java - 错误 "A JNI error has occurred. Please check your installation and try again in Eclipse x86 Windows 8.1"

Question

考虑:

public class LoginCumReg implements ActionListener, KeyListener {

    private JFrame form;
    private JTextField txtunm;
    private JTextField txtnm;
    private JTextField txteml;
    private JButton cmdcreate;
    private JPasswordField txtpass;
    private JPasswordField txtpassreg;
    private JButton cmdok;
    private JLabel lblunm;
    private JLabel lblpass;
    private JLabel lbleml;
    private JLabel lblpassreg;
    private JLabel lblnm;
    private JPanel panel_1;

    public LoginCumReg() {
        // Construct components
        form = new JFrame("Sign Up");
        form.getContentPane().setFont(
                new Font("Plantagenet Cherokee", Font.BOLD, 18));
        txtunm = new JTextField(5);
        txtunm.addKeyListener(this);
        txtunm.setBounds(637, 55, 100, 25);
        txtnm = new JTextField(5);
        txtnm.setBounds(637, 228, 100, 25);
        txteml = new JTextField(5);
        txteml.setBounds(637, 264, 100, 25);
        cmdcreate = new JButton("Create Account");
        cmdcreate.setBounds(527, 350, 188, 25);
        txtpass = new JPasswordField(5);
        txtpass.setBounds(637, 91, 100, 25);
        txtpassreg = new JPasswordField(5);
        txtpassreg.setBounds(637, 300, 100, 25);
        cmdok = new JButton("OK");
        cmdok.setBounds(527, 139, 100, 25);
        lblunm = new JLabel("UserName");
        lblunm.setBounds(527, 55, 73, 25);
        lblpass = new JLabel("Password");
        lblpass.setBounds(527, 91, 100, 25);
        lbleml = new JLabel("Email ID");
        lbleml.setBounds(527, 264, 100, 25);
        lblpassreg = new JLabel("Password");
        lblpassreg.setBounds(527, 300, 100, 25);
        lblnm = new JLabel("Full Name");
        lblnm.setBounds(527, 228, 100, 25);

        // form.setResizable(false);

        // Adjust size and set layout
        form.setPreferredSize(new Dimension(800, 450));

        form.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        form.getContentPane().setLayout(null);

        // Add components
        form.getContentPane().add(txtunm);
        form.getContentPane().add(txtnm);
        form.getContentPane().add(txteml);
        form.getContentPane().add(cmdcreate);
        form.getContentPane().add(txtpass);
        form.getContentPane().add(txtpassreg);
        form.getContentPane().add(cmdok);
        form.getContentPane().add(lblunm);
        form.getContentPane().add(lblpass);
        form.getContentPane().add(lbleml);
        form.getContentPane().add(lblpassreg);
        form.getContentPane().add(lblnm);

        cmdcreate.setActionCommand("Create Account");
        cmdcreate.addActionListener(this);
        cmdok.setActionCommand("Login");

        JPanel panel = new JPanel();
        panel.setBounds(502, 29, 254, 154);
        panel.setFont(new Font("Palatino Linotype", Font.PLAIN, 14));
        panel.setBorder(new TitledBorder(new EtchedBorder(EtchedBorder.RAISED,
                null, null), "LOGIN", TitledBorder.LEADING, TitledBorder.TOP,
                null, null));
        panel.setBackground(SystemColor.controlHighlight);
        form.getContentPane().add(panel);

        panel_1 = new JPanel();
        panel_1.setBounds(500, 204, 254, 186);
        panel_1.setFont(new Font("Palatino Linotype", Font.PLAIN, 14));
        panel_1.setBorder(new TitledBorder(new EtchedBorder(
                EtchedBorder.RAISED, null, null), "SIGN UP",
                TitledBorder.LEADING, TitledBorder.TOP, null, null));
        panel_1.setBackground(SystemColor.controlHighlight);
        form.getContentPane().add(panel_1);

