Java

The official Dgraph Java client communicates with the server using gRPC.

Installation

Via Gradle:

implementation 'io.dgraph:dgraph4j:25.0.0'

Via Maven:

<dependency>
  <groupId>io.dgraph</groupId>
  <artifactId>dgraph4j</artifactId>
  <version>25.0.0</version>
</dependency>

Supported Versions

Dgraph version	dgraph4j version	Java version
dgraph 24.X.Y	dgraph4j 24.X.Y	11
dgraph 25.X.Y	dgraph4j 25.X.Y	11

Quick Start

Using Connection Strings (v25+)

The simplest way to connect is using a connection string:

DgraphClient client = DgraphClient.open("dgraph://localhost:9080");

With ACL authentication:

DgraphClient client = DgraphClient.open("dgraph://groot:password@localhost:9080");

Running Queries and Mutations

// Set schema
client.setSchema("name: string @index(exact) .");

// Run a DQL mutation
client.runDQL("{set { _:alice <name> \"Alice\" . }}");

// Run a query
Response response = client.runDQL(
    "{ alice(func: eq(name, \"Alice\")) { name } }");
System.out.println(response.getJson().toStringUtf8());

// Clean up
client.shutdown();

Multi-tenancy

In multi-tenant environments, use loginIntoNamespace() to authenticate to a specific namespace:

ManagedChannel channel = ManagedChannelBuilder
    .forAddress("localhost", 9080)
    .usePlaintext().build();
DgraphClient client = new DgraphClient(DgraphGrpc.newStub(channel));

// Login to namespace 123
client.loginIntoNamespace("groot", "password", 123);

Once logged in, the client can perform all operations allowed for that user in the specified namespace.

Documentation

For complete API documentation, examples, and advanced usage:

• GitHub Repository — Full README with all APIs and examples
• Maven Central — Package information and releases

The GitHub README covers:

• Connection strings and advanced client creation
• Transactions (read-only, best-effort)
• Mutations (JSON and RDF formats)
• Queries with variables
• Upserts and conditional upserts
• Exception handling and automatic retry
• Namespace management and ID allocation
• TLS configuration
• Async client usage
• And more