以毫秒获取当前时间system.currentTimeMillis()

以毫秒获取当前时间system.currentTimeMillis()

public class Demo8_1 {
	public static void main(String[] args) {
		//System.currentTimeMillis();
		StopWatch watch=new StopWatch();//此时建立对象调用构造函数已经记录了时间
		//System.out.println(watch.getElapsedTime());//-1544963947421,endTime默认为0
		watch.stop();
		watch.start();
		for(int i=0;i<100000000;i++);//计算此段代码运行的时间
		watch.stop();
		System.out.println(watch.getElapsedTime());
	}
}
class StopWatch{
	private long startTime;
	private long endTime;
	//private long time=100000;
	StopWatch(){
		//startTime=System.currentTimeMillis();
		start();
	}
	public void start(){
		startTime=System.currentTimeMillis();
	}
	public void stop(){
		endTime=System.currentTimeMillis();
		//startTime=time;
	}
	public long getElapsedTime(){
		return endTime-startTime;
	}
	public long getStartTime() {
		return startTime;
	}
	public long getEndTime() {
		return endTime;
	}
}

public class Demo8_4 {
	public static void main(String[] args) {
		Time time1=new Time();
		System.out.println(time1.getHour());
		System.out.println(time1.getMinute());
		System.out.println(time1.getSecond());
		Time time2=new Time(1000000);
		System.out.println(time2.getHour());
		System.out.println(time2.getMinute());
		System.out.println(time2.getSecond());
		time2.setTime(System.currentTimeMillis());//10000+从1970年1月1日
		System.out.println(time2.getHour());
		System.out.println(time2.getMinute());
		System.out.println(time2.getSecond());
		Time time3=new Time(10,10,10);
		time3.setTime(1000);//在10小时10分钟10 秒的基础上加上1000毫秒
		System.out.println(time3.getHour());
		System.out.println(time3.getMinute());
		System.out.println(time3.getSecond());//结果应为10小时10分钟11秒	
	}
}
class Time{
	private long hour;
	private long minute;
	private long second;
	private long totalMillis;
	Time(){//以当前时间计算小时，分钟，秒
		totalMillis=System.currentTimeMillis();
		format(totalMillis);	
	}
	public Time(long millis){//从传入的毫秒值进行计算
		//format(millis);X
		totalMillis=millis;
		format(totalMillis);
	}
	public Time(long hour,long minute,long second){
		//以传入的小时，分钟，秒进行计算
		this.hour=hour;
		this.minute=minute;
		this.second=second;
		totalMillis=second*1000+minute*60*1000+hour*60*60*1000;
	}
	public void setTime(long elapseTime){
		//当前时间加上传入的时间，表示总共时间，用总共时间进行计算
		totalMillis=totalMillis+elapseTime;
		format(totalMillis);
	}
	//将毫秒值转化为小时，分钟，秒
	public void format(long totalMillis){
		hour=totalMillis/1000/60/60;
		minute=totalMillis/1000/60-hour*60;
		second=totalMillis/1000-hour*60*60-minute*60;	
	}
	public long getHour(){
		return hour;
	}
	public long getMinute(){
		return minute;
	}
	public long getSecond(){
		return second;
	}
}