Make DaprClient Closeable and properly close GRPC Managed Channel (#311)

examples/src/main/java/io/dapr/examples/bindings/http/OutputBindingExample.java

@@ -8,6 +8,8 @@ package io.dapr.examples.bindings.http;
 import io.dapr.client.DaprClient;
 import io.dapr.client.DaprClientBuilder;
 
+import java.io.IOException;
+
 /**
  * Service for output binding example.
  * 1. From your repo root, build and install jars:
@@ -36,8 +38,8 @@ public class OutputBindingExample {
    * @param args Not used.
    */
   @SuppressWarnings("checkstyle:AbbreviationAsWordInName")
-  public static void main(String[] args) {
+  public static void main(String[] args) throws IOException {
-    DaprClient client = new DaprClientBuilder().build();
+    try (DaprClient client = new DaprClientBuilder().build()) {
 
       int count = 0;
       while (!Thread.currentThread().isInterrupted()) {
@@ -68,3 +70,4 @@ public class OutputBindingExample {
       System.out.println("Done.");
     }
   }
+}

examples/src/main/java/io/dapr/examples/bindings/http/README.md

@@ -101,7 +101,7 @@ dapr run --components-path ./components --app-id inputbinding --app-port 3000 --
 
 The output binding application is a simple java class with a main method that uses the Dapr Client to invoke binding.
 
-In the `OutputBindingExample.java` file, you will find the `OutputBindingExample` class, containing the main method. The main method declares a Dapr Client using the `DaprClientBuilder` class. Notice that this builder gets two serializer implementations in the constructor: One is for Dapr's sent and recieved objects, and second is for objects to be persisted. The client publishes events using `invokeBinding` method. See the code snippet below: 
+In the `OutputBindingExample.java` file, you will find the `OutputBindingExample` class, containing the main method. The main method declares a Dapr Client using the `DaprClientBuilder` class. Notice that this builder gets two serializer implementations in the constructor: One is for Dapr's sent and recieved objects, and second is for objects to be persisted. The client publishes events using `invokeBinding` method. The Dapr client is also within a try-with-resource block to properly close the client at the end. See the code snippet below: 
 ```java
 public class OutputBindingExample{
 ///...
@@ -109,17 +109,37 @@ public class OutputBindingExample {
 
   static final String BINDING_OPERATION = "create";
 ///...
-  public static void main(String[] args) {
+  public static void main(String[] args) throws IOException {
-    DaprClient client = new DaprClientBuilder().build();
+      try (DaprClient client = new DaprClientBuilder().build()) {
-    ///...
+  
+        int count = 0;
+        while (!Thread.currentThread().isInterrupted()) {
+          String message = "Message #" + (count++);
+  
+          // Randomly decides between a class type or string type to be sent.
+          if (Math.random() >= 0.5) {
+            // This is an example of sending data in a user-defined object.  The input binding will receive:
+            //   {"message":"hello"}
             MyClass myClass = new MyClass();
             myClass.message = message;
   
-    System.out.println("sending an object instance with message: " + myClass.message);
+            System.out.println("sending a class with message: " + myClass.message);
-    client.invokeBinding(BINDING_NAME, BINDING_OPERATION, myClass); //Binding a data object
+            client.invokeBinding(BINDING_NAME, BINDING_OPERATION, myClass).block();
-    ///...
+          } else {
-    System.out.println("sending a plain string: " + m);
+            System.out.println("sending a plain string: " + message);
-    client.invokeBinding(BINDING_NAME, BINDING_OPERATION, message); //Binding a plain string text
+            client.invokeBinding(BINDING_NAME, BINDING_OPERATION, message).block();
+          }
+  
+          try {
+            Thread.sleep((long) (10000 * Math.random()));
+          } catch (InterruptedException e) {
+            e.printStackTrace();
+            Thread.currentThread().interrupt();
+          }
+        }
+  
+        System.out.println("Done.");
+      }
     }
 ///...
 }
@@ -145,4 +165,9 @@ Once running, the InputBindingExample should print the output as follows:
 
 Events have been retrieved from the binding.
 
+For bringing down the kafka cluster that was started in the beginning, run
+```sh
+docker-compose -f ./src/main/java/io/dapr/examples/bindings/http/docker-compose-single-kafka.yml down
+```
+
 For more details on Dapr Spring Boot integration, please refer to [Dapr Spring Boot](../../../springboot/DaprApplication.java)  Application implementation.

examples/src/main/java/io/dapr/examples/invoke/grpc/HelloWorldClient.java

@@ -9,6 +9,8 @@ import io.dapr.client.DaprClient;
 import io.dapr.client.DaprClientBuilder;
 import io.dapr.client.HttpExtension;
 
+import java.io.IOException;
+
 /**
  * 1. Build and install jars:
  * mvn clean install
@@ -23,8 +25,8 @@ public class HelloWorldClient {
    *
    * @param args Array of messages to be sent.
    */
-  public static void main(String[] args) throws InterruptedException {
+  public static void main(String[] args) throws InterruptedException, IOException {
-    DaprClient client = new DaprClientBuilder().build();
+    try (DaprClient client = new DaprClientBuilder().build()) {
 
       String serviceAppId = "hellogrpc";
       String method = "say";
@@ -44,3 +46,4 @@ public class HelloWorldClient {
       }
     }
   }
+}

examples/src/main/java/io/dapr/examples/invoke/grpc/README.md

@@ -87,7 +87,7 @@ The other component is the client. It will send one message per second to the se
 private static class HelloWorldClient {
 ///...
   public static void main(String[] args) {
-    DaprClient client = new DaprClientBuilder().build();
+    try (DaprClient client = new DaprClientBuilder().build()) {
     
       String serviceAppId = "hellogrpc";
       String method = "say";
@@ -100,13 +100,18 @@ private static class HelloWorldClient {
         System.out.println("Message sent: " + message);
 
         Thread.sleep(1000);
+
+        // This is an example, so for simplicity we are just exiting here.  
+        // Normally a dapr app would be a web service and not exit main.
+        System.out.println("Done");
+      }
     }
   }
 ///...
 }
 ```
 
