Package org.jboss.shrinkwrap.impl.base.io.tar

Class TarEntry

java.lang.Object

org.jboss.shrinkwrap.impl.base.io.tar.TarEntry

All Implemented Interfaces:

Cloneable

public class TarEntry
extends Object
implements Cloneable

This class represents an entry in a Tar archive. It consists of the entry's header, as well as the entry's File. Entries can be instantiated in one of three ways, depending on how they are to be used.

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
   };                       500

 

Note 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:

• TarHeader

Field Summary

Fields

Modifier and Type	Field	Description
protected File	file	If this entry represents a File, this references it.
protected boolean	gnuFormat	Set to true if this is a GNU 'ustar' format entry.
protected TarHeader	header	This is the entry's header information.
protected boolean	unixFormat	Set to true if this is a "old-unix" format entry.
protected boolean	ustarFormat	Set to true if this is a 'ustar' format entry.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	TarEntry()	The default constructor is protected for use only by subclasses.
	TarEntry(byte[] headerBuf)	Construct an entry from an archive's header bytes.
	TarEntry(File file)	Construct an entry for a file.
	TarEntry(String name)	Construct an entry with only a name.

Method Summary

Modifier and Type	Method	Description
Object	clone()	Clone the entry.
long	computeCheckSum(byte[] buf)	Compute the checksum of a tar entry header.
boolean	equals(Object obj)
boolean	equals(TarEntry it)	Determine if the two entries are equal.
TarEntry[]	getDirectoryEntries()	If this entry represents a file, and the file is a directory, return an array of TarEntries for this entry's children.
File	getFile()	Get this entry's file.
void	getFileTarHeader(TarHeader hdr, File file)	Fill in a TarHeader with information from a File.
int	getGroupId()	Get this entry's group id.
String	getGroupName()	Get this entry's group name.
TarHeader	getHeader()	Get this entry's header.
Date	getModTime()	Set this entry's modification time.
String	getName()	Get this entry's name.
long	getSize()	Get this entry's file size.
int	getUserId()	Get this entry's user id.
String	getUserName()	Get this entry's user name.
int	hashCode()	Value equality done by name only
private void	initialize()	Initialization code common to all constructors.
boolean	isDescendent(TarEntry desc)	Determine if the given entry is a descendant of this entry.
boolean	isDirectory()	Return whether or not this entry represents a directory.
boolean	isGNUTarFormat()	Returns true if this entry's header is in the GNU 'ustar' format.
boolean	isUnixTarFormat()	Returns true if this entry's header is in the old "unix-tar" format.
boolean	isUSTarFormat()	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	setGNUTarFormat()	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	setName(String name)	Set this entry's name.
void	setNames(String userName, String groupName)	Convenience method to set this entry's group and user names.
void	setSize(long size)	Set this entry's file size.
void	setUnixTarFormat()	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	setUSTarFormat()	Sets this entry's header format to "ustar".
String	toString()
void	writeEntryHeader(byte[] outbuf)	Write an entry's header information to a header buffer.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

file

protected File file

If this entry represents a File, this references it.

header

protected TarHeader header

This is the entry's header information.

unixFormat

protected boolean unixFormat

Set to true if this is a "old-unix" format entry.

ustarFormat

protected boolean ustarFormat

Set to true if this is a 'ustar' format entry.

gnuFormat

protected boolean gnuFormat

Set to true if this is a GNU 'ustar' format entry.

Constructor Details

TarEntry

protected TarEntry()

The default constructor is protected for use only by subclasses.

TarEntry

public TarEntry(String name)

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

public TarEntry(File file)
         throws InvalidHeaderException

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

TarEntry

public TarEntry(byte[] headerBuf)
         throws InvalidHeaderException

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

Method Details

initialize

private void initialize()

Initialization code common to all constructors.

clone

public Object clone()

Clone the entry.

Overrides:

clone in class Object

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.

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.

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.

setUnixTarFormat

public void setUnixTarFormat()

Sets this entry's header format to "unix-style".

equals

public boolean equals(TarEntry it)

Determine if the two entries are equal. Equality is determined by the header names being equal.

Returns:

it Entry to be checked for equality.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Value equality done by name only

Overrides:

hashCode in class Object

See Also:

• Object.hashCode()

isDescendent

public boolean isDescendent(TarEntry desc)

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.

getHeader

public TarHeader getHeader()

Get this entry's header.

Returns:

This entry's TarHeader.

getName

public String getName()

Get this entry's name.

Returns:

This entry's name.

setName

public void setName(String name)

Set this entry's name.

Parameters:

name - This entry's new name.

getUserId

public int getUserId()

Get this entry's user id.

Returns:

This entry's user id.

setUserId

public void setUserId(int userId)

Set this entry's user id.

Parameters:

userId - This entry's new user id.

getGroupId

public int getGroupId()

Get this entry's group id.

Returns:

This entry's group id.

setGroupId

public void setGroupId(int groupId)

Set this entry's group id.

Parameters:

groupId - This entry's new group id.

getUserName

public String getUserName()

Get this entry's user name.

Returns:

This entry's user name.

setUserName

public void setUserName(String userName)

Set this entry's user name.

Parameters:

userName - This entry's new user name.

getGroupName

public String getGroupName()

Get this entry's group name.

Returns:

This entry's group name.

setGroupName

public void setGroupName(String groupName)

Set this entry's group name.

Parameters:

groupName - This entry's new group name.

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.

setNames

public void setNames(String userName,
 String groupName)

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.

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.

setModTime

public void setModTime(Date time)

Set this entry's modification time.

Parameters:

time - This entry's new modification time.

getModTime

public Date getModTime()

Set this entry's modification time.

Parameters:

time - This entry's new modification time.

getFile

public File getFile()

Get this entry's file.

Returns:

This entry's file.

getSize

public long getSize()

Get this entry's file size.

Returns:

This entry's file size.

setSize

public void setSize(long size)

Set this entry's file size.

Parameters:

size - This entry's new file size.

isDirectory

public boolean isDirectory()

Return whether or not this entry represents a directory.

Returns:

True if this entry is a directory.

getFileTarHeader

public void getFileTarHeader(TarHeader hdr,
 File file)
                      throws InvalidHeaderException

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

getDirectoryEntries

public TarEntry[] getDirectoryEntries()
                               throws InvalidHeaderException

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

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.

writeEntryHeader

public void writeEntryHeader(byte[] outbuf)
                      throws InvalidHeaderException

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.

parseTarHeader

public void parseTarHeader(TarHeader hdr,
 byte[] headerBuf)
                    throws InvalidHeaderException

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

nameTarHeader

public void nameTarHeader(TarHeader hdr,
 String name)

Fill in a TarHeader given only the entry's name.

Parameters:

hdr - The TarHeader to fill in.

name - The tar entry name.

toString

public String toString()

Overrides:

toString in class Object