Java IO.pdf - Nguyen Dang Binh

public class TeeOutputStream extends FilterOutputStream {
}
OutputStream out1;
OutputStream out2;
public TeeOutputStream(OutputStream stream1, OutputStream stream2) {
super(stream1);
out1 = stream1;
out2 = stream2;
}
public synchronized void write(int b) throws IOException {
out1.write(b);
out2.write(b);
}
public synchronized void write(byte[] data, int offset, int length)
throws IOException {
out1.write(data, offset, length);
out2.write(data, offset, length);
}
public void flush() throws IOException {
out1.flush();
out2.flush();
}
public void close() throws IOException {
out1.close();
out2.close();
}
Java I/O
It would be possible to store one of the output streams in FilterOutputStream's protected
out field and the other in a field in this class. However, it's simpler and cleaner to maintain
the parallelism between the two streams by storing them both in the TeeOutputStream class.
I've synchronized the write() methods to make sure that two different threads don't try to
write to the same TeeOutputStream at the same time. Depending on unpredictable threadscheduling
issues, this could lead to data being written out of order or in different orders on
different streams. It's important to make sure that one write is completely finished on all
streams before the next write begins.
Example 6.6 demonstrates how one might use this class to write a TeeCopier program that
copies one file into two separate, new files.
Example 6.6. The TeeCopier Program
import java.io.*;
import com.macfaq.io.*;
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