Java常用工具类(字符编码,时间等)

/**
     * 将UTF编码的字符串转化为GB2312编码的字符串，主要用来处理中文显示乱码的问题
     *
     * @param UTF
     *            通过UTF编码的字符串
     * @return 通过GB2312编码的字符串
     */
    public static String GB2312FromUTF(String UTF) {
        if (UTF == null) {
            return "";
        } else {
            try {
                return new String(UTF.getBytes("UTF-8"), "GB2312");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    /**
     * 将GB2312编码的字符串转化为UTF-8编码的字符串，主要用来处理中文显示乱码的问题
     *
     * @param GB2312
     *            通过GB2312编码的字符串
     * @return 通过UTF-8编码的字符串
     */
    public static String UTFFromGB2312(String GB2312) {
        if (GB2312 == null) {
            return "";
        } else {
            try {
                return new String(GB2312.getBytes("GB2312"), "UTF-8");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    public static String GBKFromISO8859_1(String ISO8859_1) {
        if (ISO8859_1 == null) {
            return "";
        } else {
            try {
                return new String(ISO8859_1.getBytes("ISO8859_1"), "GBK");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    public static String GBKFromUTF(String UTF) {
        if (UTF == null) {
            return "";
        } else {
            try {
                return new String(UTF.getBytes("UTF-8"), "GBK");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    /**
     * 将ISO8859_1编码的字符串转化为UTF-8编码的字符串，主要用来处理中文显示乱码的问题
     *
     * @param ISO8859_1str
     *            通过ISO8859_1编码的字符串
     * @return 通过UTF-8编码的字符串
     */
    public static String UTFFromISO8859_1(String ISO8859_1str) {
        return ISO8859_1str;
    }

    public static String UTFFromGBK(String GBK) {
        if (GBK == null) {
            return "";
        } else {
            try {
                return new String(GBK.getBytes("GBK"), "UTF-8");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    /**
     * 将UTF-8编码的字符串转化为ISO8859_1编码的字符串，主要用来处理中文显示乱码的问题
     *
     * @param UTF
     *            通过UTF编码的字符串
     * @return 通过ISO8859_1编码的字符串
     */
    public static String ISO8859_1FromUTF(String UTFstr) {
        if (UTFstr == null) {
            return "";
        } else {
            try {
                return new String(UTFstr.getBytes("UTF-8"), "ISO8859_1");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    /**
     * 将GB2312编码的字符串转化为ISO8859_1编码的字符串
     *
     * @param GBstr
     *            GB2312编码的字符串
     * @return ISO8859_1编码的字符串
     */
    public static String ISO8859_1String(String GBstr) {
        if (GBstr == null) {
            return "";
        } else {
            try {
                return new String(GBstr.getBytes("GB2312"), "ISO8859_1");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    /**
     * 将GB2312编码的字符串转化为ISO8859_1编码的字符串
     *
     * @param GBstr
     *            GB2312编码的字符串
     * @return ISO8859_1编码的字符串
     */
    public String ISO8859_1FromGB2312(String GBstr) {
        if (GBstr == null) {
            return "";
        } else {
            try {
                return new String(GBstr.getBytes("GB2312"), "ISO8859_1");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    public static String ISO8859_1FromGBK(String GBK) {
        if (GBK == null) {
            return "";
        } else {
            try {
                return new String(GBK.getBytes("GBK"), "ISO8859_1");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    /**
     * 去除字符串两端空格。
     *
     * @param str
     *            需要处理的字符串
     * @return 去掉了两端空格的字符串，如果str 为 null 则返回 ""
     */
    public static String trim(String str) {
        if (str != null) {
            return str.trim();
        } else {
            return "";
        }
    }

    // static public String mm_dd_yyyy = "MM-dd-yyyy HH:mm:ss";
    /**
     * 获得当前年份
     *
     * @return 当前年份，格式如：2003
     */
    public static int getCurrentYear() {
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy");
        return Integer.parseInt(sdf.format(new java.util.Date()));
    }

    /**
     * 获得当前月份
     *
     * @return 当前月份
     */
    public static int getCurrentMonth() {
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("M");
        return Integer.parseInt(sdf.format(new java.util.Date()));
    }

