public class SomeClass {
    static {
        System.out.println("Static initialize... OK");
        // Block executes first.
        // This block executes even if no instances instantiated.
    }

    {
        System.out.println("Instance initialize... OK");
        // Block executes second.
        // This block executes when instance is instantiated BEFORE the constructor.
    }

    public SomeClass() {
        System.out.println("Constructor initialize... OK");
        // Constructor executes third.
    }

    public static void main(String[] args) {
        new SomeClass();
        // Result:
        // Static initialize... OK
        // Instance initialize... OK
        // Constructor initialize... OK
    }
}