Storing an int in an ArrayList

The same sort of shenanigans take place on retrieval:

0172:       Integer tNewWrapper = (Integer)tList.get(2);
0173:       int tNewNumber = tNewWrapper.intValue();
0174:       System.out.println(tNewNumber);

This transfer of a value from an object into a variable is called unboxing.
You can do similar things for any of the primitive types ...
because each primitive type (e.g., double) has an associated class type called its wrapper type (e.g., java.lang.Double).