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This is the official Firebase Admin Java SDK. Build extraordinary native JVM apps in
minutes with Firebase. The Firebase platform can power your app’s backend, user
authentication, static hosting, and more.
/*
* Copyright 2017 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.firebase.database;
/**
* Classes implementing this interface can be used to receive events about data changes at a
* location. Attach the listener to a location user {@link
* DatabaseReference#addValueEventListener(ValueEventListener)}.
*/
public interface ValueEventListener {
/**
* This method will be called with a snapshot of the data at this location. It will also be called
* each time that data changes.
*
* @param snapshot The current data at the location
*/
void onDataChange(DataSnapshot snapshot);
/**
* This method will be triggered in the event that this listener either failed at the server, or
* is removed as a result of the security and Firebase Database rules. For more information on
* securing your data, see:
*
* Security Quickstart
*
* @param error A description of the error that occurred
*/
void onCancelled(DatabaseError error);
}