SimpleDateFormat df =new SimpleDateFormat("yyyyMMdd");

//獲取上個月第一天時間 ，當(dāng)前月減去1獲取上月月份，獲取第一天日期

Calendar calendar = Calendar.getInstance();

calendar.add(Calendar.MONTH, -1);

calendar.set(Calendar.DAY_OF_MONTH, 1);

String berforeFirstDay = df.format(calendar.getTime());

//獲取當(dāng)前月第一天日期，減去一天，獲取上個月最后一天時間?

Calendar calendar1 = Calendar.getInstance();

calendar1.set(Calendar.DAY_OF_MONTH, 1);

calendar1.add(Calendar.DATE, -1);

String berforeLastDay = df.format(calendar1.getTime());

//獲取當(dāng)前月第一天時間?

Calendar calendar2 = Calendar.getInstance();

calendar2.set(Calendar.DAY_OF_MONTH, 1);

String firstDay = df.format(calendar2.getTime());

//先獲取下個月第一天日期，減去一天，獲取當(dāng)前月最后一天時間

Calendar calendar3 = Calendar.getInstance();

calendar3.add(Calendar.MONTH, 1);

calendar3.set(Calendar.DAY_OF_MONTH, 1);

calendar3.add(Calendar.DATE, -1);

String lastDay = df.format(calendar3.getTime());