相关疑难解决方法(0)

我正在阅读维基百科上的Singleton文章,我遇到了这个例子:

public class Singleton {
    // Private constructor prevents instantiation from other classes
    private Singleton() {}

    /**
     * SingletonHolder is loaded on the first execution of Singleton.getInstance() 
     * or the first access to SingletonHolder.INSTANCE, not before.
     */
    private static class SingletonHolder { 
        private static final Singleton INSTANCE = new Singleton();
    }

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

虽然我非常喜欢这个Singleton的行为方式,但我看不出如何调整它以将参数合并到构造函数中.在Java中执行此操作的首选方法是什么？我必须这样做吗？

public class Singleton
{
    private static Singleton singleton = null;  
    private final int x;

    private Singleton(int x) {
        this.x …