I've implemented some Java classes these containing several attributes which are Java primitive types like short and boolean. Theses attributes are often updated and it cause slow down my applet because their contents are stored in EEPROM.
Does exist some way how to store values of primitive types in RAM?
this is only slow but it also destroys your card's memory and can be a security issue.
To store volatile objects, store the attributes in a transient array.
There is support for different types, e.g. boolean, byte and short, but not for values of mixed types.
The usual technique is to map values in a single transient byte array.
See the documentation about makeTransientByteArray in the JCSytem class.