注册出现问题，找了几个方法没解决

Question

注册系统出现了一些问题，查了一些方法没有解决，希望能帮忙看一下
报错信息

java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    at java.base/java.lang.Class.forName0(Native Method)
    at java.base/java.lang.Class.forName(Class.java:383)
    at java.base/java.lang.Class.forName(Class.java:376)
    at UserUtil.userUtil.<clinit>(userUtil.java:30)
    at GUIs.Register.CheckRegister(Register.java:79)
    at GUIs.Register$1.actionPerformed(Register.java:55)
    at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1972)
    at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2313)
    at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
    at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
    at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
    at java.desktop/java.awt.Component.processMouseEvent(Component.java:6616)
    at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3398)
    at java.desktop/java.awt.Component.processEvent(Component.java:6381)
    at java.desktop/java.awt.Container.processEvent(Container.java:2266)
    at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4991)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2324)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4823)
    at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4948)
    at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4575)
    at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4516)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2310)
    at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2780)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4823)
    at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:775)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:97)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:747)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:744)
    at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

我的登陆系统能用，但注册不行就很奇怪

Answer 1

以下内容由CHATGPT及阿里嘎多学长共同生成、有用望采纳：

根据错误提示信息可以看出，是因为找不到MySQL数据库的驱动类导致的。解决方法是在项目中添加MySQL的驱动jar包，可以从MySQL官网下载。下载完成后，将jar包放到项目的lib文件夹中，然后在项目的构建路径中添加该jar包即可。具体步骤如下：

1. 下载MySQL的驱动jar包，例如mysql-connector-java-8.0.26.jar。

2. 将下载好的jar包放到项目的lib文件夹中。

3. 在Eclipse中右键点击项目名称，选择Properties，然后选择Java Build Path。

4. 在Java Build Path对话框中，选择Libraries选项卡，然后点击Add JARs...按钮。

5. 在弹出的JAR Selection对话框中，选择刚才下载好的mysql-connector-java-8.0.26.jar文件，然后点击OK按钮。

6. 点击Apply和OK按钮关闭对话框，重新编译项目即可。

示例代码：

// 加载MySQL数据库驱动类
Class.forName("com.mysql.cj.jdbc.Driver");

// 获取数据库连接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC", "root", "123456");

// 执行SQL语句
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM user");

// 处理查询结果
while (rs.next()) {
    System.out.println(rs.getString("username") + " " + rs.getString("password"));
}

// 关闭连接
rs.close();
stmt.close();
conn.close();