java.io
Class BufferedOutputStream

java.lang.Object
  extended byjava.io.OutputStream
      extended byjava.io.FilterOutputStream
          extended byjava.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