    /**
     * 获得当前天
     *
     * @return 当前天
     */
    public static int getCurrentDay() {
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.DATE);
    }

    public static String getCurrentDateTime() {
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyy-MM-dd H:mm");
        return sdf.format(new Date());
    }

    /**
     * 获得形如 19770608 格式的当前年月日
     *
     * @return 当前年月日
     */
    public static String getSimpleCurrentDate() {
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyyMMdd HH:mm:ss");
        return sdf.format(new java.util.Date());
    }

    /**
     * 返回两个日期相差天数
     *
     * @param d1
     *            日期
     * @param d2
     *            日期
     * @return 天数
     */
    public int diffDate(Date d1, Date d2) {
        if ((d1 == null) || (d2 == null))
            return 0;

        Calendar cal = Calendar.getInstance();

        // from Locale, has nothing to do with your input date format
        int zoneoffset = cal.get(Calendar.ZONE_OFFSET);
        int dstoffset = cal.get(Calendar.DST_OFFSET);

        // getTime() return absolute GMT time
        // compensate with the offsets
        long dl1 = d1.getTime() + zoneoffset + dstoffset;
        long dl2 = d2.getTime() + zoneoffset + dstoffset;

        int intDaysFirst = (int) (dl1 / (60 * 60 * 1000 * 24)); //60*60*1000
        int intDaysSecond = (int) (dl2 / (60 * 60 * 1000 * 24));

        return intDaysFirst > intDaysSecond ? intDaysFirst - intDaysSecond
                : intDaysSecond - intDaysFirst;
    }

    /**
     * 将给定的时间转换为格式是8位的字符串
     *
     * @param date
     *            给定的时间
     * @return 格式化后的字符串形式的时间
     */
    public String get8BitDate(java.util.Date date) {
        if (date == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyyMMdd");
        return sdf.format(date);
    }

    public String to_date(String strdate, String df) {
        if (strdate == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyy-MM-dd HH:mm:ss");
        java.text.SimpleDateFormat sdf1 = new java.text.SimpleDateFormat(
                "M/d/yyyy H:m:s");
        Date d = null;
        try {
            d = sdf1.parse(strdate);
        } catch (ParseException ex) {
            ex.printStackTrace();
        }
        return sdf.format(d);
    }

    public static String get8BitString(String strDate) {
        if (strDate == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        java.text.SimpleDateFormat sdf2 = new java.text.SimpleDateFormat(
                "yyyyMMdd");
        Date d = null;
        try {
            d = sdf.parse(strDate);
        } catch (ParseException ex) {
            ex.printStackTrace();
        }
        return sdf2.format(d);
    }

    public static String get8ByteTo10Byte(String strDate) {
        if (strDate == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyyMMdd");
        java.text.SimpleDateFormat sdf2 = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        Date d = null;
        try {
            d = sdf.parse(strDate);
        } catch (ParseException ex) {
            ex.printStackTrace();
        }
        return sdf2.format(d);
    }

    public static String getStandedDateTime(String strDate) {
        if (strDate == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        java.text.SimpleDateFormat sdf2 = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        Date d = null;
        try {
            d = sdf.parse(strDate);
        } catch (ParseException ex) {
            ex.printStackTrace();
        }
        return sdf2.format(d);
    }

    public static String getMonthDay(java.util.Date date) {
        if (date == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("M月d日");
        return sdf.format(date);
    }

    public static String getHourMinute(java.util.Date date) {
        if (date == null) {
            return "";
        }
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("H:mm");
        return sdf.format(date);
    }

    /**
     * 判断字符串是否符合日期格式
     *
     * @param str
     *            字符串时间
     * @return
     */
    public static boolean isDate(String strDate) {
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        sdf.setLenient(false);
        try {
            sdf.parse(strDate);
            return true;
        } catch (ParseException ex) {
            return false;
        }
    }

    /**
     * 判断是否是数字
     *
     * @param str
     * @return
     */
    public static boolean isNumber(String strNumber) {
        boolean bolResult = false;
        try {
            Double.parseDouble(strNumber);
            bolResult = true;
        } catch (NumberFormatException ex) {
            bolResult = false;
        }
        return bolResult;
    }

    public String dateadd(Date strDate, int a) {
        String str = "";

