Java Interview Questions

1. What are Soft,Phantom,Weak references in Java?
2. What is Fail Fast Iterator?
3. Why are iterators efficient than for loops
4. What are different class loaders
   
5. How does an class loader work
6. What is the API to iterate through the class level vairables of a class
7. When does a ConcurrrencyModificationException thrown?
   
8. Can static methods be synchronized?
9. On which object are static methods synchronized?
10. How do you implement singletons?
11. What is the initial size of an HashTable?
12. Is Object and Class implement Serializable interface?
13. If a class Util.java exists in test.jar and test1.jar, How will you code pick up the right class?
14. Can a class be loaded multiple times