code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.tck;
  
  /*
   * Written by Doug Lea with assistance from members of JCP JSR-166
   * Expert Group and released to the public domain, as explained at
   * http://creativecommons.org/licenses/publicdomain
   * Other contributors include Andrew Wright, Jeffrey Hayes,
   * Pat Fisher, Mike Judd.
   */
  
  import junit.framework.*;
  import java.util.*;
  import java.util.concurrent.*;
  import java.io.*;
  
  public class CopyOnWriteArrayListTest extends JSR166TestCase {
  
      public static void main(String[] args) {
          junit.textui.TestRunner.run (suite());
      }
  
      public static Test suite() {
          return new TestSuite(CopyOnWriteArrayListTest.class);
      }
  
      static CopyOnWriteArrayList populatedArray(int n) {
          CopyOnWriteArrayList a = new CopyOnWriteArrayList();
          assertTrue(a.isEmpty());
          for (int i = 0; i < n; ++i)
              a.add(new Integer(i));
          assertFalse(a.isEmpty());
          assertEquals(n, a.size());
          return a;
      }
  
  
      /**
       * a new list is empty
       */
      public void testConstructor() {
          CopyOnWriteArrayList a = new CopyOnWriteArrayList();
          assertTrue(a.isEmpty());
      }
  
      /**
       * new list contains all elements of initializing array
       */
      public void testConstructor2() {
          Integer[] ints = new Integer[SIZE];
          for (int i = 0; i < SIZE-1; ++i)
              ints[i] = new Integer(i);
          CopyOnWriteArrayList a = new CopyOnWriteArrayList(ints);
          for (int i = 0; i < SIZE; ++i)
              assertEquals(ints[i], a.get(i));
      }
  
      /**
       * new list contains all elements of initializing collection
       */
      public void testConstructor3() {
          Integer[] ints = new Integer[SIZE];
          for (int i = 0; i < SIZE-1; ++i)
              ints[i] = new Integer(i);
          CopyOnWriteArrayList a = new CopyOnWriteArrayList(Arrays.asList(ints));
          for (int i = 0; i < SIZE; ++i)
              assertEquals(ints[i], a.get(i));
      }
  
  
      /**
       *   addAll  adds each element from the given collection
       */
      public void testAddAll() {
          CopyOnWriteArrayList full = populatedArray(3);
          Vector v = new Vector();
          v.add(three);
          v.add(four);
          v.add(five);
          full.addAll(v);
          assertEquals(6, full.size());
      }
  
      /**
       *   addAllAbsent adds each element from the given collection that did not
       *  already exist in the List
       */
      public void testAddAllAbsent() {
          CopyOnWriteArrayList full = populatedArray(3);
          Vector v = new Vector();
          v.add(three);
          v.add(four);
          v.add(one); // will not add this element
          full.addAllAbsent(v);
          assertEquals(5, full.size());
      }
  
      /**
       *   addIfAbsent will not add the element if it already exists in the list
       */
      public void testAddIfAbsent() {
          CopyOnWriteArrayList full = populatedArray(SIZE);
          full.addIfAbsent(one);
          assertEquals(SIZE, full.size());
      }
  
      /**
       *   addIfAbsent adds the element when it does not exist in the list
       */
      public void testAddIfAbsent2() {
          CopyOnWriteArrayList full = populatedArray(SIZE);
          full.addIfAbsent(three);
          assertTrue(full.contains(three));
      }
  
      /**
       *   clear removes all elements from the list
       */
      public void testClear() {
          CopyOnWriteArrayList full = populatedArray(SIZE);
          full.clear();
          assertEquals(0, full.size());
      }
  
  
      /**
       *  Cloned list is equal
       */
      public void testClone() {
          CopyOnWriteArrayList l1 = populatedArray(SIZE);
          CopyOnWriteArrayList l2 = (CopyOnWriteArrayList)(l1.clone());
          assertEquals(l1, l2);
          l1.clear();
          assertFalse(l1.equals(l2));
      }
  
      /**
       *   contains is true for added elements
       */
      public void testContains() {
          CopyOnWriteArrayList full = populatedArray(3);
          assertTrue(full.contains(one));
          assertFalse(full.contains(five));
      }
  
      /**
       * adding at an index places it in the indicated index
       */
      public void testAddIndex() {
          CopyOnWriteArrayList full = populatedArray(3);
          full.add(0, m1);
          assertEquals(4, full.size());
          assertEquals(m1, full.get(0));
          assertEquals(zero, full.get(1));
  
          full.add(2, m2);
          assertEquals(5, full.size());
          assertEquals(m2, full.get(2));
          assertEquals(two, full.get(4));
      }
  
      /**
       * lists with same elements are equal and have same hashCode
       */
      public void testEquals() {
          CopyOnWriteArrayList a = populatedArray(3);
          CopyOnWriteArrayList b = populatedArray(3);
          assertTrue(a.equals(b));
          assertTrue(b.equals(a));
          assertEquals(a.hashCode(), b.hashCode());
          a.add(m1);
          assertFalse(a.equals(b));
          assertFalse(b.equals(a));
          b.add(m1);
          assertTrue(a.equals(b));
          assertTrue(b.equals(a));
          assertEquals(a.hashCode(), b.hashCode());
      }
  
