Java idiomatic client for Cloud Spanner.
If you are using Maven with BOM, add this to your pom.xml file:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>libraries-bom</artifactId>
<version>26.1.0</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-spanner</artifactId>
</dependency>
If you are using Maven without BOM, add this to your dependencies:
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-spanner</artifactId>
<version>6.27.0</version>
</dependency>
If you are using Gradle 5.x or later, add this to your dependencies:
implementation platform('com.google.cloud:libraries-bom:26.1.0')
implementation 'com.google.cloud:google-cloud-spanner'
If you are using Gradle without BOM, add this to your dependencies:
implementation 'com.google.cloud:google-cloud-spanner:6.28.0'
If you are using SBT, add this to your dependencies:
libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.28.0"
See the Authentication section in the base directory's README.
The client application making API calls must be granted authorization scopes required for the desired Cloud Spanner APIs, and the authenticated principal must have the IAM role(s) required to access GCP resources using the Cloud Spanner API calls.
You will need a Google Cloud Platform Console project with the Cloud Spanner API enabled.
You will need to enable billing to use Google Cloud Spanner.
Follow these instructions to get your project set up. You will also need to set up the local development environment by
installing the Google Cloud SDK and running the following commands in command line:
gcloud auth login
and gcloud config set project [YOUR PROJECT ID]
.
You'll need to obtain the google-cloud-spanner
library. See the Quickstart section
to add google-cloud-spanner
as a dependency in your code.
Cloud Spanner is a fully managed, mission-critical, relational database service that offers transactional consistency at global scale, schemas, SQL (ANSI 2011 with extensions), and automatic, synchronous replication for high availability.
Be sure to activate the Cloud Spanner API on the Developer's Console to use Cloud Spanner from your project.
See the Cloud Spanner client library docs to learn how to use this Cloud Spanner Client Library.
Here is a code snippet showing a simple usage example. Add the following imports at the top of your file:
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
Then, to make a query to Spanner, use the following code:
// Instantiates a client
SpannerOptions options = SpannerOptions.newBuilder().build();
Spanner spanner = options.getService();
String instance = "my-instance";
String database = "my-database";
try {
// Creates a database client
DatabaseClient dbClient = spanner.getDatabaseClient(
DatabaseId.of(options.getProjectId(), instance, database));
// Queries the database
try (ResultSet resultSet = dbClient.singleUse().executeQuery(Statement.of("SELECT 1"))) {
// Prints the results
while (resultSet.next()) {
System.out.printf("%d\n", resultSet.getLong(0));
}
}
} finally {
// Closes the client which will free up the resources used
spanner.close();
}
In DatabaseSelect.java we put together all the code shown above in a single program.
Cloud Spanner client supports Opencensus Metrics, which gives insight into the client internals and aids in debugging/troubleshooting production issues. OpenCensus metrics will provide you with enough data to enable you to spot, and investigate the cause of any unusual deviations from normal behavior.
All Cloud Spanner Metrics are prefixed with cloud.google.com/java/spanner/
. The
metrics will be tagged with:
database
: the target database name.instance_id
: the instance id of the target Spanner instance.client_id
: the user defined database client id.library_version
: the version of the library that you're using.
Note: RPC level metrics can be gleaned from gRPC’s metrics, which are prefixed with
grpc.io/client/
.
-
cloud.google.com/java/spanner/max_in_use_sessions
: This returns the maximum number of sessions that have been in use during the last maintenance window interval, so as to provide an indication of the amount of activity currently in the database. -
cloud.google.com/java/spanner/max_allowed_sessions
: This shows the maximum number of sessions allowed. -
cloud.google.com/java/spanner/num_sessions_in_pool
: This metric allows users to see instance-level and database-level data for the total number of sessions in the pool at this very moment. -
cloud.google.com/java/spanner/num_acquired_sessions
: This metric allows users to see the total number of acquired sessions. -
cloud.google.com/java/spanner/num_released_sessions
: This metric allows users to see the total number of released (destroyed) sessions. -
cloud.google.com/java/spanner/get_session_timeouts
: This gives you an indication of the total number of get session timed-out instead of being granted (the thread that requested the session is placed in a wait queue where it waits until a session is released into the pool by another thread) due to pool exhaustion since the server process started. -
cloud.google.com/java/spanner/gfe_latency
: This metric shows latency between Google's network receiving an RPC and reading back the first byte of the response. -
cloud.google.com/java/spanner/gfe_header_missing_count
: This metric shows the number of RPC responses received without the server-timing header, most likely indicating that the RPC never reached Google's network.
