Class TarEntry
- All Implemented Interfaces:
Cloneable
TarEntries that are created from the header bytes read from an archive are instantiated with the TarEntry( byte[] ) constructor. These entries will be used when extracting from or listing the contents of an archive. These entries have their header filled in using the header bytes. They also set the File to null, since they reference an archive entry not a file.
TarEntries that are created from Files that are to be written into an archive are instantiated with the TarEntry( File ) constructor. These entries have their header filled in using the File's information. They also keep a reference to the File for convenience when writing entries.
Finally, TarEntries can be constructed from nothing but a name. This allows the programmer to construct the entry by hand, for instance when only an InputStream is available for writing to the archive, and the header information is constructed from other information. In this case the header fields are set to defaults and the File is set to null.
Original Unix Tar Header: Field Field Field Width Name Meaning ----- --------- --------------------------- 100 name name of file 8 mode file mode 8 uid owner user ID 8 gid owner group ID 12 size length of file in bytes 12 mtime modify time of file 8 chksum checksum for header 1 link indicator for links 100 linkname name of linked file
POSIX "ustar" Style Tar Header: Field Field Field Width Name Meaning ----- --------- --------------------------- 100 name name of file 8 mode file mode 8 uid owner user ID 8 gid owner group ID 12 size length of file in bytes 12 mtime modify time of file 8 chksum checksum for header 1 typeflag type of file 100 linkname name of linked file 6 magic USTAR indicator 2 version USTAR version 32 uname owner user name 32 gname owner group name 8 devmajor device major number 8 devminor device minor number 155 prefix prefix for file name struct posix_header { byte offset char name[100]; 0 char mode[8]; 100 char uid[8]; 108 char gid[8]; 116 char size[12]; 124 char mtime[12]; 136 char chksum[8]; 148 char typeflag; 156 char linkname[100]; 157 char magic[6]; 257 char version[2]; 263 char uname[32]; 265 char gname[32]; 297 char devmajor[8]; 329 char devminor[8]; 337 char prefix[155]; 345 }; 500Note that while the class does recognize GNU formatted headers, it does not perform proper processing of GNU archives. I hope to add the GNU support someday. Directory "size" fix contributed by: Bert Becker invalid input: '<'becker@informatik.hu-berlin.de>
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected File
If this entry represents a File, this references it.protected boolean
Set to true if this is a GNU 'ustar' format entry.protected TarHeader
This is the entry's header information.protected boolean
Set to true if this is a "old-unix" format entry.protected boolean
Set to true if this is a 'ustar' format entry. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionclone()
Clone the entry.long
computeCheckSum
(byte[] buf) Compute the checksum of a tar entry header.boolean
boolean
Determine if the two entries are equal.TarEntry[]
If this entry represents a file, and the file is a directory, return an array of TarEntries for this entry's children.getFile()
Get this entry's file.void
getFileTarHeader
(TarHeader hdr, File file) Fill in a TarHeader with information from a File.int
Get this entry's group id.Get this entry's group name.Get this entry's header.Set this entry's modification time.getName()
Get this entry's name.long
getSize()
Get this entry's file size.int
Get this entry's user id.Get this entry's user name.int
hashCode()
Value equality done by name onlyprivate void
Initialization code common to all constructors.boolean
isDescendent
(TarEntry desc) Determine if the given entry is a descendant of this entry.boolean
Return whether or not this entry represents a directory.boolean
Returns true if this entry's header is in the GNU 'ustar' format.boolean
Returns true if this entry's header is in the old "unix-tar" format.boolean
Returns true if this entry's header is in "ustar" format.void
nameTarHeader
(TarHeader hdr, String name) Fill in a TarHeader given only the entry's name.void
parseTarHeader
(TarHeader hdr, byte[] headerBuf) Parse an entry's TarHeader information from a header buffer.void
Sets this entry's header format to GNU "ustar".void
setGroupId
(int groupId) Set this entry's group id.void
setGroupName
(String groupName) Set this entry's group name.void
setIds
(int userId, int groupId) Convenience method to set this entry's group and user ids.void
setModTime
(long time) Set this entry's modification time.void
setModTime
(Date time) Set this entry's modification time.void
Set this entry's name.void
Convenience method to set this entry's group and user names.void
setSize
(long size) Set this entry's file size.void
Sets this entry's header format to "unix-style".void
setUserId
(int userId) Set this entry's user id.void
setUserName
(String userName) Set this entry's user name.void
Sets this entry's header format to "ustar".toString()
void
writeEntryHeader
(byte[] outbuf) Write an entry's header information to a header buffer.
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Field Details
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file
If this entry represents a File, this references it. -
header
This is the entry's header information. -
unixFormat
protected boolean unixFormatSet to true if this is a "old-unix" format entry. -
ustarFormat
protected boolean ustarFormatSet to true if this is a 'ustar' format entry. -
gnuFormat
protected boolean gnuFormatSet to true if this is a GNU 'ustar' format entry.
