通过参数Feign客户端映射

Question

我有一个看起来像这样的假客户端：

@RequestMapping(method = RequestMethod.POST, value = "/breakdowns/utmMedium", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
List<Breakdown> getUtmMediumBreakdowns(
    @RequestBody Record record,
    @RequestParam("since") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime since,
    @RequestParam("until") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime until,
    @RequestParam("timezone") String timezone
);


@RequestMapping(method = RequestMethod.POST, value = "/breakdowns/utmCampaign", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
List<Breakdown> getUtmCampaignBreakdowns(
    @RequestBody Record record,
    @RequestParam("since") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime since,
    @RequestParam("until") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime until,
    @RequestParam("timezone") String timezone
);


@RequestMapping(method = RequestMethod.POST, value = "/breakdowns/utmSource", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
List<Breakdown> getUtmSourceBreakdowns(
    @RequestBody Record record,
    @RequestParam("since") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime since,
    @RequestParam("until") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime until,
    @RequestParam("timezone") String timezone
);

如您所见，除了 API 路径根据参数 utmMedium、utmCampaign 和 utmSource 更改之外，这三种方法完全相同，因为在服务器端我们确实对它们进行了不同的处理.

我无法更改服务器，因此无法更改端点以接受此参数作为请求参数或其他内容。 我想知道是否有办法让我仍然参数化这部分路径，所以我只有一个方法而不是三个。

Answer 1

您可以使用@PathVariable 注释定义附加参数，如下面的utmType。

@RequestMapping(method = RequestMethod.POST, value = "/breakdowns/{utmType}", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
List<Breakdown> getUtmCampaignBreakdowns(
    @RequestBody Record record,
    @PathVariable("utmType") String utmType,
    @RequestParam("since") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime since,
    @RequestParam("until") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime until,
    @RequestParam("timezone") String timezone
);

您必须注意的一件事是，您需要指定名称utmType，如带有注释的@PathVariable("utmType")。

Answer 2

如果您想将编译时检查添加到备用 URI，可以将字符串枚举用于 utmType 参数。这假设您使用的是 Spring Open Feign。 Plain Feign 需要备用注释 some starting guidance for that case can be found here.:

//Slight changes should be introduced in the getUtmCampaignBreakdowns method signature utmType parameter.
package test;

import java.time.ZonedDateTime;
import java.util.List;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(name = "utmThing", url = "${feign.client.config.utmThing.url}")
public interface Test {
  @PostMapping(value = "/breakdowns/{utmType}", consumes = MediaType.APPLICATION_JSON_VALUE)
  List<Breakdown> getUtmCampaignBreakdowns(
      @RequestBody Record record,
      @PathVariable("utmType") UtmTypes utmType, //<-Type changed to Enum
      @RequestParam("since") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime since,
      @RequestParam("until") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) ZonedDateTime until,
      @RequestParam("timezone") String timezone
  );
}


//An enum should be declared
package test;

enum UtmTypes {
  UTM_MEDIUM("utmMedium"),
  UTM_CAMPAIGN("utmCampaign"),
  UTM_SOURCE("utmSource");

  private final String utmType;

  UtmTypes(String utmType) {
        this.utmType = utmType;
  }

  //Do not forget to privide a toString() that would map to the URI parameter
  public String toString() {
    return utmType;
  }
}

//Can be used like so:
package test;

import java.time.ZonedDateTime;
import java.util.Arrays;
import java.util.TimeZone;
import org.springframework.beans.factory.annotation.Autowired;

public class User {

  @Autowired
  void User(Test test) {
    test.getUtmCampaignBreakdowns(new Record(), UtmTypes.UTM_CAMPAIGN, ZonedDateTime.now(),
        ZonedDateTime.now().plusDays(1),
        Arrays.stream(TimeZone.getAvailableIDs())
            .filter(zoneName -> zoneName.contains("Montevideo")).findFirst()
            .orElse(TimeZone.getAvailableIDs()[0]));
  }
}

//Assuming simple Record and Breakdown implementations
package test;

public class Record {
  private String someField;

  public void setSomeField(String someField) {
    this.someField = someField;
  }

  public String getSomeField() {
    return this.someField;
  }
}

package test;

public class Record {
  private String someField;

  Record() {
    this.someField = "defaultValue";
  }

  public void setSomeField(String someField) {
    this.someField = someField;
  }

  public String getSomeField() {
    return this.someField;
  }
}