There´s a lack of flexibility on GsonDeserialization.

[ghost]

There´s a lack of flexibility on GsonDeserialization.

"deserialize" method with Json Array as input in "inputStream", will throw "IllegalArgumentException" if there are more than 1 parameter in the "method".

So, if i try to use REST with an additional parameter (let´s say an additional "AuthentitcationToken" parameter with @HeaderParam("token")), it will throw "IllegalArgumentException".

---

Code (i´ve commented the "if" sentence):

@Deserializes({ "application/json", "json" })
@SuppressWarnings("rawtypes")
public class GsonDeserialization implements Deserializer {
...
...

public Object[] deserialize(InputStream inputStream, ResourceMethod method) {
Class<?>[] types = getTypes(method);

    if (types.length == 0) {
        throw new IllegalArgumentException(
                "Methods that consumes representations must receive at least one argument");
    }

    Gson gson = getGson();

    Object[] params = new Object[types.length];
    String[] parameterNames = paramNameProvider.parameterNamesFor(method.getMethod());

    try {
        String content = getContentOfStream(inputStream);

        if (Strings.isNullOrEmpty(content)) {
            logger.debug("json with no content");
            return params;
        }

        logger.debug("json retrieved: {}", content);

        JsonParser parser = new JsonParser();
        JsonElement jsonElement = parser.parse(content);

        if (jsonElement.isJsonObject()) {
            JsonObject root = jsonElement.getAsJsonObject();

            for (int i = 0; i < types.length; i++) {
                String name = parameterNames[i];
                JsonElement node = root.get(name);

                if (isWithoutRoot(parameterNames, root)) {
                    params[i] = gson.fromJson(root, types[i]);
                    logger.info("json without root deserialized");
                    break;
                } else if (node != null) {
                    if (node.isJsonArray()) {
                        JsonArray jsonArray = node.getAsJsonArray();

                        Type type = method.getMethod().getGenericParameterTypes()[i];
                        if (type instanceof ParameterizedType) {
                            params[i] = gson.fromJson(jsonArray, type);
                        } else {
                            params[i] = gson.fromJson(jsonArray, types[i]);
                        }
                    } else {
                        params[i] = gson.fromJson(node, types[i]);
                    }
                }
            }
        } else if (jsonElement.isJsonArray()) {
        /*  
            if ((parameterNames.length != 1) || (!(method.getMethod().getGenericParameterTypes()[0] instanceof ParameterizedType))) {
                throw new IllegalArgumentException("Methods that consumes an array representation must receive only just one collection generic typed argument");
            }
        */  
            JsonArray jsonArray= jsonElement.getAsJsonArray();
            params[0] = gson.fromJson(jsonArray, method.getMethod().getGenericParameterTypes()[0]);

        }
    } catch (Exception e) {
        throw new ResultException("Unable to deserialize data", e);
    }

    logger.debug("json deserialized: {}", (Object) params);
    return params;
}

...

}