java - ID generator for the Objects created

Question

I need a class which creates Objects assigning an ID to each Object created. This ID is as usual an int attribute to the class. I want this value (ID) to be increased each time an Object is created and then to be assigned to that Object starting with 1. It strikes me that I need a static int attribute.

How can I initialize this static attribute?

Should I create a separate method to do the increment of the ID (as an ID generator) which is invoked inside the constructor?

What is in general the most effective and well-designed manner to implement that?

Answer 1

You could also try java.util.concurrent.AtomicInteger, which generates IDs in

1. a atomic way and
2. sequential

You may use this in a static context like:

private static final AtomicInteger sequence = new AtomicInteger();
private SequenceGenerator() {}

public static int next() {
    return sequence.incrementAndGet();
}