java.io
Class BufferedOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.FilterOutputStream
          java.io.BufferedOutputStream

public class BufferedOutputStream

extends FilterOutputStream

The class implements a buffered output stream. By setting up such an output stream, an application can write bytes to the underlying output stream without necessarily causing a call to the underlying system for each byte written.

Since:

JDK1.0

Author:

Arthur van Hoff

Field Summary

protected byte[]	buf The internal buffer where data is stored.
protected int	count The number of valid bytes in the buffer.

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

BufferedOutputStream(OutputStream out)
Creates a new buffered output stream to write data to the specified underlying output stream with a default 512-byte buffer size.

BufferedOutputStream(OutputStream out, int size)
Creates a new buffered output stream to write data to the specified underlying output stream with the specified buffer size.

Method Summary

void	flush() Flushes this buffered output stream.
private void	flushBuffer() Flush the internal buffer
void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this buffered output stream.
void	write(int b) Writes the specified byte to this buffered output stream.

Methods inherited from class java.io.FilterOutputStream

close, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

buf

protected byte[] buf

The internal buffer where data is stored.

count

protected int count

The number of valid bytes in the buffer. This value is always in the range 0 through buf.length; elements buf[0] through buf[count-1] contain valid byte data.

Constructor Detail

BufferedOutputStream

public BufferedOutputStream(OutputStream out)

Creates a new buffered output stream to write data to the specified underlying output stream with a default 512-byte buffer size.

Parameters:

out - the underlying output stream.

BufferedOutputStream

public BufferedOutputStream(OutputStream out,
                            int size)

Creates a new buffered output stream to write data to the specified underlying output stream with the specified buffer size.

Parameters:

out - the underlying output stream.

size - the buffer size.

Throws:

IllegalArgumentException - if size <= 0.

Method Detail

flushBuffer

private void flushBuffer()
                  throws IOException

Flush the internal buffer

Throws:

IOException

write

public void write(int b)
           throws IOException

Writes the specified byte to this buffered output stream.

Overrides:

write in class FilterOutputStream

Parameters:

b - the byte to be written.

Throws:

IOException - if an I/O error occurs.

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Writes len bytes from the specified byte array starting at offset off to this buffered output stream.

Ordinarily this method stores bytes from the given array into this stream's buffer, flushing the buffer to the underlying output stream as needed. If the requested length is at least as large as this stream's buffer, however, then this method will flush the buffer and write the bytes directly to the underlying output stream. Thus redundant BufferedOutputStreams will not copy data unnecessarily.

Overrides:

write in class FilterOutputStream

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.write(int)

flush

public void flush()
           throws IOException

Flushes this buffered output stream. This forces any buffered output bytes to be written out to the underlying output stream.

Overrides:

flush in class FilterOutputStream

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out