TimeUtil

TimeUtil

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;

import java8.util.function.Function;

/**
 * @author puke
 * @version 2018/5/15
 */
public class TimeUtil {

    private static final String justNowFormatter = "刚刚";

    private static final String minutesAgoFormatter = "%d分钟前";

    private static final String hoursAgoFormatter = "%d小时前";

    private static final SimpleDateFormat dayBeforeYesterDayFormatter = new SimpleDateFormat(
            "前天HH:mm", Locale.getDefault());

    private static final SimpleDateFormat yesterDayFormatter = new SimpleDateFormat(
            "昨天HH:mm", Locale.getDefault());

    private static final SimpleDateFormat thisYearFormatter = new SimpleDateFormat(
            "MM-dd", Locale.getDefault());

    private static final SimpleDateFormat otherYearFormatter = new SimpleDateFormat(
            "yyyy-MM-dd", Locale.getDefault());

    /**
     * 日期统一格式化<br/>
     */
    public static String formatDate(Date date) {
        if (date == null) {
            return "";

        }

        final Calendar now = Calendar.getInstance();
        final Calendar target = Calendar.getInstance();
        target.setTime(date);

        Function<Integer, Integer> getOffset = field -> now.get(field) - target.get(field);

        if (getOffset.apply(Calendar.YEAR) != 0) {
            // 不同年
            return otherYearFormatter.format(date);
        }

        switch (getOffset.apply(Calendar.DAY_OF_YEAR)) {
            case 0:
                // 今天
                int hourOffset = getOffset.apply(Calendar.HOUR_OF_DAY);
                if (hourOffset == 0) {
                    int minuteOffset = getOffset.apply(Calendar.MINUTE);
                    if (minuteOffset == 0) {
                        // 刚刚
                        return justNowFormatter;
                    }
                    // 几分钟前
                    return String.format(Locale.getDefault(), minutesAgoFormatter, minuteOffset);
                }
                // 几小时前
                return String.format(Locale.getDefault(), hoursAgoFormatter, hourOffset);
            case 1:
                // 昨天
                return yesterDayFormatter.format(date);
            case 2:
                // 前天
                return dayBeforeYesterDayFormatter.format(date);
            default:
                // 其他
                return thisYearFormatter.format(date);
        }
    }

}