package com.pattern.singleton;

public class Train {
	private static Train train;
 private	boolean isRun;
	
	private Train(){
		train = this;
	}
	
	public static synchronized Train getTrain(){
		if(train==null){
			System.out.println("构造火车");
			train = new Train();
		}
		else{
			System.out.println("火车已经构造好了,可以直接使用");
		}
		return train;
	}
	
	public void Run(){
		if(isRun){
			System.out.println("火车正在开动,不用再次启动");
		}
		else{
			isRun = true;
			System.out.println("启动火车");
		}
	}
	
	public void Stop(){
		if(isRun){
			isRun = false;
			System.out.println("执行制动,火车马上停止。");
		}
		else{
			System.out.println("火车没有开动,制动操作没有执行。");
		}
	}

}