FirebaseApp
classFirebaseApp
The entry point of Firebase SDKs. It holds common configuration and state for Firebase APIs. Most applications don't need to directly interact with FirebaseApp.
For a vast majority of apps,FirebaseInitProvider will handle the initialization of Firebase for the default project that it's configured to work with, via the data contained in the app'sgoogle-services.json file. This ContentProvider is merged into the app's manifest by default when building with Gradle, and it runs automatically at app launch.No additional lines of code are needed in this case.
In the event that an app requires access to another Firebase projectin addition to the default project,initializeApp must be used to create that relationship programmatically. The name parameter must be unique. To connect to the resources exposed by that project, use theFirebaseApp object returned bygetInstance, passing it the same name used with initializeApp. This object must be passed to the static accessor of the feature that provides the resource. For example, getInstance is used to access the storage bucket provided by the additional project, whereas getInstance is used to access the default project.
AnyFirebaseApp initialization must occur only in the main process of the app. Use of Firebase in processes other than the main process is not supported and will likely cause problems related to resource contention.
Summary
Constants | |
|---|---|
constString | DEFAULT_APP_NAME = "[DEFAULT]" |
Public functions | |
|---|---|
Boolean | |
java-static (Mutable)List<FirebaseApp!> | Returns a mutable list of all FirebaseApps. |
java-staticFirebaseApp | Returns the default (first initialized) instance of the |
java-staticFirebaseApp | getInstance(name: String)Returns the instance identified by the unique name, or throws if it does not exist. |
Int | hashCode() |
java-staticFirebaseApp? | initializeApp(context: Context)Initializes the default FirebaseApp instance using string resource values - populated from google-services.json. |
java-staticFirebaseApp | initializeApp(context: Context, options: FirebaseOptions)Initializes the default |
java-staticFirebaseApp | initializeApp(context: Context, options: FirebaseOptions, name: String)A factory method to initialize a |
Unit | setAutomaticResourceManagementEnabled(enabled: Boolean)If set to true it indicates that Firebase should close database connections automatically when the app is in the background. |
String! | toString() |
Public properties | |
|---|---|
Context! | |
String! | |
FirebaseOptions! |
Constants
Public functions
getApps
java-static fun getApps(context: Context): (Mutable)List<FirebaseApp!>
Returns a mutable list of all FirebaseApps.
getInstance
java-static fun getInstance(): FirebaseApp
Returns the default (first initialized) instance of theFirebaseApp.
| Throws | |
|---|---|
java.lang.IllegalStateException: java.lang.IllegalStateException | if the default app was not initialized. |
getInstance
java-static fun getInstance(name: String): FirebaseApp
Returns the instance identified by the unique name, or throws if it does not exist.
| Parameters | |
|---|---|
name: String | represents the name of the |
| Throws | |
|---|---|
java.lang.IllegalStateException: java.lang.IllegalStateException | if the |
initializeApp
java-static fun initializeApp(context: Context): FirebaseApp?
Initializes the default FirebaseApp instance using string resource values - populated from google-services.json. It also initializes Firebase Analytics for the current process.
This method is called at app startup time byFirebaseInitProvider. Call this method before any Firebase APIs in components outside the main process.
TheFirebaseOptions values used by the default app instance are read from string resources.
| Returns | |
|---|---|
FirebaseApp? | the default FirebaseApp, if either it has been initialized previously, or Firebase API keys are present in string resources. Returns null otherwise. |
initializeApp
java-static fun initializeApp(context: Context, options: FirebaseOptions): FirebaseApp
Initializes the defaultFirebaseApp instance. Same asinitializeApp, but it usesDEFAULT_APP_NAME as name.
It's only required to call this to initialize Firebase if it'snot possible to do so automatically inFirebaseInitProvider. Automatic initialization that way is the expected situation.
initializeApp
java-static fun initializeApp(context: Context, options: FirebaseOptions, name: String): FirebaseApp
A factory method to initialize aFirebaseApp.
| Parameters | |
|---|---|
context: Context | represents the |
options: FirebaseOptions | represents the global |
name: String | unique name for the app. It is an error to initialize an app with an already existing name. Starting and ending whitespace characters in the name are ignored (trimmed). |
| Returns | |
|---|---|
FirebaseApp | an instance of |
| Throws | |
|---|---|
java.lang.IllegalStateException: java.lang.IllegalStateException | if an app with the same name has already been initialized. |
setAutomaticResourceManagementEnabled
fun setAutomaticResourceManagementEnabled(enabled: Boolean): Unit
If set to true it indicates that Firebase should close database connections automatically when the app is in the background. Disabled by default.
Public properties
Except as otherwise noted, the content of this page is licensed under theCreative Commons Attribution 4.0 License, and code samples are licensed under theApache 2.0 License. For details, see theGoogle Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.
Last updated 2025-07-21 UTC.