Add TBase and TEnum type adapter for JsonDataConverter

src/main/java/com/uber/cadence/converter/JsonDataConverter.java

@@ -97,7 +97,9 @@ public JsonDataConverter(Function<GsonBuilder, GsonBuilder> builderInterceptor)
     GsonBuilder gsonBuilder =
         new GsonBuilder()
             .serializeNulls()
-            .registerTypeAdapterFactory(new ThrowableTypeAdapterFactory());
+            .registerTypeAdapterFactory(new ThrowableTypeAdapterFactory())
+            .registerTypeAdapterFactory(new TBaseTypeAdapterFactory())
+            .registerTypeAdapterFactory(new TEnumTypeAdapterFactory());
     GsonBuilder intercepted = builderInterceptor.apply(gsonBuilder);
     gson = intercepted.create();
   }

src/main/java/com/uber/cadence/converter/TBaseTypeAdapterFactory.java

@@ -0,0 +1,66 @@
+package com.uber.cadence.converter;
+
+import com.google.gson.Gson;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import org.apache.thrift.TBase;
+import org.apache.thrift.TDeserializer;
+import org.apache.thrift.TException;
+import org.apache.thrift.TSerializer;
+import org.apache.thrift.protocol.TJSONProtocol;
+
+/**
+ * Special handling of TBase message serialization and deserialization. This is to support for
+ * inline Thrift fields in Java class.
+ */
+public class TBaseTypeAdapterFactory implements TypeAdapterFactory {
+
+  @Override
+  public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
+    // this class only serializes 'TBase' and its subtypes
+    if (!TBase.class.isAssignableFrom(typeToken.getRawType())) {
+      return null;
+    }
+    TypeAdapter<T> result =
+        new TypeAdapter<T>() {
+          @Override
+          public void write(JsonWriter jsonWriter, T value) throws IOException {
+            try {
+              String result =
+                  newThriftSerializer().toString((TBase) value, StandardCharsets.UTF_8.name());
+              jsonWriter.value(result);
+            } catch (TException e) {
+              throw new DataConverterException("Failed to serialize TBase", e);
+            }
+          }
+
+          @Override
+          public T read(JsonReader jsonReader) throws IOException {
+            String value = jsonReader.nextString();
+            try {
+              @SuppressWarnings("unchecked")
+              T instance = (T) typeToken.getRawType().getConstructor().newInstance();
+              newThriftDeserializer()
+                  .deserialize((TBase) instance, value, StandardCharsets.UTF_8.name());
+              return instance;
+            } catch (Exception e) {
+              throw new DataConverterException("Failed to deserialize TBase", e);
+            }
+          }
+        }.nullSafe();
+    return result;
+  }
+
+  private static TSerializer newThriftSerializer() {
+    return new TSerializer(new TJSONProtocol.Factory());
+  }
+
+  private static TDeserializer newThriftDeserializer() {
+    return new TDeserializer(new TJSONProtocol.Factory());
+  }
+}

src/main/java/com/uber/cadence/converter/TEnumTypeAdapterFactory.java

@@ -0,0 +1,48 @@
+package com.uber.cadence.converter;
+
+import com.google.gson.Gson;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import org.apache.thrift.TEnum;
+
+/**
+ * Special handling of TEnum serialization and deserialization. This is to support for inline TEnum
+ * fields in Java class. The default gson serde serialize the TEnum with its String name
+ * representation, this adapter serialize the TEnum class with its int representation.
+ */
+public class TEnumTypeAdapterFactory implements TypeAdapterFactory {
+
+  @Override
+  public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
+    // this class only serializes 'TEnum' and its subtypes
+    if (!TEnum.class.isAssignableFrom(typeToken.getRawType())) {
+      return null;
+    }
+    TypeAdapter<T> result =
+        new TypeAdapter<T>() {
+          @Override
+          public void write(JsonWriter jsonWriter, T value) throws IOException {
+            jsonWriter.value(((TEnum) value).getValue());
+          }
+
+          @Override
+          public T read(JsonReader jsonReader) throws IOException {
+            int value = jsonReader.nextInt();
+            try {
+              Method m = (typeToken.getRawType().getDeclaredMethod("findByValue", Integer.TYPE));
+              @SuppressWarnings("unchecked")
+              T instance = (T) m.invoke(null, value);
+              return instance;
+            } catch (Exception e) {
+              throw new DataConverterException("Failed to deserilize TEnum", e);
+            }
+          }
+        }.nullSafe();
+    return result;
+  }
+}

src/test/java/com/uber/cadence/converter/JsonDataConverterTest.java

@@ -19,6 +19,7 @@
 
 import static org.junit.Assert.assertEquals;
 
+import com.uber.cadence.EventType;
 import com.uber.cadence.History;
 import com.uber.cadence.HistoryEvent;
 import com.uber.cadence.TaskList;
@@ -29,13 +30,44 @@
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import java.util.UUID;
 import org.junit.Test;
 
 public class JsonDataConverterTest {
 
   private final DataConverter converter = JsonDataConverter.getInstance();
 
+  static class TestData {
+    String val1;
+    // TBase value;
+    HistoryEvent val2;
+    // TEnum value;
+    EventType val3;
+
+    public TestData(String val1, HistoryEvent val2, EventType val3) {
+      this.val1 = val1;
+      this.val2 = val2;
+      this.val3 = val3;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (!(o instanceof TestData)) return false;
+      TestData testData = (TestData) o;
+      return Objects.equals(val1, testData.val1)
+          && Objects.equals(val2, testData.val2)
+          && val3 == testData.val3;
+    }
+
+    @Override
+    public int hashCode() {
+
+      return Objects.hash(val1, val2, val3);
+    }
+  }
+
   @Test
   public void testThrift() {
     List<HistoryEvent> events = new ArrayList<>();
@@ -57,6 +89,29 @@ public void testThrift() {
     assertEquals(new String(converted, StandardCharsets.UTF_8), history, fromConverted);
   }
 
+  @Test
+  public void testThriftFieldsInPOJO() {
+    WorkflowExecutionStartedEventAttributes started =
+        new WorkflowExecutionStartedEventAttributes()
+            .setExecutionStartToCloseTimeoutSeconds(11)
+            .setIdentity("testIdentity")
+            .setInput("input".getBytes(StandardCharsets.UTF_8))
+            .setWorkflowType(new WorkflowType().setName("workflowType1"))
+            .setTaskList(new TaskList().setName("taskList1"));
+
+    HistoryEvent historyEvent =
+        new HistoryEvent()
+            .setTimestamp(1234567)
+            .setEventId(321)
+            .setWorkflowExecutionStartedEventAttributes(started);
+
+    TestData testData = new TestData("test-thrift", historyEvent, EventType.ActivityTaskCompleted);
+
+    byte[] converted = converter.toData(testData);
+    TestData fromConverted = converter.fromData(converted, TestData.class, TestData.class);
+    assertEquals(new String(converted, StandardCharsets.UTF_8), testData, fromConverted);
+  }
+
   public static void foo(List<UUID> arg) {}
 
   @Test