-First, it creates an instance of `DaprClient` via `DaprClientBuilder`. The protocol used by DaprClient is transparent to the application. The HTTP and GRPC ports used by Dapr's sidecar are automatically chosen and exported as environment variables: `DAPR_HTTP_PORT` and `DAPR_GRPC_PORT`. Dapr's Java SDK references these environment variables when communicating to Dapr's sidecar.
+First, it creates an instance of `DaprClient` via `DaprClientBuilder`. The protocol used by DaprClient is transparent to the application. The HTTP and GRPC ports used by Dapr's sidecar are automatically chosen and exported as environment variables: `DAPR_HTTP_PORT` and `DAPR_GRPC_PORT`. Dapr's Java SDK references these environment variables when communicating to Dapr's sidecar. The Dapr client is also within a try-with-resource block to properly close the client at the end.
 
 Finally, it will go through in an infinite loop and invoke the `say` method every second. Notice the use of `block()` on the return from `invokeService` - it is required to actually make the service invocation via a [Mono](https://projectreactor.io/docs/core/release/api/reactor/core/publisher/Mono.html) object.
 

examples/src/main/java/io/dapr/examples/invoke/http/InvokeClient.java

@@ -9,6 +9,8 @@ import io.dapr.client.DaprClient;
 import io.dapr.client.DaprClientBuilder;
 import io.dapr.client.HttpExtension;
 
+import java.io.IOException;
+
 /**
  * 1. Build and install jars:
  * mvn clean install
@@ -29,8 +31,8 @@ public class InvokeClient {
    *
    * @param args Messages to be sent as request for the invoke API.
    */
-  public static void main(String[] args) {
+  public static void main(String[] args) throws IOException {
-    DaprClient client = (new DaprClientBuilder()).build();
+    try (DaprClient client = (new DaprClientBuilder()).build()) {
       for (String message : args) {
         byte[] response = client.invokeService(SERVICE_APP_ID, "say", message, HttpExtension.POST, null,
             byte[].class).block();
@@ -42,3 +44,4 @@ public class InvokeClient {
       System.out.println("Done");
     }
   }
+}

