Calendar c = Calendar.getInstance();
Date date=null;
try {
date = new SimpleDateFormat("yy-MM-dd").parse("2019-04-05");
} catch (ParseException e) {
e.printStackTrace();
}
c.setTime(date);
int day=c.get(Calendar.DATE);
c.set(Calendar.DATE,day-1);
String dayBefore=new SimpleDateFormat("yyyy-MM-dd").format(c.getTime());
System.out.println(dayBefore);
根据指定的时间"2019-04-05" 获得前一天的时间为:“2019-04-04”