java时间转换

@Test
public void test1(){
Date today=new java.util.Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat dateFormat1 = new SimpleDateFormat("yyyy/MM/dd");
SimpleDateFormat dateFormat2 = new SimpleDateFormat("yy-MM-dd");
SimpleDateFormat dateTimeFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println("Today is "+dateFormat.format(today));
System.out.println("Today is "+dateFormat1.format(today));
System.out.println("Today is "+dateFormat2.format(today));
System.out.println("Now is "+dateTimeFormat.format(today));
}

================================================

Today is 2017-09-22
Today is 2017/09/22
Today is 17-09-22
Now is 2017-09-22 16:26:19