Add support for metadata in Bindings + fix serialization of output bi… (#186)

* Add support for metadata in Bindings + fix serialization of output binding."

* Remove generics from new bindings method.

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

@@ -16,7 +16,7 @@ import reactor.core.publisher.Mono;
 @RestController
 public class InputBindingController {
 
-  @PostMapping(path = "/bindingSample")
+  @PostMapping(path = "/sample123")
   public Mono<Void> handleInputBinding(@RequestBody(required = false) byte[] body) {
     return Mono.fromRunnable(() ->
             System.out.println("Received message through binding: " + (body == null ? "" : new String(body))));

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

@@ -18,7 +18,7 @@ import org.apache.commons.cli.Options;
  * 2. cd to [repo-root]/examples
  * 3. Run :
  * dapr run --app-id inputbinding --app-port 3000 --port 3005  \
- *   -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.InputBindingExample -D exec.args="-p 3000"
+ *   -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.http.InputBindingExample -D exec.args="-p 3000"
  */
 public class InputBindingExample {
 

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

@@ -15,7 +15,7 @@ import io.dapr.client.DaprClientBuilder;
  * 2. cd to [repo-root]/examples
  * 3. Run the program:
  * dapr run --app-id outputbinding --port 3006 \
- *   -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.OutputBindingExample
+ *   -- mvn exec:java -D exec.mainClass=io.dapr.examples.bindings.http.OutputBindingExample
  */
 public class OutputBindingExample {
 
@@ -26,7 +26,7 @@ public class OutputBindingExample {
     public String message;
   }
 
-  static final String BINDING_NAME = "bindingSample";
+  static final String BINDING_NAME = "sample123";
 
   /**
    * The main method of this app.
@@ -37,26 +37,30 @@ public class OutputBindingExample {
   public static void main(String[] args) {
     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 = "hello";
+        myClass.message = message;
 
         System.out.println("sending a class with message: " + myClass.message);
         client.invokeBinding(BINDING_NAME, myClass).block();
-
-    // This is an example of sending a plain string.  The input binding will receive:
-    //   "cat"
-    final String m = "cat";
-    System.out.println("sending a plain string: " + m);
-    client.invokeBinding(BINDING_NAME, m).block();
+      } else {
+        System.out.println("sending a plain string: " + message);
+        client.invokeBinding(BINDING_NAME, message).block();
+      }
 
       try {
         Thread.sleep((long) (10000 * Math.random()));
       } catch (InterruptedException e) {
         e.printStackTrace();
         Thread.currentThread().interrupt();
-      return;
+      }
     }
 
     System.out.println("Done.");

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

@@ -105,14 +105,13 @@ public class OutputBindingExample {
     final String BINDING_NAME = "bindingSample";
     ///...
     MyClass myClass = new MyClass();
-    myClass.message = "hello";
+    myClass.message = message;
 
     System.out.println("sending an object instance with message: " + myClass.message);
     client.invokeBinding(BINDING_NAME, myClass); //Binding a data object
-    ///..
-    final String m = "cat";
+    ///...
     System.out.println("sending a plain string: " + m);
-    client.invokeBinding(BINDING_NAME, m); //Binding a plain string text
+    client.invokeBinding(BINDING_NAME, message); //Binding a plain string text
     }
 ///...
 }

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

@@ -17,6 +17,7 @@ import org.junit.Ignore;
 import org.junit.Test;
 
 import java.util.Base64;
+import java.util.Collections;
 import java.util.List;
 
 import static io.dapr.it.Retry.callWithRetry;
@@ -45,7 +46,7 @@ public class BindingIT extends BaseIT {
         InputBindingService.class,
         true,
         60000);
-    // At this point, it is guaranteed that the service aboce is running and all ports being listened to.
+    // At this point, it is guaranteed that the service above is running and all ports being listened to.
     // TODO: figure out why this wait is needed for this scenario to work end-to-end. Kafka not up yet?
     Thread.sleep(120000);
 
@@ -59,18 +60,26 @@ public class BindingIT extends BaseIT {
     myClass.message = "hello";
 
     System.out.println("sending first message");
-    client.invokeBinding(BINDING_NAME, myClass).block();
+    client.invokeBinding(BINDING_NAME, myClass, Collections.singletonMap("MyMetadata", "MyValue")).block();
 
     // This is an example of sending a plain string.  The input binding will receive
     //   cat
     final String m = "cat";
     System.out.println("sending " + m);
-    client.invokeBinding(BINDING_NAME, m).block();
+    client.invokeBinding(BINDING_NAME, m, Collections.singletonMap("MyMetadata", "MyValue")).block();
 
+    // Metadata is not used by Kafka component, so it is not possible to validate.
     callWithRetry(() -> {
       System.out.println("Checking results ...");
-      final List<String> messages = client.invokeService(Verb.GET, daprRunInputBinding.getAppName(), "messages", null, List.class).block();
+      final List<String> messages =
+          client.invokeService(
+              Verb.GET,
+              daprRunInputBinding.getAppName(),
+              "messages",
+              null,
+              List.class).block();
       assertEquals(2, messages.size());
+
       MyClass resultClass = null;
       try {
         resultClass = new ObjectMapper().readValue(messages.get(0), MyClass.class);

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

@@ -24,7 +24,7 @@ public class InputBindingController {
 
   @GetMapping("/dapr/config")
   public String daprConfig() throws Exception {
-    return "{\"actorIdleTimeout\":\"5s\",\"actorScanInterval\":\"2s\",\"drainOngoingCallTimeout\":\"1s\",\"drainBalancedActors\":true,\"entities\":[]}";
+    return "{}";
   }
 