  
      /**
       *   containsAll returns true for collection with subset of elements
       */
      public void testContainsAll() {
          CopyOnWriteArrayList full = populatedArray(3);
          Vector v = new Vector();
          v.add(one);
          v.add(two);
          assertTrue(full.containsAll(v));
          v.add(six);
          assertFalse(full.containsAll(v));
      }
  
      /**
       *   get returns the value at the given index
       */
      public void testGet() {
          CopyOnWriteArrayList full = populatedArray(3);
          assertEquals(0, full.get(0));
      }
  
      /**
       *   indexOf gives the index for the given object
       */
      public void testIndexOf() {
          CopyOnWriteArrayList full = populatedArray(3);
          assertEquals(1, full.indexOf(one));
          assertEquals(-1, full.indexOf("puppies"));
      }
  
      /**
       *   indexOf gives the index based on the given index
       *  at which to start searching
       */
      public void testIndexOf2() {
          CopyOnWriteArrayList full = populatedArray(3);
          assertEquals(1, full.indexOf(one, 0));
          assertEquals(-1, full.indexOf(one, 2));
      }
  
      /**
       *   isEmpty returns true when empty, else false
       */
      public void testIsEmpty() {
          CopyOnWriteArrayList empty = new CopyOnWriteArrayList();
          CopyOnWriteArrayList full = populatedArray(SIZE);
          assertTrue(empty.isEmpty());
          assertFalse(full.isEmpty());
      }
  
      /**
       *   iterator() returns an iterator containing the elements of the list
       */
      public void testIterator() {
          CopyOnWriteArrayList full = populatedArray(SIZE);
          Iterator i = full.iterator();
          int j;
          for (j = 0; i.hasNext(); j++)
              assertEquals(j, i.next());
          assertEquals(SIZE, j);
      }
  
      /**
       * iterator.remove throws UnsupportedOperationException
       */
      public void testIteratorRemove () {
          CopyOnWriteArrayList full = populatedArray(SIZE);
          Iterator it = full.iterator();
          it.next();
          try {
              it.remove();
              shouldThrow();
          } catch (UnsupportedOperationException success) {}
      }
  
      /**
       * toString contains toString of elements
       */
      public void testToString() {
          CopyOnWriteArrayList full = populatedArray(3);
          String s = full.toString();
          for (int i = 0; i < 3; ++i) {
              assertTrue(s.indexOf(String.valueOf(i)) >= 0);
          }
      }
  
      /**
       *   lastIndexOf returns the index for the given object
       */
      public void testLastIndexOf1() {
          CopyOnWriteArrayList full = populatedArray(3);
          full.add(one);
          full.add(three);
          assertEquals(3, full.lastIndexOf(one));
          assertEquals(-1, full.lastIndexOf(six));
      }
  
      /**
       *   lastIndexOf returns the index from the given starting point
       */
      public void testlastIndexOf2() {
          CopyOnWriteArrayList full = populatedArray(3);
          full.add(one);
          full.add(three);
          assertEquals(3, full.lastIndexOf(one, 4));
          assertEquals(-1, full.lastIndexOf(three, 3));
      }
  
      /**
       *  listIterator traverses all elements
       */
      public void testListIterator1() {
          CopyOnWriteArrayList full = populatedArray(SIZE);
          ListIterator i = full.listIterator();
          int j;
          for (j = 0; i.hasNext(); j++)
              assertEquals(j, i.next());
          assertEquals(SIZE, j);
      }
  
      /**
       *  listIterator only returns those elements after the given index
       */
      public void testListIterator2() {
          CopyOnWriteArrayList full = populatedArray(3);
          ListIterator i = full.listIterator(1);
          int j;
          for (j = 0; i.hasNext(); j++)
              assertEquals(j+1, i.next());
          assertEquals(2, j);
      }
  
      /**
       *   remove  removes and returns the object at the given index
       */
      public void testRemove() {
          CopyOnWriteArrayList full = populatedArray(3);
          assertEquals(2, full.remove(2));
          assertEquals(2, full.size());
      }
  
      /**
       *   removeAll  removes all elements from the given collection
       */
      public void testRemoveAll() {
          CopyOnWriteArrayList full = populatedArray(3);
          Vector v = new Vector();
          v.add(one);
          v.add(two);
          full.removeAll(v);
          assertEquals(1, full.size());
      }
  
      /**
       *   set  changes the element at the given index
       */
      public void testSet() {
          CopyOnWriteArrayList full = populatedArray(3);
          assertEquals(2, full.set(2, four));
          assertEquals(4, full.get(2));
      }
  
