Problema com java.sql.SQLException: No suitable driver found for jdbc:derby://localhost:1527/sample

package conexaobd;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;



public class ConexaoBD {

    
    public static void main(String[] args) {
        Connection conn = null;
        Statement st = null;
        
        try {
        
            DriverManager.registerDriver(
                    new ClientDriver());

            conn =
                    DriverManager.getConnection(
                            "jdbc:derby://localhost:1527/sample",
                            "APP",
                            "app"
                    );

            conn.setAutoCommit(false);

            System.out.println("Conexao realizada");

            st = conn.createStatement();
  
           
  
              
          
        } catch (Exception e) {  
             e.printStackTrace();  
        }  
    }  
}