Firebase ServerValue.TIMESTAMP in Java data models objects

Question

I\'m new to Firebase, and I\'ve been really enjoying it so far. I\'m running into a problem; I\'m using the FirebaseListAdapter similar to the tutorial outline here: https:

Answer 1

Kotlin provides an easy way to achieve this by data classes. You can create it like

data class FirebaseRequestModel(
        var start_time: Any = ServerValue.TIMESTAMP,
        var stop_time: Long = 0,
        var total_time: Long = 0,
)

and use it directly by

val firebaseModel = FirebaseRequestModel()
firebaseRef.setValue(firebaseModel)

This will get default values from data class.

Or even you can initiate your own values by

val firebaseModel = FirebaseRequestModel(ServerValue.TIMESTAMP, 2134, 0)
firebaseRef.setValue(firebaseModel)

Answer 2

This sounds similar to this question: When making a POJO in Firebase, can you use ServerValue.TIMESTAMP?

When creating POJOs used to store/retrieve data apart from the default empty constructor I usually use a constructor similar to this:

Param param1;
Param param2;
HashMap<String, Object> timestampCreated;

//required empty constructor
public DataObject(){}

public DataObject(Param param1, Param param2) {
       this.param1 = param1;
       this.param2 = param2;
       HashMap<String, Object> timestampNow = new HashMap<>();
       timestampNow.put("timestamp", ServerValue.TIMESTAMP);
       this.timestampCreated = timestampNow;
}

Be sure to include a getter for the HashMap<> used to store the Timestamp:

public HashMap<String, Object> getTimestampCreated(){
    return timestampCreated;
}

Then use the @Exclude annotation to create a getter that you can use in your code to get the value of the timestamp if you need it. The @Exclude annotation will cause Firebase to ignore this getter and not look for a corresponding property

@Exclude
public long getTimestampCreatedLong(){
    return (long)timestampCreated.get("timestamp");
}

Answer 3

You can do it:

public class MyTimeStamp {
    private Object timestamp;

    public MyTimeStamp() {

    }

    public Object getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Object timestamp) {
        this.timestamp = timestamp;
    }
}

And so:

public static void start(Context context) {
    MyTimeStamp timeStamp = new MyTimeStamp();
    timeStamp.setTimestamp(ServerValue.TIMESTAMP);

    Log.d(TAG, "start: ", timeStamp.getTimestamp().toString());
}

Answer 4

Here's how I do it

//member variable
Object createdTimestamp;

public YourConstructor(){
    createdTimestamp = ServerValue.TIMESTAMP
}

@Exclude
public long getCreatedTimestampLong(){
    return (long)createdTimestamp;
}

Answer 5

Similar to Urgurcan's answer, but a bit cleaner so the caller doesn't have trouble guessing between getTimestamp vs timestamp.

public class FirebaseDbObject {

    private Object timestamp = ServerValue.TIMESTAMP;

    //........
    //........
    @PropertyName("timestamp")
    Object getRawTimestamp() {
        return timestamp;
    }

    @Exclude
    public long getTimestamp() {
        return (long) timestamp;
    }

}

Answer 6

Your db object should include these:

public class FirebaseDbObject {

    private final Object timestamp = ServerValue.TIMESTAMP;

    //........
    //........

    Object getTimestamp() {
        return timestamp;
    }

    @Exclude
    public long timestamp() {
        return (long) timestamp;
    }

}

This will add an extra field called "timestamp" to your object.

Edit: The answer posted by MobileMon is not fully correct as it does not have getter method. This is the complete and correct answer.