SignUpController.java

package com.example.loanproject;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import java.net.URL;
import java.util.ResourceBundle;
public class SignUpController implements Initializable {
@FXML
private Button button_signup;
@FXML
private Button button_login;
@FXML
private TextField tf_username;
@FXML
private TextField tf_password;
    @Override
    public void initialize(URL location, ResourceBundle resources) {
        button_signup.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                if (!(tf_username.getText().trim().isEmpty() && tf_password.getText().trim().isEmpty()))
                {
                    DBUtils.signUpUser(event,tf_username.getText(),tf_password.getText());
                }
                else {
                    System.out.println("Please fill in all information");
                    Alert alert=new Alert(Alert.AlertType.ERROR);
                    alert.setContentText("Please fill in all information to sign up");
                    alert.show();
                }
            }
        });
        button_login.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                DBUtils.changeScene(event,"sample.fxml","Log in",null);
            }
        });
    }
}