Class FileWriter

Class used to write to files residing in filesystem.

Implemented Interfaces

Constructors

• (fileWriter) new fileWriter <string filename> [append <bool appendToEnd = false>]

Methods

• set position to <int newPosition>
• (int) get position
• (int) get size

main
  FileWriter fw = null
  try
    fw = new FileWriter "existingFile.dat" append true
  catch IOException e
    print "Could not open file for writing."
    return

  // contentsToWrite holds byte data which needs to be written.
  Byte[] contentsToWrite
  print "Initial file size: " & fw.get size
  fw.write contentsToWrite
  print "Size after write: " & fw.get size
  fw.close
            

(fileWriter) new fileWriter <string filename> [append <bool appendToEnd = false>]

Opens a file for writing. The file will be truncated unless appendToEnd parameter is true.

Parameters

• filename - Path and name of the file.
• appendToEnd - If true, the previous contents of the file is preserved and the current position is set to the end of the file. If false, the contents of the file will be truncated.

Exceptions

• InvalidArgumentException - If the filename is empty.
• IOException - If opening the file fails.

main
  FileWriter fw = null
  try
    fw = new FileWriter "existingFile.dat" append true
  catch IOException e
    print "File could not be opened."
    return

  print "File open successful."
  fw.close
                

set position to <int newPosition>

Sets the current position. The newPosition should be non-negative and not more than the current size of the file.

Parameters

• newPosition - New position.

Exceptions

• IOException - If setting the position fails.

main
  FileWriter fw = new FileWriter "file.dat"
  try
    fw.set position to 1000
  catch IOException e
    print "File position could not be set."
    return

  print "Position set successfully."
                

(int) get position

Gets the current file position.

Return value

• Current file position.

Exceptions

• IOException - If the file is not open

main
  FileWriter fw = new FileWriter "file.dat"
  print "Current file position: " & fw.get position
  fw.close
                

(int) get size

Gets the size of the file.

Return value

• The size of the file.

Exceptions

• IOException - If the file is not open.

main
  FileWriter fw = new FileWriter "file.dat"
  print "File size: " & fw.get size
  fw.close