Java

• installed
• Initialized Dapr environment
• JDK 11 or above - the published jars are compatible with Java 8:
  • Oracle’s JDK 15
  • OpenJDK
• Install one of the following build tools for Java:
  • Gradle 6.x

dependencies {
...
    // Dapr's core SDK with all features, except Actors.
    compile('io.dapr:dapr-sdk:1.4.0')
    // Dapr's SDK for Actors (optional).
    compile('io.dapr:dapr-sdk-actors:1.4.0')
    // Dapr's SDK integration with SpringBoot (optional).
    compile('io.dapr:dapr-sdk-springboot:1.4.0')
}

<dependency>
  <groupId>com.squareup.okhttp3</groupId>
  <artifactId>okhttp</artifactId>
  <version>1.3.1</version>
</dependency>

• Visit for code samples and instructions to try out service invocation

Save & get application state

import io.dapr.client.DaprClient;
import io.dapr.client.DaprClientBuilder;
import io.dapr.client.domain.State;
import reactor.core.publisher.Mono;
try (DaprClient client = (new DaprClientBuilder()).build()) {
  // Save state
  client.saveState(STATE_STORE_NAME, FIRST_KEY_NAME, myClass).block();
  // Get state
  // Delete state
  client.deleteState(STATE_STORE_NAME, FIRST_KEY_NAME).block();
}

• For a full list of state operations visit .
• Visit Java SDK examples for code samples and instructions to try out state management

Publish messages

import io.dapr.client.DaprClient;
import io.dapr.client.DaprClientBuilder;
import io.dapr.client.domain.Metadata;
import static java.util.Collections.singletonMap;
try (DaprClient client = (new DaprClientBuilder()).build()) {
  client.publishEvent(PUBSUB_NAME, TOPIC_NAME, message, singletonMap(Metadata.TTL_IN_SECONDS, MESSAGE_TTL_IN_SECONDS)).block();
}

Subscribe to messages

• For a full list of state operations visit .
• Visit Java SDK examples for code samples and instructions to try out pub/sub

Interact with output bindings

import io.dapr.client.DaprClient;
import io.dapr.client.DaprClientBuilder;
try (DaprClient client = (new DaprClientBuilder()).build()) {
  // sending a class with message; BINDING_OPERATION="create"
  client.invokeBinding(BINDING_NAME, BINDING_OPERATION, myClass).block();
  // sending a plain string
  client.invokeBinding(BINDING_NAME, BINDING_OPERATION, message).block();

• For a full guide on output bindings visit How-To: Use bindings.
• Visit for code samples and instructions to try out output bindings

import com.fasterxml.jackson.databind.ObjectMapper;
import io.dapr.client.DaprClient;
import io.dapr.client.DaprClientBuilder;
try (DaprClient client = (new DaprClientBuilder()).build()) {
  Map<String, String> secret = client.getSecret(SECRET_STORE_NAME, secretKey).block();
  System.out.println(JSON_SERIALIZER.writeValueAsString(secret));
}

• For a full guide on secrets visit How-To: Retrieve secrets.
• Visit for code samples and instructions to try out retrieving secrets

Actors

• For a full guide on actors visit .
• Visit Java SDK examples for code samples and instructions to try actors

import io.dapr.client.DaprClientBuilder;
import io.dapr.client.DaprPreviewClient;
import io.dapr.client.domain.ConfigurationItem;
import io.dapr.client.domain.GetConfigurationRequest;
import io.dapr.client.domain.SubscribeConfigurationRequest;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
try (DaprPreviewClient client = (new DaprClientBuilder()).buildPreviewClient()) {
  // Get configuration for a single key
  Mono<ConfigurationItem> item = client.getConfiguration(CONFIG_STORE_NAME, CONFIG_KEY).block();
// Get Configurations for multiple keys
  Mono<List<ConfigurationItem>> items =
          client.getConfiguration(CONFIG_STORE_NAME, CONFIG_KEY_1, CONFIG_KEY_2);
  // Susbcribe to Confifuration changes
  Flux<List<ConfigurationItem>> outFlux = client.subscribeToConfiguration(CONFIG_STORE_NAME, CONFIG_KEY_1, CONFIG_KEY_2);
  outFlux.subscribe(configItems -> configItems.forEach(...));
}

• For a full list of configuration operations visit .
• Visit Java SDK examples for code samples and instructions to try out different configuration operations.