The Map interface abstracts what it means to be a map. Classes such as HashMap and java.util.TreeMap implement Map, describing different kinds of map implementations.

Learn the difference between classes and interfaces once and for all, then get started declaring, implementing, and extending interfaces in your Java programs ...

The functional Predicate interface gets used extensively by the Java 8 Streams API. Any developer who wants to master functional programming in Java will need to be comfortable with the Predicate ...

Functional supplier interface in Java tutorial There are only half a dozen classes you really need to master to become competent in the world of functional programming. The java.util.function package ...