content: /*
   ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
   ~                                                                               ~
   ~ The MIT License (MIT)                                                         ~
   ~                                                                               ~
   ~ Copyright (c) 2015-2025 miaixz.org and other contributors.                    ~
   ~                                                                               ~
   ~ Permission is hereby granted, free of charge, to any person obtaining a copy  ~
   ~ of this software and associated documentation files (the "Software"), to deal ~
   ~ in the Software without restriction, including without limitation the rights  ~
   ~ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell     ~
   ~ copies of the Software, and to permit persons to whom the Software is         ~
   ~ furnished to do so, subject to the following conditions:                      ~
   ~                                                                               ~
   ~ The above copyright notice and this permission notice shall be included in    ~
   ~ all copies or substantial portions of the Software.                           ~
   ~                                                                               ~
   ~ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR    ~
   ~ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,      ~
   ~ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE   ~
   ~ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER        ~
   ~ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, ~
   ~ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN     ~
   ~ THE SOFTWARE.                                                                 ~
   ~                                                                               ~
   ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
  */
  package org.miaixz.bus.cron;
  
  import java.io.Serial;
  import java.io.Serializable;
  import java.text.ParseException;
  import java.util.*;
  
  import org.miaixz.bus.core.lang.Symbol;
  import org.miaixz.bus.core.xyz.DateKit;
  
  /**
   * 类似unix cron表达式提供解析器和执行器 Crontab表达式提供了指定复杂时间组合的能力
   *
   * @author Kimi Liu
   * @since Java 17+
   */
  public final class Expression implements Serializable, Cloneable {
  
      @Serial
      private static final long serialVersionUID = 2852287029125L;
  
      public static final int MAX_YEAR = Calendar.getInstance().get(Calendar.YEAR) + 100;
      protected static final int SECOND = 0;
      protected static final int MINUTE = 1;
      protected static final int HOUR = 2;
      protected static final int DAY_OF_MONTH = 3;
      protected static final int MONTH = 4;
      protected static final int DAY_OF_WEEK = 5;
      protected static final int YEAR = 6;
      protected static final int ALL_SPEC_INT = 99; // '*'
      protected static final int NO_SPEC_INT = 98; // '?'
      protected static final Integer ALL_SPEC = ALL_SPEC_INT;
      protected static final Integer NO_SPEC = NO_SPEC_INT;
      protected static final Map<String, Integer> monthMap = new HashMap<>(20);
      protected static final Map<String, Integer> dayMap = new HashMap<>(60);
  
      static {
          monthMap.put("JAN", 0);
          monthMap.put("FEB", 1);
          monthMap.put("MAR", 2);
          monthMap.put("APR", 3);
          monthMap.put("MAY", 4);
          monthMap.put("JUN", 5);
          monthMap.put("JUL", 6);
          monthMap.put("AUG", 7);
          monthMap.put("SEP", 8);
          monthMap.put("OCT", 9);
          monthMap.put("NOV", 10);
          monthMap.put("DEC", 11);
  
          dayMap.put("SUN", 1);
          dayMap.put("MON", 2);
          dayMap.put("TUE", 3);
          dayMap.put("WED", 4);
          dayMap.put("THU", 5);
          dayMap.put("FRI", 6);
          dayMap.put("SAT", 7);
      }
  
      private final String cronExpression;
      protected transient TreeSet<Integer> seconds;
      protected transient TreeSet<Integer> minutes;
      protected transient TreeSet<Integer> hours;
      protected transient TreeSet<Integer> daysOfMonth;
      protected transient TreeSet<Integer> months;
      protected transient TreeSet<Integer> daysOfWeek;
      protected transient TreeSet<Integer> years;
  
      protected transient boolean lastdayOfWeek = false;
      protected transient int nthdayOfWeek = 0;
      protected transient boolean lastdayOfMonth = false;
      protected transient boolean nearestWeekday = false;
      protected transient int lastdayOffset = 0;
      protected transient boolean expressionParsed = false;
      private TimeZone timeZone = null;
  
      /**
       * 根据指定的参数构造一个新的<code> CronExpression </code>
       *
       * @param cronExpression 新对象应表示的cron表达式的字符串表示形式
       * @throws ParseException 如果字符串表达式不能解析为有效的<code> CronExpression </code>
       */
      public Expression(String cronExpression) throws ParseException {
          if (null == cronExpression) {
              throw new IllegalArgumentException("cronExpression cannot be null");
          }
  
          this.cronExpression = cronExpression.toUpperCase(Locale.US);
  
          buildExpression(this.cronExpression);
      }
  
      /**
       * 构造一个新的{@code CronExpression}作为现有*实例的副本
       *
       * @param expression 要复制的现有cron表达式
       */
      public Expression(Expression expression) {
          this.cronExpression = expression.getCronExpression();
          try {
              buildExpression(cronExpression);
          } catch (ParseException ex) {
              throw new AssertionError();
          }
          if (null != expression.getTimeZone()) {
              setTimeZone((TimeZone) expression.getTimeZone().clone());
          }
      }
  