      /**
       *   size returns the number of elements
       */
      public void testSize() {
          CopyOnWriteArrayList empty = new CopyOnWriteArrayList();
          CopyOnWriteArrayList full = populatedArray(SIZE);
          assertEquals(SIZE, full.size());
          assertEquals(0, empty.size());
      }
  
      /**
       *   toArray returns an Object array containing all elements from the list
       */
      public void testToArray() {
          CopyOnWriteArrayList full = populatedArray(3);
          Object[] o = full.toArray();
          assertEquals(3, o.length);
          assertEquals(0, o[0]);
          assertEquals(1, o[1]);
          assertEquals(2, o[2]);
      }
  
      /**
       *   toArray returns an Integer array containing all elements from
       *   the list
       */
      public void testToArray2() {
          CopyOnWriteArrayList full = populatedArray(3);
          Integer[] i = new Integer[3];
          i = (Integer[])full.toArray(i);
          assertEquals(3, i.length);
          assertEquals(0, i[0].intValue());
          assertEquals(1, i[1].intValue());
          assertEquals(2, i[2].intValue());
      }
  
  
      /**
       * sublists contains elements at indexes offset from their base
       */
      public void testSubList() {
          CopyOnWriteArrayList a = populatedArray(10);
          assertTrue(a.subList(1,1).isEmpty());
          for (int j = 0; j < 9; ++j) {
              for (int i = j ; i < 10; ++i) {
                  List b = a.subList(j,i);
                  for (int k = j; k < i; ++k) {
                      assertEquals(new Integer(k), b.get(k-j));
                  }
              }
          }
  
          List s = a.subList(2, 5);
          assertEquals(s.size(), 3);
          s.set(2, m1);
          assertEquals(a.get(4), m1);
          s.clear();
          assertEquals(a.size(), 7);
      }
  
      // Exception tests
  
      /**
       *   toArray throws an ArrayStoreException when the given array
       *  can not store the objects inside the list
       */
      public void testToArray_ArrayStoreException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("zfasdfsdf");
              c.add("asdadasd");
              c.toArray(new Long[5]);
              shouldThrow();
          } catch (ArrayStoreException success) {}
      }
  
      /**
       *   get throws an IndexOutOfBoundsException on a negative index
       */
      public void testGet1_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.get(-1);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   get throws an IndexOutOfBoundsException on a too high index
       */
      public void testGet2_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("asdasd");
              c.add("asdad");
              c.get(100);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   set throws an IndexOutOfBoundsException on a negative index
       */
      public void testSet1_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.set(-1,"qwerty");
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   set throws an IndexOutOfBoundsException on a too high index
       */
      public void testSet2() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("asdasd");
              c.add("asdad");
              c.set(100, "qwerty");
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   add throws an IndexOutOfBoundsException on a negative index
       */
      public void testAdd1_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add(-1,"qwerty");
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   add throws an IndexOutOfBoundsException on a too high index
       */
      public void testAdd2_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("asdasd");
              c.add("asdasdasd");
              c.add(100, "qwerty");
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   remove throws an IndexOutOfBoundsException on a negative index
       */
      public void testRemove1_IndexOutOfBounds() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.remove(-1);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   remove throws an IndexOutOfBoundsException on a too high index
       */
      public void testRemove2_IndexOutOfBounds() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("asdasd");
              c.add("adasdasd");
              c.remove(100);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   addAll throws an IndexOutOfBoundsException on a negative index
       */
      public void testAddAll1_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.addAll(-1,new LinkedList());
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   addAll throws an IndexOutOfBoundsException on a too high index
       */
      public void testAddAll2_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("asdasd");
              c.add("asdasdasd");
              c.addAll(100, new LinkedList());
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   listIterator throws an IndexOutOfBoundsException on a negative index
       */
      public void testListIterator1_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.listIterator(-1);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   listIterator throws an IndexOutOfBoundsException on a too high index
       */
      public void testListIterator2_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("adasd");
              c.add("asdasdas");
              c.listIterator(100);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   subList throws an IndexOutOfBoundsException on a negative index
       */
      public void testSubList1_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.subList(-1,100);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   subList throws an IndexOutOfBoundsException on a too high index
       */
      public void testSubList2_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.add("asdasd");
              c.subList(1,100);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       *   subList throws IndexOutOfBoundsException when the second index
       *  is lower then the first
       */
      public void testSubList3_IndexOutOfBoundsException() {
          try {
              CopyOnWriteArrayList c = new CopyOnWriteArrayList();
              c.subList(3,1);
              shouldThrow();
          } catch (IndexOutOfBoundsException success) {}
      }
  
      /**
       * a deserialized serialiszed list is equal
       */
      public void testSerialization() throws Exception {
          CopyOnWriteArrayList q = populatedArray(SIZE);
  
          ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
          ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
          out.writeObject(q);
          out.close();
  
          ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
          ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
          CopyOnWriteArrayList r = (CopyOnWriteArrayList)in.readObject();
          assertEquals(q.size(), r.size());
          assertTrue(q.equals(r));
          assertTrue(r.equals(q));
      }
  
  }
  