时间显示工具方法 今天？昨天？星期？年月日？

简单的一个方法，转换显示一下时间。

利用下文formatDateTime方法，即可将一个时间转换为

• 今天
• 昨天
• 星期x (昨天到一周以内)
• yyyy-MM-dd HH:mm:ss
  输出。

关于星期几的部分，目前代码已经转为中国时间星期计算方式，即周一为一周的第一天

    /**
     * 根据传入时间格式为 yyyy-MM-dd HH:mm:ss 的字符串时间，得出是 今天，昨天，星期几，那个具体时间
     *
     * @param time
     *
     * @return
     */
    private static String formatDateTime(String time) {
        SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        if(time==null ||"".equals(time)){
            return "";
        }
        Date operateDate = null;
        try {
            operateDate = format.parse(time);
        } catch (ParseException e) {
            e.printStackTrace();
        }

        Calendar current = Calendar.getInstance();
        
        Calendar today = Calendar.getInstance();    //今天
        today.set(Calendar.YEAR, current.get(Calendar.YEAR));
        today.set(Calendar.MONTH, current.get(Calendar.MONTH));
        today.set(Calendar.DAY_OF_MONTH,current.get(Calendar.DAY_OF_MONTH));
        //  Calendar.HOUR——12小时制的小时数 Calendar.HOUR_OF_DAY——24小时制的小时数
        today.set( Calendar.HOUR_OF_DAY, 0);
        today.set( Calendar.MINUTE, 0);
        today.set(Calendar.SECOND, 0);

        Calendar yesterday = Calendar.getInstance();    //昨天
        yesterday.set(Calendar.YEAR, current.get(Calendar.YEAR));
        yesterday.set(Calendar.MONTH, current.get(Calendar.MONTH));
        yesterday.set(Calendar.DAY_OF_MONTH,current.get(Calendar.DAY_OF_MONTH)-1);
        yesterday.set( Calendar.HOUR_OF_DAY, 0);
        yesterday.set( Calendar.MINUTE, 0);
        yesterday.set(Calendar.SECOND, 0);

        Calendar oneWeek = Calendar.getInstance();    //一个礼拜以内
        oneWeek.set(Calendar.YEAR, current.get(Calendar.YEAR));
        oneWeek.set(Calendar.MONTH, current.get(Calendar.MONTH));
        oneWeek.set(Calendar.DAY_OF_MONTH,current.get(Calendar.DAY_OF_MONTH)-7);
        oneWeek.set( Calendar.HOUR_OF_DAY, 0);
        oneWeek.set( Calendar.MINUTE, 0);
        oneWeek.set(Calendar.SECOND, 0);

        current.setTime(operateDate);
        if(current.after(today)){
            //return youApplicationContext.getResources().getString(R.string.today);
            return "今天";
        }else if(current.before(today) && current.after(yesterday)){
            return "昨天";
        }else if(current.before(yesterday) && current.after(oneWeek)){
            //一周第一天是否为星期天
            boolean isFirstSunday = (current.getFirstDayOfWeek() == Calendar.SUNDAY);
            //获取周几
            int weekDay = current.get(Calendar.DAY_OF_WEEK);
            //若一周第一天为星期天，则-1，即中国时间
            if(isFirstSunday){
                weekDay = weekDay - 1;
                if(weekDay == 0){
                    weekDay = 7;
                }
            }
            switch (weekDay){
                case 1:
                    return  "星期一";
                case 2:
                    return  "星期二";
                case 3:
                    return  "星期三";
                case 4:
                    return  "星期四";
                case 5:
                    return  "星期五";
                case 6:
                    return  "星期六";
                case 7:
                    return  "星期天";
            }
        }
        else{
            SimpleDateFormat sdformat = new SimpleDateFormat("yyyy-MM-dd");//24小时制
            String LgTime = sdformat.format(operateDate);
            return LgTime;
        }
        return  "error";
    }

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测试代码

        String tset1 = formatDateTime("2017-04-26 08:08:08");
        Log.d("TEST_DATE", "取 tset1 2017-04-26 08:08:08 数据: " +tset1);

        String tset2 = formatDateTime("2017-04-25 08:08:08");
        Log.d("TEST_DATE", "取 tset2 2017-04-25 08:08:08 数据: " +tset2);

        String tset3 = formatDateTime("2017-04-24 08:08:08");
        Log.d("TEST_DATE", "取 tset3 2017-04-24 08:08:08 数据: " +tset3);

        String tset4 = formatDateTime("2017-04-23 08:08:08");
        Log.d("TEST_DATE", "取 tset4 2017-04-23 08:08:08 数据: " +tset4);

        String tset5 = formatDateTime("2017-04-22 08:08:08");
        Log.d("TEST_DATE", "取 tset5 2017-04-22 08:08:08 数据: " +tset5);

        String tset6 = formatDateTime("2017-04-21 08:08:08");
        Log.d("TEST_DATE", "取 tset6 2017-04-21 08:08:08 数据: " +tset6);

        String tset7 = formatDateTime("2017-04-20 08:08:08");
        Log.d("TEST_DATE", "取 tset7 2017-04-20 08:08:08 数据: " +tset7);


        String tset8 = formatDateTime("2017-04-19 08:08:08");
        Log.d("TEST_DATE", "取 tset8 2017-04-19 08:08:08 数据: " +tset8);

        String tset9 = formatDateTime("2017-04-18 08:08:08");
        Log.d("TEST_DATE", "取 tset9 2017-04-18 08:08:08数据: " +tset9);

        String tset10 = formatDateTime("2017-04-17 08:08:08");
        Log.d("TEST_DATE", "取 tset10 2017-04-17 08:08:08数据: " +tset10);

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输出

D/TEST_DATE: 取 tset1 2017-04-26 08:08:08 数据: 今天
D/TEST_DATE: 取 tset2 2017-04-25 08:08:08 数据: 昨天
D/TEST_DATE: 取 tset3 2017-04-24 08:08:08 数据: 星期一
D/TEST_DATE: 取 tset4 2017-04-23 08:08:08 数据: 星期天
D/TEST_DATE: 取 tset5 2017-04-22 08:08:08 数据: 星期六
D/TEST_DATE: 取 tset6 2017-04-21 08:08:08 数据: 星期五
D/TEST_DATE: 取 tset7 2017-04-20 08:08:08 数据: 星期四
D/TEST_DATE: 取 tset8 2017-04-19 08:08:08 数据: 星期三
D/TEST_DATE: 取 tset9 2017-04-18 08:08:08数据: 2017-04-18
D/TEST_DATE: 取 tset10 2017-04-17 08:08:08数据: 2017-04-17

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大概如此，自由发挥

撰文时间为2017-04-26。

如上。