+- 0Day Forums (https://zeroday.vip)
+-- Forum: Coding (https://zeroday.vip/Forum-Coding)
+--- Forum: Database (https://zeroday.vip/Forum-Database)
+---- Forum: Firebase (https://zeroday.vip/Forum-Firebase)
+---- Thread: Firebase "Failed to convert a value of type java.util.HashMap to int" (/Thread-Firebase-quot-Failed-to-convert-a-value-of-type-java-util-HashMap-to-int-quot)
Firebase "Failed to convert a value of type java.util.HashMap to int" - raidenbh - 07-31-2023
At this line of my code in my `OnDataChange()` method in the `ValueEvenListener`:
int latest = dataSnapshot.getValue(Integer.class);
I'm getting a `DatabaseException` with the error `Failed to convert a value of type java.util.HashMap to int`.
However, in my database, you can take a look at the image below:
[![enter image description here][1]][1]
It is obviously not a `HashMap` but an `int`. Is this a bug or am I doing something wrong? What can I do to fix it? Why is it retrieving a `Hashmap` when the value is `int`?
**Full dataSnapshot:**
final DatabaseReference database = FirebaseDatabase.getInstance().getReference();
database.child("Campaigns").child(key).child("count");
database.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int latest = dataSnapshot.getValue(Integer.class);
button.setText(latest + "");
}
@Override
public void onCancelled(DatabaseError databaseError) {
Toast.makeText(context, context.getString(R.string.error) + ": " + databaseError.getMessage(), Toast.LENGTH_SHORT).show();
}
});
**Database:**
Campaigns:{
-JDKKDJIIDJFIDJKDK:{
count:2432
}
}
[1]:
RE: Firebase "Failed to convert a value of type java.util.HashMap to int" - sortie473 - 07-31-2023
It turns out I had to child dataSnapshot to my destination again. E.g:
int latest = dataSnapshot.child("Campaigns").child(key).child("count").getValue(Integer.class);
By default `dataSnapshot` is actually my whole database.
RE: Firebase "Failed to convert a value of type java.util.HashMap to int" - spelaean729 - 07-31-2023
This should work if we assume that the dataSnapshot is right.
final DatabaseReference database = FirebaseDatabase.getInstance().getReference();
database = database.child("Campaigns").child(key).child("count"); // replaced
database.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
int latest = Integer.valueOf(dataSnapshot.getValue().toString()); // replaced
button.setText(latest + "");
}
@Override
public void onCancelled(DatabaseError databaseError) {
Toast.makeText(context, context.getString(R.string.error) + ": " + databaseError.getMessage(), Toast.LENGTH_SHORT).show();
}
});
Reminder : **addValueEventListener** will run everytime there is a change in the dataSnapshot.
If you want to run it just once use **addListenerForSingleValueEvent** instead.
RE: Firebase "Failed to convert a value of type java.util.HashMap to int" - pleurolysis503733 - 07-31-2023
Your `ValueEventListener` is attached to the whole database.
// This line gets a reference to the whole database
final DatabaseReference database = FirebaseDatabase.getInstance().getReference();
// This line creates a child DatabaseReference, but you don't assign
// the child to a variable
database.child("Campaigns").child(key).child("count");
// This line adds a ValueEventListener to the whole database
database.addValueEventListener(new ValueEventListener() {
What you want instead is this:
final DatabaseReference database = FirebaseDatabase.getInstance().getReference()
final DatabaseReference countRef = database.child("Campaigns").child(key).child("count")
countRef.addValueEventListener(new ValueEventListener() {
// ...
});
You can see that in the latter example the ValueEventListener is attached to the child reference, not to the root.
RE: Firebase "Failed to convert a value of type java.util.HashMap to int" - borofluohydric399771 - 07-31-2023
HashMap<String, String> hashMap = (HashMap<String, String>) dataSnapshot1.getValue();
System.out.println("hehe " + hashMap);
String demo = String.valueOf(hashMap.get("sets"));
String name = String.valueOf(hashMap.get("name"));
The COde Above ^^^ Worked fine for me.