JDBC

List list = new ArrayList();

        Class.forName("com.mysql.jdbc.Driver");

        try {

            Properties properties = new Properties();

            properties.setProperty("user","root");

            properties.setProperty("password","root");

            Connection connection =  DriverManager.getConnection("jdbc:mysql://localhost:3306/read",properties);

            Statement statement = connection.createStatement();

            ResultSet resultSet = statement.executeQuery("select *  from  user where id = 5");


            //获取数据库 列总数  和 列名
            ResultSetMetaData resultSetMetaData = resultSet.getMetaData();


            int count  = resultSetMetaData.getColumnCount();



            while(resultSet.next())
            {

                Map columnList  = new HashMap();

                for(int i = 1  ; i<=count ; i ++ )
                {

                    columnList.put(resultSetMetaData.getColumnName(i),resultSet.getObject(i));

                }


                list.add(columnList);
            }

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


        String l = JSON.toJSONString(list);




        System.out.println(JSON.toJSONString(l));