public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return FastJsonHttpMessageConverter.class.isAssignableFrom(converterType)
                &&
                (returnType.getContainingClass().isAnnotationPresent(ResponseJSONP.class) || returnType.hasMethodAnnotation(ResponseJSONP.class));
    }
Created by SongLing.Dong on 7/22/2017.
<p>
Wrap with the return object from method annotated by <code>@ResponseJSONP</code>
in order to be serialized into jsonp format.
</p>
<p>
url: /path/to/your/api?<b>callback=functionName</b>
</p>

@see JSONPObject
@see ResponseJSONP
@since Spring 4.2 when ResponseBodyAdvice is supported.
<p>
In Spring 3.x, use method directly return a <code>JSONPObject</code> instead.
</p>
fastjson1-compatible/src/main/java/com/alibaba/fastjson/support/spring/JSONPResponseBodyAdvice.java