Question

I am getting NullPointerException when I am trying to get text from TextField in one of my Button on action method. This is my textField definition:

TextField textField = new TextField();
textField.setPromptText("Some text");
GridPane.setMargin(textField, new Insets(50, 50, 10, 50));
gridPane.add(textField, 0, 0);  

And this is my button with its on action method:

Button button = new Button("Button");       
GridPane.setMargin(button , new Insets(0, 50, 0, 50));
gridPane.add(button , 0, 1);
button.setOnAction(new EventHandler<ActionEvent>() {

    @Override
    public void handle(ActionEvent event) {
        String text = textField.getText();                              
    }
});

I am getting NullPointerExcpetion in this line: String text = textField.getText();. How can I get text from textField in onAction method?

Answer 1

One possibility is that you are shadowing your TextField in a method or constructor. This appears to be a possibility given that the local variable has not been declared as final.
If your EventHandler is using a class member variable called textField, then replace

TextField textField = new TextField();

with

textField = new TextField();