Is Static Initialization Good Programming Practice?

Question

In Java, we use the static initialization block:

private static final ApiKey API_KEY;

static {
    API_KEY = new ApiKey();
}

I was wondering that

• Is it a good programming practice?
• Where should we use this pattern?

Thanks in advance.

Answer 1

You could avoid using a static initializer block completely by using the following code:

private static final ApiKey API_KEY = new ApiKey();

or

private static final ApiKey API_KEY = createNewApiKey();

if the API key creation requires more than just a constructor call. That makes the code more readable, IMHO. But it doesn't matter much.

The static initializer is useful when two static fields depend on the same initialization code:

static {
    // compute some values
    A = somePartOfTheComputedValues();
    B = someOtherPartOfTheComputedValues();
}

But even then, A and B could perhaps be refactored into a single object, which would be created in a single method.

Answer 2

I like using enums whenever possible.

Instead of

class ApiKey {        
    private static final ApiKey API_KEY;

    static {
        API_KEY = new ApiKey();
    }

I would write

enum ApiKey {
    INSTANCE;