Guice配置錯誤：找不到合適的構造函數

Question

我使用GUICE進行依賴注入，使用Dropwizard進行RESTful API構建。 這是我得到的錯誤：

com.google.inject.ConfigurationException：Guice配置錯誤：

1）在com.api.analytics.visitor.web.VisitorParams中找不到合適的構造函數。 類必須有一個（也是唯一一個）使用@Inject注釋的構造函數或一個非私有的零參數構造函數。 在com.api.analytics.visitor.weitor.wev.v1查找參數0的com.api.analytics.visitor.web.VisitorParams時，請訪問com.api.analytics.visitor.web.VisitorParams.class（VisitorParams.java:27）。 VisitorResource。（VisitorResource.java:68），同時定位com.api.analytics.visitor.web.v1.VisitorResource

以下是我的資源設置方式：

package com.api.analytics.visitor.web.v1;

//imports

@Path("/visitor")
@Produces({MediaType.APPLICATION_JSON, ExtraMediaTypes.PROTOBUF})
@Consumes(MediaType.APPLICATION_JSON)
public class VisitorResource {
  private final ContactsManager contactsManager;
  private final ActivityFetcher.Provider activityFetcherProvider;
  private final VisitSourceMapper visitSourceMapper;
  private final TimeZoneClient timeZoneClient;
  private final GatesClient gatesClient;
  private final Value<Integer> smallScanLimit;
  private final Provider<Integer> portalIdProvider;
  private final VisitorParams visitorParams;

  @Inject
  public VisitorResource(@Bind({Bind.Params.QUERY}) VisitorParams visitorParams,
                         ContactsManager contactsManager,
                         ActivityFetcher.Provider activityFetcherProvider,
                         VisitSourceMapper visitSourceMapper,
                         TimeZoneClient timeZoneClient,
                         GatesClient gatesClient,
                         @Named("analytics.activities.fetch.small.scan.limit") Value<Integer> smallScanLimit,
                         @StashedHubId Provider<Integer> portalIdProvider) {
    this.contactsManager = contactsManager;
    this.activityFetcherProvider = activityFetcherProvider;
    this.visitSourceMapper = visitSourceMapper;
    this.timeZoneClient = timeZoneClient;
    this.gatesClient = gatesClient;
    this.smallScanLimit = smallScanLimit;
    this.portalIdProvider = portalIdProvider;
    this.visitorParams = visitorParams;
  }

  @Timed
  @GET
  @Path("/{identity}/activities")
  public List<Activity> getActivitiesGet(@PathParam("identity") String identity) throws Exception {
    return getActivities(identity);
  }

  //other methods
}

這是我的VisitorParams類：

package com.api.analytics.visitor.web;

//imports

public class VisitorParams {
  private final Optional<Long> start;
  private final Optional<Long> end;
  private final Set<ActivityType> activityTypes;
  private final Optional<Integer> limit;
  private final boolean reversed;
  private final Set<Long> vids;

  @JsonCreator
  public VisitorParams (@JsonProperty("start") Optional<Long> start,
                        @JsonProperty("end") Optional<Long> end,
                        @JsonProperty("type") Optional<Set<ActivityType>> activityTypes,
                        @JsonProperty("limit") Optional<Integer> limit,
                        @JsonProperty("reversed") @DefaultValue("false") boolean reversed,
                        @JsonProperty("vid") Optional<Set<Long>> vids) {
    this.start = start;
    this.end = end;
    this.activityTypes = activityTypes.or(Collections.emptySet());
    this.limit = limit;
    this.reversed = reversed;
    this.vids = vids.or(Collections.emptySet());
  }

  public Optional<Long> getStart() {
    return this.start;
  }

  //other getters
}

我嘗試過的一件事是在我的VisitorParams類中添加一個構造函數，如下所示：

public VisitorParams () {}

當我這樣做時，我得到一些變量可能沒有被初始化的錯誤。

那我在這里做錯了什么導致這個配置錯誤？ 我是使用Guice和Dropwizard的新手，所以如果您需要任何其他信息，請告訴我。 謝謝！

Answer 1

閱讀消息： VisitorParams沒有零參數構造函數，也沒有使用@Inject注釋的構造函數。

將@Inject添加到構造函數中：

@Inject
@JsonCreator
public VisitorParams ( ...

Answer 2

我最終從VisitorResource構造函數中刪除了VisitorParams visitorParams並將其移動到各個方法，如下所示：

//imports

@Path("/visitor")
@Produces({MediaType.APPLICATION_JSON, ExtraMediaTypes.PROTOBUF})
@Consumes(MediaType.APPLICATION_JSON)
public class VisitorResource {
  //other variables
  private final VisitorParams visitorParams;

  @Inject
  public VisitorResource(/*other variables*/) {
    this.contactsManager = contactsManager;
    this.activityFetcherProvider = activityFetcherProvider;
    this.visitSourceMapper = visitSourceMapper;
    this.timeZoneClient = timeZoneClient;
    this.gatesClient = gatesClient;
    this.smallScanLimit = smallScanLimit;
    this.portalIdProvider = portalIdProvider;
    //removed visitorParams here
  }

  @Timed
  @GET
  @Path("/{identity}/activities")
  //moved it to the methods
  public List<Activity> getActivitiesGet(@PathParam("identity") String identity, @Bind({Bind.Params.QUERY}) VisitorParams visitorParams) throws Exception {
    this.visitorParams = visitorParams;
    return getActivities(identity);
  }

  //other methods
}