Java取昨天、今天和明天的日期并格式化

java.text.SimpleDateFormat df = new java.text.SimpleDateFormat("yyyy-MM-dd");
java.util.Calendar calendar = java.util.Calendar.getInstance();

calendar.roll(java.util.Calendar.DAY_OF_YEAR, -1);
System.out.println("昨天： " + df.format(calendar.getTime()));

calendar = java.util.Calendar.getInstance();
System.out.println("今天： " + df.format(calendar.getTime()));

calendar.roll(java.util.Calendar.DAY_OF_YEAR, 1);
System.out.println("明天： " + df.format(calendar.getTime()));