com.alibaba.excel.util.DateUtils Maven / Gradle / Ivy
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package com.alibaba.excel.util;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;
/**
* Date utils
*
* @author Jiaju Zhuang
**/
public class DateUtils {
/**
* Is a cache of dates
*/
private static final ThreadLocal> DATE_THREAD_LOCAL =
new ThreadLocal>();
/**
* Is a cache of dates
*/
private static final ThreadLocal> DATE_FORMAT_THREAD_LOCAL =
new ThreadLocal>();
/**
* The following patterns are used in {@link #isADateFormat(Integer, String)}
*/
private static final Pattern date_ptrn1 = Pattern.compile("^\\[\\$\\-.*?\\]");
private static final Pattern date_ptrn2 = Pattern.compile("^\\[[a-zA-Z]+\\]");
private static final Pattern date_ptrn3a = Pattern.compile("[yYmMdDhHsS]");
// add "\u5e74 \u6708 \u65e5" for Chinese/Japanese date format:2017 \u5e74 2 \u6708 7 \u65e5
private static final Pattern date_ptrn3b =
Pattern.compile("^[\\[\\]yYmMdDhHsS\\-T/\u5e74\u6708\u65e5,. :\"\\\\]+0*[ampAMP/]*$");
// elapsed time patterns: [h],[m] and [s]
private static final Pattern date_ptrn4 = Pattern.compile("^\\[([hH]+|[mM]+|[sS]+)\\]");
// for format which start with "[DBNum1]" or "[DBNum2]" or "[DBNum3]" could be a Chinese date
private static final Pattern date_ptrn5 = Pattern.compile("^\\[DBNum(1|2|3)\\]");
// for format which start with "年" or "月" or "日" or "时" or "分" or "秒" could be a Chinese date
private static final Pattern date_ptrn6 = Pattern.compile("(年|月|日|时|分|秒)+");
public static final String DATE_FORMAT_10 = "yyyy-MM-dd";
public static final String DATE_FORMAT_14 = "yyyyMMddHHmmss";
public static final String DATE_FORMAT_17 = "yyyyMMdd HH:mm:ss";
public static final String DATE_FORMAT_19 = "yyyy-MM-dd HH:mm:ss";
public static final String DATE_FORMAT_19_FORWARD_SLASH = "yyyy/MM/dd HH:mm:ss";
private static final String MINUS = "-";
private DateUtils() {}
/**
* convert string to date
*
* @param dateString
* @param dateFormat
* @return
* @throws ParseException
*/
public static Date parseDate(String dateString, String dateFormat) throws ParseException {
if (StringUtils.isEmpty(dateFormat)) {
dateFormat = switchDateFormat(dateString);
}
return getCacheDateFormat(dateFormat).parse(dateString);
}
/**
* convert string to date
*
* @param dateString
* @return
* @throws ParseException
*/
public static Date parseDate(String dateString) throws ParseException {
return parseDate(dateString, switchDateFormat(dateString));
}
/**
* switch date format
*
* @param dateString
* @return
*/
private static String switchDateFormat(String dateString) {
int length = dateString.length();
switch (length) {
case 19:
if (dateString.contains(MINUS)) {
return DATE_FORMAT_19;
} else {
return DATE_FORMAT_19_FORWARD_SLASH;
}
case 17:
return DATE_FORMAT_17;
case 14:
return DATE_FORMAT_14;
case 10:
return DATE_FORMAT_10;
default:
throw new IllegalArgumentException("can not find date format for：" + dateString);
}
}
/**
* Format date
*
* yyyy-MM-dd HH:mm:ss
*
* @param date
* @return
*/
public static String format(Date date) {
return format(date, null);
}
/**
* Format date
*
* @param date
* @param dateFormat
* @return
*/
public static String format(Date date, String dateFormat) {
if (date == null) {
return "";
}
if (StringUtils.isEmpty(dateFormat)) {
dateFormat = DATE_FORMAT_19;
}
return getCacheDateFormat(dateFormat).format(date);
}
private static DateFormat getCacheDateFormat(String dateFormat) {
Map dateFormatMap = DATE_FORMAT_THREAD_LOCAL.get();
if (dateFormatMap == null) {
dateFormatMap = new HashMap();
DATE_FORMAT_THREAD_LOCAL.set(dateFormatMap);
} else {
SimpleDateFormat dateFormatCached = dateFormatMap.get(dateFormat);
if (dateFormatCached != null) {
return dateFormatCached;
}
}
SimpleDateFormat simpleDateFormat = new SimpleDateFormat(dateFormat);
dateFormatMap.put(dateFormat, simpleDateFormat);
return simpleDateFormat;
}
/**
* Determine if it is a date format.
