java JDBC-PreparedStatement接口操作數據庫-ResultSet

//關閉打開的所有連接

public class Demo4 {
    public static void main(String[] args) {
        Connection conn=null;
        PreparedStatement ps=null;
        ResultSet rs=null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
                conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","dyl123");

        String sql="select * from t_user where id>?";
        ps=conn.prepareStatement(sql);
        ps.setInt(1, 2);

        rs=ps.executeQuery(); //返回結果集

        //遍歷結果集
        //rs.next(),指向結果集中的第一條，然後每次指向下一條
        //rs.getInt(num),獲得結果集中第num列的int類型的內容，rs.getString(num)獲得結果集中第num列的String類型的內容
        while(rs.next())
        {
            System.out.println(rs.getInt(1)+"--"+rs.getString(2)+"--"+rs.getString(3));
        }

    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (SQLException e) {
        e.printStackTrace();
    }finally {
        try {
            if(null!=rs)
            {
                rs.close();
            }
        }catch (SQLException e) {
            e.printStackTrace();
        }
            try {
                if(null!=ps)
                {
                    ps.close();
                }
            }catch (SQLException e) {
                e.printStackTrace();
            }
            try{
                if(null!=conn)
                {
                    conn.close();
                }

            }catch (SQLException e) {
                e.printStackTrace();
            }

    }

}
}