JavaFX，java.lang.ClassNotFoundException：com.postgresql.jdbc.Driver，App

Question

我遵循了一个教程，但我更改了很多代码，所以在我的 DatabseHandler 中，我有连接、查询和执行

我没有遇到任何问题，直到这一刻我预计它会在 PgAdmin 中插入数据但是代码却给我发送了问题

数据库处理程序

package com.example.esginterface.database;


import java.sql.*;

import com.example.esginterface.config.Config;
import com.example.esginterface.config.Constants;
import javafx.scene.control.TextField;

public class DatabaseHandler extends Config {
    private final static String url = "jdbc:postgresql://localhost:5432/esg-calculator";
    private final static String user = "postgres";
    private final static String password = "1234";

        Connection dbConnection;
        public Connection getDbConnection()
                throws ClassNotFoundException, SQLException{
//            String connectionString = "jdbc:postgresql://"+dbHost+":"+dbPort+"/"+dbName;
            Class.forName("com.postgresql.jdbc.Driver");
//            dbConnection = DriverManager.getConnection(connectionString,
//                    dbUser,dbPass);
            dbConnection = DriverManager.getConnection(url, user, password);
            return dbConnection;
        }
        public void signUpUser(String user_id, String firstname, String lastname, String login, String password, String email)
                throws SQLException, ClassNotFoundException {
                    String insert = "INSERT INTO" + Constants.USER_TABLE + "(" + Constants.USER_ID + "," +
                        Constants.FIRSTNAME + "," + Constants.LASTNAME + "," +
                        Constants.LOGIN + "," +Constants.PASSWORD + "," + Constants.EMAIL + ")" + "VALUES(?,?,?,?,?,?)";


            try {
                PreparedStatement preparedStatement = getDbConnection().prepareStatement(insert);


                preparedStatement.setString(1, user_id);
                preparedStatement.setString(2, firstname);
                preparedStatement.setString(3, lastname);
                preparedStatement.setString(4, login);
                preparedStatement.setString(5, password);
                preparedStatement.setString(6, email);

                preparedStatement.executeUpdate();
            }
            catch (SQLException | ClassNotFoundException e){
                System.out.println("problem is in database handler "+e);
            }
        }

}

注册控制器

package com.example.esginterface.controller;

import java.net.URL;
import java.sql.SQLException;
import java.util.Date;
import java.util.ResourceBundle;

import com.example.esginterface.database.DatabaseHandler;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;

public class SignUpController {

    @FXML
    private TextField login_field;

    @FXML
    private TextField password_field;

    @FXML
    private Button sign_in_button;

    @FXML
    private TextField sign_up_email;

    @FXML
    private TextField sign_up_firstname;

    @FXML
    private TextField sign_up_lastname;

    @FXML
    void initialize() {
        DatabaseHandler databaseHandler = new DatabaseHandler();

        sign_in_button.setOnAction(actionEvent -> {
            try {
                databaseHandler.signUpUser(sign_in_button.getId(), sign_up_firstname.getText(),sign_up_lastname.getText(),login_field.getText(),password_field.getText(),sign_up_email.getText());
            } catch (SQLException | ClassNotFoundException e) {
                System.out.println("problem in sign up controller " + e);
            }
        });
    }

}

登录控制器

package com.example.esginterface.controller;

import java.io.IOException;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.stage.Stage;

public class SignInController {


    @FXML
    private TextField login_field;

    @FXML
    private TextField password_field;

    @FXML
    private Button sign_in_button;

    @FXML
    private Button sign_up_button;

    @FXML
    void initialize() {
//        sign_in.setOnAction(actionEvent -> {
//            sign_in.getScene().getWindow().hide();
//
//            FXMLLoader loader = new FXMLLoader();
//            loader.setLocation(getClass().getResource("/com/example/esginterface/calculator.fxml"));
//
//            try{
//                loader.load();
//            }
//            catch (IOException e){
//                e.printStackTrace();
//            }
//            Parent root = loader.getRoot();
//            Stage stage = new Stage();
//            stage.setScene(new Scene(root));
//            stage.showAndWait();
//
//
//        });
        sign_in_button.setOnAction(actionEvent -> {
            String loginText =  login_field.getText().trim();
            String passwordText = password_field.getText().trim();

            if (!loginText.equals("")&&!passwordText.equals(""))
                loginUser(loginText, passwordText);
            else
                System.out.println("err");
        });


        sign_up_button.setOnAction(actionEvent -> {
            sign_up_button.getScene().getWindow().hide();

