java.io.FileOutputStream
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
Summary
Public Constructors
Public Methods
Protected Methods
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void |
close() |
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void |
flush() |
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void |
write(byte[] buffer) |
abstract |
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void |
write(int oneByte) |
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void |
write(byte[] buffer, int offset, int count) |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
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. |
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. |
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. |
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. |
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.
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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.
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.
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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.
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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.
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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 |
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.
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