Java: When is a static initialization block useful?

You can use try/catch block inside static{} like below:

MyCode{

    static Scanner input = new Scanner(System.in);
    static boolean flag = true;
    static int B = input.nextInt();
    static int H = input.nextInt();

    static{
        try{
            if(B <= 0 || H <= 0){
                flag = false;
                throw new Exception("Breadth and height must be positive");
            }
        }catch(Exception e){
            System.out.println(e);
        }

    }
}

PS: Referred from this!

A static initialization blocks allows more complex initialization, for example using conditionals:

static double a;
static {
    if (SomeCondition) {
      a = 0;
    } else {
      a = 1;
    }
}

Or when more than just construction is required: when using a builder to create your instance, exception handling or work other than creating static fields is necessary.

A static initialization block also runs after the inline static initializers, so the following is valid:

static double a;
static double b = 1;

static {
    a = b * 4; // Evaluates to 4
}