在创建我的应用程序时.体系结构我面临着一种结构的需求,下面将对此进行描述.

我很确定,有一个众所周知的具有相同功能的设计模式,因为我认为我为之开发的这个问题确实很普遍.

我为此编写了自己的实现,但是我始终尝试使用模式的“语言构建”实现,所以-请帮助我命名此结构.

这个想法接近于读者-作家模式.我们有一个“容器”,可以在其中通过键()添加对象.我们也可以通过键获取此对象,并将其从容器中删除.

因此,实现的类应具有两种方法：

void putObject(Key key, Object object);
Object getObject(Key key); // remove <Key,Object> from container.

接下来是最有趣的.
此容器应在多线程环境中工作,如下所示：

>如果没有与键关联的对象,则在调用get(Key
key)方法,调用者线程应为此对象等待
容器.
>当另一个线程将调用putObject(Key key,Object object)
它应该检查是否有一些线程正在等待的方法
这个对象,如果是,则发出信号并唤醒线程,
等待.

我认为这是通用结构,是否具有“正式”名称？

我的Java实现此模式：

private static interface BlackBox {

        public void addObject(IdObject object);

        public IdObject getObject(ObjectId id);

    }

    private static class BlackBoxImpl implements BlackBox {

        private final Lock conditionLock = new ReentrantLock();
        private final Map<ObjectId, IdObject> savedObjects;
        private final Map<ObjectId, Condition> waitingConditions;

        public BlackBoxImpl() {
            this.savedObjects = new ConcurrentHashMap<ObjectId, IdObject>(20);
            this.waitingConditions = new ConcurrentHashMap<ObjectId, Condition>(20);
        }

        @Override
        public void addObject(IdObject object) {
            savedObjects.put(object.getId(), object);
            if (waitingConditions.containsKey(object.getId())) {
                Condition waitCondition = waitingConditions.get(object.getId());
                conditionLock.lock();
                waitCondition.signal();
                conditionLock.unlock();
            }
        }

        @Override
        public IdObject getObject(ObjectId id) {
            if (savedObjects.containsKey(id)) {
                return savedObjects.get(id);
            } else {
                conditionLock.lock();
                Condition waitCondition = conditionLock.newCondition();
                waitingConditions.put(id, waitCondition);
                waitCondition.awaitUninterruptibly();
                conditionLock.unlock();
                return savedObjects.get(id);
            }
        }

    }

    private static interface IdObject {

        public ObjectId getId();

    }

    private static class IdObjectImpl implements IdObject {

        protected final ObjectId id;

        public IdObjectImpl(ObjectId id) {
            this.id = id;
        }

        @Override
        public ObjectId getId() {
            return id;
        }

    }

    private static interface ObjectId {

    }

    private static class ObjectIdImpl implements ObjectId {

    }

解决方法:

我可能会使用类似

ConcurrentMap<K,BlockingQue<V>>. 

使用Map的并发方法添加对.从您的队列中获取价值.使用ArrayBlockingQue(1).

大概是这样的：

static class MultiQueue<K, V> {

    // The base structure.
    final ConcurrentMap<K, BlockingQueue<V>> queues = new ConcurrentHashMap<>();

    /**
     * Put an item in the structure.
     *
     * The entry in the map will be created if no entry is currently there.
     *
     * The value will then be posted to the queue.
     */
    public void put(K k, V v) throws InterruptedException {
        // Make it if not present.
        ensurePresence(k).put(v);
    }

    /**
     * Get an item from the structure.
     *
     * The entry in the map will be created if no entry is currently there.
     *
     * The value will then be taken from the queue.
     */
    public void get(K k) throws InterruptedException {
        // Make it if not present - and wait for it.
        ensurePresence(k).take();
    }

    private BlockingQueue<V> ensurePresence(K k) {
        // Make it if not present.
        return queues.computeIfAbsent(k, v -> new ArrayBlockingQueue(1));
    }
}