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io.realm

Class RealmConfiguration.Builder

On this page

  • io.realm
  • Constructors
  • Method Summary
  • Inherited Methods
  • Constructor Detail
  • Method Detail
  • addModule
  • allowQueriesOnUiThread
  • allowWritesOnUiThread
  • assetFile
  • build
  • compactOnLaunch
  • deleteRealmIfMigrationNeeded
  • directory
  • encryptionKey
  • flowFactory
  • inMemory
  • initialData
  • maxNumberOfActiveVersions
  • migration
  • modules
  • name
  • readOnly
  • rxFactory
  • schemaVersion

io.realm

java.lang.Object
io.realm.RealmConfiguration.Builder

Enclosing class:

RealmConfiguration

RealmConfiguration.Builder used to construct instances of a RealmConfiguration in a fluent manner.

Constructors

Constructor and Description
Builder ()

Creates an instance of the Builder for the RealmConfiguration.

Method Summary

Modifier and Type
Method and Description
addModule (
Object module
)

FIXME: Temporary visible DEBUG method.

allowQueriesOnUiThread (
boolean allowQueriesOnUiThread
)

Sets whether or not a RealmQuery can be launched from the UI thread.

allowWritesOnUiThread (
boolean allowWritesOnUiThread
)

Sets whether or not calls to Realm.executeTransaction are allowed from the UI thread.

assetFile (
String assetFile
)

Copies the Realm file from the given asset file path.

build ()

Creates the RealmConfiguration based on the builder parameters.

compactOnLaunch (
CompactOnLaunchCallback compactOnLaunch
)

Sets this to determine if the Realm file should be compacted before returned to the user.

compactOnLaunch ()

Setting this will cause Realm to compact the Realm file if the Realm file has grown too large and a significant amount of space can be recovered.

deleteRealmIfMigrationNeeded ()

Setting this will change the behavior of how migration exceptions are handled.

directory (
File directory
)

Specifies the directory where the Realm file will be saved.

encryptionKey (
byte[] key
)

Sets the 64 byte key used to encrypt and decrypt the Realm file.

flowFactory (
FlowFactory factory
)

Sets the FlowFactory used to create coroutines Flows from Realm objects.

inMemory ()

Setting this will create an in-memory Realm instead of saving it to disk.

initialData (
Realm.Transaction transaction
)

Sets the initial data in io.realm.Realm .

maxNumberOfActiveVersions (
long number
)

Sets the maximum number of live versions in the Realm file before an IllegalStateException is thrown when attempting to write more data.

migration (
RealmMigration migration
)

Sets the io.realm.RealmMigration to be run if a migration is needed.

modules (
Object baseModule,
java.lang.Object[] additionalModules
)

Replaces the existing module(s) with one or more RealmModule s.

name (
String filename
)

Sets the filename for the Realm file.

readOnly ()

Setting this will cause the Realm to become read only and all write transactions made against this Realm will fail with an IllegalStateException .

rxFactory (
RxObservableFactory factory
)

Sets the RxObservableFactory used to create Rx Observables from Realm objects.

schemaVersion (
long schemaVersion
)

Sets the schema version of the Realm.

Inherited Methods

  • Methods inherited from class java.lang.Object : getClass , hashCode , equals , clone , toString , notify , notifyAll , wait , wait , wait , finalize

Constructor Detail

public Builder ()

Creates an instance of the Builder for the RealmConfiguration.This will use the app's own internal directory for storing the Realm file. This does not require any additional permissions. The default location is /data/data/<packagename>/files , but can change depending on vendor implementations of Android.

Method Detail

addModule

FIXME: Temporary visible DEBUG method. Will add a module unconditionally. Adds a module to already defined modules.

allowQueriesOnUiThread

public RealmConfiguration.Builder allowQueriesOnUiThread (
boolean allowQueriesOnUiThread
)

Sets whether or not a RealmQuery can be launched from the UI thread.

By default Realm allows queries on the main thread. However, by doing so your application may experience a drop of frames or even ANRs. We recommend diverting queries to non-UI threads or, alternatively, using RealmQuery.findAllAsync() or RealmQuery.findFirstAsync() .

allowWritesOnUiThread

public RealmConfiguration.Builder allowWritesOnUiThread (
boolean allowWritesOnUiThread
)

Sets whether or not calls to Realm.executeTransaction are allowed from the UI thread.

WARNING: Realm does not allow synchronous transactions to be run on the main thread unless users explicitly opt in with this method. We recommend diverting calls to executeTransaction to non-UI threads or, alternatively, using Realm.executeTransactionAsync .

assetFile

Copies the Realm file from the given asset file path.When opening the Realm for the first time, instead of creating an empty file, the Realm file will be copied from the provided asset file and used instead.

