Register subtypes for deserialization in Jackson Module

src/main/java/de/thm/arsnova/entities/Content.java

 package de.thm.arsnova.entities;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.fasterxml.jackson.annotation.JsonView;
 import de.thm.arsnova.entities.serialization.View;
 

src/main/java/de/thm/arsnova/entities/serialization/CouchDbDocumentModule.java

@@ -17,8 +17,14 @@
  */
 package de.thm.arsnova.entities.serialization;
 
+import com.fasterxml.jackson.databind.jsontype.NamedType;
 import com.fasterxml.jackson.databind.module.SimpleModule;
+import de.thm.arsnova.entities.Answer;
+import de.thm.arsnova.entities.ChoiceAnswer;
+import de.thm.arsnova.entities.ChoiceQuestionContent;
+import de.thm.arsnova.entities.Content;
 import de.thm.arsnova.entities.Entity;
+import de.thm.arsnova.entities.TextAnswer;
 
 public class CouchDbDocumentModule extends SimpleModule {
 	public CouchDbDocumentModule() {
@@ -29,5 +35,11 @@ public class CouchDbDocumentModule extends SimpleModule {
 	public void setupModule(SetupContext context) {
 		context.setMixInAnnotations(Entity.class, CouchDbDocumentMixIn.class);
 		context.setMixInAnnotations(de.thm.arsnova.entities.migration.v2.Entity.class, CouchDbDocumentV2MixIn.class);
+		context.registerSubtypes(
+				new NamedType(Content.class, Content.class.getSimpleName()),
+				new NamedType(ChoiceQuestionContent.class, ChoiceQuestionContent.class.getSimpleName()),
+				new NamedType(Answer.class, Answer.class.getSimpleName()),
+				new NamedType(ChoiceAnswer.class, ChoiceAnswer.class.getSimpleName()),
+				new NamedType(TextAnswer.class, TextAnswer.class.getSimpleName()));
 	}
 }