Question

I wrote like this; but it fails to integer only textfields

if(textField_1.getText().length()==0)  

JOptionPane.showMessageDialog(null, "enter text in textfield");  

Please help…

Answer 1

Typically, when you are validating user input in Java, you will want to check for both null and empty string values. To check String objects for equality, you must use the .equals() method (not the == operator). Thus, a check for an empty String value might look something like this:

if ( val == null || val.trim().equals( "" ) )
{
    // handle empty String case
}
else
{
    // handle non-empty String case
}

Hope this helps