com.google.cloud.spanner.watcher

Class SpannerDatabaseTailer

java.lang.Object

com.google.api.core.AbstractApiService

com.google.cloud.spanner.watcher.SpannerDatabaseTailer

All Implemented Interfaces:

com.google.api.core.ApiService, SpannerDatabaseChangeWatcher

public class SpannerDatabaseTailer
extends com.google.api.core.AbstractApiService
implements SpannerDatabaseChangeWatcher

Implementation of the SpannerDatabaseChangeWatcher interface that continuously polls a set of tables for changes based on commit timestamp columns in the tables.

Example usage for watching all tables in a database:

{@code
 String instance = "my-instance";
 String database = "my-database";

 Spanner spanner = SpannerOptions.getDefaultInstance().getService();
 DatabaseId databaseId = DatabaseId.of(SpannerOptions.getDefaultProjectId(), instance, database);
 SpannerDatabaseChangeWatcher watcher =
     SpannerDatabaseTailer.newBuilder(spanner, databaseId).allTables().build();
 watcher.addCallback(
     new RowChangeCallback() {

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SpannerDatabaseTailer.Builder Builder for a SpannerDatabaseTailer.
static interface	SpannerDatabaseTailer.TableExcluder Interface for excluding specific tables from a SpannerDatabaseTailer.
static interface	SpannerDatabaseTailer.TableSelecter Interface for selecting the tables that should be monitored by a SpannerDatabaseTailer.

Nested classes/interfaces inherited from interface com.google.api.core.ApiService

com.google.api.core.ApiService.Listener, com.google.api.core.ApiService.State

Method Summary

Modifier and Type	Method and Description
void	addCallback(SpannerTableChangeWatcher.RowChangeCallback callback) Adds a SpannerTableChangeWatcher.RowChangeCallback for this SpannerDatabaseChangeWatcher.
protected void	doStart()
protected void	doStop()
com.google.cloud.spanner.DatabaseId	getDatabaseId() Returns the id of the database that is being monitored for changes.
List<TableId>	getTables() Returns the ids of the tables that are monitored by this watcher.
static SpannerDatabaseTailer.TableSelecter	newBuilder(com.google.cloud.spanner.Spanner spanner, com.google.cloud.spanner.DatabaseId databaseId) Creates a builder for a SpannerDatabaseTailer.

Methods inherited from class com.google.api.core.AbstractApiService

addListener, awaitRunning, awaitRunning, awaitTerminated, awaitTerminated, failureCause, isRunning, notifyFailed, notifyStarted, notifyStopped, startAsync, state, stopAsync

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.api.core.ApiService

addListener, awaitRunning, awaitRunning, awaitTerminated, awaitTerminated, failureCause, isRunning, startAsync, state, stopAsync

Method Detail

newBuilder

public static SpannerDatabaseTailer.TableSelecter newBuilder(com.google.cloud.spanner.Spanner spanner,
                                                             com.google.cloud.spanner.DatabaseId databaseId)

Creates a builder for a SpannerDatabaseTailer.

addCallback

public void addCallback(SpannerTableChangeWatcher.RowChangeCallback callback)

Description copied from interface: SpannerDatabaseChangeWatcher

Adds a SpannerTableChangeWatcher.RowChangeCallback for this SpannerDatabaseChangeWatcher. Callbacks may only be added when the ApiService.state() of this SpannerDatabaseChangeWatcher is ApiService.State.NEW. Callbacks for one table will always be in order of commit timestamp, and only one callback will be active at any time for a table. Callbacks for different tables may be called in parallel, and there is no guarantee to the ordering of callbacks over multiple tables.

Specified by:

addCallback in interface SpannerDatabaseChangeWatcher

doStart

protected void doStart()

Specified by:

doStart in class com.google.api.core.AbstractApiService

doStop

protected void doStop()

Specified by:

doStop in class com.google.api.core.AbstractApiService

getDatabaseId

public com.google.cloud.spanner.DatabaseId getDatabaseId()

Description copied from interface: SpannerDatabaseChangeWatcher

Returns the id of the database that is being monitored for changes.

Specified by:

getDatabaseId in interface SpannerDatabaseChangeWatcher

getTables

public List<TableId> getTables()

Description copied from interface: SpannerDatabaseChangeWatcher

Returns the ids of the tables that are monitored by this watcher. This call can require the SpannerDatabaseChangeWatcher to make a round-trip to the database to determine the actual tables that are being monitored.

Specified by:

getTables in interface SpannerDatabaseChangeWatcher