一尘不染

Spring可选分页

spring-boot

我对java和spring很陌生。

我要实现的是/tickets带有分页和排序功能的api端点。我做到了,而且有效。但也是我想做的是,如果返回所有门票的普通列表size,并page没有在查询参数指定的,所以在FE我可以使用选择框该列表。

我试图做的是getTickets在服务外观上实现并返回所有票证列表。但是我没有找到一种方法来检查是否设置了Pageable,因为它总是返回默认值(size
= 20,page = 0)

//控制器

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity<Page<TicketListItemResponseModel>> getTickets(Pageable pageable) {
    logger.info("> getTickets");
    Page<TicketListItemResponseModel> tickets = ticketServiceFacade.getTickets(pageable);
    logger.info("< getTickets");
    return new ResponseEntity<>(tickets, HttpStatus.OK);
}

// TicketServiceFacade

public Page<TicketListItemResponseModel> getTickets(Pageable pageable) {
    Page<Ticket> tickets = ticketService.findAll(pageable);
    return tickets.map(new ConverterFromPagesToListItem());
}

public List<TicketListItemResponseModel> getTickets() {
    List<Ticket> tickets = ticketService.findAll();
    return tickets.stream()
            .map(t -> modelMapper.map(t, TicketListItemResponseModel.class))
            .collect(Collectors.toList());
}

也许我做错了吗?


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2020-05-30

共1个答案

一尘不染

如果像这样构建控制器方法,则可以通过检查请求参数来管理是否要实现分页:

@Override
public ResponseEntity<Page<TicketListItemResponseModel>> getTickets(
        @RequestParam(value = "page", defaultValue = "0", required = false) int page,
        @RequestParam(value = "count", defaultValue = "10", required = false) int size,
        @RequestParam(value = "order", defaultValue = "ASC", required = false) Sort.Direction direction,
        @RequestParam(value = "sort", defaultValue = "name", required = false) String sortProperty) {
    // here you would check your request params and decide whether or not to do paging and then return what you need to return
}

如果您需要构建PageRequest传递到服务方法中,则可以手动进行操作,如下所示:

new PageRequest(page, size, new Sort(direction, sortProperty));
2020-05-30