// streams/CollectionToStream.java

// (c)2017 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

import java.util.*;

import java.util.stream.*;

public class CollectionToStream {

public static void main(String[] args) {

List<Bubble> bubbles = Arrays.asList(

new Bubble(1), new Bubble(2), new Bubble(3));

System.out.println(

bubbles.stream()

.mapToInt(b -> b.i)

.sum());

Set<String> w = new HashSet<>(Arrays.asList(

"It's a wonderful day for pie!".split(" ")));

w.stream()

.map(x -> x + " ")

.forEach(System.out::print);

System.out.println();

Map<String, Double> m = new HashMap<>();

m.put("pi", 3.14159);

m.put("e", 2.718);

m.put("phi", 1.618);

m.entrySet().stream()

.map(e -> e.getKey() + ": " + e.getValue())

.forEach(System.out::println);

}

}

/* Output:

6

a pie! It's for wonderful day

phi: 1.618

e: 2.718

pi: 3.14159

*/