Android
java.io
public class

java.io.FileOutputStream

java.lang.Object
java.io.OutputStream Closeable Flushable
java.io.FileOutputStream Closeable

FileOutputStream is a class whose underlying stream is represented by a file in the operating system. The bytes that are written to this stream are passed directly to the underlying operating system equivalent function. Since overhead may be high in writing to the OS, FileOutputStreams are usually wrapped with a BufferedOutputStream to reduce the number of times the OS is called.

BufferedOutputStream buf = new BufferedOutputStream(new FileOutputStream("aFile.txt"));

Known Direct Subclasses

See Also

Summary

Public Constructors

            FileOutputStream(File file)
Constructs a new FileOutputStream on the File file.
            FileOutputStream(File file, boolean append)
Constructs a new FileOutputStream on the File file.
            FileOutputStream(FileDescriptor fd)
Constructs a new FileOutputStream on the FileDescriptor fd.
            FileOutputStream(String filename)
Constructs a new FileOutputStream on the file named fileName.
            FileOutputStream(String filename, boolean append)
Constructs a new FileOutputStream on the file named filename.

Public Methods

          void  close()
Close the FileOutputStream.
          FileChannel  getChannel()
Returns the FileChannel equivalent to this output stream.
    final      FileDescriptor  getFD()
Returns a FileDescriptor which represents the lowest level representation of a OS stream resource.
          void  write(byte[] buffer)
Writes the entire contents of the byte array buffer to this FileOutputStream.
          void  write(int oneByte)
Writes the specified byte oneByte to this FileOutputStream.
          void  write(byte[] buffer, int offset, int count)
Writes count bytes from the byte array buffer starting at offset to this FileOutputStream.

Protected Methods

          void  finalize()
Frees any resources allocated to represent this FileOutputStream before it is garbage collected.
Methods inherited from class java.io.OutputStream
Methods inherited from class java.lang.Object
Methods inherited from interface java.io.Closeable
Methods inherited from interface java.io.Flushable

Details

Public Constructors

public FileOutputStream(File file)

Constructs a new FileOutputStream on the File file. If the file exists, it is written over. See the constructor which can append to the file if so desired.

Parameters

file the File on which to stream reads.

Throws

FileNotFoundException If the file cannot be opened for writing.

public FileOutputStream(File file, boolean append)

Constructs a new FileOutputStream on the File file. If the file exists, it is written over. The parameter append determines whether or not the file is opened and appended to or just opened empty.

Parameters

file the File on which to stream reads.
append a boolean indicating whether or not to append to an existing file.

Throws

FileNotFoundException If the file cannot be opened for writing.

public FileOutputStream(FileDescriptor fd)

Constructs a new FileOutputStream on the FileDescriptor fd. The file must already be open, therefore no FileIOException will be thrown.

Parameters

fd the FileDescriptor on which to stream writes.

public FileOutputStream(String filename)

Constructs a new FileOutputStream on the file named fileName. If the file exists, it is written over. See the constructor which can append to the file if so desired. The fileName may be absolute or relative to the System property "user.dir".

Parameters

filename the file on which to stream writes.

Throws

FileNotFoundException If the filename cannot be opened for writing.

public FileOutputStream(String filename, boolean append)

Constructs a new FileOutputStream on the file named filename. If the file exists, it is written over. The parameter append determines whether or not the file is opened and appended to or just opened empty. The filename may be absolute or relative to the System property "user.dir".

Parameters

filename the file on which to stream writes.
append a boolean indicating whether or not to append to an existing file.

Throws

FileNotFoundException If the filename cannot be opened for writing.

Public Methods

public void close()

Close the FileOutputStream. This implementation closes the underlying OS resources allocated to represent this stream.

Throws

IOException If an error occurs attempting to close this FileOutputStream.

public FileChannel getChannel()

Returns the FileChannel equivalent to this output stream.

The file channel is write-only and has an initial position within the file that is the same as the current position of this FileOutputStream within the file. All changes made to the underlying file descriptor state via the channel are visible by the output stream and vice versa.

Returns

  • the file channel representation for this FileOutputStream.

public final FileDescriptor getFD()

Returns a FileDescriptor which represents the lowest level representation of a OS stream resource.

Returns

  • a FileDescriptor representing this FileOutputStream.

Throws

IOException If the Stream is already closed and there is no FileDescriptor.

public void write(byte[] buffer)

Writes the entire contents of the byte array buffer to this FileOutputStream.

Parameters

buffer the buffer to be written

Throws

IOException If an error occurs attempting to write to this FileOutputStream.

public void write(int oneByte)

Writes the specified byte oneByte to this FileOutputStream. Only the low order byte of oneByte is written.

Parameters

oneByte the byte to be written

Throws

IOException If an error occurs attempting to write to this FileOutputStream.

public void write(byte[] buffer, int offset, int count)

Writes count bytes from the byte array buffer starting at offset to this FileOutputStream.

Parameters

buffer the buffer to be written
offset offset in buffer to get bytes
count number of bytes in buffer to write

Throws

IOException If an error occurs attempting to write to this FileOutputStream.
IndexOutOfBoundsException If offset or count are outside of bounds.
NullPointerException If buffer is null.

Protected Methods

protected void finalize()

Frees any resources allocated to represent this FileOutputStream before it is garbage collected. This method is called from the Java Virtual Machine.

Throws

IOException If an error occurs attempting to finalize this FileOutputStream.
Copyright 2007 Google Inc. Build 0.9_r1-98467 - 14 Aug 2008 18:48