java代码获取当前月第一天和最后一天的毫秒值

		Calendar calendar = Calendar.getInstance();//获取当前日期
        calendar.add(Calendar.MONTH, 0);//n代表和本月偏移 0本月、1后一月，-1前一月
        calendar.set(Calendar.DAY_OF_MONTH, 1);//设置为1号,当前日期既为本月第一天
        calendar.set(Calendar.HOUR_OF_DAY,0);//将小时至0
        calendar.set(Calendar.MINUTE,0);//将分钟至0
        calendar.set(Calendar.SECOND,0);//将秒至0
        long start = calendar.getTime().getTime();

        calendar.add(Calendar.MONTH, 1);
        calendar.set(Calendar.SECOND,-1);
        long end = calendar.getTime().getTime();