java.lang.NumberFormatException: Invalid int: “” in android

Question

I already know what is causing this error, I just do not know how to handle the case when a user doesn\'t enter anything into the dialogue box, then hit the button which par

Answer 1

Problem: How do you check to see if the dialogue box has text in it, before it tries to run the rest of the code.

Solution: An if statement.

 int parseToInt(String maybeInt, int defaultValue){
     if (maybeInt == null) return defaultValue;
     maybeInt = maybeInt.trim();
     if (maybeInt.isEmpty()) return defaultValue;
     return Integer.parseInt(maybeInt);
 }

If you can spare the extra dependency, I'd pull in Common Lang StringUtils, to use StringUtils.isBlank instead of trim/isEmpty, because that also handles Unicode.

Answer 2

Some code would help with the syntax but basically

 if ("".equals(text)  // where text is the text that you get from an EditText or wherever you get it
 {    // give message to enter valid text;    }

Also, you can surround with a try/catch and catch a numberFormatException then print an appropriate message

Answer 3

   String text = editText.getText().toString(); 
   if(!text.equals("") && text.matches("^\\d+$")){
       cast to int
    }

Answer 4

The Same Error Was Causing My Application To Crash. Ans is Simple- Put the code in the

try{ }

and

catch()

Block which causes Exception ,like this code snip.This Works for me.

public void setAge(String age) {

    final Calendar c = Calendar.getInstance();
    int yearCurrent = c.get(Calendar.YEAR);
    try {
        int yearPrev = (int) Integer.parseInt(age.substring(0, 4));//this line was causing the error
        int ageYear=yearCurrent-yearPrev;
        ageUser="Age : "+Integer.toString(ageYear);
    }
    catch(NumberFormatException numberEx) {
        System.out.print(numberEx);
    }


}