examples/src/main/java/io/dapr/examples/invoke/http/README.md

@@ -110,13 +110,18 @@ public class InvokeClient {
 
 private static final String SERVICE_APP_ID = "invokedemo";
 ///...
-  public static void main(String[] args) {
+public static void main(String[] args) throws IOException {
-    DaprClient client = (new DaprClientBuilder()).build();
+    try (DaprClient client = (new DaprClientBuilder()).build()) {
       for (String message : args) {
-      byte[] response = client.invokeService(SERVICE_APP_ID, "say", 
+        byte[] response = client.invokeService(SERVICE_APP_ID, "say", message, HttpExtension.POST, null,
-        message, HttpExtension.POST, null, byte[].class).block();
+            byte[].class).block();
         System.out.println(new String(response));
       }
+
+      // This is an example, so for simplicity we are just exiting here.
+      // Normally a dapr app would be a web service and not exit main.
+      System.out.println("Done");
+    }
   }
 ///...
 }

examples/src/main/java/io/dapr/examples/pubsub/http/Publisher.java

@@ -8,6 +8,7 @@ package io.dapr.examples.pubsub.http;
 import io.dapr.client.DaprClient;
 import io.dapr.client.DaprClientBuilder;
 
+import java.io.IOException;
 import java.util.Collections;
 
 /**
@@ -32,7 +33,7 @@ public class Publisher {
    */
   public static void main(String[] args) throws Exception {
     //Creating the DaprClient: Using the default builder client produces an HTTP Dapr Client
-    DaprClient client = new DaprClientBuilder().build();
+    try (DaprClient client = new DaprClientBuilder().build()) {
       for (int i = 0; i < NUM_MESSAGES; i++) {
         String message = String.format("This is message #%d", i);
         //Publishing messages
@@ -60,3 +61,4 @@ public class Publisher {
       System.out.println("Done.");
     }
   }
+}

examples/src/main/java/io/dapr/examples/pubsub/http/README.md

@@ -84,19 +84,22 @@ dapr run --components-path ./components --app-id subscriber --app-port 3000 --po
 
 The other component is the publisher. It is a simple java application with a main method that uses the Dapr HTTP Client to publish 10 messages to an specific topic.
 
-In the `Publisher.java` file, you will find the `Publisher` class, containing the main method. The main method declares a Dapr Client using the `DaprClientBuilder` class. Notice that this builder gets two serializer implementations in the constructor: One is for Dapr's sent and recieved objects, and second is for objects to be persisted. The client publishes messages using `publishEvent` method. See the code snippet below:  
+In the `Publisher.java` file, you will find the `Publisher` class, containing the main method. The main method declares a Dapr Client using the `DaprClientBuilder` class. Notice that this builder gets two serializer implementations in the constructor: One is for Dapr's sent and recieved objects, and second is for objects to be persisted. The client publishes messages using `publishEvent` method. The Dapr client is also within a try-with-resource block to properly close the client at the end. See the code snippet below:  
 ```java
 public class Publisher {
     private static final int NUM_MESSAGES = 10;
     private static final String TOPIC_NAME = "testingtopic";
 ///...
   public static void main(String[] args) throws Exception {
-    DaprClient client = new DaprClientBuilder().build();
+      //Creating the DaprClient: Using the default builder client produces an HTTP Dapr Client
+      try (DaprClient client = new DaprClientBuilder().build()) {
         for (int i = 0; i < NUM_MESSAGES; i++) {
           String message = String.format("This is message #%d", i);
+          //Publishing messages
           client.publishEvent(TOPIC_NAME, message).block();
           System.out.println("Published message: " + message);
-      //..
+          //...
+        }
       }
   }
 ///...

examples/src/main/java/io/dapr/examples/secrets/README.md

@@ -43,8 +43,8 @@ mvn install
 
 Before getting into the application code, follow these steps in order to setup a local instance of Vault. This is needed for the local instances. Steps are:
 
-1. navigate to the [repo-root] with `cd java-sdk`
+1. navigate to the [examples] with `cd examples`
-2. Run `docker-compose -f ./examples/src/main/java/io/dapr/examples/secrets/docker-compose-vault.yml up -d` to run the container locally
+2. Run `docker-compose -f ./src/main/java/io/dapr/examples/secrets/docker-compose-vault.yml up -d` to run the container locally
 3. Run `docker ps` to see the container running locally: 
 
