Integer increment and concat with string

Question

I'm in the process of creating a method to generate a unique id, of type Integer, and was wondering how to do the following.

In my Object I want to call the generateUniqueID method from my setter method. The generateUniqueID will generate an incrementing number and then append it to a string

eg Reminder-1, Reminder-2 etc....

I'm not quite sure how to do this though and was wondering if anyone could help?

Thank you

Answer 1

As long as there is no concurrency.

private static int reminderID = 1;

public synchronized static String generateUniqueID() {
    String uniqueId = "Reminder-" + reminderID;
    reminderID++;
    return uniqueId;
}

Answer 2

private static final AtomicInteger counter = new AtomicInteger(1);

public String generateUniqueID() {
    return "Reminder-" + counter.getAndIncrement();
}

Answer 3

If you have lot of these you can use base 36 encoding.

private final AtomicLong counter = new AtomicLong();

public String generateUniqueID() {
    return "Reminder-" + Long.toString(counter.incrementAndGet(), 36);
}

Answer 4

Perhaps:

class Classname {
    private static int highestId = 0;
    int object_id;

    public Classname() {
        object_id = highestId++;
    }
}

Would work?

As noted above, this is not threadsafe.