java - 使用 Spring HATEOAS 构建模板化搜索资源 uri

Question

我有一个实现了 ResourceProcessor<RepositorySearchesResource> 的 Controller ，它包含以下请求映射并覆盖 process为此请求映射创建搜索 uri 的方法。我完成它的方式似乎非常脆弱，因为我将 uri 中的参数名称指定为字符串，我还将路径指定为字符串。

理想情况下，我正在寻找某种方式来使用请求映射中定义的参数名称来构建搜索 uri，这样如果我更改它们，就不必更改搜索 uri。最后，我想避免在 uri 中也将路径指定为字符串，因此我不确定是否可以根据请求映射方法名称或其他方式动态构建它。

此外，我想避免构建 Pageable TemplateVariable

@RequestMapping(method = RequestMethod.GET, value = "/orders/search/exceptionsByDate")
public @ResponseBody ResponseEntity<?> getAllExceptionsByDate(Pageable pageable, @RequestParam BigDecimal earlyPickupDate, @RequestParam List<String> status, @RequestParam String costCenter) {
    Page<OrderExceptionProjection> exceptions = orderService.getExceptions(pageable, earlyPickupDate, status, costCenter);
    return ResponseEntity.ok(new Resources<>(exceptions));
}

@Override
public RepositorySearchesResource process(RepositorySearchesResource resource) {
    TemplateVariable earlyPickupDate = new TemplateVariable("earlyPickupeDate", TemplateVariable.VariableType.REQUEST_PARAM, "Selects all records with earlyPickupDate >= to the value specified.");
    TemplateVariable status = new TemplateVariable("status", TemplateVariable.VariableType.REQUEST_PARAM_CONTINUED, "Specifies the order status.");
    TemplateVariable costCenter = new TemplateVariable("costCenter", TemplateVariable.VariableType.REQUEST_PARAM_CONTINUED, "Specified the cost center to return orders for.");
    TemplateVariables vars = new TemplateVariables(earlyPickupDate, status, costCenter);
    UriTemplate uri = new UriTemplate(resource.getId().getHref() + "exceptionsByDate", vars);
    resource.add(new Link(uri, "exceptionsByDate"));
    return resource;
}

Answer 1

您应该将 RequestParams 的名称定义为注释的参数，如下所示:

private static final String EARLY_PICKUP_DATE_PARAM = "earlyPickupDate";
private static final String STATUS_PARAM = "status";
private static final String COST_CENTER_PARAM = "costCenter";

@RequestMapping(method = RequestMethod.GET, value = "/orders/search/exceptionsByDate")
public @ResponseBody ResponseEntity<?> getAllExceptionsByDate(Pageable pageable, 
    @RequestParam(EARLY_PICKUP_DATE_PARAM) BigDecimal earlyPickupDate, 
    @RequestParam(STATUS_PARAM) List<String> status, 
    @RequestParam(COST_CENTER_PARAM) String costCenter) {
  Page<OrderExceptionProjection> exceptions = orderService.getExceptions(pageable, earlyPickupDate, status, costCenter);
  return ResponseEntity.ok(new Resources<>(exceptions));
}

然后在定义 TemplateVariables 时只需使用相同的字符串常量:

@Override
public RepositorySearchesResource process(RepositorySearchesResource resource) {
  TemplateVariable earlyPickupDate = new TemplateVariable(EARLY_PICKUP_DATE_PARAM, TemplateVariable.VariableType.REQUEST_PARAM, "Selects all records with earlyPickupDate >= to the value specified.");
  TemplateVariable status = new TemplateVariable(STATUS_PARAM, TemplateVariable.VariableType.REQUEST_PARAM_CONTINUED, "Specifies the order status.");
  TemplateVariable costCenter = new TemplateVariable(COST_CENTER_PARAM, TemplateVariable.VariableType.REQUEST_PARAM_CONTINUED, "Specified the cost center to return orders for.");
  TemplateVariables vars = new TemplateVariables(earlyPickupDate, status, costCenter);
  UriTemplate uri = new UriTemplate(resource.getId().getHref() + "exceptionsByDate", vars);
  resource.add(new Link(uri, "exceptionsByDate"));
  return resource;
}