OnJava8-Examples/collectiontopics/SuppliersCollectionTest.java

// collectiontopics/SuppliersCollectionTest.java
// (c)2021 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.function.*;
import java.util.stream.*;
import onjava.*;

class Government implements Supplier<String> {
  static String[] foundation = (
    "strange women lying in ponds " +
    "distributing swords is no basis " +
    "for a system of government").split(" ");
  private int index;
  @Override public String get() {
    return foundation[index++];
  }
}

public class SuppliersCollectionTest {
  public static void main(String[] args) {
    // Suppliers class from the Generics chapter:
    Set<String> set = Suppliers.create(
      LinkedHashSet::new, new Government(), 15);
    System.out.println(set);
    List<String> list = Suppliers.create(
      LinkedList::new, new Government(), 15);
    System.out.println(list);
    list = new ArrayList<>();
    Suppliers.fill(list, new Government(), 15);
    System.out.println(list);

    // Or we can use Streams:
    set = Arrays.stream(Government.foundation)
      .collect(Collectors.toSet());
    System.out.println(set);
    list = Arrays.stream(Government.foundation)
      .collect(Collectors.toList());
    System.out.println(list);
    list = Arrays.stream(Government.foundation)
      .collect(Collectors
        .toCollection(LinkedList::new));
    System.out.println(list);
    set = Arrays.stream(Government.foundation)
      .collect(Collectors
        .toCollection(LinkedHashSet::new));
    System.out.println(set);
  }
}
/* Output:
[strange, women, lying, in, ponds, distributing,
swords, is, no, basis, for, a, system, of, government]
[strange, women, lying, in, ponds, distributing,
swords, is, no, basis, for, a, system, of, government]
[strange, women, lying, in, ponds, distributing,
swords, is, no, basis, for, a, system, of, government]
[ponds, no, a, in, swords, for, is, basis, strange,
system, government, distributing, of, women, lying]
[strange, women, lying, in, ponds, distributing,
swords, is, no, basis, for, a, system, of, government]
[strange, women, lying, in, ponds, distributing,
swords, is, no, basis, for, a, system, of, government]
[strange, women, lying, in, ponds, distributing,
swords, is, no, basis, for, a, system, of, government]
*/