Class TarEntry


  • public class TarEntry
    extends java.lang.Object
    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.

    The C structure for a Tar Entry's header is:

     struct header {
     char name[NAMSIZ];
     char mode[8];
     char uid[8];
     char gid[8];
     char size[12];
     char mtime[12];
     char chksum[8];
     char linkflag;
     char linkname[NAMSIZ];
     char magic[8];
     char uname[TUNMLEN];
     char gname[TGNMLEN];
     char devmajor[8];
     char devminor[8];
     } header;
     
    Version:
    $Revision: 155439 $ $Date: 2008-07-06 01:07:12 -0400 (Sun, 06 Jul 2008) $
    Author:
    Timothy Gerard Endres, Stefano Mazzocchi, Peter Donald
    See Also:
    TarInputStream, TarOutputStream
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static int CHKSUMLEN
      The length of the checksum field in a header buffer.
      private static int DEVLEN
      The length of the devices field in a header buffer.
      private static int GIDLEN
      The length of the group id field in a header buffer.
      private static int GNAMELEN
      The length of the group name field in a header buffer.
      (package private) static java.lang.String GNU_LONGLINK
      The name of the GNU tar entry which contains a long name.
      private static byte LF_DIR
      Directory file type.
      (package private) static byte LF_GNUTYPE_LONGNAME
      Identifies the *next* file on the tape as having a long name.
      private static byte LF_NORMAL
      Normal file type.
      private int m_checkSum
      The entry's modification time.
      private int m_devMajor
      The entry's group name.
      private int m_devMinor
      The entry's major device number.
      private java.io.File m_file
      The entry's minor device number.
      private int m_groupID
      The entry's user id.
      private java.lang.StringBuffer m_groupName
      The entry's user name.
      private byte m_linkFlag
      The entry's checksum.
      private java.lang.StringBuffer m_linkName
      The entry's link flag.
      private java.lang.StringBuffer m_magic
      The entry's link name.
      private int m_mode  
      private long m_modTime
      The entry's size.
      private java.lang.StringBuffer m_name
      The entry's name.
      private long m_size
      The entry's group id.
      private int m_userID
      The entry's permission mode.
      private java.lang.StringBuffer m_userName
      The entry's magic tag.
      private static int MAGICLEN
      The length of the magic field in a header buffer.
      private static int MODELEN
      The length of the mode field in a header buffer.
      private static int MODTIMELEN
      The length of the modification time field in a header buffer.
      static int NAMELEN
      The length of the name field in a header buffer.
      private static int SIZELEN
      The length of the size field in a header buffer.
      private static java.lang.String TMAGIC
      The magic tag representing a POSIX tar archive.
      private static int UIDLEN
      The length of the user id field in a header buffer.
      private static int UNAMELEN
      The length of the user name field in a header buffer.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private TarEntry()
      Construct an empty entry and prepares the header values.
        TarEntry​(byte[] header)
      Construct an entry from an archive's header bytes.
        TarEntry​(java.io.File file)
      Construct an entry for a file.
        TarEntry​(java.lang.String name)
      Construct an entry with only a name.
        TarEntry​(java.lang.String name, byte linkFlag)
      Construct an entry with a name an a link flag.
    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      boolean equals​(TarEntry other)
      Determine if the two entries are equal.
      int getCheckSum()
      Get this entry's checksum.
      TarEntry[] getDirectoryEntries()
      If this entry represents a file, and the file is a directory, return an array of TarEntries for this entry's children.
      java.io.File getFile()
      Get this entry's file.
      int getGroupId()
      Deprecated.
      Use getGroupID() instead
      int getGroupID()
      Get this entry's group id.
      java.lang.String getGroupName()
      Get this entry's group name.
      int getMode()
      Get this entry's mode.
      java.util.Date getModTime()
      Set this entry's modification time.
      java.lang.String getName()
      Get this entry's name.
      long getSize()
      Get this entry's file size.
      int getUserId()
      Deprecated.
      Use getUserID() instead
      int getUserID()
      Get this entry's user id.
      java.lang.String getUserName()
      Get this entry's user name.
      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 isGNULongNameEntry()
      Indicate if this entry is a GNU long name block
      private void parseTarHeader​(byte[] header)
      Parse an entry's header information from a header buffer.
      void setGroupId​(int groupId)
      Deprecated.
      Use setGroupID() instead
      void setGroupID​(int groupId)
      Set this entry's group id.
      void setGroupName​(java.lang.String groupName)
      Set this entry's group name.
      void setMode​(int mode)
      Set the mode for this entry
      void setModTime​(long time)
      Set this entry's modification time.
      void setModTime​(java.util.Date time)
      Set this entry's modification time.
      void setName​(java.lang.String name)
      Set this entry's name.
      void setSize​(long size)
      Set this entry's file size.
      void setUserId​(int userId)
      Deprecated.
      Use setUserID() instead
      void setUserID​(int userId)
      Set this entry's user id.
      void setUserName​(java.lang.String userName)
      Set this entry's user name.
      void writeEntryHeader​(byte[] buffer)
      Write an entry's header information to a header buffer.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • MODELEN

