Guice配置错误：找不到合适的构造函数

Question

我使用GUICE进行依赖注入，使用Dropwizard进行RESTful API构建。 这是我得到的错误：

com.google.inject.ConfigurationException：Guice配置错误：

1）在com.api.analytics.visitor.web.VisitorParams中找不到合适的构造函数。 类必须有一个（也是唯一一个）使用@Inject注释的构造函数或一个非私有的零参数构造函数。 在com.api.analytics.visitor.weitor.wev.v1查找参数0的com.api.analytics.visitor.web.VisitorParams时，请访问com.api.analytics.visitor.web.VisitorParams.class（VisitorParams.java:27）。 VisitorResource。（VisitorResource.java:68），同时定位com.api.analytics.visitor.web.v1.VisitorResource

以下是我的资源设置方式：

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
}

这是我的VisitorParams类：

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
}

我尝试过的一件事是在我的VisitorParams类中添加一个构造函数，如下所示：

public VisitorParams () {}

当我这样做时，我得到一些变量可能没有被初始化的错误。

那我在这里做错了什么导致这个配置错误？ 我是使用Guice和Dropwizard的新手，所以如果您需要任何其他信息，请告诉我。 谢谢！

Answer 1

阅读消息： VisitorParams没有零参数构造函数，也没有使用@Inject注释的构造函数。

将@Inject添加到构造函数中：

@Inject
@JsonCreator
public VisitorParams ( ...

Answer 2

我最终从VisitorResource构造函数中删除了VisitorParams visitorParams并将其移动到各个方法，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
}