Firebase Java Admin SDK don't work

Question

I am following the documentation on Firebase website on setting up an Java Admin SDK. So I add the dependency to the build.gradle, and added the following code:

Answer 1

I found the problem, the problem was that the program will terminate before connecting to the Firebase server. What you need to do is to delay the termination of the program, by either calling Thread.sleep(20000);, or like I did it

Scanner scanner = new Scanner(System.in);
while(!scanner.nextLine().equals("Quit")){}
System.exit(0);  

Answer 2

One other thing you can try is to explicitly wait until the setValue() task is complete using the Tasks API:

Task<Void> task = usersRef.setValue(users);
try {
    Tasks.await(task);
} catch (ExecutionException | InterruptedException e) {
    // Handle error if necessary
}

Answer 3

Add this code:

ApiFuture api=/*your reference to database*/usersRef.setValueAsync(users/*the data*/);

Object o = api.get(/*time out*/8,TimeUnit.SECONDS/*unite for time out her is seconds*/);

And at last you can check with

api.isDone();

Answer 4

below code is pushing data into firebase database using java async call api from firebase sdk but listeners code is not executing . I am running below code in server side backend.

 public enum Firebase {
INSTANCE;

FirebaseApp firebaseApp;


public void initilizeFirebaseApp(ConfigLoader configReader) {

    CountDownLatch done = new CountDownLatch(1);
    final AtomicInteger message1 = new AtomicInteger(0);
    InputStream firebaseSecret = getClass().getClassLoader().getResourceAsStream("ServiceAccount.json");
    final GoogleCredentials credentials;
    try {
        credentials = GoogleCredentials.fromStream(firebaseSecret);
    } catch (IOException e) {
        e.printStackTrace();
        System.out.println("Error while reading Firebase config file." + e.toString());
        throw new IllegalStateException(e);
    }

    Map<String, Object> auth = new HashMap<>();
    auth.put("uid", "my_resources");

    FirebaseOptions options = new Builder()
            .setConnectTimeout(1000)
            .setCredentials(credentials)
            .setDatabaseAuthVariableOverride(auth)
            .setDatabaseUrl(configReader.getFirebaseDatabaseURL())
            .setStorageBucket(configReader.getFirebaseStorageBucket())
            .setProjectId(configReader.getFirebseProjectId())
            .build();

    firebaseApp = FirebaseApp.initializeApp(options);


    System.out.println(firebaseApp.getName());
    //System.out.println(firebaseApp.getName());
    // Use the shorthand notation to retrieve the default app's service
    FirebaseAuth defaultAuth = FirebaseAuth.getInstance();
    FirebaseDatabase defaultDatabase = FirebaseDatabase.getInstance();


    // The app only has access as defined in the Security Rules
    DatabaseReference ref = FirebaseDatabase
            .getInstance()
            .getReference("/analyst_profiles");


    DateTime dt = new DateTime(java.util.Date.from(Instant.now()), java.util.TimeZone.getDefault());
    System.out.println(dt.getValue());
    //test data push
    // https://firebase.google.com/docs/database/admin/save-data
    AnalystProfiles analystProfilesObjTemp = new AnalystProfiles("test2", Long.toString(dt.getValue()), "dsds", "ds", "ds",
            "dsa2323", "32ddss232");

    ref.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            AnalystProfiles post = dataSnapshot.getValue(AnalystProfiles.class);
            System.out.println(post);
            //done.countDown();
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            System.out.println("The read failed: " + databaseError.getCode());
        }


    });


    CompletableFuture<String> welcomeText = CompletableFuture.supplyAsync(() -> {
        try {
            ref.push().setValueAsync(analystProfilesObjTemp).get();
        } catch (ExecutionException | InterruptedException e) {
            throw new RuntimeException("Error while waiting for future", e);
        }
        return "ok";

    }).thenApply(x -> {
        System.out.println(x);
        System.out.println("Listeners code is not executing");
        return x;
    });


    done.countDown();
    try {
        System.out.println(welcomeText.get());
        done.await();
    } catch (InterruptedException e) {
        e.printStackTrace();
    } catch (ExecutionException e) {
        e.printStackTrace();
    }


}


public void testdataLoad() {

    // The app only has access as defined in the Security Rules
    DatabaseReference ref = FirebaseDatabase
            .getInstance()
            .getReference("/analyst_profiles");


    DateTime dt = new DateTime(java.util.Date.from(Instant.now()), java.util.TimeZone.getDefault());
    System.out.println(dt.getValue());
    //test data push
    // https://firebase.google.com/docs/database/admin/save-data
    AnalystProfiles analystProfilesObjTemp = new AnalystProfiles("test2", Long.toString(dt.getValue()), "dsds", "ds", "ashutsh",
            "dsa2323", "32ddss232");

    CompletableFuture<String> welcomeText = CompletableFuture.supplyAsync(() -> {
        try {
            ref.push().setValueAsync(analystProfilesObjTemp).get();
        } catch (ExecutionException | InterruptedException e) {
            throw new RuntimeException("Error while waiting for future", e);
        }
        return "ok";

    }).thenApply(x -> {
        System.out.println(x);
        return x;
    });



    try {
        System.out.println(welcomeText.get());

    } catch (InterruptedException e) {
        e.printStackTrace();
    } catch (ExecutionException e) {
        e.printStackTrace();
    }

}

}