Java静态内部类实现单例过程

public enum SingletonFactory {
   
  //枚举元素本身就是单例
  INSTANCE;
   
  //添加自己需要的操作
  public SingletonObject getInstance(){
   return new SingletonObject();
  }
}

public class SingletonFactory {
 public static SingletonObj getInstance() {
  return SingletonObj.instance.context;
 }

 private static class instance {
  private static final SingletonObj context = new SingletonObj();
 }
}