尚未加载数据库驱动程序，为此，请包含以下代码：

Class.forName("com.mysql.jdbc.Driver");

如果还没有驱动程序，请下载并放入项目库。

这是你应该做的，准备好的声明，以防止注射

String dburl = "jdbc:mysql://localhost:3306/librarymanagementsystem";
String user = "nandika";
String password = "nandika";
private PreparedStatement preparedStatement;
private Connection con = null;

      public static void main(String[] args) {

}

public void createConnection(int id, String name, String author, String publisher) {
    try {

con = DriverManager.getConnection(dburl, user, password);
String stmt = "INSERT INTO addbook (Book ID,Book Name,Author,Publisher) VALUES (?, ?, ?, ?)";

            preparedStatement = con.prepareStatement(stmt);
            preparedStatement.setInt(1, id);
            preparedStatement.setString(2, name);
            preparedStatement.setString(3, author);
            preparedStatement.setString(4, publisher);
            preparedStatement.executeUpdate();
            con.close();

        System.out.println("updated");
    } catch (Exception ex) {

    }

他们发现这个代码片段有一些问题。一是你没有加载数据库。你也没有使用用户名和密码。
我建议您单独创建数据库连接。可能在一个单独的java文件中。如下所示，

public class DatabaseConnection {
    public static Statement getConnection() throws Exception{
        Class.forName("com.mysql.jdbc.Driver"); //Loading the database
        Connection c = DriverManager.getConnection("jdbc:mysql://localhost:3307/restaurentsystem","nandika","nandika"); //username and password can save as variables and pass here

        Statement statement = c.createStatement();
        return statement;
    }
}

然后你可以随时使用它。在这种情况下，

try {
    Statement s = DatabaseConnection.getConnection();
    s.executeUpdate("INSERT INTO addbook (Book ID, Book Name, Author, Publisher) VALUES (?, ?, ?, ?);"); //Values should assign here.
    System.out.println("updated");

} catch (Exception e) {
    System.out.println(e);
}

如果我这么做，我会这么做。我建议你试试这个方法。