 ```bash
@@ -61,6 +61,8 @@ Dapr's API for secret store only support read operations. For this sample to run
 vault login myroot
 ```
 
+> Note: If you get `http: server gave HTTP response to HTTPS client` make sure the local vault address is set `export VAULT_ADDR=http://127.0.0.1:8200/`
+
 2. Create secret (replace `[my favorite movie]` with a title of our choice):
 ```bash
 vault kv put secret/dapr/movie title="[my favorite movie]"
@@ -78,24 +80,36 @@ The example's main function is in `SecretClient.java`.
 
 ```java
 public class SecretClient {
-
+    /**
+     * Identifier in Dapr for the secret store.
+     */
     private static final String SECRET_STORE_NAME = "vault";
   
+    /**
+     * JSON Serializer to print output.
+     */
+    private static final ObjectMapper JSON_SERIALIZER = new ObjectMapper();
+  
   ///...
 
   public static void main(String[] args) throws Exception {
-    ///...
+      if (args.length != 1) {
+        throw new IllegalArgumentException("Use one argument: secret's key to be retrieved.");
+      }
+  
       String secretKey = args[0];
-    DaprClient client = (new DaprClientBuilder()).build();
+      try (DaprClient client = (new DaprClientBuilder()).build()) {
         Map<String, String> secret = client.getSecret(SECRET_STORE_NAME, secretKey).block();
         System.out.println(JSON_SERIALIZER.writeValueAsString(secret));
       }
+    }
 ///...
 }
 ```
 The program receives one and only one argument: the secret's key to be fetched.
 After identifying the key to be fetched, it will retrieve it from the pre-defined secret store: `vault`.
 The secret store's name **must** match the component's name defined in `< repo dir >/examples/components/hashicorp_vault.yaml`.
+The Dapr client is also within a try-with-resource block to properly close the client at the end.
 
  Execute the follow script in order to run the example:
 ```sh
@@ -109,4 +123,11 @@ Once running, the program should print the output as follows:
 == APP == {"title":"[my favorite movie]"}
 ```
 
+To close the app, press CTRL+c.
+
+To cleanup and bring the vault container down, run
+```sh
+docker-compose -f ./src/main/java/io/dapr/examples/secrets/docker-compose-vault.yml down
+```
+
 Thanks for playing.

examples/src/main/java/io/dapr/examples/secrets/SecretClient.java

@@ -9,6 +9,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import io.dapr.client.DaprClient;
 import io.dapr.client.DaprClientBuilder;
 
+import java.io.IOException;
 import java.util.Map;
 
 /**
@@ -44,8 +45,9 @@ public class SecretClient {
     }
 
     String secretKey = args[0];
-    DaprClient client = (new DaprClientBuilder()).build();
+    try (DaprClient client = (new DaprClientBuilder()).build()) {
       Map<String, String> secret = client.getSecret(SECRET_STORE_NAME, secretKey).block();
       System.out.println(JSON_SERIALIZER.writeValueAsString(secret));
     }
   }
+}

examples/src/main/java/io/dapr/examples/state/README.md

@@ -32,21 +32,21 @@ cd examples
 ### Running the StateClient
 This example uses the Java SDK Dapr client in order to save, retrieve and delete a state, in this case, an instance of a class. Multiple state stores are supported since Dapr 0.4. See the code snippet bellow: 
 
-```
+```java
 public class StateClient {
   ///...
   private static final String STATE_STORE_NAME = "statestore";
 
   private static final String KEY_NAME = "mykey";
   ///...
-  public static void main(String[] args) {
+  public static void main(String[] args) throws IOException {
-    DaprClient client = new DaprClientBuilder().build();
+      try (DaprClient client = new DaprClientBuilder().build()) {
         String message = args.length == 0 ? " " : args[0];
   
