public
class
FileOutputStream
extends OutputStream
| java.lang.Object | ||
| ↳ | java.io.OutputStream | |
| ↳ | java.io.FileOutputStream | |
 Known Direct Subclasses
|
|
Known Indirect Subclasses
|
A file output stream is an output stream for writing data to a
File or to a FileDescriptor. Whether or not
a file is available or may be created depends upon the underlying
platform. Some platforms, in particular, allow a file to be opened
for writing by only one FileOutputStream (or other
file-writing object) at a time. In such situations the constructors in
this class will fail if the file involved is already open.
FileOutputStream is meant for writing streams of raw bytes
such as image data. For writing streams of characters, consider using
FileWriter.
Public constructors | |
|---|---|
FileOutputStream(String name)
Creates a file output stream to write to the file with the specified name. |
|
FileOutputStream(String name, boolean append)
Creates a file output stream to write to the file with the specified name. |
|
FileOutputStream(File file)
Creates a file output stream to write to the file represented by
the specified |
|
FileOutputStream(File file, boolean append)
Creates a file output stream to write to the file represented by
the specified |
|
FileOutputStream(FileDescriptor fdObj)
Creates a file output stream to write to the specified file descriptor, which represents an existing connection to an actual file in the file system. |
|
Public methods | |
|---|---|
void
|
close()
Closes this file output stream and releases any system resources associated with this stream. |
FileChannel
|
getChannel()
Returns the unique |
final
FileDescriptor
|
getFD()
Returns the file descriptor associated with this stream. |
void
|
write(byte[] b)
Writes |
void
|
write(byte[] b, int off, int len)
Writes |
void
|
write(int b)
Writes the specified byte to this file output stream. |
Protected methods | |
|---|---|
void
|
finalize()
Cleans up the connection to the file, and ensures that the
|
Inherited methods | |
|---|---|
From
class
java.io.OutputStream
| |
From
class
java.lang.Object
| |
From
interface
java.io.Closeable
| |
From
interface
java.io.Flushable
| |
From
interface
java.lang.AutoCloseable
| |
FileOutputStream (String name)
Creates a file output stream to write to the file with the
specified name. A new FileDescriptor object is
created to represent this file connection.
First, if there is a security manager, its checkWrite
method is called with name as its argument.
If the file exists but is a directory rather than a regular file, does
not exist but cannot be created, or cannot be opened for any other
reason then a FileNotFoundException is thrown.
| Parameters | |
|---|---|
name |
String:
the system-dependent filename |
| Throws | |
|---|---|
FileNotFoundException |
if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason |
SecurityException |
if a security manager exists and its
checkWrite method denies write access
to the file. |
See also:
FileOutputStream (String name, boolean append)
Creates a file output stream to write to the file with the specified
name. If the second argument is true, then
bytes will be written to the end of the file rather than the beginning.
A new FileDescriptor object is created to represent this
file connection.
First, if there is a security manager, its checkWrite
method is called with name as its argument.
If the file exists but is a directory rather than a regular file, does
not exist but cannot be created, or cannot be opened for any other
reason then a FileNotFoundException is thrown.
| Parameters | |
|---|---|
name |
String:
the system-dependent file name |
append |
boolean:
if true, then bytes will be written
to the end of the file rather than the beginning |
| Throws | |
|---|---|
FileNotFoundException |
if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason. |
SecurityException |
if a security manager exists and its
checkWrite method denies write access
to the file. |
See also:
FileOutputStream (File file)
Creates a file output stream to write to the file represented by
the specified File object. A new
FileDescriptor object is created to represent this
file connection.
First, if there is a security manager, its checkWrite
method is called with the path represented by the file
argument as its argument.
If the file exists but is a directory rather than a regular file, does
not exist but cannot be created, or cannot be opened for any other
reason then a FileNotFoundException is thrown.
| Parameters | |
|---|---|
file |
File:
the file to be opened for writing. |
| Throws | |
|---|---|
FileNotFoundException |
if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason |
SecurityException |
if a security manager exists and its
checkWrite method denies write access
to the file. |
FileOutputStream (File file, boolean append)
Creates a file output stream to write to the file represented by
the specified File object. If the second argument is
true, then bytes will be written to the end of the file
rather than the beginning. A new FileDescriptor object is
created to represent this file connection.
First, if there is a security manager, its checkWrite
method is called with the path represented by the file
argument as its argument.
If the file exists but is a directory rather than a regular file, does
not exist but cannot be created, or cannot be opened for any other
reason then a FileNotFoundException is thrown.
| Parameters | |
|---|---|
file |
File:
the file to be opened for writing. |
append |
boolean:
if true, then bytes will be written
to the end of the file rather than the beginning |
| Throws | |
|---|---|
FileNotFoundException |
if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason |
SecurityException |
if a security manager exists and its
checkWrite method denies write access
to the file. |
FileOutputStream (FileDescriptor fdObj)
Creates a file output stream to write to the specified file descriptor, which represents an existing connection to an actual file in the file system.
First, if there is a security manager, its checkWrite
method is called with the file descriptor fdObj
argument as its argument.
If fdObj is null then a NullPointerException
is thrown.
This constructor does not throw an exception if fdObj
is invalid.
However, if the methods are invoked on the resulting stream to attempt
I/O on the stream, an IOException is thrown.
| Parameters | |
|---|---|
fdObj |
FileDescriptor:
the file descriptor to be opened for writing |
| Throws | |
|---|---|
SecurityException |
if a security manager exists and its
checkWrite method denies
write access to the file descriptor |
See also:
void close ()
Closes this file output stream and releases any system resources associated with this stream. This file output stream may no longer be used for writing bytes.
If this stream has an associated channel then the channel is closed as well.
| Throws | |
|---|---|
IOException |
if an I/O error occurs. |
FileChannel getChannel ()
Returns the unique FileChannel
object associated with this file output stream.
The initial position of the returned channel will be equal to the
number of bytes written to the file so far unless this stream is in
append mode, in which case it will be equal to the size of the file.
Writing bytes to this stream will increment the channel's position
accordingly. Changing the channel's position, either explicitly or by
writing, will change this stream's file position.
| Returns | |
|---|---|
FileChannel |
the file channel associated with this file output stream |
FileDescriptor getFD ()
Returns the file descriptor associated with this stream.
| Returns | |
|---|---|
FileDescriptor |
the FileDescriptor object that represents
the connection to the file in the file system being used
by this FileOutputStream object. |
| Throws | |
|---|---|
IOException |
if an I/O error occurs. |
See also:
void write (byte[] b)
Writes b.length bytes from the specified byte array
to this file output stream.
| Parameters | |
|---|---|
b |
byte:
the data. |
| Throws | |
|---|---|
IOException |
if an I/O error occurs. |
Developers
void write (byte[] b,
int off,
int len)
Writes len bytes from the specified byte array
starting at offset off to this file output stream.
| Parameters | |
|---|---|
b |
byte:
the data. |
off |
int:
the start offset in the data. |
len |
int:
the number of bytes to write. |
| Throws | |
|---|---|
IOException |
if an I/O error occurs. |
void write (int b)
Writes the specified byte to this file output stream. Implements
the write method of OutputStream.
| Parameters | |
|---|---|
b |
int:
the byte to be written. |
| Throws | |
|---|---|
IOException |
if an I/O error occurs. |
void finalize ()
Cleans up the connection to the file, and ensures that the
close method of this file output stream is
called when there are no more references to this stream.
| Throws | |
|---|---|
IOException |
if an I/O error occurs. |
See also: