Help making an error message.

I am new to programming and need help creating an error message for one of my programs. My question is how do I make java show an error if the user were to enter letters instead of a number and how can I make a loop to keep asking for the input and show the error as long as the input is not a number.

The following is only part of my code and the only part I want to show an error message for incorrect input.

Code Java:

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	String YearString = JOptionPane.showInputDialog(null,
    			"Please enter a year, for example 1700:",
    			"Finding Easter",
    			JOptionPane.QUESTION_MESSAGE);
 
                	int YEAR = Integer.parseInt(YearString);

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Thanks in advance to all who helped!

Quote:

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My question is how do I make java show an error if the user were to enter letters instead of a number and how can I make a loop to keep asking for the input and show the error as long as the input is not a number.

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A while loop would work in this scenario, looping until the year string validates. Rather than catching the exception, you could simply validate the string. For example in pseudo-code:

Code :

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String value = "";
while ( isValid(value) ){
  value = //optionPane input
}
 
private boolean isValid(String s){
    //validate the string for digits.
}

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Thank-you for the assistance!