         MyClass myClass = new MyClass();
         myClass.message = message;
   
-    client.saveState(KEY_NAME, myClass).block();
+        client.saveState(STATE_STORE_NAME, KEY_NAME, myClass).block();
         System.out.println("Saving class with message: " + message);
   
         Mono<State<MyClass>> retrievedMessageMono = client.getState(STATE_STORE_NAME, KEY_NAME, MyClass.class);
@@ -58,10 +58,15 @@ public class StateClient {
   
         Mono<State<MyClass>> retrievedDeletedMessageMono = client.getState(STATE_STORE_NAME, KEY_NAME, MyClass.class);
         System.out.println("Trying to retrieve deleted state: " + retrievedDeletedMessageMono.block().getValue());
+  
+        // This is an example, so for simplicity we are just exiting here.
+        // Normally a dapr app would be a web service and not exit main.
+        System.out.println("Done");
+      }
     }
 }
 ```
-The code uses the `DaprClient` created by the `DaprClientBuilder`. Notice that this builder uses default settings. Internally, it is using `DefaultObjectSerializer` for two properties: `objectSerializer` is for Dapr's sent and recieved objects, and `stateSerializer` is for objects to be persisted. This client performs three operations: `client.saveState(...)` for persisting an instance of `MyClass`, then uses the `client.getState(...)` operation in order to retrieve back the persisted state using the same key. `client.deleteState(...)` operation is used to remove the persisted state. Finally, the code tries to retrieve the deleted state, which should not be found.
+The code uses the `DaprClient` created by the `DaprClientBuilder`. Notice that this builder uses default settings. Internally, it is using `DefaultObjectSerializer` for two properties: `objectSerializer` is for Dapr's sent and received objects, and `stateSerializer` is for objects to be persisted. This client performs three operations: `client.saveState(...)` for persisting an instance of `MyClass`, then uses the `client.getState(...)` operation in order to retrieve back the persisted state using the same key. `client.deleteState(...)` operation is used to remove the persisted state. Finally, the code tries to retrieve the deleted state, which should not be found. The Dapr client is also within a try-with-resource block to properly close the client at the end.
 
 ### Running the example
 

examples/src/main/java/io/dapr/examples/state/StateClient.java

@@ -10,6 +10,8 @@ import io.dapr.client.DaprClientBuilder;
 import io.dapr.client.domain.State;
 import reactor.core.publisher.Mono;
 
+import java.io.IOException;
+
 /**
  * 1. Build and install jars:
  * mvn clean install
@@ -32,8 +34,8 @@ public class StateClient {
    * Executes the sate actions.
    * @param args messages to be sent as state value.
    */
-  public static void main(String[] args) {
+  public static void main(String[] args) throws IOException {
-    DaprClient client = new DaprClientBuilder().build();
+    try (DaprClient client = new DaprClientBuilder().build()) {
       String message = args.length == 0 ? " " : args[0];
 
       MyClass myClass = new MyClass();
@@ -57,3 +59,4 @@ public class StateClient {
       System.out.println("Done");
     }
   }
+}

sdk-tests/src/test/java/io/dapr/it/binding/http/BindingIT.java

@@ -73,7 +73,7 @@ public class BindingIT extends BaseIT {
       daprRun.switchToHTTP();
     }
 
-    DaprClient client = new DaprClientBuilder().build();
+    try(DaprClient client = new DaprClientBuilder().build()) {
 
       // This is an example of sending data in a user-defined object.  The input binding will receive:
       //   {"message":"hello"}
@@ -121,3 +121,4 @@ public class BindingIT extends BaseIT {
       }, 8000);
     }
   }
+}

sdk-tests/src/test/java/io/dapr/it/methodinvoke/http/MethodInvokeIT.java

@@ -6,11 +6,13 @@ import io.dapr.client.DaprHttp;
