OnJava8-Examples/collectiontopics/SuppliersCollectionTest.java
2020-10-07 13:35:40 -06:00

68 lines
2.3 KiB
Java

// collectiontopics/SuppliersCollectionTest.java
// (c)2020 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]
*/