Java获取任意时间、时间字符串

/*
* 获取时间字符串
*/
public String getCurrentTime() {
        
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
        Date date = new Date();
        return sdf.format(date);
    }
    
    public String getFutureTime(int changeDay) {
        
        Calendar date = Calendar.getInstance();
        String year = String.valueOf(date.get(Calendar.YEAR));
        String month = String.valueOf(date.get(Calendar.MONTH) + 1);
        String day = String.valueOf(date.get(Calendar.DAY_OF_MONTH) + changeDay);
        String hour = String.valueOf(date.get(Calendar.HOUR));
        String minute = String.valueOf(date.get(Calendar.MINUTE));
        String second = String.valueOf(date.get(Calendar.SECOND));
        while (Integer.valueOf(day) > date.getActualMaximum(Calendar.DAY_OF_MONTH)) {
            day = String.valueOf(Integer.valueOf(day) - date.getActualMaximum(Calendar.DAY_OF_MONTH));
            month = String.valueOf(Integer.valueOf(month) + 1);
            if (Integer.valueOf(month) > 12) {
                month = String.valueOf(Integer.valueOf(month) - 12);
                year = String.valueOf(Integer.valueOf(year) + 1);
            }
        }
        if (month.length() < 2) {
            month = "0" + month;
        }
        if (day.length() < 2) {
            day = "0" + day;
        }
        if (hour.length() < 2) {
            hour = "0" + hour;
        }
        if (minute.length() < 2) {
            minute = "0" + minute;
        }
        if (second.length() < 2) {
            second = "0" + second;
        }
        String currentTime = year + "-" + month + "-" + day + " " + hour + ":" + minute + ":" + second;
        return currentTime;
    }

/*
     * 获取自定义时间
     */
    public Date getTime(int year,int month,int day,int hour,int minute,int second) {
        
        Calendar calendar =  Calendar.getInstance();
        calendar.set(Calendar.YEAR, year);
        calendar.set(Calendar.MONTH, month-1);
        calendar.set(Calendar.DAY_OF_MONTH, day);
        
        calendar.set(Calendar.HOUR_OF_DAY, hour);
        calendar.set(Calendar.MINUTE, minute);
        calendar.set(Calendar.SECOND, second);
        
        Date date = calendar.getTime();
        return date;
    }

/* * 获取自定义时间 */public Date getTime(int year,int month,int day,int hour,int minute,int second) {Calendar calendar = Calendar.getInstance();calendar.set(Calendar.YEAR, year);calendar.set(Calendar.MONTH, month-1);calendar.set(Calendar.DAY_OF_MONTH, day);calendar.set(Calendar.HOUR_OF_DAY, hour);calendar.set(Calendar.MINUTE, minute);calendar.set(Calendar.SECOND, second);Date date = calendar.getTime();return date;}