public class FileOutputStream extends OutputStream implements Closeable
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.
BufferedOutputStream,
FileInputStream| Constructor and Description |
|---|
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. |
| Modifier and Type | Method and Description |
|---|---|
void |
close()
Closes this stream.
|
protected void |
finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
|
FileChannel |
getChannel()
Returns a write-only
FileChannel that shares its position with
this stream. |
FileDescriptor |
getFD()
Returns the underlying file descriptor.
|
void |
write(byte[] buffer,
int byteOffset,
int byteCount)
Writes
count bytes from the byte array buffer starting at
position offset to this stream. |
void |
write(int oneByte)
Writes a single byte to this stream.
|
flush, writepublic FileOutputStream(File file) throws FileNotFoundException
FileOutputStream that writes to file. The file will be
truncated if it exists, and created if it doesn't exist.FileNotFoundException - if file cannot be opened for writing.public FileOutputStream(File file, boolean append) throws FileNotFoundException
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.FileNotFoundException - if the file cannot be opened for writing.public FileOutputStream(FileDescriptor fd)
FileOutputStream that writes to fd.NullPointerException - if fd is null.public FileOutputStream(String path) throws FileNotFoundException
FileOutputStream that writes to path. The file will be
truncated if it exists, and created if it doesn't exist.FileNotFoundException - if file cannot be opened for writing.public FileOutputStream(String path, boolean append) throws FileNotFoundException
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.FileNotFoundException - if the file cannot be opened for writing.public void close()
throws IOException
OutputStreamclose in interface Closeableclose in interface AutoCloseableclose in class OutputStreamIOException - if an error occurs while closing this stream.protected void finalize()
throws IOException
ObjectNote that objects that override finalize are significantly more expensive than
objects that don't. Finalizers may be run a long time after the object is no longer
reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup.
Note also that finalizers are run on a single VM-wide finalizer thread,
so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary
for a class that has a native peer and needs to call a native method to destroy that peer.
Even then, it's better to provide an explicit close method (and implement
Closeable), and insist that callers manually dispose of instances. This
works well for something like files, but less well for something like a BigInteger
where typical calling code would have to deal with lots of temporaries. Unfortunately,
code that creates lots of temporaries is the worst kind of code from the point of view of
the single finalizer thread.
If you must use finalizers, consider at least providing your own
ReferenceQueue and having your own thread process that queue.
Unlike constructors, finalizers are not automatically chained. You are responsible for
calling super.finalize() yourself.
Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.
finalize in class ObjectIOExceptionpublic FileChannel getChannel()
FileChannel that shares its position with
this stream.public final FileDescriptor getFD() throws IOException
IOExceptionpublic void write(byte[] buffer,
int byteOffset,
int byteCount)
throws IOException
OutputStreamcount bytes from the byte array buffer starting at
position offset to this stream.write in class OutputStreambuffer - the buffer to be written.byteOffset - the start position in buffer from where to get bytes.byteCount - the number of bytes from buffer to write to this
stream.IOException - if an error occurs while writing to this stream.public void write(int oneByte)
throws IOException
OutputStreamoneByte is written to the stream.write in class OutputStreamoneByte - the byte to be written.IOException - if an error occurs while writing to this stream.