如何在java中访问并命名单例？

public class Singleton {
    // 私有化构造方法，防止外部直接创建对象
    private Singleton() {
    }
    
    // 静态变量保存唯一实例对象
    private static Singleton instance;
    
    // 提供静态方法获取唯一实例对象
    public static Singleton getInstance() {
        if (instance == null) {
            instance = new Singleton();
        }
        return instance;
    }
}

Singleton singleton = Singleton.getInstance();

public class MySingleton {
    // 单例实例对象
    private static MySingleton instance;
    
    // 私有化构造方法
    private MySingleton() {
    }
    
    // 获取单例实例对象
    public static MySingleton getInstance() {
        if (instance == null) {
            instance = new MySingleton();
        }
        return instance;
    }
}