利用java连接mysql数据库时怎么测试是否连接成功

package com.test.tool;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class JDBCUtlTool {  public static Connection getConnection(){    String driver="com.mysql.jdbc.Driver";  //获取mysql数据库的驱动类    String url="jdbc:mysql://localhost:3306/test"; //连接数据库（kucun是数据库名）    String name="root";//连接mysql的用户名    String pwd="123456";//连接mysql的密码    try{      Class.forName(driver);      Connection conn=DriverManager.getConnection(url,name,pwd);//获取连接对象      return conn;    }catch(ClassNotFoundException e){      e.printStackTrace();      return null;    }catch(SQLException e){      e.printStackTrace();      return null;    }  }  public static void closeAll(Connection conn,PreparedStatement ps,ResultSet rs){    try{      if(rs!=null){        rs.close();      }    }catch(SQLException e){      e.printStackTrace();    }    try{      if(ps!=null){        ps.close();      }    }catch(SQLException e){      e.printStackTrace();    }    try{      if(conn!=null){        conn.close();      }    }catch(SQLException e){      e.printStackTrace();    }  }  public static void main(String[] args) throws SQLException  {    Connection cc=JDBCUtlTool.getConnection();    if(!cc.isClosed())    System.out.println("Succeeded connecting to the Database!");    Statement statement = cc.createStatement();    String sql = "select * from test2";    ResultSet rs = statement.executeQuery(sql);    while(rs.next()) {      System.out.println(rs.getString("id")+"");    }  }}