 import io.dapr.client.HttpExtension;
 import io.dapr.it.BaseIT;
 import io.dapr.it.DaprRun;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 
+import java.io.IOException;
 import java.util.*;
 
 import static org.junit.Assert.assertEquals;
@@ -58,11 +60,11 @@ public class MethodInvokeIT extends BaseIT {
     }
 
     @Test
-    public void testInvoke() {
+    public void testInvoke() throws IOException {
 
         // At this point, it is guaranteed that the service above is running and all ports being listened to.
 
-        DaprClient client = new DaprClientBuilder().build();
+        try (DaprClient client = new DaprClientBuilder().build()) {
             for (int i = 0; i < NUM_MESSAGES; i++) {
                 String message = String.format("This is message #%d", i);
                 //Publishing messages
@@ -82,13 +84,12 @@ public class MethodInvokeIT extends BaseIT {
             client.invokeService(daprRun.getAppName(), "messages/2", "updated message".getBytes(), HttpExtension.PUT).block();
             messages = client.invokeService(daprRun.getAppName(), "messages", null, HttpExtension.GET, Map.class).block();
             assertEquals("updated message", messages.get("2"));
-
+        }
     }
 
     @Test
-    public void testInvokeWithObjects()  {
+    public void testInvokeWithObjects() throws IOException {
-        DaprClient client = new DaprClientBuilder().build();
+        try (DaprClient client = new DaprClientBuilder().build()) {
-
             for (int i = 0; i < NUM_MESSAGES; i++) {
                 Person person = new Person();
                 person.setName(String.format("Name %d", i));
@@ -120,3 +121,4 @@ public class MethodInvokeIT extends BaseIT {
             assertEquals("Smith", resultPerson.getLastName());
         }
     }
+}

sdk-tests/src/test/java/io/dapr/it/pubsub/http/PubSubIT.java

@@ -37,6 +37,7 @@ public class PubSubIT extends BaseIT {
   /**
    * Parameters for this test.
    * Param #1: useGrpc.
+   *
    * @return Collection of parameter tuples.
    */
   @Parameterized.Parameters
@@ -65,7 +66,7 @@ public class PubSubIT extends BaseIT {
     }
 
     // Send a batch of messages on one topic
-        DaprClient client = new DaprClientBuilder().build();
+    try (DaprClient client = new DaprClientBuilder().build()) {
       for (int i = 0; i < NUM_MESSAGES; i++) {
         String message = String.format("This is message #%d on topic %s", i, TOPIC_NAME);
         //Publishing messages
@@ -94,7 +95,6 @@ public class PubSubIT extends BaseIT {
         System.out.println("Checking results for topic " + TOPIC_NAME);
         final List<String> messages = client.invokeService(daprRun.getAppName(), "messages/testingtopic", null, HttpExtension.GET, List.class).block();
         assertEquals(11, messages.size());
-
         for (int i = 0; i < NUM_MESSAGES; i++) {
           assertTrue(messages.contains(String.format("This is message #%d on topic %s", i, TOPIC_NAME)));
         }
@@ -119,5 +119,6 @@ public class PubSubIT extends BaseIT {
         }
       }, 2000);
     }
+  }
 
 }

sdk-tests/src/test/java/io/dapr/it/secrets/SecretsClientIT.java

@@ -14,12 +14,14 @@ import io.dapr.client.DaprClientHttp;
 import io.dapr.it.BaseIT;
 import io.dapr.it.DaprRun;
 import io.dapr.it.services.EmptyService;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 
+import java.io.IOException;
 import java.util.*;
 
 import static org.junit.Assert.*;
@@ -96,6 +98,11 @@ public class SecretsClientIT extends BaseIT {
     }
   }
 
+  @After
+  public void tearDown() throws IOException {
+    daprClient.close();
+  }
+
   @Test
   public void getSecret() throws Exception {
     String key = UUID.randomUUID().toString();

sdk-tests/src/test/java/io/dapr/it/state/GRPCStateClientIT.java

@@ -13,11 +13,13 @@ import io.dapr.client.domain.StateOptions;
