CSE 341 - Programming Languages - Autumn 2012

Java Generics & Nested Classes

• Java Generics (Notes)
• Java Nested Classes (Notes)
• More on Subtypes and Overloading in Java

Mini-Exercises

• Java Generics -- Mini-exercises #1; solution
• Java Generics -- Mini-exercises #2; solution

Code examples

• ArrayTest.java - demonstrates covariant typing rule for arrays
• OldLinkedListExample.java - Linked list example without generics
• LinkedListExample.java - Linked list of integers with generics
• ObjectLinkedListExample.java - Linked list of objects with generics
• Wild1.java - simple example of using a wildcard
• Wild2.java - method with a wildcard
• Wild3.java - method with a bounded wildcard
• OldMyArray.java - an array-like class (written without generics)
• MyArray.java - an array-like class (written with generics)

Additional Code examples

• Ambig.java - shows potential for ambiguity in selecting an overloaded method
• Widest.java - generic method example
• Wild2a.java - like Wild2, but uses a type parameter rather than a wildcard. (The Sun Java tutorial says this isn't as good style as using a wildcard - it's included here for comparison sake.)
• Wild3a.java - like Wild3, but uses a bounded type parameter rather than a wildcard. (Again Sun recommends using a wildcard in this case though.)
• Wild4.java - example of casting a generic of unknown (wildcard) type to a known type

References

• Gilad Bracha's useful tutorial on Java Generics
• Java API documentation - see the collection classes for lots of examples of using generics