java中mysql數據庫配置與ResultSet的操作

import java.lang.reflect.Array;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;

public class t {
    public static void main(String args[]) throws ClassNotFoundException, SQLException{
     Class.forName("com.mysql.jdbc.Driver");
     String url = "jdbc:mysql://localhost:3306/javaweb?user=root&password=080302&useUnicode=true&characterEncoding=gbk";
     Connection conn= (Connection) DriverManager.getConnection(url);
     Statement ps=(Statement) conn.createStatement();
     String sql="select * from user";
     ResultSet rs=ps.executeQuery(sql);  
     System.out.println(rs);
     if(rs.next()){//只顯示一行
      System.out.println(rs.getString(3));//從1開始
     }
     ResultSet rs1=ps.executeQuery(sql);  
     while(rs1.next()){//顯示所有行相關信息
      System.out.println(rs1.getString(2));
     }
    }
}