Java example source code file (IteratorAtEnd.java)

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Java - Java tags/keywords

concurrenthashmap, concurrentlinkeddeque, expected, fun, iteratoratend, list, listiterator, object, size, some, suppresswarnings, threading, threads, throwable, unsupportedoperationexception, util, vector

The IteratorAtEnd.java Java example source code

/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug 6529795
 * @summary next() does not change iterator state if throws NoSuchElementException
 * @author Martin Buchholz
 */

import java.util.*;
import java.util.concurrent.*;

@SuppressWarnings("unchecked")
public class IteratorAtEnd {
    private static final int SIZE = 6;

    static void realMain(String[] args) throws Throwable {
        testCollection(new ArrayList());
        testCollection(new Vector());
        testCollection(new LinkedList());
        testCollection(new ArrayDeque());
        testCollection(new TreeSet());
        testCollection(new CopyOnWriteArrayList());
        testCollection(new CopyOnWriteArraySet());
        testCollection(new ConcurrentSkipListSet());

        testCollection(new PriorityQueue());
        testCollection(new LinkedBlockingQueue());
        testCollection(new ArrayBlockingQueue(100));
        testCollection(new ConcurrentLinkedDeque());
        testCollection(new ConcurrentLinkedQueue());
        testCollection(new LinkedTransferQueue());

        testMap(new HashMap());
        testMap(new Hashtable());
        testMap(new LinkedHashMap());
        testMap(new WeakHashMap());
        testMap(new IdentityHashMap());
        testMap(new ConcurrentHashMap());
        testMap(new ConcurrentSkipListMap());
        testMap(new TreeMap());
    }

    static void testCollection(Collection c) {
        try {
            for (int i = 0; i < SIZE; i++)
                c.add(i);
            test(c);
        } catch (Throwable t) { unexpected(t); }
    }

    static void testMap(Map m) {
        try {
            for (int i = 0; i < 3*SIZE; i++)
                m.put(i, i);
            test(m.values());
            test(m.keySet());
            test(m.entrySet());
        } catch (Throwable t) { unexpected(t); }
    }

    static void test(Collection c) {
        try {
            final Iterator it = c.iterator();
            THROWS(NoSuchElementException.class,
                   new Fun() {void f() { while (true) it.next(); }});
            try { it.remove(); }
            catch (UnsupportedOperationException _) { return; }
            pass();
        } catch (Throwable t) { unexpected(t); }

        if (c instanceof List) {
            final List list = (List) c;
            try {
                final ListIterator it = list.listIterator(0);
                it.next();
                final Object x = it.previous();
                THROWS(NoSuchElementException.class,
                       new Fun() {void f() { it.previous(); }});
                try { it.remove(); }
                catch (UnsupportedOperationException _) { return; }
                pass();
                check(! list.get(0).equals(x));
            } catch (Throwable t) { unexpected(t); }

            try {
                final ListIterator it = list.listIterator(list.size());
                it.previous();
                final Object x = it.next();
                THROWS(NoSuchElementException.class,
                       new Fun() {void f() { it.next(); }});
                try { it.remove(); }
                catch (UnsupportedOperationException _) { return; }
                pass();
                check(! list.get(list.size()-1).equals(x));
            } catch (Throwable t) { unexpected(t); }
        }
    }

    //--------------------- Infrastructure ---------------------------
    static volatile int passed = 0, failed = 0;
    static void pass() {passed++;}
    static void fail() {failed++; Thread.dumpStack();}
    static void fail(String msg) {System.out.println(msg); fail();}
    static void unexpected(Throwable t) {failed++; t.printStackTrace();}
    static void check(boolean cond) {if (cond) pass(); else fail();}
    static void equal(Object x, Object y) {
        if (x == null ? y == null : x.equals(y)) pass();
        else fail(x + " not equal to " + y);}
    public static void main(String[] args) throws Throwable {
        try {realMain(args);} catch (Throwable t) {unexpected(t);}
        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
        if (failed > 0) throw new AssertionError("Some tests failed");}
    private static abstract class Fun {abstract void f() throws Throwable;}
    static void THROWS(Class<? extends Throwable> k, Fun... fs) {
        for (Fun f : fs)
            try { f.f(); fail("Expected " + k.getName() + " not thrown"); }
            catch (Throwable t) {
                if (k.isAssignableFrom(t.getClass())) pass();
                else unexpected(t);}}
}