What is a Java Stream?
Java Stream is a sequence of elements supporting the sequential and parallel aggregate operation. This example shows an aggregate operation using Stream and IntStream
int sum = widgets.stream() .filter(w -> w.getColor() == RED) .mapToInt(w -> w.getWeight()) .sum();
In this example (from Oracle Stream doc),
widgets is a Collection<Widget>. A stream of
Widget objects was created via
Collection.stream(), filter it to product a stream containing only the red widgets, and then transform it into a stream of int values representing the weight of each red widget. Finally this stream is summed to produce a total weight.
This post lists Java Streams code snippets that I find very useful