java - 如何在firebase android中同时向一个节点的两个子节点写入数据？

Question

我正在制作一个 Android 应用程序，客户和服务提供商通过该应用程序进行协作。首先，服务提供商向客户发送拜访请求，指定可能的拜访时间。客户接受访问请求后，计时器启动，计算服务提供商访问的剩余时间。如果时间到期，则应将“访问请求”从“已接受/待处理访问列表”中删除并添加到“已完成访问列表”中，并且应自动为两者(即服务提供商和客户)提供“5”评级。我创建了两个函数，一个函数将访问请求从“待处理访问列表”传输到“已完成访问列表”，第二个函数在第一个函数内调用，为两个用户提供“5”评级。问题是，当第二个函数运行时，第一个函数无法完成其功能，因为第二个函数在 fires 函数完成之前运行。我在帖子末尾粘贴了这两个函数及其调用顺序的 Spinet 代码以及更简单的代码版本，以便于理解。

   // this functions Transfers Pending/Accepted Visit Request to Completed Visit Request.

public void transferPendingVisitToCompletedVisitListOfCustomerAndServiceProvider(final VisitRequest 
 visitRequest, final String customerUserName, final int position, final String 
  serviceProviderUserName){
    final DatabaseReference cus_ref = 
  FirebaseDatabase.getInstance().getReference("Users").child("Customers");

    final Customer customer[] = new Customer[1];

    cus_ref.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for(DataSnapshot ssn:dataSnapshot.getChildren()){
                customer[0] = ssn.getValue(Customer.class);
                if(customer[0].getUserName().equals(customerUserName)){
                    alCompletedVisitRequests = customer[0].getCompletedVisitsList();

                    if(alCompletedVisitRequests==null){
                        alCompletedVisitRequests = new ArrayList<>();
                        alCompletedVisitRequests.add(visitRequest);
                        customer[0].setCompletedVisitsList(alCompletedVisitRequests);
                        alPendingVisitRequests.remove(position);
                        customer[0].setPendingVisitsList(alPendingVisitRequests);

                         // updating the UI
                        PendingVisitRequestsAdapter pendingVisitRequestsAdapter = new 
                         PendingVisitRequestsAdapter();
                        listViewPendingVisits.setAdapter(pendingVisitRequestsAdapter);
                        cus_ref.child(customer[0].getId()).setValue(customer[0]);

                   //  Now Checking if the Visit Request is  is expired then rating of 5 should be 
                   // given to both users.
                        if(isPendingVisitExpired==true){


            // now handling the responseTime Rating of Service Provider and Customer
                             automaticallyAddResponseRatingOfServiceProviderandCustomer
             (MainActivity.mcustomer.getUserName(),serviceProviderUserName);
                        }

                    }

                    else{  //i-e alCompletedVisitRequests!=null

                        alCompletedVisitRequests.add(visitRequest);
                        customer[0].setCompletedVisitsList(alCompletedVisitRequests);
                        alPendingVisitRequests.remove(position);
                        customer[0].setPendingVisitsList(alPendingVisitRequests);

                          // updating the UI
                        PendingVisitRequestsAdapter pendingVisitRequestsAdapter = new 
                        PendingVisitRequestsAdapter();
                        listViewPendingVisits.setAdapter(pendingVisitRequestsAdapter);
                        cus_ref.child(customer[0].getId()).setValue(customer[0]);

                   // adding Response Time Rating automatically.Definition of this function is below

              automaticallyAddResponseRatingOfServiceProviderandCustomer
             (MainActivity.mcustomer.getUserName(),serviceProviderUserName);
                    }

                    visitRequest.setUserName(MainActivity.mcustomer.getUserName());


      addPendingVisitToCompletedVisitInServiceProvider(visitRequest,serviceProviderUserName);



                }
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });
}

现在我粘贴响应时间评级函数的定义，该函数已在第一个函数内调用，如上所示。

 private void automaticallyAddResponseRatingOfServiceProviderandCustomer(final String CustomerUserName, final String ServiceProviderUserName){

    DatabaseReference databaseReference = 
      FirebaseDatabase.getInstance().getReference("Users").child("ServiceProviders");
    final String[] ServiceProviderId = new String[1];
    final String[] ServiceProviderImageUrl = new String[1];
    final ServiceProvider[] serviceProvider = new ServiceProvider[1];

    databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

            for(DataSnapshot ssn:dataSnapshot.getChildren()){
                serviceProvider[0] = ssn.getValue(ServiceProvider.class);

                if(serviceProvider[0].getUserName().equals(ServiceProviderUserName)){

                    ServiceProviderId[0] = serviceProvider[0].getId();
                    ServiceProviderImageUrl[0] = serviceProvider[0].getProfilePicUrl();
                    ResponseTimeRating responseTimeRating = new 
                           ResponseTimeRating(MainActivity.mcustomer.getImageUrl(),
                            MainActivity.mcustomer.getUserName(),5);

