Problem while nvoking services from browser

Can some one tell what the problem is with respect to the following code? I do not find any compilation errors but could not succeed in invoking getNewMessage() from the browser (it says internal server error). However, I could invoke the other method getAllMessages().

public Message[] getAllMessages() throws TeamRepositoryException {




IQueryService queryService = getService(IQueryService.class);

MessageQueryModel queryModel = BaseMessageQueryModel.MessageQueryModel.ROOT;
IItemQuery itemQuery = IItemQuery.FACTORY.newInstance(queryModel);

IItemQueryPage itemQueryPage = queryService.queryItems(itemQuery,
IQueryService.EMPTY_PARAMETERS, IQueryService.ITEM_QUERY_MAX_PAGE_SIZE);

IRepositoryItemService repositoryItemService = getService(IRepositoryItemService.class);
IItem[] items = repositoryItemService.fetchItems(itemQueryPage.handlesAsArray(), null);

ArrayList<Message> messages = new ArrayList<Message>();

for (IItem item : items) {
if (item instanceof Message) {
messages.add((Message) item);

}
}

return (Message[]) messages.toArray(new Message);




}

public Message getNewMessage()
throws TeamRepositoryException {
IRepositoryItemService repositoryItemService = getService(IRepositoryItemService.class);
Message message = (Message) getMessageItemType().createItem();
message.setText("hello");
message.setTest("hi");

message = (Message) repositoryItemService.saveItem(message);
return message;
}


static IItemType getMessageItemType() {
return IItemType.IRegistry.INSTANCE
.getItemType(JazztalkPackage.eINSTANCE.getMessage().getName(), JazztalkPackage.eNS_URI);
}

These are the related warnings on console. Why they are being raised for only of these methods "getNewMessage()" and not for the other?

21:59:04,687 WARN ory.servlet.internal.ModelledRestServiceMethodInfo - CRJAZ1177I Unable to find matching method for $Proxy76, GET, newmessage
22:00:52,578 WARN ory.servlet.internal.ModelledRestServiceMethodInfo - CRJAZ1177I Unable to find matching method for $Proxy76, GET, newmessage