Spring Feign GetMapping传Criteria参数遇405错误的问题排查

我尝试从Organisation微服务获取UserConfig，随着应用规模扩大，需要通过UserConfigFeignCriteria筛选UserConfig。编写Feign服务、调用实现代码后，调用时抛出405错误，且Organisation微服务的目标端点未被触发，需排查原因并实现UserConfigFeignCriteria的正常传递。

Feign服务代码 #

@AuthorizedFeignClient(name = "organization")
@Service
public interface UserConfigFeignService {
    @RequestMapping(
        value = "/api/feign-user-configs",
        consumes = "application/json",
        produces = "application/json",
        method = RequestMethod.GET
    )
    ResponseEntity<List<UserConfigFein>> getUserConfig(UserConfigFeignCriteria criteria);
}

调用实现代码 #

public List<UserConfigFein> UserConfigByDepartment(UserConfigFeignCriteria criteria) {
    try {
        return userConfigFeignService.getUserConfig(criteria).getBody();
    } catch (Exception e) {
        e.printStackTrace();
        throw new RuntimeException("feign error: couldn't get all userConfigs with criteria " + criteria);
    }
}

Organisation微服务端点代码 #

@GetMapping("/feign-user-configs")
public ResponseEntity<List<UserConfigDTO>> getUserConfig(UserConfigCriteria criteria) {
    log.debug("REST request to get a page of UserConfigs by criteria: {}", criteria);
 //未执行到此处代码
}

错误信息 #

调用时在throw new RuntimeException("feign error: couldn't get all userConfigs with criteria " + criteria);处抛出以下错误：

[405 Method Not Allowed] during [GET] to [http://organization/api/feign-user-configs] [UserConfigFeignService#getUserConfigByDepartmentId(UserConfigFeignCriteria)]: [{
  "title" : "Method Not Allowed",
  "status" : 405,
  "detail" : "Request method 'POST' not supported",
  "path" : "/api/feign-user-configs",
  "message" : "error.http.405"
}]

补充：UserConfigFeignCriteria代码 #

@ParameterObject
public class UserConfigFeignCriteria implements Serializable, Criteria {

    private LongFilter id;
    private StringFilter userId;
    private StringFilter nickname;
    private Boolean focusMode;

    private LongFilter departmentId;
    private Boolean distinct;

    public UserConfigFeignCriteria(UserConfigFeignCriteria other) {
        this.id = other.id == null ? null : other.id.copy();
        this.userId = other.userId == null ? null : other.userId.copy();
        this.nickname = other.nickname == null ? null : other.nickname.copy();
        this.focusMode = other.focusMode;
        this.distinct = other.distinct;
    }

    public UserConfigFeignCriteria() {}

    @Override
    public UserConfigFeignCriteria copy() {
        return new UserConfigFeignCriteria(this);
    }

//getters and setters

    @Override
    public boolean equals(Object o) 
    @Override
    public int hashCode()

    @Override
    public String toString() 

}

1. Feign GET请求的参数处理逻辑：Feign默认会将GET方法中的对象参数放入请求体发送，导致实际请求变为POST，但目标端点仅支持GET，因此返回405方法不允许错误。
2. 缺少参数绑定注解：Feign接口中的UserConfigFeignCriteria参数未添加注解，无法被解析为URL查询参数，只能退化为POST请求传递请求体。

方案一：使用@SpringQueryMap注解（推荐） #

修改Feign接口方法，添加@SpringQueryMap注解，让Feign将对象属性解析为URL查询参数传递：

@AuthorizedFeignClient(name = "organization")
@Service
public interface UserConfigFeignService {
    @RequestMapping(
        value = "/api/feign-user-configs",
        produces = "application/json",
        method = RequestMethod.GET
    )
    ResponseEntity<List<UserConfigFein>> getUserConfig(@SpringQueryMap UserConfigFeignCriteria criteria);
}

提示：可以移除consumes = "application/json"，因为GET请求不存在请求体。

方案二：拆分对象为多个@RequestParam参数 #

若UserConfigFeignCriteria属性较少，可直接将每个属性作为单独的@RequestParam参数传递：

@AuthorizedFeignClient(name = "organization")
@Service
public interface UserConfigFeignService {
    @RequestMapping(
        value = "/api/feign-user-configs",
        produces = "application/json",
        method = RequestMethod.GET
    )
    ResponseEntity<List<UserConfigFein>> getUserConfig(
        @RequestParam(required = false) LongFilter id,
        @RequestParam(required = false) StringFilter userId,
        // 依次添加其他属性参数
        @RequestParam(required = false) Boolean distinct
    );
}

此方式在属性较多时会显得繁琐，不如方案一简洁。

端点参数接收验证 #

Organisation微服务的端点已添加@ParameterObject注解，Spring Boot会自动将URL查询参数绑定到UserConfigCriteria对象属性，无需额外修改，只要Feign正确传递参数即可触发端点逻辑。

内容的提问来源于stack exchange，提问作者Fendri