JAVA 获取当前时间前一天，前一月，前一年

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

Calendar calendar = Calendar.getInstance();
calendar.setTime(new Date());
calendar.add(calendar.DATE,-1);
Date date = calendar.getTime();
String day = format.format(date);
System.out.println("昨天时间为：" + day);

calendar.setTime(new Date());
calendar.add(Calendar.MONTH,-1);
Date date = calendar.getTime();
String month = format.format(date);
System.out.println("上个月的时间为：" + month);

calendar.setTime(new Date());
calendar.add(Calendar.YEAR,-1);
Date date = calendar.getTime();
String year= format.format(date);
System.out.println("上一年的时间为：" + year);