The interfaces provided are listed below, along with usage samples.
SpannerClient
Service Description: Cloud Spanner API
The Cloud Spanner API can be used to manage sessions and execute transactions on data stored in Cloud Spanner databases.
Sample for SpannerClient:
try (SpannerClient spannerClient = SpannerClient.create()) {
DatabaseName database = DatabaseName.of("[PROJECT]", "[INSTANCE]", "[DATABASE]");
Session response = spannerClient.createSession(database);
}
Classes
SpannerClient
Service Description: Cloud Spanner API
The Cloud Spanner API can be used to manage sessions and execute transactions on data stored in Cloud Spanner databases.
This class provides the ability to make remote calls to the backing service through method calls that map to API methods. Sample code to get started:
try (SpannerClient spannerClient = SpannerClient.create()) {
DatabaseName database = DatabaseName.of("[PROJECT]", "[INSTANCE]", "[DATABASE]");
Session response = spannerClient.createSession(database);
}
Note: close() needs to be called on the SpannerClient object to clean up resources such as threads. In the example above, try-with-resources is used, which automatically calls close().
The surface of this class includes several types of Java methods for each of the API's methods:
- A "flattened" method. With this type of method, the fields of the request type have been converted into function parameters. It may be the case that not all fields are available as parameters, and not every API method will have a flattened method entry point.
- A "request object" method. This type of method only takes one parameter, a request object, which must be constructed before the call. Not every API method will have a request object method.
- A "callable" method. This type of method takes no parameters and returns an immutable API callable object, which can be used to initiate calls to the service.
See the individual methods for example code.
Many parameters require resource names to be formatted in a particular way. To assist with these names, this class includes a format method for each type of name, and additionally a parse method to extract the individual identifiers contained within names that are returned.
This class can be customized by passing in a custom instance of SpannerSettings to create(). For example:
To customize credentials:
SpannerSettings spannerSettings =
SpannerSettings.newBuilder()
.setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
.build();
SpannerClient spannerClient = SpannerClient.create(spannerSettings);
To customize the endpoint:
SpannerSettings spannerSettings = SpannerSettings.newBuilder().setEndpoint(myEndpoint).build();
SpannerClient spannerClient = SpannerClient.create(spannerSettings);
Please refer to the GitHub repository's samples for more quickstart code snippets.
SpannerClient.ListSessionsFixedSizeCollection
SpannerClient.ListSessionsPage
SpannerClient.ListSessionsPagedResponse
SpannerSettings
Settings class to configure an instance of SpannerClient.
The default instance has everything set to sensible defaults:
- The default service address (spanner.googleapis.com) and default port (443) are used.
- Credentials are acquired automatically through Application Default Credentials.
- Retries are configured for idempotent methods but not for non-idempotent methods.
The builder of this class is recursive, so contained classes are themselves builders. When build() is called, the tree of builders is called to create the complete settings object.
For example, to set the total timeout of createSession to 30 seconds:
SpannerSettings.Builder spannerSettingsBuilder = SpannerSettings.newBuilder();
spannerSettingsBuilder
.createSessionSettings()
.setRetrySettings(
spannerSettingsBuilder
.createSessionSettings()
.getRetrySettings()
.toBuilder()
.setTotalTimeout(Duration.ofSeconds(30))
.build());
SpannerSettings spannerSettings = spannerSettingsBuilder.build();
SpannerSettings.Builder
Builder for SpannerSettings.