Lazy loader class Java

LazyLoader.java

	private static class Lazy<T> {

		private T object = null;
		private Supplier<T> supplier;

		private static final ReentrantLock lock = new ReentrantLock();

		public Lazy(Supplier<T> supplier) {
			this.supplier = supplier;
		}

		public T get() {

			if (object != null) {
				return object;
			}

			lock.lock();
			try {
				if (object == null) {
					this.object = supplier.get();
				}
				return this.object;
			} finally {
				lock.unlock();
			}
		}
	}

ProxyLazyLoader.java

	private static class Proxy extends UuidFactory {

		private UuidFactory factory = null;
		private Supplier<UuidFactory> supplier;

		private static final ReentrantLock lock = new ReentrantLock();

		public Proxy(Supplier<UuidFactory> supplier) {
			this.supplier = supplier;
		}

		public Proxy(Suppliers supplier) {
			this((Supplier<UuidFactory>) supplier.getValue());
		}

		private UuidFactory get() {

			if (factory != null) {
				return factory;
			}

			lock.lock();
			try {
				if (factory == null) {
					this.factory = supplier.get();
				}
				return this.factory;
			} finally {
				lock.unlock();
			}
		}

		@Override
		public UUID create() {
			return get().create();
		}

		@Override
		public UUID create(Parameters parameters) {
			return get().create(parameters);
		}
	}