public void test_position() throws IOException { File tmp = File.createTempFile("hmy", "tmp"); tmp.deleteOnExit(); RandomAccessFile f = new RandomAccessFile(tmp, "rw"); FileChannel ch = f.getChannel(); MappedByteBuffer mbb = ch.map(MapMode.READ_WRITE, 0L, 100L); ch.close(); mbb.putInt(1, 1); mbb.position(50); mbb.putInt(50); mbb.flip(); mbb.get(); assertEquals(1, mbb.getInt()); mbb.position(50); assertEquals(50, mbb.getInt()); }