Question

Since generics are only checked during compile time with Java 5, can they avoid ClassCastExceptions in all
situations?

Answer 1

First of all, you should make sure that your code compiles without unckeched warnings. That is a good indicator. To understand why, I suggest you take a look at the sample chapter for generics from Effective Java.

Second of all, generics can’t guard you from code such as:

public void methodOne(Integer argument)  {
     methodTwo(argument);
} 

public void methodTwo(Object argument) {
     System.out.println(((Date) argument).getTime());
}

Third of all, if you’re in some way or another messing with Class Loaders, you might get strange ClassCastExceptions, such as in this discussion thread. It is mind-numbing to see

java.lang.ClassCastException: javax.mail.Session cannot be cast to
javax.mail.Session

So the answer is no, you can’t get rid of ClassCastExceptions just by properly using generics.