java - 如何进行分页请求 - Spring boot

Question

在我的系统(Spring boot 项目)中，我需要向每 350 个搜索我的数据的人发出请求，我需要寻呼并发送。我寻找了很多方法来做到这一点，发现很多都是用 JPA 实现的，但我使用的是 Jooq，所以我向用户的工具寻求帮助，他们指导我使用 limit 和 offset 选项。

这是我进行研究、设置 DTO 并最终返回人员列表的方法。

 public static ArrayList getAllPeople(Connection connection) {
    ArrayList<peopleDto> peopleList = new ArrayList<>();
    DSLContext ctx = null;
    peopleDto peopleDto;
    try {
        ctx = DSL.using(connection, SQLDialect.MYSQL);
        Result<Record> result = ctx.select()
                .from(people)
                .orderBy(people.GNUM)
                .offset(0)
                .limit(350)
                .fetch();

        for (Record r : result) {

            peopleDto = new peopleDto();
            peopleDto.setpeopleID(r.getValue(people.GNUM));
            peopleDto.setName(r.get(people.SNAME));
            peopleDto.setRM(r.get(people.SRM));
            peopleDto.setRG(r.get(people.SRG));
            peopleDto.setCertidaoLivro(r.get(people.SCERT));
            peopleDto.setCertidaoDistrito(r.get(people.SCERTD));
            peopleList.add(peopleDto);
        }
    } catch (Exception e) {
        log.error(e.toString());
    } finally {
        if (ctx != null) {
            ctx.close();
        }
    }
    return peopleList;
}

无限制的搜索会返回 1,400 人。问题是如何发送限制数量，然后返回到此方法以从上次中断的地方继续，直到达到记录总数？

Answer 1

向您的方法提供 Pageable 参数，并从您的方法返回一个 Page。类似于...

public static ArrayList getAllPeople(Connection connection, Pageable pageable) {
    ArrayList<peopleDto> peopleList = new ArrayList<>();
    DSLContext ctx = null;
    peopleDto peopleDto;
    try {
        ctx = DSL.using(connection, SQLDialect.MYSQL);
        Result<Record> result = ctx.select()
                .from(people)
                .orderBy(people.GNUM)
                .offset(pageable.getOffset())
                .limit(pageable.getPageSize())
                .fetch();

        for (Record r : result) {

            peopleDto = new peopleDto();
            peopleDto.setpeopleID(r.getValue(people.GNUM));
            peopleDto.setName(r.get(people.SNAME));
            peopleDto.setRM(r.get(people.SRM));
            peopleDto.setRG(r.get(people.SRG));
            peopleDto.setCertidaoLivro(r.get(people.SCERT));
            peopleDto.setCertidaoDistrito(r.get(people.SCERTD));
            peopleList.add(peopleDto);
        }
    } catch (Exception e) {
        log.error(e.toString());
    } finally {
        if (ctx != null) {
        ctx.close();
        }
    }
    return new PageImpl(peopleList, pageable, hereyoushouldQueryTheTotalItemCount());
}

现在您可以对这 350 个用户做一些事情。借助该页面，您现在可以迭代剩余的人员:

if(page.hasNext())
    getAllPeople(connection, page.nextPageable());

受到这篇文章的启发Sorting and Pagination with Spring and Jooq