Removing/shutdown Firebase in Java app (for hot redepoy) - spring

Question

I tried to use org.springframework.boot:spring-boot-devtools to speed up development.
My project uses Firebase to authenticate some requests. Firebase initialized via:
#PostConstruct
public void instantiateFirebase() throws IOException {
FirebaseOptions options = new FirebaseOptions.Builder()
.setDatabaseUrl(String.format("https://%s.firebaseio.com", configuration.getFirebaseDatabase()))
.setServiceAccount(serviceJson.getInputStream())
.build();
FirebaseApp.initializeApp(options);
}
After context reloading on changing .class file Spring reports error:
Caused by: java.lang.IllegalStateException: FirebaseApp name [DEFAULT] already exists!
at com.google.firebase.internal.Preconditions.checkState(Preconditions.java:173)
at com.google.firebase.FirebaseApp.initializeApp(FirebaseApp.java:180)
at com.google.firebase.FirebaseApp.initializeApp(FirebaseApp.java:160)
What Firebase API allow deregister/destroy FirebaseApp that I should use in #PreDestroy?

Answer 1

Looks like it is not possible to disable/shutdown/reinitialize Firebase app.
In my case it is fine to keep that instance in memory without changes.
Depending on your requirements you may use as simple as:
#PostConstruct
public void instantiateFirebase() throws IOException {
// We use only FirebaseApp.DEFAULT_APP_NAME, so check is simple.
if ( ! FirebaseApp.getApps().isEmpty())
return;
Resource serviceJson = applicationContext.getResource(String.format("classpath:firebase/%s", configuration.getFirebaseServiceJson()));
FirebaseOptions options = new FirebaseOptions.Builder()
.setDatabaseUrl(String.format("https://%s.firebaseio.com", configuration.getFirebaseDatabase()))
.setServiceAccount(serviceJson.getInputStream())
.build();
FirebaseApp.initializeApp(options);
}
or filter data like:
for (FirebaseApp app : FirebaseApp.getApps()) {
if (app.getName().equals(FirebaseApp.DEFAULT_APP_NAME))
return;
}