// concurrent/SynchronizedFactory.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.concurrent.atomic.*;

final class SyncFactory implements HasID {
 private final int id;
 private SyncFactory(SharedArg sa) {
 id = sa.get();
 }
 @Override
 public int getID() { return id; }
 public static synchronized
 SyncFactory factory(SharedArg sa) {
 return new SyncFactory(sa);
 }
}

public class SynchronizedFactory {
 public static void main(String[] args) {
 Unsafe unsafe = new Unsafe();
 IDChecker.test(() ->
 SyncFactory.factory(unsafe));
 }
}
/* Output:
0
*/