byte[] buf=new byte[100];
buf[0]='B'; buf[1]='e'; buf[2]='l'; buf[3]='a';
ByteArrayDataInputStream in=new ByteArrayDataInputStream(buf);
assert in.position() == 0;
assert in.limit() == buf.length;
assert in.capacity() == buf.length;
in=new ByteArrayDataInputStream(buf, 0, 4);
assert in.position() == 0;
assert in.limit() == 4;
assert in.capacity() == buf.length;