SpannerDatabaseChangeWatcher (Google Cloud Spanner Change Watcher 0.2.0 API)

All Superinterfaces:

com.google.api.core.ApiService

All Known Implementing Classes:

SpannerDatabaseTailer
```
public interface SpannerDatabaseChangeWatcher
extends com.google.api.core.ApiService
```
Interface for capturing changes to a set of tables in a Spanner database.

Nested Class Summary
- 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

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`addCallback(SpannerTableChangeWatcher.RowChangeCallback callback)`	Adds a `SpannerTableChangeWatcher.RowChangeCallback` for this `SpannerDatabaseChangeWatcher`.
`com.google.cloud.spanner.DatabaseId`	`getDatabaseId()`	Returns the id of the database that is being monitored for changes.
`Collection<TableId>`	`getTables()`	Returns the ids of the tables that are monitored by this watcher.

Methods inherited from interface com.google.api.core.ApiService
addListener, awaitRunning, awaitRunning, awaitTerminated, awaitTerminated, failureCause, isRunning, startAsync, state, stopAsync

- Method Detail
  - getDatabaseId
```
com.google.cloud.spanner.DatabaseId getDatabaseId()
```
    Returns the id of the database that is being monitored for changes.
  - getTables
```
Collection<TableId> getTables()
```
    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.
  - addCallback
```
void addCallback(SpannerTableChangeWatcher.RowChangeCallback callback)
```
    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.