Class DirFile

java.lang.Object
java.io.File
org.apache.derby.impl.io.DirFile
All Implemented Interfaces:
Serializable, Comparable<File>, StorageFile
class DirFile extends File implements StorageFile
This class provides a disk based implementation of the StorageFile interface. It is used by the database engine to access persistent data and transaction logs under the directory (default) subsubprotocol.

  • Field Details

  • Constructor Details

    • DirFile

      DirFile(String path)
      Construct a DirFile from a path name.
      Parameters:
      path - The path name.

    • DirFile

      DirFile(String directoryName, String fileName)
      Construct a DirFile from a directory name and a file name.
      Parameters:
      directoryName - The directory part of the path name.
      fileName - The name of the file within the directory.

    • DirFile

      DirFile(DirFile directoryName, String fileName)
      Construct a DirFile from a directory name and a file name.
      Parameters:
      directoryName - The directory part of the path name.
      fileName - The name of the file within the directory.

  • Method Details

    • getParentDir

      public StorageFile getParentDir()
      Get the name of the parent directory if this name includes a parent.
      Specified by:
      getParentDir in interface StorageFile
      Returns:
      An StorageFile denoting the parent directory of this StorageFile, if it has a parent, null if it does not have a parent.

    • getOutputStream

      public OutputStream getOutputStream() throws FileNotFoundException
      Creates an output stream from a file name.
      Specified by:
      getOutputStream in interface StorageFile
      Returns:
      an output stream suitable for writing to the file.
      Throws:
      FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.

    • getOutputStream

      public OutputStream getOutputStream(boolean append) throws FileNotFoundException
      Creates an output stream from a file name.
      Specified by:
      getOutputStream in interface StorageFile
      Parameters:
      append - If true then data will be appended to the end of the file, if it already exists. If false and a normal file already exists with this name the file will first be truncated to zero length.
      Returns:
      an output stream suitable for writing to the file.
      Throws:
      FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.

    • getInputStream

      public InputStream getInputStream() throws FileNotFoundException
      Creates an input stream from a file name.
      Specified by:
      getInputStream in interface StorageFile
      Returns:
      an input stream suitable for reading from the file.
      Throws:
      FileNotFoundException - if the file is not found.

    • getExclusiveFileLock

      public int getExclusiveFileLock() throws StandardException
      Get an exclusive lock. This is used to ensure that two or more JVMs do not open the same database at the same time.
      Specified by:
      getExclusiveFileLock in interface StorageFile
      Returns:
      EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE if the lock cannot be acquired because it is already held.
      EXCLUSIVE_FILE_LOCK if the lock was successfully acquired.
      NO_FILE_LOCK_SUPPORT if the system does not support exclusive locks.
      Throws:
      StandardException

    • releaseExclusiveFileLock

      public void releaseExclusiveFileLock()
      Release the resource associated with an earlier acquired exclusive lock
      Specified by:
      releaseExclusiveFileLock in interface StorageFile
      See Also:

    • getRandomAccessFile

      public StorageRandomAccessFile getRandomAccessFile(String mode) throws FileNotFoundException
      Get a random access (read/write) file.
      Specified by:
      getRandomAccessFile in interface StorageFile
      Parameters:
      mode - "r", "rw", "rws", or "rwd". The "rws" and "rwd" modes specify that the data is to be written to persistent store, consistent with the java.io.RandomAccessFile class ("synchronized" with the persistent storage, in the file system meaning of the word "synchronized"). However the implementation is not required to implement the "rws" or "rwd" modes. The implementation may treat "rws" and "rwd" as "rw". It is up to the user of this interface to call the StorageRandomAccessFile.sync method. If the "rws" or "rwd" modes are supported and the RandomAccessFile was opened in "rws" or "rwd" mode then the implementation of StorageRandomAccessFile.sync need not do anything.
      Returns:
      an object that can be used for random access to the file.
      Throws:
      IllegalArgumentException - if the mode argument is not equal to one of "r", "rw".
      FileNotFoundException - if the file exists but is a directory rather than a regular file, or cannot be opened or created for any other reason .
      See Also:

    • renameTo

      public boolean renameTo(StorageFile newName)
      Rename the file denoted by this name. Note that StorageFile objects are immutable. This method renames the underlying file, it does not change this StorageFile object. The StorageFile object denotes the same name as before, however the exists() method will return false after the renameTo method executes successfully.

      It is not specified whether this method will succeed if a file already exists under the new name.

      Specified by:
      renameTo in interface StorageFile
      Parameters:
      newName - the new name.
      Returns:
      true if the rename succeeded, false if not.

    • deleteAll

      public boolean deleteAll()
      Deletes the named file and, if it is a directory, all the files and directories it contains.
      Specified by:
      deleteAll in interface StorageFile
      Returns:
      true if the named file or directory is successfully deleted, false if not

    • limitAccessToOwner

      public void limitAccessToOwner() throws IOException
      Description copied from interface: StorageFile
      Use when creating a new file. By default, a file created in an underlying file system, if applicable, will have read and write access for the file owner unless the property derby.useDefaultFilePermissions is set to true.
      Specified by:
      limitAccessToOwner in interface StorageFile
      Throws:
      IOException