12. RandomAccessFile class

• Class java.io.RandomAccessFile provides random access to a file for reading and/or writing

• Constructors of the RandomAccessFile class:

  
      Constructor                         Throws
      ----------------------------------  ----------------------
      RandomAccessFile(File, stringMode)  FileNotFoundException
      RandomAccessFile(stringPathName,
          stringMode)                     FileNotFoundException
  
  

• Access mode values:

  • "r" -- Open for reading only

  • "rw" -- Open for reading and writing. If the file doesn't already exist, an attempt will be made to create it

  • "rws" -- Open for reading and writing. Updates to file content or metadata written synchronously to storage device

  • "rwd" -- Open for reading and writing. Updates to file content written synchronously to the storage device

• Notes:

  • The "rwd" mode forces writes to be synchronous with the physical media, which can be a very slow mode.

  • Latest RandomAccessFile implementation uses the NIO ( Java New IO ) classes in its implementation -- FileChannel and FileDescriptor.