未指定的值参数:: type [T] Scala

Question

我有以下功能，并在第二行收到错误Unspecified value parameters :: type[T], Type mismatch, expected: Command[NotInferedT], actual: DeletePrivilegeMappingCmd。

execute()接受Command[T]参数，DeletePrivilegeMappingCmd扩展Command[T]要求。

我根据错误想出我需要在签名中添加[Object]，但我不确定我必须在[]中包含哪种类型。添加任何Object可以消除错误，但我假设如果没有使用正确的类型，将会出现运行时错误。

我应该添加什么类型？

错误讯息签名

def deleteGroupPrivilegeMapping(privilegeId: String, groupId: String) {
  commandExecutor.execute(new DeletePrivilegeMappingCmd(privilegeId, null, groupId))
}

更新了邮件签名

def deleteGroupPrivilegeMapping(privilegeId: String, groupId: String) {
  commandExecutor.execute(new DeletePrivilegeMappingCmd(privilegeId, null, groupId)[String][String])
}

编辑：

Command和execute

的签名

public interface Command<T> extends BaseCommand<T, CommandContext> {

  T execute(CommandContext commandContext);

}

DeletePrivilegeMappingCmd的实现

public class DeletePrivilegeCmd implements Command<Void>, Serializable {

  private static final long serialVersionUID = 1L;

  protected String id;

  public DeletePrivilegeCmd(String id) {
    if (id == null) {
      throw new FlowableIllegalArgumentException("id is null");
    }

    this.id = id;
  }

  public Void execute(CommandContext commandContext) {
    commandContext.gePrivilegeMappingEntityManager().deleteByPrivilegeId(id);
    commandContext.getPrivilegeEntityManager().delete(id);
    return null;
  }
}

命令上下文定义

public class CommandContext extends AbstractCommandContext {
    private static Logger log = LoggerFactory.getLogger(CommandContext.class);
    protected ProcessEngineConfigurationImpl processEngineConfiguration;
    protected FailedJobCommandFactory failedJobCommandFactory;
    protected FlowableEngineAgenda agenda;
    protected Map<String, ExecutionEntity> involvedExecutions = new HashMap(1);
    protected LinkedList<Object> resultStack = new LinkedList();

    public CommandContext(Command<?> command, ProcessEngineConfigurationImpl processEngineConfiguration) {
        super(command);
        this.processEngineConfiguration = processEngineConfiguration;
        this.failedJobCommandFactory = processEngineConfiguration.getFailedJobCommandFactory();
        this.sessionFactories = processEngineConfiguration.getSessionFactories();
        this.agenda = processEngineConfiguration.getAgendaFactory().createAgenda(this);
    }

    protected void logException() {
        if(!(this.exception instanceof JobNotFoundException) && !(this.exception instanceof FlowableTaskAlreadyClaimedException)) {
            super.logException();
        } else {
            log.info("Error while closing command context", this.exception);
        }

    }

    public void addCloseListener(CommandContextCloseListener commandContextCloseListener) {
        if(this.closeListeners == null) {
            this.closeListeners = new ArrayList(1);
        }

        this.closeListeners.add(commandContextCloseListener);
    }

    public DbSqlSession getDbSqlSession() {
        return (DbSqlSession)this.getSession(DbSqlSession.class);
    }

    public EntityCache getEntityCache() {
        return (EntityCache)this.getSession(EntityCache.class);
    }

    public DeploymentEntityManager getDeploymentEntityManager() {
        return this.processEngineConfiguration.getDeploymentEntityManager();
    }

    public ResourceEntityManager getResourceEntityManager() {
        return this.processEngineConfiguration.getResourceEntityManager();
    }

    public ByteArrayEntityManager getByteArrayEntityManager() {
        return this.processEngineConfiguration.getByteArrayEntityManager();
    }

    public ProcessDefinitionEntityManager getProcessDefinitionEntityManager() {
        return this.processEngineConfiguration.getProcessDefinitionEntityManager();
    }

    public ModelEntityManager getModelEntityManager() {
        return this.processEngineConfiguration.getModelEntityManager();
    }

    public ProcessDefinitionInfoEntityManager getProcessDefinitionInfoEntityManager() {
        return this.processEngineConfiguration.getProcessDefinitionInfoEntityManager();
    }

