Class TarEntry

  • All Implemented Interfaces:
    TarConstants

    public class TarEntry
    extends java.lang.Object
    implements TarConstants
    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;
     All unused bytes are set to null.
     New-style GNU tar files are slightly different from the above.
     For values of size larger than 077777777777L (11 7s)
     or uid and gid larger than 07777777L (7 7s)
     the sign bit of the first byte is set, and the rest of the
     field is the binary representation of the number.
     See TarUtils.parseOctalOrBinary.
     
    The C structure for a old GNU Tar Entry's header is:
     struct oldgnu_header {
     char unused_pad1[345]; // TarConstants.PAD1LEN_GNU       - offset 0
     char atime[12];        // TarConstants.ATIMELEN_GNU      - offset 345
     char ctime[12];        // TarConstants.CTIMELEN_GNU      - offset 357
     char offset[12];       // TarConstants.OFFSETLEN_GNU     - offset 369
     char longnames[4];     // TarConstants.LONGNAMESLEN_GNU  - offset 381
     char unused_pad2;      // TarConstants.PAD2LEN_GNU       - offset 385
     struct sparse sp[4];   // TarConstants.SPARSELEN_GNU     - offset 386
     char isextended;       // TarConstants.ISEXTENDEDLEN_GNU - offset 482
     char realsize[12];     // TarConstants.REALSIZELEN_GNU   - offset 483
     char unused_pad[17];   // TarConstants.PAD3LEN_GNU       - offset 495
     };
     
    Whereas, "struct sparse" is:
     struct sparse {
     char offset[12];   // offset 0
     char numbytes[12]; // offset 12
     };
     
    • Field Detail

      • MAX_NAMELEN

        public static final int MAX_NAMELEN
        Maximum length of a user's name in the tar file
        See Also:
        Constant Field Values
      • DEFAULT_DIR_MODE

        public static final int DEFAULT_DIR_MODE
        Default permissions bits for directories
        See Also:
        Constant Field Values
      • DEFAULT_FILE_MODE

        public static final int DEFAULT_FILE_MODE
        Default permissions bits for files
        See Also:
        Constant Field Values
      • MILLIS_PER_SECOND

        public static final int MILLIS_PER_SECOND
        Convert millis to seconds
        See Also:
        Constant Field Values
    • 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 entry name
      • TarEntry

        public TarEntry​(java.lang.String name,
                        boolean preserveLeadingSlashes)
        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 entry name
        preserveLeadingSlashes - whether to allow leading slashes in the name.
      • TarEntry

        public TarEntry​(java.lang.String name,
                        byte linkFlag)
        Construct an entry with a name and a link flag.
        Parameters:
        name - the entry name
        linkFlag - the entry link flag.
      • 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. The name is set from the normalized file path.
        Parameters:
        file - The file that the entry represents.
      • TarEntry

        public TarEntry​(java.io.File file,
                        java.lang.String fileName)
        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.
        fileName - the name to be used for the entry.
      • TarEntry

        public TarEntry​(byte[] headerBuf)
        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:
        java.lang.IllegalArgumentException - if any of the numeric fields have an invalid format
      • TarEntry

        public TarEntry​(byte[] headerBuf,
                        ZipEncoding encoding)
                 throws java.io.IOException
        Construct an entry from an archive's header bytes. File is set to null.
        Parameters:
        headerBuf - The header bytes from a tar archive entry.
        encoding - encoding to use for file names
        Throws:
        java.lang.IllegalArgumentException - if any of the numeric fields have an invalid format
        java.io.IOException - if an error occurs during reading the archive
    • Method Detail

      • equals

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

        public boolean equals​(java.lang.Object it)
        Determine if the two entries are equal. Equality is determined by the header names being equal.
        Overrides:
        equals in class java.lang.Object
        Parameters:
        it - Entry to be checked for equality.
        Returns:
        True if the entries are equal.
      • hashCode

        public int hashCode()
        Hashcodes are based on entry names.
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        the entry 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 descendant of this.
        Returns:
        True if entry is a descendant of this.
      • getName

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

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

        public void setMode​(int mode)
        Set the mode for this entry
        Parameters:
        mode - the mode for this entry
      • getLinkName

        public java.lang.String getLinkName()
        Get this entry's link name.
        Returns:
        This entry's link name.
      • setLinkName

        public void setLinkName​(java.lang.String link)
        Set this entry's link name.
        Parameters:
        link - the link name to use.
      • getUserId

        @Deprecated
        public int getUserId()
        Deprecated.
        use #getLongUserId instead as user ids can be bigger than Integer.MAX_VALUE
        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.
      • getLongUserId

        public long getLongUserId()
        Get this entry's user id.
        Returns:
        This entry's user id.
        Since:
        1.9.5
      • setUserId

        public void setUserId​(long userId)
        Set this entry's user id.
        Parameters:
        userId - This entry's new user id.
        Since:
        1.9.5
      • getGroupId

        @Deprecated
        public int getGroupId()
        Deprecated.
        use #getLongGroupId instead as group ids can be bigger than Integer.MAX_VALUE
        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.
      • getLongGroupId

        public long getLongGroupId()
        Get this entry's group id.
        Returns:
        This entry's group id.
        Since:
        1.9.5
      • setGroupId

        public void setGroupId​(long groupId)
        Set this entry's group id.
        Parameters:
        groupId - This entry's new group id.
        Since:
        1.9.5
      • getUserName

        public java.lang.String getUserName()
        Get this entry's user name.
        Returns:
        This entry's user name.
      • setUserName

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

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

        public void setGroupName​(java.lang.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​(java.lang.String userName,
                             java.lang.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​(java.util.Date time)
        Set this entry's modification time.
        Parameters:
        time - This entry's new modification time.
      • getModTime

        public java.util.Date getModTime()
        Set this entry's modification time.
        Returns:
        time This entry's new modification time.
      • getFile

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

        public int getMode()
        Get this entry's mode.
        Returns:
        This entry's mode.
      • 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.
        Throws:
        java.lang.IllegalArgumentException - if the size is < 0.
      • getDevMajor

        public int getDevMajor()
        Get this entry's major device number.
        Returns:
        This entry's major device number.
      • setDevMajor

        public void setDevMajor​(int devNo)
        Set this entry's major device number.
        Parameters:
        devNo - This entry's major device number.
        Throws:
        java.lang.IllegalArgumentException - if the devNo is < 0.
      • getDevMinor

        public int getDevMinor()
        Get this entry's minor device number.
        Returns:
        This entry's minor device number.
      • setDevMinor

        public void setDevMinor​(int devNo)
        Set this entry's minor device number.
        Parameters:
        devNo - This entry's minor device number.
        Throws:
        java.lang.IllegalArgumentException - if the devNo is < 0.
      • isExtended

        public boolean isExtended()
        Indicates in case of a sparse file if an extension sparse header follows.
        Returns:
        true if an extension sparse header follows.
      • getRealSize

        public long getRealSize()
        Get this entry's real file size in case of a sparse file.
        Returns:
        This entry's real file size.
      • isGNUSparse

        public boolean isGNUSparse()
        Indicate if this entry is a GNU sparse block.
        Returns:
        true if this is a sparse extension provided by GNU tar
      • isGNULongLinkEntry

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

        public boolean isPaxHeader()
        Check if this is a Pax header.
        Returns:
        true if this is a Pax header.
      • isGlobalPaxHeader

        public boolean isGlobalPaxHeader()
        Check if this is a Pax header.
        Returns:
        true if this is a Pax header.
      • isDirectory

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

        public boolean isFile()
        Check if this is a "normal file".
        Returns:
        true if it is a 'normal' file
      • isSymbolicLink

        public boolean isSymbolicLink()
        Check if this is a symbolic link entry.
        Returns:
        true if it is a symlink
      • isLink

        public boolean isLink()
        Check if this is a link entry.
        Returns:
        true if it is a link
      • isCharacterDevice

        public boolean isCharacterDevice()
        Check if this is a character device entry.
        Returns:
        true if it is a character device entry
      • isBlockDevice

        public boolean isBlockDevice()
        Returns:
        true if this is a block device entry.
      • isFIFO

        public boolean isFIFO()
        Returns:
        true if this is a FIFO (pipe) entry.
      • 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.
      • writeEntryHeader

        public void writeEntryHeader​(byte[] outbuf)
        Write an entry's header information to a header buffer.

        This method does not use the star/GNU tar/BSD tar extensions.

        Parameters:
        outbuf - The tar entry header buffer to fill in.
      • writeEntryHeader

        public void writeEntryHeader​(byte[] outbuf,
                                     ZipEncoding encoding,
                                     boolean starMode)
                              throws java.io.IOException
        Write an entry's header information to a header buffer.
        Parameters:
        outbuf - The tar entry header buffer to fill in.
        encoding - encoding to use when writing the file name.
        starMode - whether to use the star/GNU tar/BSD tar extension for numeric fields if their value doesn't fit in the maximum size of standard tar archives
        Throws:
        java.io.IOException - if an error occurs while writing the archive
      • parseTarHeader

        public 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.
        Throws:
        java.lang.IllegalArgumentException - if any of the numeric fields have an invalid format
      • parseTarHeader

        public void parseTarHeader​(byte[] header,
                                   ZipEncoding encoding)
                            throws java.io.IOException
        Parse an entry's header information from a header buffer.
        Parameters:
        header - The tar entry header buffer to get information from.
        encoding - encoding to use for file names
        Throws:
        java.lang.IllegalArgumentException - if any of the numeric fields have an invalid format
        java.io.IOException - if an error occurs while reading the archive