Large Amounts of Data
Encapsulation and Information Hiding
Algorithms
Efficiency and How to Measure It.
Correctness and How to Guarantee It.
Arrays
Strings
Vectors
Stacks and Queues
Lists
Binary Trees and Binary Search Trees
Balanced Trees
Hashtables
Graphs
A good source of information is the book:
Duane Bailey, Java Structures: Data Structures in Java for the Principled Programmer, McGraw-Hill, 1999