Workaround to get state for actors given runtime API response issue. (#165)

sdk-actors/src/main/java/io/dapr/actors/runtime/DaprStateAsyncProvider.java

@@ -7,11 +7,14 @@ package io.dapr.actors.runtime;
 
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import io.dapr.actors.ActorId;
 import io.dapr.serializer.DaprObjectSerializer;
 import io.dapr.serializer.StringContentType;
+
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+
 import reactor.core.publisher.Mono;
 
 /**
@@ -19,6 +22,11 @@ import reactor.core.publisher.Mono;
  */
 class DaprStateAsyncProvider {
 
+  /**
+   * Used to fix problem from Dapr's state response.
+   */
+  private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+
   /**
    * Shared Json Factory as per Jackson's documentation, used only for this class.
    */
@@ -56,7 +64,7 @@ class DaprStateAsyncProvider {
 
     return result.flatMap(s -> {
       try {
-        T response = this.stateSerializer.deserialize(s, clazz);
+        T response = this.stateSerializer.deserialize(fixDaprStateResponse(s), clazz);
         if (response == null) {
           return Mono.empty();
         }
@@ -164,4 +172,29 @@ class DaprStateAsyncProvider {
 
     return this.daprClient.saveActorStateTransactionally(actorType, actorId.toString(), payload);
   }
+
+  /**
+   * Workaround for a bug in Dapr's runtime where actor state is saved as a JSON string and
+   * returned as-is without deserializing first.
+   *
+   * @param raw Bytes received from Dapr.
+   * @return Corrected byte[].
+   */
+  private byte[] fixDaprStateResponse(byte[] raw) {
+    if (raw == null) {
+      return raw;
+    }
+
+    if (raw.length == 0) {
+      return raw;
+    }
+
+    try {
+      return OBJECT_MAPPER.readValue(raw, String.class).getBytes();
+    } catch (IOException e) {
+      // We could not fix it, so iit goes as-is.
+      return raw;
+    }
+  }
+
 }