public String getComment()
```
    The comment string or null. Not available for locally-created torrents.
    Returns:
    the comment
  - getCreatedBy
```
public String getCreatedBy()
```
    The created-by string or null. Not available for locally-created torrents.
    Returns:
    the created by
  - getCreationDate
```
public long getCreationDate()
```
    The creation date (ms) or zero. As of 0.9.19, available for locally-created torrents.
    Returns:
    the creation date
  - getFiles
```
public List<List<String>> getFiles()
```
    Returns a list of lists of file name hierarchies or null if it is a single name. It has the same size as the list returned by getLengths().
    Returns:
    the files
  - getInfoBytes
```
public byte[] getInfoBytes()
```
    Side effect: Caches infoBytesLength.
    Returns:
    the info bytes
  - getInfoBytesLength
```
public int getInfoBytesLength()
```
    The size of getInfoBytes(). Cached.
    Returns:
    the info bytes length
  - getInfoHash
```
public byte[] getInfoHash()
```
    Returns the original 20 byte SHA1 hash over the bencoded info map.
  - getLengths
```
public List<Long> getLengths()
```
    Returns a list of Longs indication the size of the individual files, or null if it is a single file. It has the same size as the list returned by getFiles().
    Returns:
    the lengths
  - getName
```
public String getName()
```
    Returns the requested name for the file or toplevel directory. If it is a toplevel directory name getFiles() will return a non-null List of file name hierarchy name.
    Returns:
    the name
  - getNameAndInfoHash
```
public static String getNameAndInfoHash(InputStream in,
                                        byte[] infoHashOut)
                                 throws IOException
```
    Efficiently returns the name and the 20 byte SHA1 hash of the info dictionary in a torrent file. Caller must close the stream.
    Parameters:
    in - the stream containing the bencoded torrent data
    infoHashOut - 20-byte array that receives the info hash
    Returns:
    the name field from the info dictionary
    Throws:
    IOException - if the stream cannot be read or the data is malformed
  - getPieceHashes
```
public byte[] getPieceHashes()
```
    Returns the piece hashes.
    Returns:
    not a copy, do not modify
  - getPieceLength
```
public int getPieceLength(int piece)
```
    Return the length of a piece. All pieces are of equal length except for the last one (getPieces()-1).
    Returns:
    the piece length
    Throws:
    IndexOutOfBoundsException - when piece is equal to or greater then the number of pieces in the torrent.
  - getPieces
```
public int getPieces()
```
    Returns the number of pieces in the torrent.
    Returns:
    the piece count computed from the hash array length divided by 20
  - getPrivateTrackerStatus
```
public int getPrivateTrackerStatus()
```
    Returns:
    0 (default), 1 (set to 1), -1 (set to 0)
  - getTorrentData
```
public byte[] getTorrentData()
```
    Returns the bencoded torrent file data. Used by the servlet when saving a torrent generated from local data.
    Returns:
    the bencoded byte array representing the complete torrent file
  - getTotalLength
```
public long getTotalLength()
```
    Returns the total length of the torrent in bytes. This includes any padding files.
  - getWebSeedURLs
```
public List<String> getWebSeedURLs()
```
    Returns the web seed URLs for BEP 19 HTTP seeding.
    Returns:
    list of web seed URLs, or null if none were specified
  - isPaddingFile
```
public boolean isPaddingFile(int filenum)
```
    Is this file a padding file?
    Parameters:
    filenum - the index of the file in the files list
    Returns:
    true if the file has the padding attribute set
  - isPrivate
```
public boolean isPrivate()
```
    Is it a private torrent?
    Returns:
    whether private
  - main
```
public static void main(String[] args)
```
    Command-line utility to inspect and optionally modify torrent file metadata. Usage: MetaInfo [-a announceURL] [-c created-by] [-m comment] [-w webseed-url]* file.torrent [file2.torrent...]
    Parameters:
    args - command-line arguments
  - reannounce
```
public MetaInfo reannounce(String announce)
                    throws InvalidBEncodingException
```
    Creates a copy of this MetaInfo that shares everything except the announce URL. Drops any announce-list. Preserves infohash and info map, including any non-standard fields.
    Parameters:
    announce - may be null
    Throws:
    InvalidBEncodingException
  - toString
```
public String toString()
```
    Returns a human-readable summary of this torrent's metadata.
    Overrides:
    toString in class Object
    Returns:
    string containing name, infohash, announce URL, size, file count, and piece count

Class MetaInfo

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MetaInfo

MetaInfo

MetaInfo

MetaInfo

MetaInfo

Method Detail

checkPiece

checkPiece

getAnnounce

getAnnounceList

getComment

getCreatedBy

getCreationDate

getFiles

getInfoBytes

getInfoBytesLength

getInfoHash

getLengths

getName

getNameAndInfoHash

getPieceHashes

getPieceLength

getPieces

getPrivateTrackerStatus

getTorrentData

getTotalLength

getWebSeedURLs

isPaddingFile

isPrivate

main

reannounce

toString