            FXMLLoader loader = new FXMLLoader();
            loader.setLocation(getClass().getResource("/com/example/esginterface/sign-up.fxml"));

            try {
                loader.load();
            } catch (IOException e) {
                e.printStackTrace();
            }
            Parent root = loader.getRoot();
            Stage stage =  new Stage();
            stage.setScene(new Scene(root));
            stage.showAndWait();

        });

    }

    private void loginUser(String loginText, String passwordText) {
    }

}

注册.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>
<?import javafx.scene.text.Text?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="700.0" prefWidth="800.0" style="-fx-background-color: DAE3E2;" xmlns="http://javafx.com/javafx/19" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.example.esginterface.controller.SignUpController">
    <children>
        <AnchorPane prefHeight="146.0" prefWidth="800.0" style="-fx-background-color: #2F4F4F;">
            <children>
                <Text fill="WHITE" layoutX="315.0" layoutY="85.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Trust Me">
                    <font>
                        <Font name="Times New Roman" size="48.0" />
                    </font>
                </Text>
            </children>
        </AnchorPane>
      <TextField fx:id="sign_up_firstname" layoutX="20.0" layoutY="222.0" prefHeight="60.0" prefWidth="370.0" promptText="Имя">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
      <Button fx:id="sign_in_button" layoutX="319.0" layoutY="535.0" mnemonicParsing="false" prefHeight="46.0" prefWidth="177.0" text="Войти">
         <font>
            <Font name="Times New Roman" size="25.0" />
         </font>
      </Button>
      <TextField fx:id="login_field" layoutX="408.0" layoutY="222.0" prefHeight="60.0" prefWidth="370.0" promptText="Логин">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
      <TextField fx:id="sign_up_lastname" layoutX="20.0" layoutY="320.0" prefHeight="60.0" prefWidth="370.0" promptText="Фамилия">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
      <TextField fx:id="password_field" layoutX="408.0" layoutY="320.0" prefHeight="60.0" prefWidth="370.0" promptText="Пароль">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
      <TextField fx:id="sign_up_email" layoutX="215.0" layoutY="406.0" prefHeight="60.0" prefWidth="370.0" promptText="почта">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
    </children>
</AnchorPane>

签到

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>
<?import javafx.scene.text.Text?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="700.0" prefWidth="800.0" style="-fx-background-color: DAE3E2;" xmlns="http://javafx.com/javafx/19" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.example.esginterface.controller.SignInController">
   <children>
      <AnchorPane prefHeight="146.0" prefWidth="800.0" style="-fx-background-color: #2F4F4F;">
         <children>
            <Text fill="WHITE" layoutX="315.0" layoutY="85.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Trust Me">
               <font>
                  <Font name="Times New Roman" size="48.0" />
               </font>
            </Text>
         </children>
      </AnchorPane>
      <TextField fx:id="password_field" layoutX="235.0" layoutY="389.0" prefHeight="60.0" prefWidth="370.0" promptText="Пароль">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
      <TextField fx:id="login_field" layoutX="233.0" layoutY="278.0" prefHeight="60.0" prefWidth="370.0" promptText="Логин">
         <font>
            <Font name="Times New Roman Bold" size="20.0" />
         </font>
      </TextField>
      <Label layoutX="326.0" layoutY="214.0" text="Авторизация">
         <font>
            <Font name="Times New Roman Bold" size="28.0" />
         </font>
      </Label>
      <Button fx:id="sign_in_button" layoutX="359.0" layoutY="508.0" mnemonicParsing="false" text="Войти">
         <font>
            <Font name="Times New Roman" size="25.0" />
         </font>
      </Button>
      <Button fx:id="sign_up_button" layoutX="325.0" layoutY="604.0" mnemonicParsing="false" text="Регистрация">
         <font>
            <Font size="25.0" />
         </font>
      </Button>
   </children>
</AnchorPane>