A modern, feature-rich and tunable Java client library for Google Cloud Datastore.
- Supports a asynchronous (non blocking) design that returns ListenableFutures for all queries and mutations.
- Also supports synchronous alternatives.
- Insulates the consumer from having to deal with Protobuf payloads.
- Includes a simple
QueryBuilderto construct natural looking queries.
The current implementations of Google Datastore Client
and Google Cloud Java Client
are synchronous, meaning they block when making HTTP calls to their backend.
This client uses async-http-client
and returns ListenableFutures which can be nicer to work with, especially
running at scale.
Add this to your pom.xml file
<dependency>
<groupId>com.spotify</groupId>
<artifactId>async-datastore-client</artifactId>
<version>3.0.2</version>
</dependency>NOTE: Version 3.0.0+ depends on Guava 19 which contains breaking changes to
Futures.transform. If you require support for Guava version 18 or lower then use async-datastore-client version 2.1.0.
import com.spotify.asyncdatastoreclient.DatastoreConfig;
import com.spotify.asyncdatastoreclient.Datastore;
import com.spotify.asyncdatastoreclient.QueryBuilder;
import com.spotify.asyncdatastoreclient.Insert;
import com.spotify.asyncdatastoreclient.MutationResult;
import com.google.api.services.datastore.client.DatastoreHelper;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListenableFuture;
final DatastoreConfig config = DatastoreConfig.builder()
.requestTimeout(1000)
.requestRetry(3)
.project(PROJECT_ID)
.credential(GoogleCredential
.fromStream(credentialsInputStream)
.createScoped(DatastoreConfig.SCOPES))
.build();
final Datastore datastore = Datastore.create(config);
final Insert insert = QueryBuilder.insert("employee", 1234567L)
.value("fullname", "Fred Blinge")
.value("age", 40)
.value("workdays", ImmutableList.of("Monday", "Tuesday", "Friday"));
// for asynchronous call...
final ListenableFuture<MutationResult> resultAsync = datastore.executeAsync(insert);
// ...or for synchronous
final MutationResult result = datastore.execute(insert);import com.spotify.asyncdatastoreclient.QueryBuilder;
import com.spotify.asyncdatastoreclient.Query;
import static com.spotify.asyncdatastoreclient.QueryBuilder.eq;
import static com.spotify.asyncdatastoreclient.QueryBuilder.asc;
final Query query = QueryBuilder.query()
.kindOf("employee")
.filterBy(eq("role", "engineer"))
.orderBy(asc("age"));
// call datastore.executeAsync() to get a ListenableFuture<QueryResult>
for (final Entity entity : datastore.execute(query)) {
System.out.println("Name: " + entity.getString("fullname));
...
}mvn clean compileBy default integration tests are executed against a Local Development Server on port 8080. To run tests, first download the Development Server, at least version 1.4.1 and start the emulator:
gcloud beta emulators datastore start --host-port localhost:8080 --consistency 1.0 --project async-test --data-dir project-testNOTE: The
--consistency=1.0option is sometimes necessary in order for unit tests to run successful.
All integration tests may by run with maven as follows:
mvn verifyProperties may also be provided to override unit test configuration:
mvn verify -Dhost=https://www.googleapis.com -Dproject=testing -Dkeypath=./my-key.jsonThis software is released under the Apache License 2.0. More information in the file LICENSE distributed with this project.