how to know if updateChildren() on Firebase Realtime database was successful or not?-CodePudding

I am incrementing multiple nodes' value using ServerValue.increment() method

In below DB I want to increment Wallet/uID/bal value for multiple UIDs:

OnComplete callback always runs, but it doesn't always increments balance. I want to retry if values were not incremented, how can I know if values were incremented or not and how to retry?

Below is the code:

Map<String, Object> children = new HashMap<>();
children.put("Wallet"   "/"   UID1 "/bal", ServerValue.increment(10));
children.put("Wallet"   "/"   UID2 "/bal", ServerValue.increment(10));
children.put("Wallet"   "/"   UID3 "/bal", ServerValue.increment(10));
//and so on
        FirebaseDatabase.getInstance().getReference().updateChildren(children, new DatabaseReference.CompletionListener() {
            @Override
            public void onComplete(@Nullable DatabaseError error, @NonNull DatabaseReference ref) {
              // how to know here? if successful or any error?
            }
        });

CodePudding user response：

All operations in a single call to updateChildren either succeed or they all fail.

If they fail on the server, the error parameter of your onComplete handler will indicate why it failed; typically that'll be related to the security rules of your database.

CodePudding user response：

Why don't you try to check if the error is null or not? If the error is null, it's successful. Else fail. Try this code:

FirebaseDatabase.getInstance().getReference().updateChildren(children, new DatabaseReference.CompletionListener() {
            @Override
            public void onComplete(@Nullable DatabaseError error, @NonNull DatabaseReference ref) {
              if(error == null && ref != null){ 
                 // there was no error and the value is modified
              }
              else{
                 // there was an error. try to update again
              }
            }
        });