java.lang.ClassCastException : java. lang.Boolean 无法转换为 java.util.Map

Question

我在这一行中收到错误:“Map map = (Map) dataSnapshot.getValue();”

     private void getAssignedCustomer(){
    String driverId = FirebaseAuth.getInstance().getCurrentUser().getUid();
    DatabaseReference assignedCustomerRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverId);
    assignedCustomerRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            if(dataSnapshot.exists()){

                Map<String, Object> map = (Map<String, Object>) dataSnapshot.getValue();

                if(map.get("customerRideId") != null){
                    customerId = map.get("customerRideId").toString();
                    getAssignedCustomerPickupLocation();
                }
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
        }
    });
}

如何摆脱这个错误？？？

Answer 1

引自 Firebase 文档:

getValue() returns the data contained in this snapshot as native types. The possible types returned are:

Boolean

String

Long

Double

Map

List

This list is recursive; the possible types for Object in the above list is given by the same list. These types correspond to the types available in JSON.

从 dataSnapshot.getValue() 返回的值似乎是Boolean，它当然不能分配给Map<String, Object> .

确保您使用的是来自 dataSnapshot 的正确数据