                    ArrayList<ResponseTimeRating> responseTimeRatingArrayListOfServiceProvider = 
                       serviceProvider[0].getResponseTimeRatingList();

                    if(responseTimeRatingArrayListOfServiceProvider==null){
                        responseTimeRatingArrayListOfServiceProvider = new ArrayList<>();
                        responseTimeRatingArrayListOfServiceProvider.add(responseTimeRating);

   serviceProvider[0].setResponseTimeRatingList(responseTimeRatingArrayListOfServiceProvider);
                        int averageResponseTimeRatingOfServiceProvider = 0;
                        int sum = 0;
                        for (int i = 0; i < responseTimeRatingArrayListOfServiceProvider.size(); i++) 
    {
                            sum = sum + 
          responseTimeRatingArrayListOfServiceProvider.get(i).getResponseRating();
                        }

                        averageResponseTimeRatingOfServiceProvider = sum / 
                      responseTimeRatingArrayListOfServiceProvider.size();

            serviceProvider[0].setResponseRating(averageResponseTimeRatingOfServiceProvider);

     automaticallyAddResponseRatingOfCustomer(ServiceProviderImageUrl[0],ServiceProviderUserName);

                        break;
                    }
                    else{
                        responseTimeRatingArrayListOfServiceProvider.add(responseTimeRating);

      serviceProvider[0].setResponseTimeRatingList(responseTimeRatingArrayListOfServiceProvider);
                        int averageResponseTimeRatingOfServiceProvider = 0;
                        int sum = 0;
                        for (int i = 0; i < responseTimeRatingArrayListOfServiceProvider.size(); i++) {
                            sum = sum + 
      responseTimeRatingArrayListOfServiceProvider.get(i).getResponseRating();
                        }
                        averageResponseTimeRatingOfServiceProvider = sum / 
 responseTimeRatingArrayListOfServiceProvider.size();

     serviceProvider[0].setResponseRating(averageResponseTimeRatingOfServiceProvider);

   automaticallyAddResponseRatingOfCustomer(ServiceProviderImageUrl[0],ServiceProviderUserName);
                        break;
                    }
                }
            }
            DatabaseReference newDatabaseReference = 
         FirebaseDatabase.getInstance().getReference("Users").
        child("ServiceProviders").child(serviceProvider[0].getId()
            );
            newDatabaseReference.setValue(serviceProvider[0]);

        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });

现在我为这两个函数代码粘贴了更简单版本的代码，以便于理解。

// definition of first function which transfers Pending Visit  From 'Pending Visits List' to 
//  'Completed Visit List'

      transferPendingVisitToCompletedVisitListOfCustomerAndServiceProvider
     (visitRequest,MainActivity.mcustomer.getUserName(),position,ServiceProviderUserName){

       // logic for transferring  'Visit Request' From 'Pending Visit List' to 'Completed Visit List'

         bla bla bla bla 
         bla bla bla bla 

         // now calling the function which gives rating to both Users
            automaticallyAddResponseRatingOfServiceProviderandCustomer
            (MainActivity.mcustomer.getUserName(),serviceProviderUserName);

       }// end definition of first function

问题是，当在第一个函数内调用第二个函数时，第一个函数的功能(即，将“访问请求”从“待处理访问列表”转移到“已完成访问列表”)无法完成，这意味着它不会传输“访问请求”但给出评级。

但是，如果我从第一个函数内部删除第二个函数(即评级函数)，那么第一个函数的功能将完美运行，并将“访问请求”转移到“已完成的访问” 列表'。如何才能完美地运行这两个函数的功能？

Answer 1

如果您想通过一次操作写入多个位置，则可以使用多位置更新。

假设你有这两个写:

cus_ref.child(customer[0].getId()).setValue(customer[0]);
DatabaseReference newDatabaseReference =  FirebaseDatabase.getInstance().getReference("Users").child("ServiceProviders").child(serviceProvider[0].getId());
newDatabaseReference.setValue(serviceProvider[0]);

它们可以组合为:

Map<String,Object> updates = new HashMap<String,Object>();
updates.put("/path/to/cus_ref/"+customer[0].getId(), customer[0]);
updates.put("/Users/ServiceProviders/"+serviceProvider[0].getId(), serviceProvider[0]);

FirebaseDatabase.getInstance().getReference().updateChildValues(updates);