Java IO.pdf - Nguyen Dang Binh

}
}
synchronized (in) {
synchronized (out) {
BufferedInputStream bin = new BufferedInputStream(in);
BufferedOutputStream bout = new BufferedOutputStream(out);
}
}
while (true) {
int datum = bin.read();
if (datum == -1) break;
bout.write(datum);
}
bout.flush();
Java I/O
This copy() method copies byte by byte, which is normally not very efficient. However,
almost all the copies take place in memory, because the input stream and the output stream are
buffered. Therefore, this is reasonably quick.
It wouldn't hurt to read and write byte arrays in the copy() method instead of individual
bytes, as long as the arrays you were reading and writing were significantly smaller than the
buffer size. However, one level of buffering is usually sufficient. Detailed performance
calculations depend on the virtual machine and the host OS, so it's hard to make any definite
conclusions.
Also note that the output stream is deliberately flushed. The data only reaches its eventual
destination in the underlying stream out when the stream is flushed or the buffer fills up.
Therefore, it's important to call flush() explicitly before the method returns.
6.3.1 BufferedInputStream Details
The buffer and the current state of the buffer are stored in protected fields. The buffer itself is
a byte array called buf; the number of bytes in the buffer is an int named count; the index of
the next byte that will be returned by read() is an int called pos; the mark, if any, is an int
called markpos; the read-ahead limit be- fore the mark is invalidated is an int called
marklimit. Subclasses of BufferedInputStream can directly access all these fields, which
can be important for performance.
protected byte[] buf
protected int count
protected int pos
protected int markpos
protected int marklimit
BufferedInputStream only overrides methods from InputStream. It does not declare any
new methods of its own. Marking and resetting are supported.
public synchronized int read() throws IOException
public synchronized int read(byte[] data, int offset, int length)
throws IOException
public synchronized long skip(long n) throws IOException
public synchronized int available() throws IOException
public synchronized void mark(int readLimit)
public synchronized void reset() throws IOException
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