        JLabel lblNewLabel = new JLabel("New label");
        lblNewLabel.setBounds(91, 139, 286, 101);
        lblNewLabel.setIcon(new ImageIcon(
                "C:\\Users\\JAsh\\Desktop\\Projects\\JAsh.png"));
        form.getContentPane().add(lblNewLabel);

        JPanel panel_2 = new JPanel();
        panel_2.setBounds(77, 118, 315, 145);
        panel_2.setBorder(new EtchedBorder(EtchedBorder.RAISED,
                SystemColor.activeCaptionBorder, SystemColor.menu));
        panel_2.setBackground(SystemColor.controlHighlight);
        form.getContentPane().add(panel_2);
        cmdok.addActionListener(this);

        form.setResizable(false);
        form.pack();
        form.setVisible(true);
        System.out.println("const..");
    }

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

    @Override
    public void actionPerformed(ActionEvent ae) {
        // TODO Auto-generated method stub

        if (ae.getActionCommand().equals("Create Account")) {
            new Registration(txtnm.getText(), txteml.getText(), new String(
                    txtpassreg.getPassword()));
            form.setVisible(false);
        }

        if (ae.getActionCommand().equals("Login")) {
            try {
                if (txtunm.getText().equalsIgnoreCase("admin")
                        && new String(txtpass.getPassword()).equals("admin")) {
                    form.setVisible(false);
                    new Admin();
                } else {
                    DataBase db = new DataBase();
                    db.connect();
                    String sql = "SELECT * FROM LOGIN WHERE USERNAME='"
                            + txtunm.getText() + "'";
                    ResultSet rs = db.getDDL(sql);
                    boolean found = false;
                    while (rs.next()) {
                        if (rs.getString("Password").equals(
                                new String(txtpass.getPassword()))) {
                            found = true;
                            form.setVisible(false);
                            String name = rs.getString("FullName");
                            Session.startSession(txtunm.getText(), name);
                            new FacultyWelcome();
                        }
                    }
                    if (!found)
                        JOptionPane.showMessageDialog(new JFrame(),
                                "Invalid Credentials");
                    db.close();
                }
            }
            catch (Exception e) {
            }
        }
    }

    @Override
    public void keyPressed(KeyEvent arg0) {
        // TODO Auto-generated method stub
    }

    @Override
    public void keyReleased(KeyEvent arg0) {
        // TODO Auto-generated method stub
    }

    @Override
    public void keyTyped(KeyEvent arg0) {

        // TODO Auto-generated method stub
        // JOptionPane.showMessageDialog(new JFrame(), arg0.getKeyChar() + "-" + arg0.getKeyCode());
    }
}

上面的代码在我 friend 的笔记本电脑上完美运行，并在我的笔记本电脑上抛出了这个错误。我已在 Eclipse v4.2 上运行代码(Juno) 使用 Java 7。

我还在我的笔记本电脑上测试并运行了许多 Java 程序，它们都运行良好。这是唯一出现此类错误的程序。

我该如何解决这个问题？

Answer 1

这个问题我已经有一段时间了，但现在我想通了。

事实证明，Java JDK 12 在 Java 12 JDK 的 bin 文件夹中同时具有 JRE 和 JDK。 (我一直认为 JRE 和 JDK 是不同的应用程序，但事实证明事情已经改变了。)

我的问题是我的计算机上安装了 Java JDK 12。同时，我的计算机上安装了 Java 8 (JRE)。所以我的电脑开始糊涂了。

将我的命令提示符环境设置为运行 Java 和 Javac 命令:

我输入了以下命令:

java -version

这给了我 Java 8。

然后，我输入:

javac -version

这给了我 Java 12。

换句话说，我的程序正在使用 Java 12 编译，而我正在尝试使用 Java 8 运行。

为了解决这个问题，我从我的计算机上卸载了 Java 8 JRE。

我返回命令提示符检查“java -version”和“javac -version”是否返回相同的版本号，是的，它返回的是 Java 12。

我尝试再次重新编译我的程序并运行它。成功了!!