io.realm

Class SyncSession

java.lang.Object

io.realm.SyncSession

public class SyncSession
extends Object

A session controls how data is synchronized between a single Realm on the device and the server Realm on the Realm Object Server.

A Session is created by opening a Realm instance using a SyncConfiguration. Once a session has been created, it will continue to exist until the app is closed or all threads using this SyncConfiguration closes their respective Realms.

A session is controlled by Realm, but can provide additional information in case of errors. These errors are passed along in the SyncSession.ErrorHandler.

When creating a session, Realm will establish a connection to the server. This connection is controlled by Realm and might be shared between multiple sessions. It is possible to get insight into the connection using addConnectionChangeListener(ConnectionListener) and isConnected().

The session itself has a different lifecycle than the underlying connection. The state of the session can be found using getState().

The SyncSession object is thread safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SyncSession.ErrorHandler Interface used to report any session errors.
static class	SyncSession.State Enum describing the states a SyncSession can be in.

Method Summary

Modifier and Type	Method and Description
void	addConnectionChangeListener(ConnectionListener listener) Adds a listener tracking changes to the connection backing this session.
void	addDownloadProgressListener(ProgressMode mode, ProgressListener listener) Adds a progress listener tracking changes that need to be downloaded from the Realm Object Server.
void	addUploadProgressListener(ProgressMode mode, ProgressListener listener) Adds a progress listener tracking changes that need to be uploaded from the device to the Realm Object Server.
void	downloadAllServerChanges() Calling this method will block until all known remote changes have been downloaded and applied to the Realm.
boolean	downloadAllServerChanges(long timeout, TimeUnit unit) Calling this method will block until all known remote changes have been downloaded and applied to the Realm or the specified timeout is hit.
SyncConfiguration	getConfiguration() Returns the SyncConfiguration that is responsible for controlling the session.
ConnectionState	getConnectionState() Get the current state of the connection used by the session as defined in ConnectionState.
URI	getServerUrl() Returns the URI describing the remote Realm which this session connects to and synchronizes changes with.
SyncSession.State	getState() Get the current session's state, as defined in SyncSession.State.
SyncUser	getUser() Returns the SyncUser defined by the SyncConfiguration that is used to connect to the Realm Object Server.
boolean	isConnected() Checks if the session is connected to the server and can synchronize data.
void	removeConnectionChangeListener(ConnectionListener listener) Removes a previously registered ConnectionListener.
void	removeProgressListener(ProgressListener listener) Removes a progress listener.
void	start() Attempts to start the session and enable synchronization with the Realm Object Server.
void	stop() Stops any synchronization with the Realm Object Server until the Realm is re-opened again after fully closing it.
void	uploadAllLocalChanges() Calling this method will block until all known local changes have been uploaded to the server.
boolean	uploadAllLocalChanges(long timeout, TimeUnit unit) Calling this method will block until all known local changes have been uploaded to the server or the specified timeout is hit.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getConfiguration

public SyncConfiguration getConfiguration()

Returns the SyncConfiguration that is responsible for controlling the session.

Returns:

SyncConfiguration that defines and controls this session.

getUser

public SyncUser getUser()

Returns the SyncUser defined by the SyncConfiguration that is used to connect to the Realm Object Server.

Returns:

SyncUser used to authenticate the session on the Realm Object Server.

getServerUrl

public URI getServerUrl()

Returns the URI describing the remote Realm which this session connects to and synchronizes changes with.

Returns:

URI describing the remote Realm.

getState

public SyncSession.State getState()

Get the current session's state, as defined in SyncSession.State. Note that the state may change after this method returns, example: the authentication token will expire, causing the session to move to SyncSession.State.WAITING_FOR_ACCESS_TOKEN after it was in SyncSession.State.ACTIVE.

Returns:

the state of the session.

See Also:

SyncSession.State

getConnectionState

public ConnectionState getConnectionState()

Get the current state of the connection used by the session as defined in ConnectionState.

Returns:

the state of connection used by the session.

See Also:

ConnectionState

isConnected

public boolean isConnected()

Checks if the session is connected to the server and can synchronize data. This is a best guess effort. To conserve battery the underlying implementation uses heartbeats to detect if the connection is still available. So if no data is actively being synced and some time has elapsed since the last heartbeat, the connection could have been dropped but this method will still return true.

