JavaFX TextField causes NullPointerException - nullpointerexception

Question

I am using a Button with an event to control the input of a user, but I am having trouble checking whether or not the TextField is empty.
The TextField and Button are declared before the button event, like
TextField svar = new TextField();
Button submitB = new Button("submit");
This is my code:
submitB.setOnAction((event) -> {
if (svar.getText().equals(null) {
primaryStage.setTitle("No input!");
}
if (svar.getText().subSequence(0, 1).toString().toLowerCase().equals(animals.get(pic).getName().subSequence(0, 1).toString().toLowerCase())) {
primaryStage.setTitle("RÄTT!");
bild.setImage(new Image(animals.get(pic+=1).getImgsrc()));
svar.setText(null);
svar.requestFocus();
}
else
{
primaryStage.setTitle("FEL!");
svar.setText(null);
svar.requestFocus();
}
});
This piece of the code above is what in my mind should handle a situation where the TextField is empty:
if (svar.getText().equals(null) {
primaryStage.setTitle("No input!");
}
However I am still getting a NullPointerException no matter what. I've tried some different solutions which have all failed and I'm hoping someone can point me in the right direction. Thanks!

Answer 1

Instead of calling equals to check for null, you should use "==" like:
if (svar.getText() == null) {
Reason you get NPE (NullPointerException) is, since as you say svar.getText() is null, you are trying to call equals on null and a reason for NPE.

Answer 2

The correct way to do it, is not check for Null, but to check for a empty String:
if (svar.getText().equals("") {
primaryStage.setTitle("No input!");
}
Some prefer:
if ("".equals(svar.getText() {
primaryStage.setTitle("No input!");
}