使用JDBC连接到MySQL时出错

Question

我正在学习Java，我遵循了一个教程，这是代码：

package simplejdbcapplication;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class SimpleJDBCApplication {

   static final String DB_URL ="jdbc:mysql://localhost:3306/testdb";
   static final String DB_DRV = "com.mysql.jdbc.Driver";
   static final String DB_USER = "mickey";
   static final String DB_PASSWD = "mickey";

    public static void main(String[] args) {

      Connection connection = null;
      Statement statement = null;
      ResultSet resultSet = null;

      try {
         connection=DriverManager.getConnection(DB_URL,DB_USER,DB_PASSWD);
         statement=connection.createStatement();
         resultSet=statement.executeQuery("SELECT * FROM books");
         while (resultSet.next()) {
            System.out.printf("%s\t%s\t%s\t%f\n",
            resultSet.getString(1),
            resultSet.getString(2),
            resultSet.getString(3),
            resultSet.getFloat(4));
         }
      } catch(SQLException ex){
          System.out.println("SQLException: "+ex);
      } finally {
         try {
            resultSet.close();
            statement.close();
            connection.close();
         } catch (SQLException ex) {
             System.out.println("SQLException: "+ex);
         }
      }
   }
}

但是我抛出一个连接错误，我认为这是Xampp的某些配置，我留下了项目的图像：

非常感谢您的帮助。

PS：我留下了教程链接：https://www.developer.com/java/data/creating-a-jdbc-application-in-netbeans-a-step-by-step-guide.html