        private static final int MODELEN
        The length of the mode field in a header buffer.
        See Also:
        Constant Field Values
      • UIDLEN

        private static final int UIDLEN
        The length of the user id field in a header buffer.
        See Also:
        Constant Field Values
      • GIDLEN

        private static final int GIDLEN
        The length of the group id field in a header buffer.
        See Also:
        Constant Field Values
      • CHKSUMLEN

        private static final int CHKSUMLEN
        The length of the checksum field in a header buffer.
        See Also:
        Constant Field Values
      • SIZELEN

        private static final int SIZELEN
        The length of the size field in a header buffer.
        See Also:
        Constant Field Values
      • MAGICLEN

        private static final int MAGICLEN
        The length of the magic field in a header buffer.
        See Also:
        Constant Field Values
      • MODTIMELEN

        private static final int MODTIMELEN
        The length of the modification time field in a header buffer.
        See Also:
        Constant Field Values
      • UNAMELEN

        private static final int UNAMELEN
        The length of the user name field in a header buffer.
        See Also:
        Constant Field Values
      • GNAMELEN

        private static final int GNAMELEN
        The length of the group name field in a header buffer.
        See Also:
        Constant Field Values
      • DEVLEN

        private static final int DEVLEN
        The length of the devices field in a header buffer.
        See Also:
        Constant Field Values
      • TMAGIC

        private static final java.lang.String TMAGIC
        The magic tag representing a POSIX tar archive.
        See Also:
        Constant Field Values
      • GNU_LONGLINK

        static java.lang.String GNU_LONGLINK
        The name of the GNU tar entry which contains a long name.
      • LF_GNUTYPE_LONGNAME

        static byte LF_GNUTYPE_LONGNAME
        Identifies the *next* file on the tape as having a long name.
      • NAMELEN

        public static final int NAMELEN
        The length of the name field in a header buffer.
        See Also:
        Constant Field Values
      • m_checkSum

        private int m_checkSum
        The entry's modification time.
      • m_devMajor

        private int m_devMajor
        The entry's group name.
      • m_devMinor

        private int m_devMinor
        The entry's major device number.
      • m_file

        private java.io.File m_file
        The entry's minor device number.
      • m_groupID

        private int m_groupID
        The entry's user id.
      • m_groupName

        private java.lang.StringBuffer m_groupName
        The entry's user name.
      • m_linkFlag

        private byte m_linkFlag
        The entry's checksum.
      • m_linkName

        private java.lang.StringBuffer m_linkName
        The entry's link flag.
      • m_magic

        private java.lang.StringBuffer m_magic
        The entry's link name.
      • m_modTime

        private long m_modTime
        The entry's size.
      • m_mode

        private int m_mode
      • m_name

        private java.lang.StringBuffer m_name
        The entry's name.
      • m_size

        private long m_size
        The entry's group id.
      • m_userID

        private int m_userID
        The entry's permission mode.
      • m_userName

        private java.lang.StringBuffer m_userName
        The entry's magic tag.
    • Constructor Detail

      • TarEntry

        public TarEntry​(java.lang.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.
        Parameters:
        name - the name of the entry
      • TarEntry

        public TarEntry​(java.lang.String name,
                        byte linkFlag)
        Construct an entry with a name an a link flag.
        Parameters:
        name - Description of Parameter
        linkFlag - Description of Parameter
      • TarEntry

        public TarEntry​(java.io.File file)
        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.
      • TarEntry

        public TarEntry​(byte[] header)
        Construct an entry from an archive's header bytes. File is set to null.
        Parameters:
        header - The header bytes from a tar archive entry.
      • TarEntry

        private TarEntry()
        Construct an empty entry and prepares the header values.
    • Method Detail

