Question

I met a small problem when running a Java class that I wrote, though the design is pretty straightforward. I’ve created a JPanel, and I’ve added four JTextFields onto it and I’ve attached a button to this JPanel, too. Then, I’ve associated an ActionListener to this button being pressed. The code is like:

okButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) 
    {
       if (imageIdField.getText() == "" && 
           captionField.getText() == "" &&
           creditField.getText() == "" &&
           titleField.getText()== "") 
           {
              mediaXML = "";                        
              results.clear();
              results.put("error1", "more");

           } 
           else
           { ....
           }
    }

The strange thing is after I’ve pressed the OK button, and I did input text in those four JTextFields, still it will fall in the IF branch as if I didn’t input any text in any of these four fields.
I’ve been debugging this for a while, but no clue. Could anyone give me some hint like whether .getText() == “” is a valid way for testing no input?

Thanks in advance!

Answer 1

As has been mentioned, using == is not correct. For readability, try:

field.getText().isEmpty()

or

field.getText().trim().isEmpty()