This cannot be combined with deleteRealmIfMigrationNeeded() as doing so would just result in the copied file being deleted.

WARNING: This could potentially be a lengthy operation and should ideally be done on a background thread.

Parameters

  • assetFile - path to the asset database file.

Throws

build

Creates the RealmConfiguration based on the builder parameters.

Returns

the created RealmConfiguration .

compactOnLaunch

Sets this to determine if the Realm file should be compacted before returned to the user. It is passed the total file size (data + free space) and the bytes used by data in the file.

Parameters

  • compactOnLaunch - a callback called when opening a Realm for the first time during the life of a process to determine if it should be compacted before being returned to the user. It is passed the total file size (data + free space) and the bytes used by data in the file.

Setting this will cause Realm to compact the Realm file if the Realm file has grown too large and a significant amount of space can be recovered. See DefaultCompactOnLaunchCallback for details.

deleteRealmIfMigrationNeeded

Setting this will change the behavior of how migration exceptions are handled. Instead of throwing a io.realm.exceptions.RealmMigrationNeededException the on-disc Realm will be cleared and recreated with the new Realm schema.

This cannot be configured to have an asset file at the same time by calling assetFile(String) as the provided asset file will be deleted in migrations.

WARNING! This will result in loss of data.

Throws

directory

Specifies the directory where the Realm file will be saved. The default value is context.getFilesDir() . If the directory does not exist, it will be created.

Parameters

  • directory - the directory to save the Realm file in. Directory must be writable.

Throws

encryptionKey

Sets the 64 byte key used to encrypt and decrypt the Realm file. Sets the io.realm.Realm#ENCRYPTION_KEY_LENGTH bytes key used to encrypt and decrypt the Realm file.

flowFactory

Sets the FlowFactory used to create coroutines Flows from Realm objects. The default factory is RealmFlowFactory .

Parameters

  • factory - factory to use.

inMemory

Setting this will create an in-memory Realm instead of saving it to disk. In-memory Realms might still use disk space if memory is running low, but all files created by an in-memory Realm will be deleted when the Realm is closed.Note that because in-memory Realms are not persisted, you must be sure to hold on to at least one non-closed reference to the in-memory Realm object with the specific name as long as you want the data to last.

initialData

Sets the initial data in io.realm.Realm . This transaction will be executed only for the first time when database file is created or while migrating the data when Builder.deleteRealmIfMigrationNeeded() is set.

Parameters

  • transaction - transaction to execute.

maxNumberOfActiveVersions

Sets the maximum number of live versions in the Realm file before an IllegalStateException is thrown when attempting to write more data.

Realm is capable of concurrently handling many different versions of Realm objects. This can e.g. happen if you have a Realm open on many different threads or are freezing objects while data is being written to the file.

Under normal circumstances this is not a problem, but if the number of active versions grow too large, it will have a negative effect on the filesize on disk. Setting this parameters can therefore be used to prevent uses of Realm that can result in very large Realms.

Parameters

  • number - the maximum number of active versions before an exception is thrown.

Tip

See also:

migration

Sets the io.realm.RealmMigration to be run if a migration is needed. If this migration fails to upgrade the on-disc schema to the runtime schema, a io.realm.exceptions.RealmMigrationNeededException will be thrown.

modules

public RealmConfiguration.Builder modules (
Object baseModule,
java.lang.Object[] additionalModules
)

Replaces the existing module(s) with one or more RealmModule s. Using this method will replace the current schema for this Realm with the schema defined by the provided modules.

A reference to the default Realm module containing all Realm classes in the project (but not dependencies), can be found using Realm.getDefaultModule() . Combining the schema from the app project and a library dependency is thus done using the following code:

builder.modules(Realm.getDefaultMode(), new MyLibraryModule());

Parameters

  • baseModule - the first Realm module (required).

  • additionalModules - the additional Realm modules

Throws

Tip

See also:

name

Sets the filename for the Realm file.

readOnly

Setting this will cause the Realm to become read only and all write transactions made against this Realm will fail with an IllegalStateException .

This in particular mean that initialData(Realm.Transaction) will not work in combination with a read only Realm and setting this will result in a IllegalStateException being thrown.

Marking a Realm as read only only applies to the Realm in this process. Other processes can still write to the Realm.

rxFactory

Sets the RxObservableFactory used to create Rx Observables from Realm objects. The default factory is RealmObservableFactory .

Parameters

  • factory - factory to use.

schemaVersion

public RealmConfiguration.Builder schemaVersion (
long schemaVersion
)

Sets the schema version of the Realm. This must be equal to or higher than the schema version of the existing Realm file, if any. If the schema version is higher than the already existing Realm, a migration is needed.If no migration code is provided, Realm will throw a io.realm.exceptions.RealmMigrationNeededException .

Tip

See also:

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