java - 在 Mac 上使用 Netbeans 连接 SQLite

Question

我不断收到没有这样的表的错误:employeeInfo。该表确实存在于我用于代码的目录中。顺便说一句，我用的是 Mac。这是代码:

import java.sql.*;
import javax.swing.*;

public class javaconnect {
    Connection conn = null;
    public static Connection ConnecrDb(){
        try{
            Class.forName("org.sqlite.JDBC");
            Connection conn = DriverManager.getConnection("jdbc:sqlite:Macintosh HD\\Users\\as\\Documents\\Netbeans projects\\Project123.sqlite");
            JOptionPane.showMessageDialog(null, "Connection Established");
            return conn;
        }
        catch(Exception ex){
            JOptionPane.showMessageDialog(null,ex);
            return null;
        }
    }

    public static void main(String args[]){
        ConnecrDb();
    }

我感觉错误就在这一行: 连接 conn = DriverManager.getConnection("jdbc:sqlite:Macintosh HD\Users\as\Documents\Netbeans 项目\Project123.sqlite");

employeeInfo 表确实存在于该数据库中，并且这也是当前目录。这是我的代码的第二部分:

import java.awt.*;
import java.sql.*;
import javax.swing.*;
public class Login_jframe extends javax.swing.JFrame {
Connection conn = null;
ResultSet rs = null;
PreparedStatement pst = null;

    /**
     * Creates new form Login_jframe
     */
    public Login_jframe() {
        initComponents();
        conn = javaconnect.ConnecrDb();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        txt_password = new javax.swing.JPasswordField();
        jLabel2 = new javax.swing.JLabel();
        txt_username = new javax.swing.JTextField();
        jLabel1 = new javax.swing.JLabel();
        cmd_login = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "Login", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Lucida Grande", 1, 18), new java.awt.Color(102, 102, 255))); // NOI18N

        txt_password.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                txt_passwordActionPerformed(evt);
            }
        });

        jLabel2.setText("Password");

        jLabel1.setText("Username");

        cmd_login.setText("Login");
        cmd_login.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                cmd_loginActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel1)
                            .addComponent(jLabel2))
                        .addGap(18, 18, 18)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(txt_username, javax.swing.GroupLayout.PREFERRED_SIZE, 167, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(txt_password, javax.swing.GroupLayout.PREFERRED_SIZE, 167, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addContainerGap())
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addComponent(cmd_login)
                        .addGap(67, 67, 67))))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1)
                    .addComponent(txt_username, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(64, 64, 64)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(txt_password, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(18, 18, 18)
                .addComponent(cmd_login)
                .addContainerGap(12, Short.MAX_VALUE))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(218, Short.MAX_VALUE)
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(40, 40, 40))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(57, 57, 57)
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(28, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void txt_passwordActionPerformed(java.awt.event.ActionEvent evt) {                                             
        // TODO add your handling code here:
    }                                            

    private void cmd_loginActionPerformed(java.awt.event.ActionEvent evt) {                                          
        // TODO add your handling code here:
        String sql = "select * from employeeInfo where username=? and password=?";
        try{
            pst = conn.prepareStatement(sql);
            pst.setString(1, txt_username.getText());
            pst.setString(2,txt_password.getText());

            rs = pst.executeQuery();
            if(rs.next()){
                JOptionPane.showMessageDialog(null,"Username and Password is correct");
                Employee_info s = new Employee_info();
                s.setVisible(true);
            }
            else{
                JOptionPane.showMessageDialog(null,"Username and/or Password is not correct");
            }
        }
        catch(Exception ex){
            JOptionPane.showMessageDialog(null, ex);
        }
    }                                         

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Login_jframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Login_jframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Login_jframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Login_jframe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Login_jframe().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton cmd_login;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPasswordField txt_password;
    private javax.swing.JTextField txt_username;
    // End of variables declaration                   
}

Answer 1

没关系，我已经弄清楚了，伙计们。显然，我必须单击“数据库”，选择“连接数据库”，然后浏览到保存数据库的位置。我正在观看的教程视频中从未提到过这一点。希望这个答案对遇到同样问题的其他人有所帮助。