 import io.dapr.it.BaseIT;
 import io.dapr.it.DaprRun;
 import io.dapr.it.services.EmptyService;
+import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Test;
 import reactor.core.publisher.Mono;
 
+import java.io.IOException;
 import java.time.Duration;
 
 import static org.junit.Assert.*;
@@ -46,6 +48,11 @@ public class GRPCStateClientIT extends BaseIT {
     assertTrue(daprClient instanceof DaprClientGrpc);
   }
 
+  @AfterClass
+  public static void tearDown() throws IOException {
+    daprClient.close();
+  }
+
 
   @Test
   public void saveAndGetState() {

sdk-tests/src/test/java/io/dapr/it/state/HelloWorldClientIT.java

@@ -64,5 +64,6 @@ public class HelloWorldClientIT extends BaseIT {
       System.out.println("Got: " + value);
       Assert.assertEquals("", value);
     }
+    channel.shutdown();
   }
 }

sdk/src/main/java/io/dapr/client/DaprClient.java

@@ -11,6 +11,7 @@ import io.dapr.client.domain.Verb;
 import io.dapr.utils.TypeRef;
 import reactor.core.publisher.Mono;
 
+import java.io.Closeable;
 import java.util.List;
 import java.util.Map;
 
@@ -19,7 +20,7 @@ import java.util.Map;
  *
  * @see io.dapr.client.DaprClientBuilder for information on how to make instance for this interface.
  */
-public interface DaprClient {
+public interface DaprClient extends Closeable {
 
   /**
    * Publish an event.

sdk/src/main/java/io/dapr/client/DaprClientBuilder.java

@@ -14,10 +14,13 @@ import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import okhttp3.OkHttpClient;
 
+import java.io.Closeable;
+
 /**
  * A builder for the DaprClient,
  * Currently only and HTTP Client will be supported.
  */
+
 public class DaprClientBuilder {
 
   /**
@@ -105,7 +108,13 @@ public class DaprClientBuilder {
       throw new IllegalStateException("Invalid port.");
     }
     ManagedChannel channel = ManagedChannelBuilder.forAddress(Constants.DEFAULT_HOSTNAME, port).usePlaintext().build();
-    return new DaprClientGrpc(DaprGrpc.newFutureStub(channel), this.objectSerializer, this.stateSerializer);
+    Closeable closeableChannel = () -> {
+      if (channel != null && !channel.isShutdown()) {
+        channel.shutdown();
+      }
+    };
+    DaprGrpc.DaprFutureStub stub = DaprGrpc.newFutureStub(channel);
+    return new DaprClientGrpc(closeableChannel, stub, this.objectSerializer, this.stateSerializer);
   }
 
   /**

sdk/src/main/java/io/dapr/client/DaprClientGrpc.java

@@ -19,6 +19,7 @@ import io.dapr.v1.DaprGrpc;
 import io.dapr.v1.DaprProtos;
 import reactor.core.publisher.Mono;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
@@ -34,6 +35,11 @@ import static io.dapr.client.domain.StateOptions.RetryPolicy;
  */
 public class DaprClientGrpc implements DaprClient {
 
+  /**
+   * The GRPC managed channel to be used.
+   */
+  private Closeable channel;
+
   /**
    * The GRPC client to be used.
    *
@@ -54,15 +60,18 @@ public class DaprClientGrpc implements DaprClient {
   /**
    * Default access level constructor, in order to create an instance of this class use io.dapr.client.DaprClientBuilder
    *
+   * @param closeableChannel A closeable for a Managed GRPC channel
    * @param futureClient     GRPC client
    * @param objectSerializer Serializer for transient request/response objects.
    * @param stateSerializer  Serializer for state objects.
    * @see DaprClientBuilder
    */
   DaprClientGrpc(
+      Closeable closeableChannel,
       DaprGrpc.DaprFutureStub futureClient,
       DaprObjectSerializer objectSerializer,
       DaprObjectSerializer stateSerializer) {
+    this.channel = closeableChannel;
     this.client = futureClient;
     this.objectSerializer = objectSerializer;
     this.stateSerializer = stateSerializer;
@@ -642,4 +651,15 @@ public class DaprClientGrpc implements DaprClient {
     return this.getSecret(secretStoreName, secretName, null);
   }
 
+  /**
