OutputStream (Java Platform SE 8 ) (original) (raw)
- java.io.OutputStream
All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
Direct Known Subclasses:
ByteArrayOutputStream, FileOutputStream, FilterOutputStream, ObjectOutputStream, OutputStream, PipedOutputStream
public abstract class OutputStream
extends Object
implements Closeable, Flushable
This abstract class is the superclass of all classes representing an output stream of bytes. An output stream accepts output bytes and sends them to some sink.
Applications that need to define a subclass ofOutputStream must always provide at least a method that writes one byte of output.
Since:
JDK1.0
See Also:
BufferedOutputStream, ByteArrayOutputStream, DataOutputStream, FilterOutputStream, InputStream, write(int)
Constructor Summary
Constructors
Constructor Description OutputStream() Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods
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. void write(byte[] b) Writes b.length bytes from the specified byte array to this output stream. void write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this output stream. abstract void write(int b) Writes the specified byte to this output stream. * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang") `[clone](../../java/lang/Object.html#clone--), [equals](../../java/lang/Object.html#equals-java.lang.Object-), [finalize](../../java/lang/Object.html#finalize--), [getClass](../../java/lang/Object.html#getClass--), [hashCode](../../java/lang/Object.html#hashCode--), [notify](../../java/lang/Object.html#notify--), [notifyAll](../../java/lang/Object.html#notifyAll--), [toString](../../java/lang/Object.html#toString--), [wait](../../java/lang/Object.html#wait--), [wait](../../java/lang/Object.html#wait-long-), [wait](../../java/lang/Object.html#wait-long-int-)`Constructor Detail
* #### OutputStream public OutputStream()Method Detail
* #### write public abstract void write(int b) throws [IOException](../../java/io/IOException.html "class in java.io") 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: `b` \- the `byte`. Throws: `[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs. In particular, an `IOException` may be thrown if the output stream has been closed. * #### write public void write(byte[] b) throws [IOException](../../java/io/IOException.html "class in java.io") Writes `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)`. Parameters: `b` \- the data. Throws: `[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs. See Also: [write(byte\[\], int, int)](../../java/io/OutputStream.html#write-byte:A-int-int-) * #### write public void write(byte[] b, int off, int len) throws [IOException](../../java/io/IOException.html "class in java.io") 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: `b` \- the data. `off` \- the start offset in the data. `len` \- the number of bytes to write. Throws: `[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs. In particular, an `IOException` is thrown if the output stream is closed. * #### flush public void flush() throws [IOException](../../java/io/IOException.html "class in java.io") Flushes this output stream and forces any buffered output bytes to be written out. The general contract of `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. The `flush` method of `OutputStream` does nothing. Specified by: `[flush](../../java/io/Flushable.html#flush--)` in interface `[Flushable](../../java/io/Flushable.html "interface in java.io")` Throws: `[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs. * #### close public void close() throws [IOException](../../java/io/IOException.html "class in java.io") 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. Specified by: `[close](../../java/io/Closeable.html#close--)` in interface `[Closeable](../../java/io/Closeable.html "interface in java.io")` Specified by: `[close](../../java/lang/AutoCloseable.html#close--)` in interface `[AutoCloseable](../../java/lang/AutoCloseable.html "interface in java.lang")` Throws: `[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2025, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.