Returns:

true if the session is connected and ready to synchronize data, false if not or if it is in the process of connecting.

addDownloadProgressListener

public void addDownloadProgressListener(ProgressMode mode,
                                        ProgressListener listener)

Adds a progress listener tracking changes that need to be downloaded from the Realm Object Server.

The ProgressListener will be triggered immediately when registered, and periodically afterwards.

Parameters:

mode - type of mode used. See ProgressMode for more information.

listener - the listener to register.

addUploadProgressListener

public void addUploadProgressListener(ProgressMode mode,
                                      ProgressListener listener)

Adds a progress listener tracking changes that need to be uploaded from the device to the Realm Object Server.

The ProgressListener will be triggered immediately when registered, and periodically afterwards.

Parameters:

mode - type of mode used. See ProgressMode for more information.

listener - the listener to register.

removeProgressListener

public void removeProgressListener(ProgressListener listener)

Removes a progress listener. If the listener wasn't registered, this method will do nothing.

Parameters:

listener - listener to remove.

addConnectionChangeListener

public void addConnectionChangeListener(ConnectionListener listener)

Adds a listener tracking changes to the connection backing this session. See ConnectionState for further details.

Parameters:

listener - the listener to register.

Throws:

IllegalArgumentException - if the listener is null.

See Also:

ConnectionState

removeConnectionChangeListener

public void removeConnectionChangeListener(ConnectionListener listener)

Removes a previously registered ConnectionListener.

Parameters:

listener - listener to remove

Throws:

IllegalArgumentException - if the listener is null.

downloadAllServerChanges

public void downloadAllServerChanges()
                              throws InterruptedException

Calling this method will block until all known remote changes have been downloaded and applied to the Realm. This will involve network access, so calling this method should only be done from a non-UI thread.

If the device is offline, this method might never return.

This method cannot be called before the session has been started.

Throws:

IllegalStateException - if called on the Android main thread.

InterruptedException - if the thread was interrupted while downloading was in progress.

downloadAllServerChanges

public boolean downloadAllServerChanges(long timeout,
                                        TimeUnit unit)
                                 throws InterruptedException

Calling this method will block until all known remote changes have been downloaded and applied to the Realm or the specified timeout is hit. This will involve network access, so calling this method should only be done from a non-UI thread.

This method cannot be called before the Realm has been opened.

Returns:

true if the data was downloaded before the timeout. false if the operation timed out or otherwise failed.

Throws:

IllegalStateException - if called on the Android main thread.

InterruptedException - if the download took longer than the specified timeout or the thread was interrupted while downloading was in progress. The download will continue in the background even after this exception is thrown.

IllegalArgumentException - if timeout is less than or equal to 0 or unit is null.

uploadAllLocalChanges

public void uploadAllLocalChanges()
                           throws InterruptedException

Calling this method will block until all known local changes have been uploaded to the server. This will involve network access, so calling this method should only be done from a non-UI thread.

If the device is offline, this method might never return.

This method cannot be called before the Realm has been opened.

Throws:

IllegalStateException - if called on the Android main thread.

InterruptedException - if the thread was interrupted while downloading was in progress.

uploadAllLocalChanges

public boolean uploadAllLocalChanges(long timeout,
                                     TimeUnit unit)
                              throws InterruptedException

Calling this method will block until all known local changes have been uploaded to the server or the specified timeout is hit. This will involve network access, so calling this method should only be done from a non-UI thread.

This method cannot be called before the Realm has been opened.

Returns:

true if the data was uploaded before the timeout. false if the operation timed out or otherwise failed.

Throws:

IllegalStateException - if called on the Android main thread.

InterruptedException - if the upload took longer than the specified timeout or the thread was interrupted while uploading was in progress. The upload will continue in the background even after this exception is thrown.

IllegalArgumentException - if timeout is less than or equal to 0 or unit is null.

start

public void start()

Attempts to start the session and enable synchronization with the Realm Object Server.

This happens automatically when opening the Realm instance, so doing it manually should only be needed if the session was stopped using stop().

If the session was already started, calling this method will do nothing.

A session is considered started if getState() returns either SyncSession.State.ACTIVE or SyncSession.State.WAITING_FOR_ACCESS_TOKEN. If the session is SyncSession.State.DYING, the session will be moved back to SyncSession.State.ACTIVE.

See Also:

getState(), stop()

stop

public void stop()

Stops any synchronization with the Realm Object Server until the Realm is re-opened again after fully closing it.

Synchronization can be re-enabled by calling start() again.

If the session is already stopped, calling this method will do nothing.