+   * Closes the ManagedChannel for GRPC.
+   * @see io.grpc.ManagedChannel#shutdown()
+   * @throws IOException on exception.
+   */
+  @Override
+  public void close() throws IOException {
+    if (channel != null) {
+      channel.close();
+    }
+  }
 }

sdk/src/main/java/io/dapr/client/DaprClientHttp.java

@@ -592,4 +592,8 @@ public class DaprClientHttp implements DaprClient {
     return this.getSecret(secretStoreName, secretName, null);
   }
 
+  @Override
+  public void close() throws IOException {
+    client.close();
+  }
 }

sdk/src/main/java/io/dapr/client/DaprHttp.java

@@ -16,6 +16,7 @@ import okhttp3.Request;
 import okhttp3.RequestBody;
 import reactor.core.publisher.Mono;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
@@ -25,7 +26,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
 
-public class DaprHttp {
+public class DaprHttp implements Closeable {
   /**
    * Dapr's http default scheme.
    */
@@ -239,4 +240,13 @@ public class DaprHttp {
     return OBJECT_MAPPER.readValue(json, DaprError.class);
   }
 
+  /**
+   * Shutdown call is not necessary for OkHttpClient.
+   * @see OkHttpClient
+   */
+  @Override
+  public void close() throws IOException {
+    // No code needed
+  }
+
 }

sdk/src/test/java/io/dapr/client/DaprClientGrpcTest.java

@@ -12,18 +12,19 @@ import com.google.protobuf.ByteString;
 import com.google.protobuf.Empty;
 import io.dapr.client.domain.State;
 import io.dapr.client.domain.StateOptions;
-import io.dapr.client.domain.Verb;
 import io.dapr.serializer.DefaultObjectSerializer;
 import io.dapr.utils.TypeRef;
 import io.dapr.v1.CommonProtos;
 import io.dapr.v1.DaprGrpc;
 import io.dapr.v1.DaprProtos;
 import org.checkerframework.checker.nullness.compatqual.NullableDecl;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.ArgumentMatcher;
 import reactor.core.publisher.Mono;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.time.Duration;
 import java.util.Collections;
@@ -43,15 +44,25 @@ public class DaprClientGrpcTest {
 
   private static final String SECRET_STORE_NAME = "MySecretStore";
 
+  private Closeable closeable;
   private DaprGrpc.DaprFutureStub client;
   private DaprClientGrpc adapter;
   private ObjectSerializer serializer;
 
   @Before
-  public void setup() {
+  public void setup() throws IOException {
+    closeable = mock(Closeable.class);
     client = mock(DaprGrpc.DaprFutureStub.class);
-    adapter = new DaprClientGrpc(client, new DefaultObjectSerializer(), new DefaultObjectSerializer());
+    adapter = new DaprClientGrpc(closeable, client, new DefaultObjectSerializer(), new DefaultObjectSerializer());
     serializer = new ObjectSerializer();
+    doNothing().when(closeable).close();
+  }
+
+  @After
+  public void tearDown() throws IOException {
+    adapter.close();
+    verify(closeable).close();
+    verifyNoMoreInteractions(closeable);
   }
 
   @Test(expected = RuntimeException.class)

sdk/src/test/java/io/dapr/client/DaprClientHttpTest.java

@@ -434,6 +434,14 @@ public class DaprClientHttpTest {
     assertNull(mono.block());
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void saveStateNullStateStoreName() {
+    daprHttp = new DaprHttp(3000, okHttpClient);
+    daprClientHttp = new DaprClientHttp(daprHttp);
+    Mono<Void> mono = daprClientHttp.saveStates(null, null);
+    assertNull(mono.block());
+  }
+
   @Test
   public void saveStatesNull() {
     State<String> stateKeyValue = new State("value", "key", "", null);
@@ -621,6 +629,13 @@ public class DaprClientHttpTest {
     });
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void getSecretsNullStoreName() {
+    daprHttp = new DaprHttp(3000, okHttpClient);
+    daprClientHttp = new DaprClientHttp(daprHttp);
+    daprClientHttp.getSecret(null, "key").block();
+  }
+
   @Test
   public void getSecretsWithMetadata() {
     mockInterceptor.addRule()