java单例模式 （同步方法 解决多线程问题）

[java]代码库

public class SingletonDoubleLocking
{

	private volatile static SingletonDoubleLocking uniqueInstance;

	private SingletonDoubleLocking() {}

	public static SingletonDoubleLocking getInstance()
	{
		if ( uniqueInstance == null )
		{
			synchronized ( SingletonDoubleLocking.class )
			{
				if ( uniqueInstance == null )
				{
					uniqueInstance = new SingletonDoubleLocking();
				}
			}
		}
		return uniqueInstance;
	}
}