      • setGroupID

        public void setGroupID​(int groupId)
        Set this entry's group id.
        Parameters:
        groupId - This entry's new group id.
      • setGroupId

        public void setGroupId​(int groupId)
        Deprecated.
        Use setGroupID() instead
        Set this entry's group id.
        Parameters:
        groupId - This entry's new group id.
        See Also:
        setGroupID(int)
      • setGroupName

        public void setGroupName​(java.lang.String groupName)
        Set this entry's group name.
        Parameters:
        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​(java.util.Date time)
        Set this entry's modification time.
        Parameters:
        time - This entry's new modification time.
      • setMode

        public void setMode​(int mode)
        Set the mode for this entry
        Parameters:
        mode - The new Mode value
      • setName

        public void setName​(java.lang.String name)
        Set this entry's name.
        Parameters:
        name - This entry's new name.
      • setSize

        public void setSize​(long size)
        Set this entry's file size.
        Parameters:
        size - This entry's new file size.
      • setUserID

        public void setUserID​(int userId)
        Set this entry's user id.
        Parameters:
        userId - This entry's new user id.
      • setUserId

        public void setUserId​(int userId)
        Deprecated.
        Use setUserID() instead
        Set this entry's user id.
        Parameters:
        userId - This entry's new user id.
        See Also:
        setUserID(int)
      • setUserName

        public void setUserName​(java.lang.String userName)
        Set this entry's user name.
        Parameters:
        userName - This entry's new user name.
      • getDirectoryEntries

        public TarEntry[] 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.
      • getFile

        public java.io.File getFile()
        Get this entry's file.
        Returns:
        This entry's file.
      • getGroupId

        public int getGroupId()
        Deprecated.
        Use getGroupID() instead
        Get this entry's group id.
        Returns:
        This entry's group id.
        See Also:
        getGroupID()
      • getGroupID

        public int getGroupID()
        Get this entry's group id.
        Returns:
        This entry's group id.
      • getGroupName

        public java.lang.String getGroupName()
        Get this entry's group name.
        Returns:
        This entry's group name.
      • getModTime

        public java.util.Date getModTime()
        Set this entry's modification time.
        Returns:
        The ModTime value
      • getMode

        public int getMode()
        Get this entry's mode.
        Returns:
        This entry's mode.
      • getName

        public java.lang.String getName()
        Get this entry's name.
        Returns:
        This entry's name.
      • getSize

        public long getSize()
        Get this entry's file size.
        Returns:
        This entry's file size.
      • getCheckSum

        public int getCheckSum()
        Get this entry's checksum.
        Returns:
        This entry's checksum.
      • getUserId

        public int getUserId()
        Deprecated.
        Use getUserID() instead
        Get this entry's user id.
        Returns:
        This entry's user id.
        See Also:
        getUserID()
      • getUserID

        public int getUserID()
        Get this entry's user id.
        Returns:
        This entry's user id.
      • getUserName

        public java.lang.String getUserName()
        Get this entry's user name.
        Returns:
        This entry's user name.
      • 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
        Returns:
        True if entry is a descendant of
      • isDirectory

        public boolean isDirectory()
        Return whether or not this entry represents a directory.
        Returns:
        True if this entry is a directory.
      • isGNULongNameEntry

        public boolean isGNULongNameEntry()
        Indicate if this entry is a GNU long name block
        Returns:
        true if this is a long name extension provided by GNU tar
      • equals

        public boolean equals​(TarEntry other)
        Determine if the two entries are equal. Equality is determined by the header names being equal.
        Parameters:
        other - Entry to be checked for equality.
        Returns:
        True if the entries are equal.
      • parseTarHeader

        private void parseTarHeader​(byte[] header)
        Parse an entry's header information from a header buffer.
        Parameters:
        header - The tar entry header buffer to get information from.
      • writeEntryHeader

        public void writeEntryHeader​(byte[] buffer)
        Write an entry's header information to a header buffer.
        Parameters:
        buffer - The tar entry header buffer to fill in.