FileOutputStream

public class FileOutputStream extends OutputStream

An output stream that writes bytes to a file. If the output file exists, it can be replaced or appended to. If it does not exist, a new file will be created.

   File file = ...
   OutputStream out = null;
   try {
     out = new BufferedOutputStream(new FileOutputStream(file));
     ...
   } finally {
     if (out != null) {
       out.close();
     }
   }
 

This stream is not buffered. Most callers should wrap this stream with a BufferedOutputStream.

Use FileWriter to write characters, as opposed to bytes, to a file.

Public Constructor Summary

FileOutputStream(File file)
Constructs a new FileOutputStream that writes to file.
FileOutputStream(File file, boolean append)
Constructs a new FileOutputStream that writes to file.
FileOutputStream(FileDescriptor fd)
Constructs a new FileOutputStream that writes to fd.
FileOutputStream(String path)
Constructs a new FileOutputStream that writes to path.
FileOutputStream(String path, boolean append)
Constructs a new FileOutputStream that writes to path.

Public Method Summary

void
close()
Closes this output stream and releases any system resources associated with this stream.
FileChannel
getChannel()
Returns a write-only FileChannel that shares its position with this stream.
final FileDescriptor
getFD()
Returns the underlying file descriptor.
void
write(byte[] buffer, int byteOffset, int byteCount)
Writes len bytes from the specified byte array starting at offset off to this output stream.
void
write(int oneByte)
Writes the specified byte to this output stream.

Protected Method Summary

void

Inherited Method Summary

Public Constructors

public FileOutputStream (File file)

Constructs a new FileOutputStream that writes to file. The file will be truncated if it exists, and created if it doesn't exist.

Parameters
file
Throws
FileNotFoundException if file cannot be opened for writing.

public FileOutputStream (File file, boolean append)

Constructs a new FileOutputStream that writes to file. If append is true and the file already exists, it will be appended to; otherwise it will be truncated. The file will be created if it does not exist.

Parameters
file
append
Throws
FileNotFoundException if the file cannot be opened for writing.

public FileOutputStream (FileDescriptor fd)

Constructs a new FileOutputStream that writes to fd.

Parameters
fd
Throws
NullPointerException if fd is null.

public FileOutputStream (String path)

Constructs a new FileOutputStream that writes to path. The file will be truncated if it exists, and created if it doesn't exist.

Parameters
path
Throws
FileNotFoundException if file cannot be opened for writing.

public FileOutputStream (String path, boolean append)

Constructs a new FileOutputStream that writes to path. If append is true and the file already exists, it will be appended to; otherwise it will be truncated. The file will be created if it does not exist.

Parameters
path
append
Throws
FileNotFoundException if the file cannot be opened for writing.

Public Methods

public void close ()

Closes this output stream and releases any system resources associated with this stream. The general contract of close is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.

The close method of OutputStream does nothing.

Throws
IOException

public FileChannel getChannel ()

Returns a write-only FileChannel that shares its position with this stream.

public final FileDescriptor getFD ()

Returns the underlying file descriptor.

Throws
IOException

public void write (byte[] buffer, int byteOffset, int byteCount)

Writes len bytes from the specified byte array starting at offset off to this output stream. The general contract for write(b, off, len) is that some of the bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation.

The write method of OutputStream calls the write method of one argument on each of the bytes to be written out. Subclasses are encouraged to override this method and provide a more efficient implementation.

If b is null, a NullPointerException is thrown.

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

Parameters
buffer the data.
byteOffset the start offset in the data.
byteCount the number of bytes to write.
Throws
IOException

public void write (int oneByte)

Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Subclasses of OutputStream must provide an implementation for this method.

Parameters
oneByte the byte.
Throws
IOException

Protected Methods

protected void finalize ()

Throws
IOException