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Constructor Details
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TarEntry
protected TarEntry()The default constructor is protected for use only by subclasses. -
TarEntry
Construct an entry with only a name. This allows the programmer to construct the entry's header "by hand". File is set to null. -
TarEntry
Construct an entry for a file. File is set to file, and the header is constructed from information from the file.- Parameters:
file
- The file that the entry represents.- Throws:
InvalidHeaderException
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TarEntry
Construct an entry from an archive's header bytes. File is set to null.- Parameters:
headerBuf
- The header bytes from a tar archive entry.- Throws:
InvalidHeaderException
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Method Details
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initialize
private void initialize()Initialization code common to all constructors. -
clone
Clone the entry. -
isUSTarFormat
public boolean isUSTarFormat()Returns true if this entry's header is in "ustar" format.- Returns:
- True if the entry's header is in "ustar" format.
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setUSTarFormat
public void setUSTarFormat()Sets this entry's header format to "ustar". -
isGNUTarFormat
public boolean isGNUTarFormat()Returns true if this entry's header is in the GNU 'ustar' format.- Returns:
- True if the entry's header is in the GNU 'ustar' format.
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setGNUTarFormat
public void setGNUTarFormat()Sets this entry's header format to GNU "ustar". -
isUnixTarFormat
public boolean isUnixTarFormat()Returns true if this entry's header is in the old "unix-tar" format.- Returns:
- True if the entry's header is in the old "unix-tar" format.
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setUnixTarFormat
public void setUnixTarFormat()Sets this entry's header format to "unix-style". -
equals
Determine if the two entries are equal. Equality is determined by the header names being equal.- Returns:
- it Entry to be checked for equality.
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equals
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hashCode
public int hashCode()Value equality done by name only -
isDescendent
Determine if the given entry is a descendant of this entry. Descendancy is determined by the name of the descendant starting with this entry's name.- Parameters:
desc
- Entry to be checked as a descendent of this.- Returns:
- True if entry is a descendant of this.
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getHeader
Get this entry's header.- Returns:
- This entry's TarHeader.
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getName
Get this entry's name.- Returns:
- This entry's name.
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setName
Set this entry's name.- Parameters:
name
- This entry's new name.
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getUserId
public int getUserId()Get this entry's user id.- Returns:
- This entry's user id.
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setUserId
public void setUserId(int userId) Set this entry's user id.- Parameters:
userId
- This entry's new user id.
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getGroupId
public int getGroupId()Get this entry's group id.- Returns:
- This entry's group id.
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setGroupId
public void setGroupId(int groupId) Set this entry's group id.- Parameters:
groupId
- This entry's new group id.
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getUserName
Get this entry's user name.- Returns:
- This entry's user name.
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setUserName
Set this entry's user name.- Parameters:
userName
- This entry's new user name.
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getGroupName
Get this entry's group name.- Returns:
- This entry's group name.
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setGroupName
Set this entry's group name.- Parameters:
groupName
- This entry's new group name.
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setIds
public void setIds(int userId, int groupId) Convenience method to set this entry's group and user ids.- Parameters:
userId
- This entry's new user id.groupId
- This entry's new group id.
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setNames
Convenience method to set this entry's group and user names.- Parameters:
userName
- This entry's new user name.groupName
- This entry's new group name.
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setModTime
public void setModTime(long time) Set this entry's modification time. The parameter passed to this method is in "Java time".- Parameters:
time
- This entry's new modification time.
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setModTime
Set this entry's modification time.- Parameters:
time
- This entry's new modification time.
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getModTime
Set this entry's modification time.- Parameters:
time
- This entry's new modification time.
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getFile
Get this entry's file.- Returns:
- This entry's file.
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getSize
public long getSize()Get this entry's file size.- Returns:
- This entry's file size.
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setSize
public void setSize(long size) Set this entry's file size.- Parameters:
size
- This entry's new file size.
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isDirectory
public boolean isDirectory()Return whether or not this entry represents a directory.- Returns:
- True if this entry is a directory.
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getFileTarHeader
Fill in a TarHeader with information from a File.- Parameters:
hdr
- The TarHeader to fill in.file
- The file from which to get the header information.- Throws:
InvalidHeaderException
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getDirectoryEntries
If this entry represents a file, and the file is a directory, return an array of TarEntries for this entry's children.- Returns:
- An array of TarEntry's for this entry's children.
- Throws:
InvalidHeaderException
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computeCheckSum
public long computeCheckSum(byte[] buf) Compute the checksum of a tar entry header.- Parameters:
buf
- The tar entry's header buffer.- Returns:
- The computed checksum.
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writeEntryHeader
Write an entry's header information to a header buffer. This method can throw an InvalidHeaderException- Parameters:
outbuf
- The tar entry header buffer to fill in.- Throws:
InvalidHeaderException
- If the name will not fit in the header.
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parseTarHeader
Parse an entry's TarHeader information from a header buffer. Old unix-style code contributed by David Mehringer invalid input: '<'dmehring@astro.uiuc.edu>.- Parameters:
hdr
- The TarHeader to fill in from the buffer information.header
- The tar entry header buffer to get information from.- Throws:
InvalidHeaderException
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nameTarHeader
Fill in a TarHeader given only the entry's name.- Parameters:
hdr
- The TarHeader to fill in.name
- The tar entry name.
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toString
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