using ByteBuffer

public static void main(String[] args)
{
// Create a ByteBuffer using a byte array
byte[] bytes = new byte[10];
ByteBuffer buf = ByteBuffer.wrap(bytes);

// Create a non-direct ByteBuffer with a 10 byte capacity
// The underlying storage is a byte array.
buf = ByteBuffer.allocate(10);

// Create a direct (memory-mapped) ByteBuffer with a 10 byte capacity.
buf = ByteBuffer.allocateDirect(10);

// Get the ByteBuffer's capacity
int capacity = bbuf.capacity(); // 10

// Use the absolute get(). This method does not affect the position.
byte b = bbuf.get(5); // position=0

// Set the position
bbuf.position(5);

// Use the relative get()
b = bbuf.get();

// Get the new position
int pos = bbuf.position(); // 6

// Get remaining byte count
int rem = bbuf.remaining(); // 4

// Set the limit
bbuf.limit(7); // remaining=1

// This convenience method sets the position to 0
bbuf.rewind(); // remaining=7

// Use the absolute put(). This method does not affect the position.
bbuf.put((byte)0xFF); // position=0

// Use the relative put()
bbuf.put((byte)0xFF);

// This convenience method sets the position to 0
bbuf.rewind(); // remaining=7


/*
Use ByteBuffer to store Strings
*/
// Create a character ByteBuffer
CharBuffer cbuf = buf.asCharBuffer();

// Write a string
cbuf.put("str");

// Convert character ByteBuffer to a string.
// Uses characters between current position and limit so flip it first
cbuf.flip();
String s = cbuf.toString(); // str Does not affect position

// Get a substring
int start = 2; // start is relative to cbuf's current position
int end = 5;
CharSequence sub = cbuf.subSequence(start, end); // str

/*
Set Byte Ordering for a ByteBuffer
*/
// Get default byte ordering
ByteOrder order = buf.order(); // ByteOrder.BIG_ENDIAN

// Put a multibyte value
buf.putShort(0, (short)123);
buf.get(0); // 0
buf.get(1); // 123

// Set to little endian
buf.order(ByteOrder.LITTLE_ENDIAN);

// Put a multibyte value
buf.putShort(0, (short)123);
buf.get(0); // 123
buf.get(1); // 0
}