单例模式实现（Java)

package ByteDance;

class SingleObject {
	//创建SingleObjec的一个对象
	private static SingleObject instance = new SingleObject();
	
	//让构造函数为private，这样该类就不会被实例化
	private SingleObject(){}
	
	//获取唯一可用的对象
	public static SingleObject getInstance(){
		return instance;
	}
	
	public void showMessage(){
		System.out.println("Hello World!");
	}
}

public class SinglePatternDemo {
	
	public static void main(String[] args) {
		SingleObject object = SingleObject.getInstance();
		object.showMessage();

	}

}