提交 dfa8c4d8 编写于 作者: M mduigou

5029031: Add Collections.checkedQueue()

Reviewed-by: mduigou
Contributed-by: darryl.mocek@oracle.com
上级 18fddf5e
......@@ -2351,6 +2351,64 @@ public class Collections {
}
}
/**
* Returns a dynamically typesafe view of the specified queue.
* Any attempt to insert an element of the wrong type will result in
* an immediate {@link ClassCastException}. Assuming a queue contains
* no incorrectly typed elements prior to the time a dynamically typesafe
* view is generated, and that all subsequent access to the queue
* takes place through the view, it is <i>guaranteed</i> that the
* queue cannot contain an incorrectly typed element.
*
* <p>A discussion of the use of dynamically typesafe views may be
* found in the documentation for the {@link #checkedCollection
* checkedCollection} method.
*
* <p>The returned queue will be serializable if the specified queue
* is serializable.
*
* <p>Since {@code null} is considered to be a value of any reference
* type, the returned queue permits insertion of {@code null} elements
* whenever the backing queue does.
*
* @param queue the queue for which a dynamically typesafe view is to be
* returned
* @param type the type of element that {@code queue} is permitted to hold
* @return a dynamically typesafe view of the specified queue
* @since 1.8
*/
public static <E> Queue<E> checkedQueue(Queue<E> queue, Class<E> type) {
return new CheckedQueue<>(queue, type);
}
/**
* @serial include
*/
static class CheckedQueue<E>
extends CheckedCollection<E>
implements Queue<E>, Serializable
{
private static final long serialVersionUID = 1433151992604707767L;
final Queue<E> queue;
CheckedQueue(Queue<E> queue, Class<E> elementType) {
super(queue, elementType);
this.queue = queue;
}
public E element() {return queue.element();}
public boolean equals(Object o) {return o == this || c.equals(o);}
public int hashCode() {return c.hashCode();}
public E peek() {return queue.peek();}
public E poll() {return queue.poll();}
public E remove() {return queue.remove();}
public boolean offer(E e) {
typeCheck(e);
return add(e);
}
}
/**
* Returns a dynamically typesafe view of the specified set.
* Any attempt to insert an element of the wrong type will result in
......
/*
* Copyright (c) 2011, 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 5020931
* @summary Unit test for Collections.checkedQueue
*/
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Iterator;
import java.util.Queue;
import java.util.concurrent.ArrayBlockingQueue;
public class CheckedQueue {
static int status = 0;
public static void main(String[] args) throws Exception {
new CheckedQueue();
}
public CheckedQueue() throws Exception {
run();
}
private void run() throws Exception {
Method[] methods = this.getClass().getDeclaredMethods();
for (int i = 0; i < methods.length; i++) {
Method method = methods[i];
String methodName = method.getName();
if (methodName.startsWith("test")) {
try {
Object obj = method.invoke(this, new Object[0]);
} catch(Exception e) {
throw new Exception(this.getClass().getName() + "." +
methodName + " test failed, test exception "
+ "follows\n" + e.getCause());
}
}
}
}
/**
* This test adds items to a queue.
*/
private void test00() {
int arrayLength = 10;
ArrayBlockingQueue<String> abq = new ArrayBlockingQueue(arrayLength);
for (int i = 0; i < arrayLength; i++) {
abq.add(new String(Integer.toString(i)));
}
}
/**
* This test tests the CheckedQueue.add method. It creates a queue of
* {@code String}s gets the checked queue, and attempt to add an Integer to
* the checked queue.
*/
private void test01() throws Exception {
int arrayLength = 10;
ArrayBlockingQueue<String> abq = new ArrayBlockingQueue(arrayLength + 1);
for (int i = 0; i < arrayLength; i++) {
abq.add(new String(Integer.toString(i)));
}
Queue q = Collections.checkedQueue(abq, String.class);
try {
q.add(new Integer(0));
throw new Exception(this.getClass().getName() + "." + "test01 test"
+ " failed, should throw ClassCastException.");
} catch(ClassCastException cce) {
// Do nothing.
}
}
/**
* This test tests the CheckedQueue.add method. It creates a queue of one
* {@code String}, gets the checked queue, and attempt to add an Integer to
* the checked queue.
*/
private void test02() throws Exception {
ArrayBlockingQueue<String> abq = new ArrayBlockingQueue(1);
Queue q = Collections.checkedQueue(abq, String.class);
try {
q.add(new Integer(0));
throw new Exception(this.getClass().getName() + "." + "test02 test"
+ " failed, should throw ClassCastException.");
} catch(ClassCastException e) {
// Do nothing.
}
}
/**
* This test tests the Collections.checkedQueue method call for nulls in
* each and both of the parameters.
*/
private void test03() throws Exception {
ArrayBlockingQueue<String> abq = new ArrayBlockingQueue(1);
Queue q;
try {
q = Collections.checkedQueue(null, String.class);
throw new Exception(this.getClass().getName() + "." + "test03 test"
+ " failed, should throw NullPointerException.");
} catch(NullPointerException npe) {
// Do nothing
}
try {
q = Collections.checkedQueue(abq, null);
throw new Exception(this.getClass().getName() + "." + "test03 test"
+ " failed, should throw NullPointerException.");
} catch(Exception e) {
// Do nothing
}
try {
q = Collections.checkedQueue(null, null);
throw new Exception(this.getClass().getName() + "." + "test03 test"
+ " failed, should throw NullPointerException.");
} catch(Exception e) {
// Do nothing
}
}
/**
* This test tests the CheckedQueue.offer method.
*/
private void test04() throws Exception {
ArrayBlockingQueue<String> abq = new ArrayBlockingQueue(1);
Queue q = Collections.checkedQueue(abq, String.class);
try {
q.offer(null);
throw new Exception(this.getClass().getName() + "." + "test04 test"
+ " failed, should throw NullPointerException.");
} catch (NullPointerException npe) {
// Do nothing
}
try {
q.offer(new Integer(0));
throw new Exception(this.getClass().getName() + "." + "test04 test"
+ " failed, should throw ClassCastException.");
} catch (ClassCastException cce) {
// Do nothing
}
q.offer(new String("0"));
try {
q.offer(new String("1"));
throw new Exception(this.getClass().getName() + "." + "test04 test"
+ " failed, should throw IllegalStateException.");
} catch(IllegalStateException ise) {
// Do nothing
}
}
private void test05() {
}
}
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