Exception thrown when a new field is added to JSON (Unknown field).

[Ricardo De Lemos]

Hi,

We are using Prostuff for JSON serialization/deserialization, for communication between our server and our different clients. These clients share a common Business logic written in Javascript, and we have used Protostuff to compile the .proto files for iOS and Android (Java).

The issue we have in Java, is that the Business Logic (Javascript) adds some fields to the JSON object received from the server, before sending this data to the Java layer, which uses the POJO generated by the .proto compiled.

This data added to the JSOn is not really needed by the Java layer, and can be ignored, but the de-serialization is throwing an exception, and stopping the de-serialization of the object.

I would expect that if the deserialization cannot find a match for a field, would not populate the field -basically ignoring it, but continue to the next field.

I could not find any way to "force" the de-serialization to ignore the unknown field, but it did not work. The only way I could make this work was to add the new field to the .proto and re-compile, but this is impractical in our case, because the business logic layer adds several fields in different messages for its internal use.

There is any way to make the JsonIOUtil.mergeFrom method more lenient, and simply ignore "unknown" fields, but continue the de-serialization of the object?

## this is the partial code used to de-serialize the messages (JSON objects)

   public static <T> T parseProtoJson(Class<T> cls, Schema<T> schema, String json) throws JSONException {

        try {

            T parsedProtostuffObj = cls.newInstance();

            JsonIOUtil.mergeFrom(json.getBytes(), parsedProtostuffObj, schema, false);                    // Dump Parsed object

            return parsedProtostuffObj;

        } catch (IOException e) {

            Log.e(LOG_TAG, "## JsonIOUtil FAILED TO PARSE PROTO_JSON for %s", cls.toString());

            e.printStackTrace();

            throw new JSONException("Unable to parse JSON");

        }

  }

## JSONIoUtil throws an exception during de-serializatiion 

10-27 17:10:25.935  14661-14830/com.unify.ansible I/java﹕ [PubSubService] ## Received PROTO_JSON_EVENT '/localUser/init' --> {"isExtended":true,"shortName":"Lemos R.","isGuest":false,"hasSupportRole":false,"isTenantAdmin":false,"isSuspended":false,"isDeleted":false,"isInactive":false,"avatar":"content/images/icon-general-default-avatar-yellow.png","avatarLarge":"content/images/icon-general-default-avatar-yellow-XL.png","exchangeData":{},"locale":"en-US","userId":"52","lastName":"Ricardo","firstName":"Lemos","displayName":"Lemos Ricardo","state":"AVAILABLE","largeImageUri":"","smallImageUri":"","emailAddress":"r...@mycom.com","userPresenceState":{"userId":"52","state":"AVAILABLE","timeZoneOffset":240,"mobile":false,"inTransit":false,"latitude":1000,"longitude":1000},"tenantId":"4","roles":["USER"],"userState":"ACTIVE","clientId":"a5d15c27-dde6-40e8-81ff-c09b3b2dcf8f","company":"","jobTitle":"","updatedTimeStamp":0,"phoneNumbers":[],"emailAddresses":[]}

10-27 17:10:25.945  14661-14661/com.unify.ansible D/java﹕ [ConversationSelectorFragment] register on event bus

10-27 17:10:25.955  14661-14830/com.unify.ansible E/java﹕ [JSONParsingManager] ## JsonIOUtil FAILED TO PARSE PROTO_JSON for class net.ansible.protobuf.user.User

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ com.dyuproject.protostuff.JsonInputException: Unknown field: exchangeData on message net.ansible.protobuf.user.User

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at com.dyuproject.protostuff.JsonInput.readFieldNumber(JsonInput.java:213)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at com.dyuproject.protostuff.JsonInput.readFieldNumber(JsonInput.java:137)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at net.ansible.protobuf.user.User.mergeFrom(User.java:424)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at net.ansible.protobuf.user.User.mergeFrom(User.java:20)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at com.dyuproject.protostuff.JsonIOUtil.mergeFrom(JsonIOUtil.java:340)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at com.dyuproject.protostuff.JsonIOUtil.mergeFrom(JsonIOUtil.java:257)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at com.dyuproject.protostuff.JsonIOUtil.mergeFrom(JsonIOUtil.java:240)

10-27 17:10:25.955  14661-14830/com.unify.ansible W/System.err﹕ at com.unify.ansible.common.JSONParsingManager.parseProtoJson(JSONParsingManager.java:54)