OutputStream.write(byte[],int,int) has the bounds checks

        if ((off < 0) || (off > b.length) || (len < 0) ||
                   ((off + len) > b.length) || ((off + len) < 0)) {
            throw new IndexOutOfBoundsException();
        }

whereas InputStream.read(byte[],int,int) has

        if (off < 0 || len < 0 || len > b.length - off) {
            throw new IndexOutOfBoundsException();
        }

which appear to subsume the checks in OS::write. The write() checks should be changed to the set used in read(). With this change, the OutputStream::write documentation

     * If <code>off</code> is negative, or <code>len</code> is negative, or
     * <code>off+len</code> is greater than the length of the array
     * {@code b}, then an {@code IndexOutOfBoundsException} is thrown.

would no longer correspond exactly to the implementation but would not be strictly inaccurate so no change to it should be necessary.