Chapter 17. The Collections Class

The class java.util.Collections consists entirely of static methods that operate on or return collections. There are three main categories: generic algorithms, methods that return empty or prepopulated collections, and methods that create wrappers. We discuss these three categories in turn, followed by a number of other methods which do not fit into a neat classification.

All the methods of Collections are public and static, so for readability we will omit these modifiers from the individual declarations.