Java tutorial
import java.nio.ByteBuffer; import java.util.Arrays; public class Main { public static void main(String[] argv) throws Exception { ByteBuffer bbuf = ByteBuffer.allocate(10); int capacity = bbuf.capacity(); // 10 System.out.println(capacity); bbuf.putShort(2, (short) 123); ByteBuffer bb = bbuf.compact(); System.out.println(Arrays.toString(bb.array())); } }