关于singleton在java多线程环境下的实现
public sealed class Singleton
{
private static volatile Singleton instance;
private static object syncRoot = new Object();

private Singleton() {}

public static Singleton Instance
{
get
{
if (instance == null)
{
lock (syncRoot)
{
if (instance == null)
instance = new Singleton();
}
}

return instance;
}
}
}