*
* @param formatIndex
* @param formatString
* @return
*/
public static boolean isADateFormat(Integer formatIndex, String formatString) {
if (formatIndex == null) {
return false;
}
Map isDateCache = DATE_THREAD_LOCAL.get();
if (isDateCache == null) {
isDateCache = new HashMap();
DATE_THREAD_LOCAL.set(isDateCache);
} else {
Boolean isDateCachedData = isDateCache.get(formatIndex);
if (isDateCachedData != null) {
return isDateCachedData;
}
}
boolean isDate = isADateFormatUncached(formatIndex, formatString);
isDateCache.put(formatIndex, isDate);
return isDate;
}
/**
* Determine if it is a date format.
*
* @param formatIndex
* @param formatString
* @return
*/
public static boolean isADateFormatUncached(Integer formatIndex, String formatString) {
// First up, is this an internal date format?
if (isInternalDateFormat(formatIndex)) {
return true;
}
if (StringUtils.isEmpty(formatString)) {
return false;
}
String fs = formatString;
final int length = fs.length();
StringBuilder sb = new StringBuilder(length);
for (int i = 0; i < length; i++) {
char c = fs.charAt(i);
if (i < length - 1) {
char nc = fs.charAt(i + 1);
if (c == '\\') {
switch (nc) {
case '-':
case ',':
case '.':
case ' ':
case '\\':
// skip current '\' and continue to the next char
continue;
}
} else if (c == ';' && nc == '@') {
i++;
// skip ";@" duplets
continue;
}
}
sb.append(c);
}
fs = sb.toString();
// short-circuit if it indicates elapsed time: [h], [m] or [s]
if (date_ptrn4.matcher(fs).matches()) {
return true;
}
// If it starts with [DBNum1] or [DBNum2] or [DBNum3]
// then it could be a Chinese date
fs = date_ptrn5.matcher(fs).replaceAll("");
// If it starts with [$-...], then could be a date, but
// who knows what that starting bit is all about
fs = date_ptrn1.matcher(fs).replaceAll("");
// If it starts with something like [Black] or [Yellow],
// then it could be a date
fs = date_ptrn2.matcher(fs).replaceAll("");
// You're allowed something like dd/mm/yy;[red]dd/mm/yy
// which would place dates before 1900/1904 in red
// For now, only consider the first one
final int separatorIndex = fs.indexOf(';');
if (0 < separatorIndex && separatorIndex < fs.length() - 1) {
fs = fs.substring(0, separatorIndex);
}
// Ensure it has some date letters in it
// (Avoids false positives on the rest of pattern 3)
if (!date_ptrn3a.matcher(fs).find()) {
return false;
}
// If we get here, check it's only made up, in any case, of:
// y m d h s - \ / , . : [ ] T
// optionally followed by AM/PM
boolean result = date_ptrn3b.matcher(fs).matches();
if (result) {
return true;
}
result = date_ptrn6.matcher(fs).find();
return result;
}
/**
* Given a format ID this will check whether the format represents an internal excel date format or not.
*
* @see #isADateFormat(Integer, String)
*/
public static boolean isInternalDateFormat(int format) {
switch (format) {
// Internal Date Formats as described on page 427 in
// Microsoft Excel Dev's Kit...
// 14-22
case 0x0e:
case 0x0f:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
case 0x14:
case 0x15:
case 0x16:
// 27-36
case 0x1b:
case 0x1c:
case 0x1d:
case 0x1e:
case 0x1f:
case 0x20:
case 0x21:
case 0x22:
case 0x23:
case 0x24:
// 45-47
case 0x2d:
case 0x2e:
case 0x2f:
// 50-58
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
case 0x38:
case 0x39:
case 0x3a:
return true;
}
return false;
}
public static void removeThreadLocalCache() {
DATE_THREAD_LOCAL.remove();
DATE_FORMAT_THREAD_LOCAL.remove();
}
}