How to reverse an enumeration?… here is a solution to the problem.
How to reverse an enumeration?
I have an enum class below
public class PTalkCommand {
public enum Code {
CLR((byte) 0),
ACK((byte) 170),
SER((byte) 0),
NAK((byte) 0),
TIMEOUT((byte) 255),
DIP((byte) 173),
REQUEST_CHECKSUM((byte) 162),
REQUEST_STATUS((byte) 181),
REQUEST_FLASH((byte) 166),
REQUEST_CONFIG_READ((byte) 249),
REQUEST_STATUS_SCREEN((byte) 208),
REQUEST_MULTIPULSE_CONFIG((byte) 0),
REQUEST_SERIAL_NUMBER((byte) 62),
REQUEST_BILL_NAMES((byte) 64),
DO_FLASH((byte) 161),
DO_MOTOR((byte) 81),
DO_SEND_EE_PROM_DATA((byte) 50),
DO_ENTER_FILE_NAME((byte) 61),
DO_ENTER_SERIAL_NUMBER((byte) 63),
DO_CONFIGURE((byte) 248),
DO_MULTIPULSE_CONFIG((byte) 210),
DATA_COLLECTION_RAW_SENSORS((byte) 84),
DATA_COLLECTION_MODE((byte) 0),
DATA_COLLECTION_CAL_POINTS((byte) 0),
DATA_COLLECTION_WITH_DEBUG((byte) 68),
DATA_COLLECTION_EXIT((byte) 119),
CALIBRATE_OAS((byte) 150),
CALIBRATE_NOTE_PRESENT_PUNCH((byte) 0),
CALIBRATE_CB_REMOVED((byte) 0),
CALIBRATE_IR_BLUE_TRANSMISSIVE((byte) 0),
CALIBRATE_IR_REFLECTIVE((byte) 0),
CALIBRATE_BLUE_REFLECTIVE((byte) 0),
CALIBRATE_MONITOR_VOLTAGES((byte) 0),
STACKER_OR_STACKERLESS((byte) 158),
CALIBRATE_CURVE_LEVER((byte) 0),
REQUEST_BEZEL_REV_LEV((byte) 73),
DO_BEZEL_UPDATE((byte) 82);
private final byte valueCode;
private Code(byte value) {
this.valueCode = value;
}
public byte getValue() {
return valueCode;
}
}
}
And hope it is in reverse order. In .NET, the code looks like this
public void Prepend (PTalkCommand.Code[] commands) {
IEnumerable<PTalkCommand.Code> enumerable = commands. Reverse<PTalkCommand.Code> ();
foreach (PTalkCommand.Code current in enumerable) {
base. Insert (0, (byte)current);
}
}
In Java, I’m trying to do the same thing.
Enumeration<PTalkCommand.Code> enumerable = commands. ???????
However, I can’t. Please tell me how to do the same thing in Java?
Solution
There is a built-in .values()
method that returns an array of all enumeration constants. You can iterate it backwards.
Code[] values = Code.values();
for (int i = values.length - 1; i >= 0; i--) {
Code next = values[i];
do your thing
}