Reverse a linked list and its complexity
What is Heap
Different Sorting techniques
Different searchesSearching
About multithreading and synchronization
which is best sort and why
what is merge sort and how does it work
polymorphism and inheritance
Difference between final, finally and finalize
Try without a catch
Difference between where and having clause in SQL
Types of exception
java Generics
All this in a half an hour technical interview where first 10 mins will be explained about the company.