public void write(JSONSerializer serializer, Object fieldName, Type fieldType, int features) throws IOException {
        SerializeWriter writer = serializer.out;

        if(jsonpFunction == null){
            serializer.write(value);
            return;
        }


        if ((features & BrowserSecureMask) != 0 || (writer.isEnabled(BrowserSecureMask))) {
            writer.write(SECURITY_PREFIX);
        }

        writer.write(jsonpFunction);
        writer.write('(');
        serializer.write(value);
        writer.write(')');
    }
Return the configured JSONP function name.
src/main/java/com/alibaba/fastjson/support/spring/MappingFastJsonValue.java