    public ExecutionEntityManager getExecutionEntityManager() {
        return this.processEngineConfiguration.getExecutionEntityManager();
    }

    public TaskEntityManager getTaskEntityManager() {
        return this.processEngineConfiguration.getTaskEntityManager();
    }

    public IdentityLinkEntityManager getIdentityLinkEntityManager() {
        return this.processEngineConfiguration.getIdentityLinkEntityManager();
    }

    public VariableInstanceEntityManager getVariableInstanceEntityManager() {
        return this.processEngineConfiguration.getVariableInstanceEntityManager();
    }

    public HistoricProcessInstanceEntityManager getHistoricProcessInstanceEntityManager() {
        return this.processEngineConfiguration.getHistoricProcessInstanceEntityManager();
    }

    public HistoricDetailEntityManager getHistoricDetailEntityManager() {
        return this.processEngineConfiguration.getHistoricDetailEntityManager();
    }

    public HistoricVariableInstanceEntityManager getHistoricVariableInstanceEntityManager() {
        return this.processEngineConfiguration.getHistoricVariableInstanceEntityManager();
    }

    public HistoricActivityInstanceEntityManager getHistoricActivityInstanceEntityManager() {
        return this.processEngineConfiguration.getHistoricActivityInstanceEntityManager();
    }

    public HistoricTaskInstanceEntityManager getHistoricTaskInstanceEntityManager() {
        return this.processEngineConfiguration.getHistoricTaskInstanceEntityManager();
    }

    public HistoricIdentityLinkEntityManager getHistoricIdentityLinkEntityManager() {
        return this.processEngineConfiguration.getHistoricIdentityLinkEntityManager();
    }

    public EventLogEntryEntityManager getEventLogEntryEntityManager() {
        return this.processEngineConfiguration.getEventLogEntryEntityManager();
    }

    public JobEntityManager getJobEntityManager() {
        return this.processEngineConfiguration.getJobEntityManager();
    }

    public TimerJobEntityManager getTimerJobEntityManager() {
        return this.processEngineConfiguration.getTimerJobEntityManager();
    }

    public SuspendedJobEntityManager getSuspendedJobEntityManager() {
        return this.processEngineConfiguration.getSuspendedJobEntityManager();
    }

    public DeadLetterJobEntityManager getDeadLetterJobEntityManager() {
        return this.processEngineConfiguration.getDeadLetterJobEntityManager();
    }

    public AttachmentEntityManager getAttachmentEntityManager() {
        return this.processEngineConfiguration.getAttachmentEntityManager();
    }

    public TableDataManager getTableDataManager() {
        return this.processEngineConfiguration.getTableDataManager();
    }

    public CommentEntityManager getCommentEntityManager() {
        return this.processEngineConfiguration.getCommentEntityManager();
    }

    public PropertyEntityManager getPropertyEntityManager() {
        return this.processEngineConfiguration.getPropertyEntityManager();
    }

    public EventSubscriptionEntityManager getEventSubscriptionEntityManager() {
        return this.processEngineConfiguration.getEventSubscriptionEntityManager();
    }

    public HistoryManager getHistoryManager() {
        return this.processEngineConfiguration.getHistoryManager();
    }

    public JobManager getJobManager() {
        return this.processEngineConfiguration.getJobManager();
    }

    public void addInvolvedExecution(ExecutionEntity executionEntity) {
        if(executionEntity.getId() != null) {
            this.involvedExecutions.put(executionEntity.getId(), executionEntity);
        }

    }

    public boolean hasInvolvedExecutions() {
        return this.involvedExecutions.size() > 0;
    }

    public Collection<ExecutionEntity> getInvolvedExecutions() {
        return this.involvedExecutions.values();
    }

    public FailedJobCommandFactory getFailedJobCommandFactory() {
        return this.failedJobCommandFactory;
    }

    public ProcessEngineConfigurationImpl getProcessEngineConfiguration() {
        return this.processEngineConfiguration;
    }

    public FlowableEventDispatcher getEventDispatcher() {
        return this.processEngineConfiguration.getEventDispatcher();
    }

    public FlowableEngineAgenda getAgenda() {
        return this.agenda;
    }

    public Object getResult() {
        return this.resultStack.pollLast();
    }

    public void setResult(Object result) {
        this.resultStack.add(result);
    }
}