OnJava8-Examples/concurrency/EvenChecker.java

// concurrency/EvenChecker.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
import java.util.concurrent.*;

public class EvenChecker implements Runnable {
  private IntSupplier generator;
  private final int id;
  public EvenChecker(IntSupplier g, int ident) {
    generator = g;
    id = ident;
  }
  @Override
  public void run() {
    while(!generator.isCanceled()) {
      int val = generator.next();
      if(val % 2 != 0) {
        System.out.println(val + " not even!");
        generator.cancel(); // Cancels all EvenCheckers
      }
    }
  }
  // Test any type of IntSupplier:
  public static void test(IntSupplier gp, int count) {
    System.out.println("Press Control-C to exit");
    ExecutorService exec = Executors.newCachedThreadPool();
    for(int i = 0; i < count; i++)
      exec.execute(new EvenChecker(gp, i));
    exec.shutdown();
  }
  // Default value for count:
  public static void test(IntSupplier gp) {
    test(gp, 10);
  }
}