Java Reference
In-Depth Information
import java.io.FilterInputStream;
import java.io.InputStream;
import java.io.IOException;
class ScrambledInputStream extends FilterInputStream
{
private int[] map;
ScrambledInputStream(InputStream in, int[] map)
{
super(in);
if (map == null)
throw new NullPointerException("map is null");
if (map.length != 256)
throw new IllegalArgumentException("map.length !=
256");
this.map = map;
}
@Override
public int read() throws IOException
{
int value = in.read();
return (value == -1) ? -1 : map[value];
}
@Override
public int read(byte[] b, int off, int len) throws IOEx-
ception
{
int nBytes = in.read(b, off, len);
if (nBytes <= 0)
return nBytes;
for (int i = 0; i < nBytes; i++)
b[off+i] = (byte) map[off+i];
return nBytes;
}
}
