时间计算工具类

public class TimeUtils {
   
   public static String toTimeString(long time) {
      TimeUtils t = new TimeUtils(time);
      int day = t.get(TimeUtils.DAY);
      int hour = t.get(TimeUtils.HOUR);
      int minute = t.get(TimeUtils.MINUTE);
      int second = t.get(TimeUtils.SECOND);
      StringBuilder sb = new StringBuilder();
      if (day > 0){
         sb.append(day).append("天");
      }
      if (hour > 0){
         sb.append(hour).append("时");
      }
      if (minute > 0){
         sb.append(minute).append("分");
      }
      if (second > 0){
         sb.append(second).append("秒");
      }
      return sb.toString();
   }
   
    /**
     * 时间字段常量，表示“秒”
     */
    public final static int SECOND = 0;

    /**
     * 时间字段常量，表示“分”
     */
    public final static int MINUTE = 1;

    /**
     * 时间字段常量，表示“时”
     */
    public final static int HOUR = 2;

    /**
     * 时间字段常量，表示“天”
     */
    public final static int DAY = 3;

    /**
     * 各常量允许的最大值
     */
    private final int[] maxFields = { 59, 59, 23, Integer.MAX_VALUE - 1 };

    /**
     * 各常量允许的最小值
     */
    private final int[] minFields = { 0, 0, 0, Integer.MIN_VALUE };

    /**
     * 默认的字符串格式时间分隔符
     */
    private String timeSeparator = ":";

    /**
     * 时间数据容器
     */
    private int[] fields = new int[4];

    /**
     * 无参构造，将各字段置为 0
     */
    public TimeUtils() {
        this(0, 0, 0, 0);
    }

    /**
     * 使用时、分构造一个时间
     * @param hour      小时
     * @param minute    分钟
     */
    public TimeUtils(int hour, int minute) {
        this(0, hour, minute, 0);
    }

    /**
     * 使用时、分、秒构造一个时间
     * @param hour      小时
     * @param minute    分钟
     * @param second    秒
     */
    public TimeUtils(int hour, int minute, int second) {
        this(0, hour, minute, second);
    }

    /**
     * 使用一个字符串构造时间<br/>
     * Time time = new Time("14:22:23");
     * @param time      字符串格式的时间，默认采用“:”作为分隔符
     */
    public TimeUtils(String time) {
        this(time, null);
//     System.out.println(time);
    }

    /**
     * 使用时间毫秒构建时间
     * @param time
     */
    public TimeUtils(long time){
       this(new Date(time));
    }
    
    /**
     * 使用日期对象构造时间
     * @param date
     */
    public TimeUtils(Date date){
       this(DateFormatUtils.formatUTC(date, "HH:mm:ss"));
    }

    /**
     * 使用天、时、分、秒构造时间，进行全字符的构造
     * @param day       天
     * @param hour      时
     * @param minute    分
     * @param second    秒
     */
    public TimeUtils(int day, int hour, int minute, int second) {
        initialize(day, hour, minute, second);
    }

    /**
     * 使用一个字符串构造时间，指定分隔符<br/>
     * Time time = new Time("14-22-23", "-");
     * @param time      字符串格式的时间
     */
    public TimeUtils(String time, String timeSeparator) {
        if(timeSeparator != null) {
            setTimeSeparator(timeSeparator);
        }
        parseTime(time);
    }

    /**
     * 设置时间字段的值
     * @param field     时间字段常量
     * @param value     时间字段的值
     */
    public void set(int field, int value) {
        if(value < minFields[field]) {
            throw new IllegalArgumentException(value + ", time value must be positive.");
        }
        fields[field] = value % (maxFields[field] + 1);
        // 进行进位计算
        int carry = value / (maxFields[field] + 1);
        if(carry > 0) {
            int upFieldValue = get(field + 1);
            set(field + 1, upFieldValue + carry);
        }
    }

