ede3954d创建于 2021年3月5日历史提交
// patterns/SingletonPattern2.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.

public class SingletonPattern2 {
  public static void main(String[] args) {
    Single<Double> pi =
      new Single<>(Double.valueOf(3.14159));
    Double x = pi.get();
    System.out.println(x);
  }
}
/* Output:
3.14159
*/