   @PostMapping(path = "/sample123")

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

@@ -8,7 +8,7 @@ package io.dapr.it.binding.http;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
-@SpringBootApplication(scanBasePackages = {"io.dapr.it.binding.http"})
+@SpringBootApplication
 public class InputBindingService {
 
   public static final String SUCCESS_MESSAGE = "dapr initialized. Status: Running. Init Elapsed";

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

@@ -127,14 +127,24 @@ public interface DaprClient {
   Mono<byte[]> invokeService(Verb verb, String appId, String method, byte[] request, Map<String, String> metadata);
 
   /**
-   * Creating a Binding.
+   * Invokes a Binding.
    *
    * @param name    The name of the biding to call.
    * @param request The request needed for the binding, use byte[] to skip serialization.
-   * @return a Mono plan of type Void
+   * @return a Mono plan of type Void.
    */
   Mono<Void> invokeBinding(String name, Object request);
 
+  /**
+   * Invokes a Binding with metadata.
+   *
+   * @param name     The name of the biding to call.
+   * @param request  The request needed for the binding, use byte[] to skip serialization.
+   * @param metadata The metadata map.
+   * @return a Mono plan of type Void.
+   */
+  Mono<Void> invokeBinding(String name, Object request, Map<String, String> metadata);
+
   /**
    * Retrieve a State based on their key.
    *

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

@@ -176,12 +176,25 @@ public class DaprClientGrpc implements DaprClient {
    */
   @Override
   public Mono<Void> invokeBinding(String name, Object request) {
+    return this.invokeBinding(name, request, null);
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public Mono<Void> invokeBinding(String name, Object request, Map<String, String> metadata) {
     try {
       byte[] byteRequest = objectSerializer.serialize(request);
-      Any data = Any.newBuilder().setValue(ByteString.copyFrom(byteRequest)).build();
       DaprProtos.InvokeBindingEnvelope.Builder builder = DaprProtos.InvokeBindingEnvelope.newBuilder()
-          .setName(name)
-          .setData(data);
+          .setName(name);
+      if (byteRequest != null) {
+        Any data = Any.newBuilder().setValue(ByteString.copyFrom(byteRequest)).build();
+        builder.setData(data);
+      }
+      if (metadata != null) {
+        builder.getMetadataMap().putAll(metadata);
+      }
       DaprProtos.InvokeBindingEnvelope envelope = builder.build();
       return Mono.fromCallable(() -> {
         ListenableFuture<Empty> futureEmpty = client.invokeBinding(envelope);

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

@@ -53,7 +53,12 @@ public class DaprClientHttp implements DaprClient {
   private final DaprObjectSerializer stateSerializer;
 
   /**
-   * Flag determining if serializer's input and output contains a valid String.
+   * Flag determining if object serializer's input and output is Dapr's default.
+   */
+  private final boolean isDefaultObjectSerializer;
+
+  /**
+   * Flag determining if state serializer's input and output contains a valid String.
    */
   private final boolean isStateString;
 
@@ -70,6 +75,7 @@ public class DaprClientHttp implements DaprClient {
     this.client = client;
     this.objectSerializer = objectSerializer;
     this.stateSerializer = stateSerializer;
+    this.isDefaultObjectSerializer = objectSerializer instanceof DefaultObjectSerializer;
     this.isStateString = stateSerializer.getClass().getAnnotation(StringContentType.class) != null;
   }
 
@@ -205,13 +211,44 @@ public class DaprClientHttp implements DaprClient {
    */
   @Override
   public Mono<Void> invokeBinding(String name, Object request) {
+    return this.invokeBinding(name, request, null);
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public Mono<Void> invokeBinding(String name, Object request, Map<String, String> metadata) {
     try {
       if (name == null || name.trim().isEmpty()) {
-        throw new IllegalArgumentException("Name to bind cannot be null or empty.");
+        throw new IllegalArgumentException("Binding name cannot be null or empty.");
       }
 
       Map<String, Object> jsonMap = new HashMap<>();
+      if (metadata != null) {
+        jsonMap.put("metadata", metadata);
+      }
+
+      if (request != null) {
+        if (this.isDefaultObjectSerializer) {
+          // If we are using Dapr's default serializer, we pass the object directly and skip objectSerializer.
+          // This allows binding to receive JSON directly without having to extract it from a quoted string.
+          // Example of output binding vs body in the input binding:
+          //   This logic DOES this:
+          //     Output Binding: { "data" : { "mykey": "myvalue" } }
+          //     Input Binding: { "mykey": "myvalue" }
+          //   This logic AVOIDS this:
+          //     Output Binding: { "data" : "{ \"mykey\": \"myvalue\" }" }
+          //     Input Binding: "{ \"mykey\": \"myvalue\" }"
           jsonMap.put("data", request);
+        } else {
+          // When customer provides a custom serializer, he will get a Base64 encoded String back - always.
+          // Example of body in the input binding resulting from this logic:
+          //   { "data" : "eyJrZXkiOiAidmFsdWUifQ==" }
+          jsonMap.put("data", objectSerializer.serialize(request));
+        }
+      }
+
       StringBuilder url = new StringBuilder(Constants.BINDING_PATH).append("/").append(name);
 
       return this.client
@@ -219,7 +256,7 @@ public class DaprClientHttp implements DaprClient {
               DaprHttp.HttpMethods.POST.name(),
               url.toString(),
               null,
-              objectSerializer.serialize(jsonMap),
+              INTERNAL_SERIALIZER.serialize(jsonMap),
               null)
           .then();
     } catch (Exception ex) {