Closeable
, Flushable
, AutoCloseable
ByteArrayOutputStream
, FileOutputStream
, FilterOutputStream
, ObjectOutputStream
, PipedOutputStream
public abstract class OutputStream extends Object implements Closeable, Flushable
Applications that need to define a subclass of OutputStream
must always provide at least a method that writes one byte of output.
Constructor | Description |
---|---|
OutputStream() |
Constructor for subclasses to call. |
Modifier and Type | Method | Description |
---|---|---|
void |
close() |
Closes this output stream and releases any system resources associated with this stream. |
void |
flush() |
Flushes this output stream and forces any buffered output bytes to be written out. |
static OutputStream |
nullOutputStream() |
Returns a new OutputStream which discards all bytes. |
void |
write |
Writes b.length bytes from the specified byte array to this output stream. |
void |
write |
Writes len bytes from the specified byte array starting at offset off to this output stream. |
abstract void |
write |
Writes the specified byte to this output stream. |
public OutputStream()
public static OutputStream nullOutputStream()
OutputStream
which discards all bytes. The returned stream is initially open. The stream is closed by calling the close()
method. Subsequent calls to close()
have no effect. While the stream is open, the write(int)
,
write(byte[])
, and write(byte[], int, int)
methods do nothing. After the stream has been closed, these methods all throw
IOException
.
The flush()
method does nothing.
OutputStream
which discards all bytespublic abstract void write(int b) throws IOException
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.b
- the byte
.IOException
- if an I/O error occurs. In particular, an IOException
may be thrown if the output stream has been closed.public void write(byte[] b) throws IOException
b.length
bytes from the specified byte array to this output stream. The general contract for write(b)
is that it should have exactly the same effect as the call write(b, 0, b.length)
.b
- the data.IOException
- if an I/O error occurs.public void write(byte[] b, int off, int len) throws IOException
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. 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.
write
method of OutputStream
calls the write method of one argument on each of the bytes to be written out.b
- the data.off
- the start offset in the data.len
- the number of bytes to write.IOException
- if an I/O error occurs. In particular, an IOException
is thrown if the output stream is closed.IndexOutOfBoundsException
- If off
is negative, len
is negative, or len
is greater than b.length - off
public void flush() throws IOException
flush
is that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination. If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.
flush
in interface Flushable
flush
method of OutputStream
does nothing.IOException
- if an I/O error occurs.public void close() throws IOException
close
is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.close
in interface AutoCloseable
close
in interface Closeable
close
method of OutputStream
does nothing.IOException
- if an I/O error occurs.
© 1993, 2023, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/io/OutputStream.html