Package org.apache.activemq.console.command.store.tar

Class TarEntry

java.lang.Object
org.apache.activemq.console.command.store.tar.TarEntry
All Implemented Interfaces:
TarConstants
public class TarEntry extends 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;

  • Field Details

    • MAX_NAMELEN

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

    • DEFAULT_DIR_MODE

      public static final int DEFAULT_DIR_MODE
      Default permissions bits for directories
      See Also:

    • DEFAULT_FILE_MODE

      public static final int DEFAULT_FILE_MODE
      Default permissions bits for files
      See Also:

    • MILLIS_PER_SECOND

      public static final int MILLIS_PER_SECOND
      Convert millis to seconds
      See Also:

  • Constructor Details

    • 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.
      Parameters:
      name - the entry name

    • TarEntry

      public TarEntry(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(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(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[] 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.

  • Method Details

    • 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(Object it)
      Determine if the two entries are equal. Equality is determined by the header names being equal.
      Overrides:
      equals in class 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 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 descendent of this.
      Returns:
      True if entry is a descendant of this.

    • 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.

    • setMode

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

    • getLinkName

      public String getLinkName()
      Get this entry's link name.
      Returns:
      This entry's link 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.
      Returns:
      time This entry's new modification time.

    • getFile

      public 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.

    • 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

    • isDirectory

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

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

    • 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.