how to force jettison to write an array, even if there is only one element in the array?
I found this: https://blogs.oracle.com/japod/entry/missing_brackets_at_json_one
It seems that adding a line to your context resolver to explicitly state that tags is an array is the way to do this; i.e.
props.put(JSONJAXBContext.JSON_ARRAYS, "[\\"tags\\"]");NB: I'm not familiar with Jettison, so have no personal experience to back this up; only the info on the above blog post.
@Providerpublic class JAXBContextResolver implements ContextResolver<JAXBContext> { private JAXBContext context; private Class[] types = {ArrayWrapper.class}; public JAXBContextResolver() throws Exception { Map props = new HashMap<String, Object>(); props.put(JSONJAXBContext.JSON_NOTATION, "MAPPED"); props.put(JSONJAXBContext.JSON_ROOT_UNWRAPPING, Boolean.TRUE); props.put(JSONJAXBContext.JSON_ARRAYS, "[\\"tags\\"]"); //STATE WHICH ELEMENT IS AN ARRAY this.context = new JSONJAXBContext(types, props); } public JAXBContext getContext(Class<?> objectType) { return (types[0].equals(objectType)) ? context : null; }}