Blank field, java causing app crash

Question

When the field is left blank it makes the app crash. How can i stop it ?

EditText editText = (EditText)findViewById(R.id.editText);
userNumber = Integer.parseInt(editText.getText().toString());

I tried giving it a .setError("Don't leave this blank!"), but it doesn't seem to do the thing, the app crashes there.

Screenshots:

Answer 1

trying to parseInt from an empty or null string raises a FormatException. So, either wrap your code inside a try/catch:

try {
  userNumber = Integer.parseInt(editText.getText().toString());
}catch(Exception e){
    // friendly error to the user: field is incorrect
}

or use an if statement to make sure the editText is not empty:

if(editText.getText().length() > 0){
     // your code
}

The if solution supposes that your editText only accepts numbers (using the attribute android:inputType="number" in your xml layout).

As a side note, for good practice, note that it is always wise to wrap a parseInt inside a try/catch.

Answer 2

This code can give you an idea,

String input = editText.getText().toString();
if(input.length() > 0){
    try {
        int userNumber = Integer.parseInt(input);

        // Write your code here

    } catch (Exception e) {
        Toast.makeText(this, "Enter only a number!", Toast.LENGTH_SHORT).show();
        e.printStackTrace();
    }
} else{
    Toast.makeText(this, "Enter a number!", Toast.LENGTH_SHORT).show();
}

Answer 3

   Use this it will help you and remove your crash    


EditText editText = (EditText)findViewById(R.id.editText);

if(userNumber.length() > 0)
{
set your error screen is empty
}
else
{
userNumber = Integer.parseInt(editText.getText().toString());
}