Java 并发【参考】A01.volatile

这里借用hutool的部分源码

public class ConverterRegistry implements Serializable {
	private static final long serialVersionUID = 1L;

	
	private volatile Map> customConverterMap;

	
	private static class SingletonHolder {
		
		private static final ConverterRegistry INSTANCE = new ConverterRegistry();
	}

	
	public static ConverterRegistry getInstance() {
		return SingletonHolder.INSTANCE;
	}

}

public abstract class LazyLoader implements Loader, Serializable {
	private static final long serialVersionUID = 1L;

	
	private volatile T object;

	
	@Override
	public T get() {
		T result = object;
		if (result == null) {
			synchronized (this) {
				result = object;
				if (result == null) {
					object = result = init();
				}
			}
		}
		return result;
	}

	
	protected abstract T init();
}