Java Parse Exception to Custom Exception

Question

I'm new to Java and my problem here is a Simple Age Calculator. Here is my Code:

public class Client {
public int findAge(String birthDate) throws InvalidDateFormatException {
//  InvalidDateFormatException is a custom defined

    int age = 0;
    try {
        Calendar past = new GregorianCalendar();
        Calendar present = Calendar.getInstance();
        past.setTime(new SimpleDateFormat("dd-MM-yyyy", Locale.ENGLISH).parse(birthDate));
        age = present.get(Calendar.YEAR) - past.get(Calendar.YEAR); 
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
}
    return (age >= 0) ? age : 0;
}

In main,

try {
                System.out.println(c.findAge("08-09-1015"));
            } catch (InvalidDateFormatException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

Now, this is throwing a ParseException every time i pass a String in the wrong Format. Is there any way in which I can make it throw an InvalidDateFormatException Exception instead?

Also, please leave a comment on the style and quality of my Code, provided I'm following the correct coding standards and adhering to best practices.

Done. I realized it now. And thank you for pointing it out because I just discovered about Meta Stack Exchange and the Roll Back feature. — indieNik
– indieNik, Commented Sep 21, 2015 at 4:40

Tunaki · Accepted Answer · 2015-09-20 21:04:36Z

3

To answer your prime question, you need to throw the custom exception in the catch block:

try {
    Calendar past = new GregorianCalendar();
    Calendar present = Calendar.getInstance();
    past.setTime(new SimpleDateFormat("dd-MM-yyyy", Locale.ENGLISH).parse(birthDate));
    age = present.get(Calendar.YEAR) - past.get(Calendar.YEAR); 
} catch (ParseException e) {
    throw new InvalidDateFormatException("invalid date: " + birthDate);
}

Regarding your code, I have a couple of suggestions:

Do not use new GregorianCalendar() and prefer Calendar.getInstance().
The way you calculate the age is broken: you don't take into account the month and the day (let's say we are 2015-09-20, and the birth date is 2014-12-01, your code will output 1 even if the baby is not 1 year old yet).
Consider giving a Date argument instead of a String argument. It should not be the responsibility of the findAge method to parse the birth date.
If you are using Java 8, consider using the new Java Time API.

edited Sep 20, 2015 at 21:04

answered Sep 20, 2015 at 19:45

Tunaki

138k46 gold badges370 silver badges443 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

indieNik Over a year ago

Okay! I got it. Updated the Question with my new Code. Thanks! The Compilers we're provided are still 1.5 , So I'll stick with it for now.

D. Ben Knoble Over a year ago

Please dont update your code after youve asked the question like that. Now your code appears fine and your question relates to what was broken. Its not followable.

Vasu · Accepted Answer · 2015-09-20 19:46:20Z

Define Custom Exception class for InvalidDateFormatException as below:

public class InvalidDateFormatException extends RuntimeException {

    private String errorMessage;

    public InvalidDateFormatException(String errorMessage, Exception exe) {
        super(errorMessage);
        exe.printStackTrace();
    }
}

Modify your catch block to throw the exception as below :

public class Client {
public int findAge(String birthDate) throws InvalidDateFormatException {
    int age = 0;
    try {
        Calendar past = new GregorianCalendar();
        Calendar present = Calendar.getInstance();
        past.setTime(new SimpleDateFormat("dd-MM-yyyy", Locale.ENGLISH).parse(birthDate));
        age = present.get(Calendar.YEAR) - past.get(Calendar.YEAR);
    } catch (ParseException e) {
        throw new InvalidDateFormatException("Invalid Date Format while finding Age", e);
    }
    return (age >= 0) ? age : 0;
 }
}

Also, I would suggest you go through the below site: https://docs.oracle.com/javase/tutorial/essential/exceptions/creating.html

Collectives™ on Stack Overflow

Java Parse Exception to Custom Exception

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related