    /**
     * 获得时间字段的值
     * @param field     时间字段常量
     * @return          该时间字段的值
     */
    public int get(int field) {
        if(field < 0 || field > fields.length - 1) {
            throw new IllegalArgumentException(field + ", field value is error.");
        }
        return fields[field];
    }

    /**
     * 将时间进行“加”运算，即加上一个时间
     * @param time      需要加的时间
     * @return          运算后的时间
     */
    public TimeUtils addTime(TimeUtils time) {
       TimeUtils result = new TimeUtils();
        int up = 0;     // 进位标志
        for (int i = 0; i < fields.length; i++) {
            int sum = fields[i] + time.fields[i] + up;
            up = sum / (maxFields[i] + 1);
            result.fields[i] = sum % (maxFields[i] + 1);
        }
        return result;
    }

    /**
     * 将时间进行“减”运算，即减去一个时间
     * @param time      需要减的时间
     * @return          运算后的时间
     */
    public TimeUtils subtractTime(TimeUtils time) {
       TimeUtils result = new TimeUtils();
        int down = 0;       // 退位标志
        for (int i = 0, k = fields.length - 1; i < k; i++) {
            int difference = fields[i] + down;
            if (difference >= time.fields[i]) {
                difference -= time.fields[i];
                down = 0;
            } else {
                difference += maxFields[i] + 1 - time.fields[i];
                down = -1;
            }
            result.fields[i] = difference;
        }
        result.fields[DAY] = fields[DAY] - time.fields[DAY] + down;
        return result;
    }

    /**
     * 获得时间字段的分隔符
     * @return
     */
    public String getTimeSeparator() {
        return timeSeparator;
    }

    /**
     * 设置时间字段的分隔符（用于字符串格式的时间）
     * @param timeSeparator     分隔符字符串
     */
    public void setTimeSeparator(String timeSeparator) {
        this.timeSeparator = timeSeparator;
    }

    private void initialize(int day, int hour, int minute, int second) {        set(
DAY, day);        set(
HOUR, hour);        set(
MINUTE, minute);        set(
SECOND, second);    }    


private void parseTime(String time) {        
if(time == null) {            initialize(
0, 0, 0, 0);            
return;        }        

String t = time;        
int field = DAY;        set(field--, 
0);        
int p = -1;        
while((p = t.indexOf(timeSeparator)) > -1) {            parseTimeField(time, t.substring(
0, p), field--);            t = t.substring(p + 
timeSeparator.length());        }        parseTimeField(time, t, field--);    }    




private void parseTimeField(String time, String t, int field) {        
if(field < SECOND || t.length() < 1) {            parseTimeException(time);        }        


char[] chs = t.toCharArray();        
int n = 0;        
for(int i = 0; i < chs.length; i++) {            
if(chs[i] <= ' ') {                
continue;            }            

if(chs[i] >= '0' && chs[i] <= '9') {                n = n * 
10 + chs[i] - '0';                
continue;            }            parseTimeException(time);        }        set(field, n);    }    






private void parseTimeException(String time) {        
throw new IllegalArgumentException(time + ", time format error, HH"
                + this.timeSeparator + "mm" + this.timeSeparator + "ss");    }    


public String toString() {        
StringBuilder sb = new StringBuilder(16);        
sb.append(fields[DAY]).append(',').append(' ');        buildString(
sb, HOUR).append(timeSeparator);        buildString(
sb, MINUTE).append(timeSeparator);        buildString(
sb, SECOND);        
return sb.toString();    }    


private StringBuilder buildString(StringBuilder sb, int field) {        
if(fields[field] < 10) {            sb.append(
'0');        }        

return sb.append(fields[field]);    }    


public int hashCode() {        
final int PRIME = 31;        
int result = 1;        result = 
PRIME * result + Arrays.hashCode(fields);        
return result;    }    


public boolean equals(Object obj) {        
if (this == obj)            
return true;        
if (obj == null)            
return false;        
if (getClass() != obj.getClass())            
return false;        
final TimeUtils other = (TimeUtils) obj;        
if (!Arrays.equals(fields, other.fields)) {            
return false;        }        

return true;    }    }