Question

Say I had a String: Hello! I have to do all this:

1. Convert string into byte array
2. Send byte array
3. Convert it back to a string (for later use)

This is my code…

//Sender
String send = "Hello!";
byte[] data = send.getBytes();
DatagramPacket packetOut = new DatagramPacket(data, data.length); //send blah blah

//Receiver
//blah blah receive it
String receive = new String(packetIn.getData()); //convert it back

What’s a quick and elegant way to do this for an array of integers?

Answer 1

For an int[] you can serialize using ObjectOutputStream but a faster way might be to use a ByteBuffer.

public static byte[] intsToBytes(int[] ints) {
    ByteBuffer bb = ByteBuffer.allocate(ints.length * 4);
    IntBuffer ib = bb.asIntBuffer();
    for (int i : ints) ib.put(i);
    return bb.array();
}

public static int[] bytesToInts(byte[] bytes) {
    int[] ints = new int[bytes.length / 4];
    ByteBuffer.wrap(bytes).asIntBuffer().get(ints);
    return ints;
}