If you are using Maven, add this to your pom.xml file
<dependency>
<groupId>io.opencensus</groupId>
<artifactId>opencensus-impl</artifactId>
<version>0.30.0</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>io.opencensus</groupId>
<artifactId>opencensus-exporter-stats-stackdriver</artifactId>
<version>0.30.0</version>
</dependency>
If you are using Gradle, add this to your dependencies
compile 'io.opencensus:opencensus-impl:0.30.0'
compile 'io.opencensus:opencensus-exporter-stats-stackdriver:0.30.0'
At the start of your application configure the exporter:
import io.opencensus.exporter.stats.stackdriver.StackdriverStatsExporter;
// Enable OpenCensus exporters to export metrics to Stackdriver Monitoring.
// Exporters use Application Default Credentials to authenticate.
// See https://developers.google.com/identity/protocols/application-default-credentials
// for more details.
// The minimum reporting period for Stackdriver is 1 minute.
StackdriverStatsExporter.createAndRegister();
By default, the functionality is disabled. You need to include opencensus-impl dependency to collect the data and exporter dependency to export to backend.
Click here for more information.
Samples are in the samples/
directory.
Sample | Source Code | Try it |
---|---|---|
Database Operations | source code | |
Instance Operations | source code | |
Native Image Spanner Sample | source code | |
Add Json Column Sample | source code | |
Add Numeric Column Sample | source code | |
Async Dml Example | source code | |
Async Query Example | source code | |
Async Query To List Async Example | source code | |
Async Read Example | source code | |
Async Read Only Transaction Example | source code | |
Async Read Row Example | source code | |
Async Read Using Index Example | source code | |
Async Runner Example | source code | |
Async Transaction Manager Example | source code | |
Batch Sample | source code | |
Copy Backup Sample | source code | |
Create Backup With Encryption Key | source code | |
Create Database With Default Leader Sample | source code | |
Create Database With Encryption Key | source code | |
Create Database With Version Retention Period Sample | source code | |
Create Instance Example | source code | |
Create Instance With Processing Units Example | source code | |
Custom Timeout And Retry Settings Example | source code | |
Get Commit Stats Sample | source code | |
Get Database Ddl Sample | source code | |
Get Instance Config Sample | source code | |
List Databases Sample | source code | |
List Instance Configs Sample | source code | |
Pg Async Query To List Async Example | source code | |
Pg Async Runner Example | source code | |
Pg Async Transaction Manager Example | source code | |
Pg Batch Dml Sample | source code | |
Pg Case Sensitivity Sample | source code | |
Pg Interleaved Table Sample | source code | |
Pg Partitioned Dml Sample | source code | |
Pg Query With Numeric Parameter Sample | source code | |
Pg Spanner Sample | source code | |
Query Information Schema Database Options Sample | source code | |
Query With Json Parameter Sample | source code | |
Query With Numeric Parameter Sample | source code | |
Quickstart Sample | source code | |
Restore Backup With Encryption Key | source code | |
Spanner Sample | source code | |
Statement Timeout Example | source code | |
Tag Sample | source code | |
Tracing Sample | source code | |
Update Database With Default Leader Sample | source code | |
Update Json Data Sample | source code | |
Update Numeric Data Sample | source code |
To get help, follow the instructions in the shared Troubleshooting document.
Cloud Spanner uses gRPC for the transport layer.
Java 8 or above is required for using this client.
Google's Java client libraries, Google Cloud Client Libraries and Google Cloud API Libraries, follow the Oracle Java SE support roadmap (see the Oracle Java SE Product Releases section).
In general, new feature development occurs with support for the lowest Java LTS version covered by Oracle's Premier Support (which typically lasts 5 years from initial General Availability). If the minimum required JVM for a given library is changed, it is accompanied by a semver major release.
Java 11 and (in September 2021) Java 17 are the best choices for new development.
Google tests its client libraries with all current LTS versions covered by Oracle's Extended Support (which typically lasts 8 years from initial General Availability).
Google's client libraries support legacy versions of Java runtimes with long term stable libraries that don't receive feature updates on a best efforts basis as it may not be possible to backport all patches.
Google provides updates on a best efforts basis to apps that continue to use Java 7, though apps might need to upgrade to current versions of the library that supports their JVM.
The latest versions and the supported Java versions are identified on
the individual GitHub repository github.com/GoogleAPIs/java-SERVICENAME
and on google-cloud-java.
This library follows Semantic Versioning.
Contributions to this library are always welcome and highly encouraged.
See CONTRIBUTING for more information how to get started.
Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms. See Code of Conduct for more information.
Apache 2.0 - See LICENSE for more information.
Java Version | Status |
---|---|
Java 8 | |
Java 8 OSX | |
Java 8 Windows | |
Java 11 |
Java is a registered trademark of Oracle and/or its affiliates.