if else cascading replacement: best option [on hold]

I am developing a simple java program which is run from command prompt using the JAR that I built. My program involves a lot of if conditions. My scenario is like, even if one if condition fails there is no point in running the remaining program.

When an if condition fails I want to do the following.

1. I want to show the reason for stopping the program
2. I want to quit running the program.

When an if condition validates to true, I want to continue with my execution and check the next if condition

Approach 1

I am aware that this can be achieved by using if else construct. But it leads to a lot of if else cascading and makes the code less readable and maintainable. Please find the sample below

if(name!=null){
            //some code here before next if condition
            if(gender!=null){
                //some code here before next if condition
                if(age==20){
                    //some code here before next if condition
                    if(zip!=null){
                        //some code here before next if condition
                        if(country!=null){
                            //some code here before next if condition..........
                        }
                        else{
                            System.out.println("country can't be null");
                        }
                    }
                    else{
                        System.out.println("zip can't be null");
                    }
                }
                else{
                    System.out.println("age should be 20");
                }
            }
            else{
                System.out.println("gender can't be null");
            }
        }
        else{
            System.out.println("name can't be null");
        }

Approach 2:

I was wondering if using System.exit(0) could be a good alternative to avoid cascading. Please find the sample below.

if(name==null){
            System.out.println("name can't be null");
            System.exit(0);
        }
        //some code here before next if condition
        if(gender==null){
            System.out.println("gender can't be null");
            System.exit(0);
        }
        //some code here before next if condition
        if(age==0){
            System.out.println("age should be 20");
            System.exit(0);
        }
        //some code here before next if condition
        if(zip==null){
            System.out.println("zip can't be null");
            System.exit(0);
        }
        //some code here before next if condition
        if(country==null){
            System.out.println("country can't be null");
            System.exit(0);
        }

Approach 3:

After some research I got to know that a custom exception can be thrown as well. Please find the below code.

try {
            if (name == null) {
                throw new MyCustomException("name can't be null");
            }
            // some code here before next if condition
            if (gender == null) {
                throw new MyCustomException("gender can't be null");
            }
            // some code here before next if condition
            if (age == 0) {
                throw new MyCustomException("age should be 20");
            }
            // some code here before next if condition
            if (zip == null) {
                throw new MyCustomException("zip can't be null");
            }
            // some code here before next if condition
            if (country == null) {
                throw new MyCustomException("country can't be null");
            }
        } catch (MyCustomException cusExep) {

        }

Approach 4:

I believe this is the best approach though, your thoughts please

if (name == null) {
    return("name can't be null");
}
// some code here before next if condition
if (gender == null) {
    return("gender can't be null");
}
// some code here before next if condition
if (age == 0) {
    return("age should be 20");
}
// some code here before next if condition
if (zip == null) {
    return("zip can't be null");
}
// some code here before next if condition
if (country == null) {
    return("country can't be null");
}

My question are

1. Which is a better practice. Approach 1,2,3 or 4?

2. Can System.exit(0) be used in scenarios like mine? If no, on what scenarios should I use System.exit(0). of course I did some research. Please find the few of the many links I deemed useful.

   • Link 1
   • Link 2
   • Link 3

Thanks for being patient.