Week3 - 练习

public class OneInstance {
    private OneInstance() throws InterruptedException {
        init();
    }
    private static volatile OneInstance instance;
    private void init() throws InterruptedException {
        if (ab.compareAndSet(false, true)) {
            System.out.println("New Instance");
        }
    }
    public static OneInstance getInstance() throws InterruptedException {
        if (instance == null) {
            synchronized (OneInstance.class) {
                if (instance == null) {
                    instance = new OneInstance();
                }
            }
        } else {
            System.out.println("already not null out.");
        }
        return instance;
    }
}

public class OneInstance2 {
    private OneInstance2() {
        init();
    }
    private void init() {
        System.out.println("GetInstance");
    }
    private static class SingleTonHoler {
        private static OneInstance2 instance;
        static {
            instance = new OneInstance2();
        }
    }
    public static OneInstance2 getInstance() throws InterruptedException {
        System.out.println("get+" + counter);
        OneInstance2 in2 = SingleTonHoler.instance;
        if (in2 == null) {
            System.out.println("No Initial!");
        } else {
            System.out.println("Inited!");
        }
        return in2;
    }
}

import java.util.*;
class test {
	public static void main(String[] args) {
		System.out.println("hello");
		AnyComponent lable = new CommonComp("label", null);
		List<AnyComponent> winSub = new ArrayList<AnyComponent>();
		winSub.add(lable);
		AnyComponent window = new CommonComp("window", winSub);
		window.print();
	}
	public static abstract class AnyComponent {
		private List<AnyComponent> subComs = new ArrayList<AnyComponent>();
		private String name;
		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
		public List<AnyComponent> getSubComs() {
			return subComs;
		}
		public void setSubComs(List<AnyComponent> subComs) {
			this.subComs = subComs;
		}
		private AnyComponent() {
		}
		AnyComponent(String name, List<AnyComponent> subComs) {
			setName(name);
			setSubComs(subComs);
		}
		public void print() {
			System.out.println(getName());
			if (!(subComs == null || subComs.isEmpty())) {
				for (AnyComponent c : subComs) {
					c.print();
				}
			}
		}
	}
	public static class CommonComp extends AnyComponent {
		public CommonComp(){
			super();
		}
		public CommonComp(String name, List<AnyComponent> subComs) {
			super(name, subComs);
		}
	}
}