Please cancel your print and try again. Picklers are strongly typed and perform serialization without reflection or intermediate boxings. Try and get the WSDL of the file. In particular annotating Java Bean setter and getter methods will allow for a cleaner means to override the serialization behaviour than using fields. Try to keep any code that might create potential gadgets separate from any code that has internet connectivity. Only you and users with special permissions will be able to see it. Java objects have attributes and methods to manipulate these attributes.
Use this to set an individual option. Look for any serializers where the type is set by a user controlled variable. The last line in the file is always a trailer. Add an Image by clicking or by using Control plus G inside the text area.