apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/controller/SearchController.java/SearchController/search
class SearchController:  @GetMapping("/apps/search/by-appid-or-name")
  public PageDTO<App> search(@RequestParam(value = "query", required = false) String query, Pageable pageable) {
    if (StringUtils.isEmpty(query)) {
      return appService.findAll(pageable);
    }

    //search app
    PageDTO<App> appPageDTO = appService.searchByAppIdOrAppName(query, pageable);
    if (appPageDTO.hasContent()) {
      return appPageDTO;
    }

    if (!portalConfig.supportSearchByItem()) {
      return new PageDTO<>(Lists.newLinkedList(), pageable, 0);
    }

    //search item
    return searchByItem(query, pageable);
  }