获取枚举字段的值

Question

I have an enumeration of byte values:

        public class ByteMessage {

            public enum Messages {
                ACK(0x01), CHAT(0x02), TURN(0x02), WAITING(0x03), REMATCH(0x04), DOUBLE(0x05), LOADREQUEST(0x06), LOADCOMPLETE(0x07),
                ROLL(0x08), DBLACCEPTORDECLINE(0x09), DBLRECV(0x0A), ALERTPEERNOPOSSIBLES(0x0B), UPDATEDIES(0x0C),
                SETTURN(0x0D), SETFIRSTROLL(0x0E), CALCPOSSIBLEINDEXES(0x0F), LOADGAMEREQUEST(0x10), LOADGAMECOMPLETE(0x11), PUSHSTATUSTEXT(0x12),
                ISDOUBLESOWNER(0x13);

                private final byte id;

                Messages(int id) {
                    this.id = (byte) id;
                }

                public byte getId() {
                    return this.id;
                }
            }

In another class I have this function:

            private void SendACK()
            {
                byte[] message = new byte[10];

                //Neither one of these will compile I have to return back the byte value of ACK
                //Byte a = new Byte(ByteMessage.M.ACK);
                //message[0] = ByteMessage.M.ACK;

Is there a way to get the byte value back out of the enum?

Thank you!

Answer 1

You should use the getId method of your Message enum :

message[0] = ByteMessage.M.ACK.getId();

Each constant in an enum is an instance of the enum . Just like classes, an instance of an enum can have data. In your specific case, each enum constant has an id which is initialized when the enum constant is created and can be accessed through the getId member method.