java.util.WeakHashMap#isEmpty ( )源码实例Demo

private void enqueueWeakFinalizers() {
    // Clear any strong references.
    WeakHashMap<?, ?> strongRefs = this.reachabilityMap;
    if (!strongRefs.isEmpty()) {
        strongRefs.clear();
    }

    // Enqueue finalizer jobs.
    ReferenceQueue<ScriptObject> weakQueue = this.weakQueue;
    ArrayDeque<Job> finalizerJobs = this.finalizerJobs;
    for (Reference<? extends ScriptObject> ref; (ref = weakQueue.poll()) != null;) {
        Ref<Runnable> finalizer = ((WeakReferenceWithFinalizer) ref).getFinalizer();
        if (finalizer.get() != null) {
            finalizerJobs.add(new FinalizerJob(finalizer));
        }
    }
}
 

/**
 * <p>
 * Unregisters the given object.
 * </p>
 *
 * <p>
 * Used by the reflection methods to avoid infinite loops.
 * </p>
 *
 * @param value
 *                  The object to unregister.
 */
static void unregister(Object value) {
    if (value != null) {
        WeakHashMap<Object, Object> m;
        synchronized (ToStringStyle.class) {
            m = REGISTRY.get();
            if (m != null) {
                m.remove(value);
                if (m.isEmpty()) {
                    REGISTRY.remove();
                }
            }
        }
    }
}
 

/**
 * <p>
 * Unregisters the given object.
 * </p>
 *
 * <p>
 * Used by the reflection methods to avoid infinite loops.
 * </p>
 *
 * @param value
 *                  The object to unregister.
 */
static void unregister(Object value) {
    if (value != null) {
        WeakHashMap<Object, Object> m;
        synchronized (ToStringStyle.class) {
            m = REGISTRY.get();
            if (m != null) {
                m.remove(value);
                if (m.isEmpty()) {
                    REGISTRY.remove();
                }
            }
        }
    }
}
 

static void unregister(Object v) {
    if (v == null) return; WeakHashMap<Object, Object> m = REGISTRY.get();
    if (m == null) return; m.remove(v); if (m.isEmpty()) REGISTRY.remove();
}