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.
BufferedOutputStream, 
ByteArrayOutputStream, 
DataOutputStream, 
FilterOutputStream, 
InputStream, 
write(int)| Constructor and Description | 
|---|
| OutputStream() | 
| Modifier and Type | Method and 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.lengthbytes from the specified byte array
 to this output stream. | 
| void | write(byte[] b,
     int off,
     int len)Writes  lenbytes from the specified byte array
 starting at offsetoffto this output stream. | 
| abstract void | write(int b)Writes the specified byte to this output stream. | 
public 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.
 
 Subclasses of OutputStream must provide an
 implementation for this method.
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.write(byte[], int, int)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.
 
 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.
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.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.
 The flush method of OutputStream does nothing.
flush in interface FlushableIOException - 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.
 
 The close method of OutputStream does nothing.
close in interface Closeableclose in interface AutoCloseableIOException - 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.
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