java获取当前日 当前月的开始时间和结束时间 当前季度的开始时间和结束时间

public static void main(String[] args) {SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");Calendar cal=Calendar.getInstance();cal.add(Calendar.DATE,-1);Date time=cal.getTime();String time1 = df.format(time);System.out.println("获取昨日日期------"+time1);Date date = new Date();Date da = new Date(date.getYear(),date.getMonth(),01);String startTime=String.valueOf(df.format(da));System.out.println("获取当前月第一天------"+startTime);cal.setTime(date);cal.set(Calendar.DAY_OF_MONTH, 1);cal.roll(Calendar.DAY_OF_MONTH, -1);String time3 = df.format(cal.getTime());System.out.println("获取本月最后一天-----"+time3);cal.setTime(date);cal.set(Calendar.MONTH, (((int) cal.get(Calendar.MONTH)) / 3) * 3);cal.set(Calendar.DAY_OF_MONTH, 1);String time4 = df.format(cal.getTime());System.out.println("获取本季度第一天----"+time4);cal.setTime(date);//计算季度数：由于月份从0开始，即1月份的Calendar.MONTH值为0,所以计算季度的第三个月份只需 月份 / 3 * 3 + 2cal.set(Calendar.MONTH, (((int) cal.get(Calendar.MONTH)) / 3) * 3 + 2);cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));String time5 = df.format(cal.getTime());System.out.println("获取本季度的最后一天----"+time5);cal.setTime(date);cal.set(Calendar.DAY_OF_YEAR, 1);String time6 = df.format(cal.getTime());System.out.println("获取本年的第一天----"+time6);cal.setTime(date);cal.set(Calendar.DAY_OF_YEAR, cal.getActualMaximum(Calendar.DAY_OF_YEAR));String time7 = df.format(cal.getTime());System.out.println("获取本年最后一天-----"+time7);}