code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.Collections;
  
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   * CA 95054 USA or visit www.sun.com if you need additional information or
   * have any questions.
   */
  
  /*
   * @test
   * @bug     6267846 6275009
   * @summary Test Collections.nCopies
   * @author  Martin Buchholz
   */
  
  import java.util.*;
  import java.util.concurrent.*;
  
  public class NCopies {
      static volatile int passed = 0, failed = 0;
  
      static void fail(String msg) {
          failed++;
          new AssertionError(msg).printStackTrace();
      }
  
      static void pass() {
          passed++;
      }
  
      static void unexpected(Throwable t) {
          failed++;
          t.printStackTrace();
      }
  
      static void check(boolean condition, String msg) {
          if (condition)
              passed++;
          else
              fail(msg);
      }
  
      static void check(boolean condition) {
          check(condition, "Assertion failure");
      }
  
      private static void checkEmpty(List<String> x) {
              check(x.isEmpty());
              check(x.size() == 0);
              check(x.indexOf("foo") == -1);
              check(x.lastIndexOf("foo") == -1);
              check(x.toArray().length == 0);
              check(x.toArray().getClass() == Object[].class);
      }
  
      private static void checkFoos(List<String> x) {
              check(! x.isEmpty());
              check(x.indexOf(new String("foo")) == 0);
              check(x.lastIndexOf(new String("foo")) == x.size()-1);
              check(x.toArray().length == x.size());
              check(x.toArray().getClass() == Object[].class);
              String[] sa = x.toArray(new String[x.size()]);
              check(sa.getClass() == String[].class);
              check(sa[0].equals("foo"));
              check(sa[sa.length-1].equals("foo"));
              check(x.get(x.size()/2).equals("foo"));
              checkEmpty(x.subList(x.size()/2, x.size()/2));
      }
  
      public static void main(String[] args) {
          try {
              List<String> empty = Collections.nCopies(0, "foo");
              checkEmpty(empty);
              checkEmpty(empty.subList(0,0));
  
              List<String> foos = Collections.nCopies(42, "foo");
              check(foos.size() == 42);
              checkFoos(foos.subList(foos.size()/2, foos.size()-1));
  
          } catch (Throwable t) { unexpected(t); }
  
          System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
          if (failed > 0) throw new Error("Some tests failed");
      }
  }
  