filterTextField.setOnKeyReleased(event -> {
  if (event.getCode() == KeyCode.ENTER){
     // do what is to do
  }
});

TextField tf = new TextField();
String tfData = "";

tf.setOnAction(new EventHandler<ActionEvent>() {
    @Override
    public void handle(ActionEvent event) {
            tfData = tf.getText();
    }
});

textField.setOnKeyPressed(new
EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent event) {

if(event.getCode().equals(
KeyCode.ENTER)
) {
         // do something
    }
}
});