jdbcTemplate操作mysql 分页查询

@GetMapping("/querytest")
    public String querytest() throws SQLException {
        DriverManagerDataSource dataSource =  new DriverManagerDataSource();
        dataSource.setPassword("root");
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUsername("root");
        dataSource.setUrl("jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true&failOverReadonly=false&serverTimezone=GMT");

        jdbcTemplate = new JdbcTemplate(dataSource);
        int num = 0;
        long size = 1000;
        List> list =  new ArrayList<>();

        while(true){
            // SELECt * FROM `test`.`class` LIMIT 0, 1000
			String sql = "select * from  class  limit "+ num+"," +  size;
            if(num==0){
				System.out.println("sql:"+sql);
                 list =  jdbcTemplate.queryForList(sql);

            }else{
				String sql2 = "select * from  class  limit "+ num*size+"," +  size;
				System.out.println("sql2:"+sql2);

				list = jdbcTemplate.queryForList(sql2);

            }
         if(list.size()==0){
             break;
         }

       num++;
        }
        System.out.println("num："+num);
        return prefix + "/query";
    }