        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        String strDate1 = sdf.format(strDate);

        int year = Integer.parseInt(strDate1.substring(0, 4));
        int month = Integer.parseInt(strDate1.substring(5, 7));
        int day = Integer.parseInt(strDate1.substring(8, 10));
        int md = getdayformonth(month);
        int i = (day + a) / md;
        int j = (day + a) % md;
        if (j == 0) {
            i = i - 1;
            j = md;
        }
        String strmon = "";
        String strday = "";
        String mondiff = "";
        if (i < 2) {
            if (Integer.toString(j).length() == 1) {
                strday = "0" + Integer.toString(j);
            } else {
                strday = Integer.toString(j);
            }
            if ((month + i) > 12) {
                int yeardiff = (month + i) / 12;
                int monthmod = (month + i) % 12;
                mondiff = Integer.toString(monthmod);
                if (Integer.toString(monthmod).length() == 1) {
                    mondiff = "0" + Integer.toString(monthmod);
                }
                str = Integer.toString(year + yeardiff) + "-" + mondiff + "-"
                        + strday;
            } else {
                strmon = Integer.toString(month + i);
                if (Integer.toString(month + i).length() == 1) {
                    strmon = "0" + Integer.toString(month + i);
                }

                str = Integer.toString(year) + "-" + strmon + "-" + strday;

            }
        } else {
            //主要判断假如天数，月份溢出的处理，
        }
        return str;
    }

    public int getdayformonth(int month) {
        int a = 0;
        switch (month) {
        case 1:
            a = 31;
            break;
        case 2:
            a = 28;
            break;
        case 3:
            a = 31;
            break;
        case 4:
            a = 30;
            break;
        case 5:
            a = 31;
            break;
        case 6:
            a = 30;
            break;
        case 7:
            a = 31;
            break;
        case 8:
            a = 31;
            break;
        case 9:
            a = 30;
            break;
        case 10:
            a = 31;
            break;
        case 11:
            a = 30;
            break;
        case 12:
            a = 31;
            break;
        default:

        }
        return a;
    }

    public String addOneDay(String strDate) //YYYY-MM-DD
    {
        int[] standardDays = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        int[] leapyearDays = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        int y = Integer.parseInt(strDate.substring(0, 4));
        int m = Integer.parseInt(strDate.substring(4, 6));
        int d = Integer.parseInt(strDate.substring(6, ) + 1;
        int maxDateCount = 0;

        System.out.println(y);
        System.out.println(m);
        System.out.println(d);

        if ((y % 4 == 0 && y % 100 != 0) || y % 400 == 0) {
            maxDateCount = leapyearDays[m - 1];
        } else {
            maxDateCount = standardDays[m - 1];
        }

        if (d > maxDateCount) {
            d = 1;
            m++;
        }

        if (m > 12) {
            m = 1;
            y++;
        }
        java.text.DecimalFormat yf = new java.text.DecimalFormat("0000");
        java.text.DecimalFormat mdf = new java.text.DecimalFormat("00");
        return yf.format(y) + mdf.format(m) + mdf.format(d);
    }

    public static String subOneDay(String strDate) {
        //YYYY-MM-DD
        int[] standardDays = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        int[] leapyearDays = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
        int y = Integer.parseInt(strDate.substring(0, 4));
        int m = Integer.parseInt(strDate.substring(4, 6));
        int d = Integer.parseInt(strDate.substring(6, ) - 1;
        int maxDateCount = 0;

        System.out.println(y);
        System.out.println(m);
        System.out.println(d);

        if ((y % 4 == 0 && y % 100 != 0) || y % 400 == 0) {
            maxDateCount = leapyearDays[m - 1];
        } else {
            maxDateCount = standardDays[m - 1];
        }

        if (d > maxDateCount) {
            d = 1;
            m++;
        }

        if (m > 12) {
            m = 1;
            y++;
        }
        java.text.DecimalFormat yf = new java.text.DecimalFormat("0000");
        java.text.DecimalFormat mdf = new java.text.DecimalFormat("00");
        return yf.format(y) + mdf.format(m) + mdf.format(d);
    }

    public static void main(String[] argv) {
        System.out.println(Tools.getMonthDay(new java.util.Date()));
        System.out.println(Tools.getHourMinute(new java.util.Date()));
     
    }
}