      /**
       * 指示是否可以将指定的cron表达式解析为有效的cron表达式
       *
       * @param cronExpression 要评估的表达式
       * @return 指示给定表达式是否为有效cron表达式的布尔值
       */
      public static boolean isValidExpression(String cronExpression) {
  
          try {
              new Expression(cronExpression);
          } catch (ParseException pe) {
              return false;
          }
  
          return true;
      }
  
      public static void validateExpression(String cronExpression) throws ParseException {
  
          new Expression(cronExpression);
      }
  
      /**
       * 指示给定的日期是否满足cron表达式 请注意，毫秒将被忽略，因此两个日期在同一秒的不同毫秒 处始终具有相同的结果
       *
       * @param date 评估日期
       * @return 指示给定日期是否满足cron 表达式的布尔值
       */
      public boolean isSatisfiedBy(Date date) {
          Calendar testDateCal = Calendar.getInstance(getTimeZone());
          testDateCal.setTime(date);
          testDateCal.set(Calendar.MILLISECOND, 0);
          Date originalDate = testDateCal.getTime();
  
          testDateCal.add(Calendar.SECOND, -1);
  
          Date timeAfter = getTimeAfter(testDateCal.getTime());
  
          return ((null != timeAfter) && (timeAfter.equals(originalDate)));
      }
  
      public Date getNextValidTimeAfter(Date date) {
          return getTimeAfter(date);
      }
  
      public Date getNextInvalidTimeAfter(Date date) {
          long difference = 1000;
  
          Calendar adjustCal = Calendar.getInstance(getTimeZone());
          adjustCal.setTime(date);
          adjustCal.set(Calendar.MILLISECOND, 0);
          Date lastDate = adjustCal.getTime();
          Date newDate;
          while (difference == 1000) {
              newDate = getTimeAfter(lastDate);
              if (null == newDate)
                  break;
  
              difference = newDate.getTime() - lastDate.getTime();
  
              if (difference == 1000) {
                  lastDate = newDate;
              }
          }
  
          return new Date(lastDate.getTime() + 1000);
      }
  
      public TimeZone getTimeZone() {
          if (null == timeZone) {
              timeZone = TimeZone.getDefault();
          }
  
          return timeZone;
      }
  
      public void setTimeZone(TimeZone timeZone) {
          this.timeZone = timeZone;
      }
  
      @Override
      public String toString() {
          return cronExpression;
      }
  
      protected void buildExpression(String expression) throws ParseException {
          expressionParsed = true;
  
          try {
  
              if (null == seconds) {
                  seconds = new TreeSet<>();
              }
              if (null == minutes) {
                  minutes = new TreeSet<>();
              }
              if (null == hours) {
                  hours = new TreeSet<>();
              }
              if (null == daysOfMonth) {
                  daysOfMonth = new TreeSet<>();
              }
              if (null == months) {
                  months = new TreeSet<>();
              }
              if (null == daysOfWeek) {
                  daysOfWeek = new TreeSet<>();
              }
              if (null == years) {
                  years = new TreeSet<>();
              }
  
              int exprOn = SECOND;
  
              StringTokenizer exprsTok = new StringTokenizer(expression, " \t", false);
  
              while (exprsTok.hasMoreTokens() && exprOn <= YEAR) {
                  String expr = exprsTok.nextToken().trim();
  
                  // throw an exception if L is used with other days of the month
                  if (exprOn == DAY_OF_MONTH && expr.indexOf('L') != -1 && expr.length() > 1
                          && expr.contains(Symbol.COMMA)) {
                      throw new ParseException(
                              "Support for specifying 'L' and 'LW' with other days of the month is not implemented", -1);
                  }
                  // throw an exception if L is used with other days of the week
                  if (exprOn == DAY_OF_WEEK && expr.indexOf('L') != -1 && expr.length() > 1
                          && expr.contains(Symbol.COMMA)) {
                      throw new ParseException(
                              "Support for specifying 'L' with other days of the week is not implemented", -1);
                  }
                  if (exprOn == DAY_OF_WEEK && expr.indexOf(Symbol.C_HASH) != -1
                          && expr.indexOf(Symbol.C_HASH, expr.indexOf(Symbol.C_HASH) + 1) != -1) {
                      throw new ParseException("Support for specifying multiple \"nth\" days is not implemented.", -1);
                  }
  
                  StringTokenizer vTok = new StringTokenizer(expr, Symbol.COMMA);
                  while (vTok.hasMoreTokens()) {
                      String v = vTok.nextToken();
                      storeExpressionVals(0, v, exprOn);
                  }
  
                  exprOn++;
              }
  
              if (exprOn <= DAY_OF_WEEK) {
                  throw new ParseException("Unexpected end of expression.", expression.length());
              }
  
              if (exprOn <= YEAR) {
                  storeExpressionVals(0, Symbol.STAR, YEAR);
              }
  
              TreeSet<Integer> dow = getSet(DAY_OF_WEEK);
              TreeSet<Integer> dom = getSet(DAY_OF_MONTH);
  
              // Copying the logic from the UnsupportedOperationException below
              boolean dayOfMSpec = !dom.contains(NO_SPEC);
              boolean dayOfWSpec = !dow.contains(NO_SPEC);
  
              if (!dayOfMSpec || dayOfWSpec) {
                  if (!dayOfWSpec || dayOfMSpec) {
                      throw new ParseException(
                              "Support for specifying both a day-of-week AND a day-of-month parameter is not implemented.",
                              0);
                  }
              }
          } catch (ParseException pe) {
              throw pe;
          } catch (Exception e) {
              throw new ParseException("Illegal cron expression format (" + e + ")", 0);
          }
      }
  
      protected int storeExpressionVals(int pos, String s, int type) throws ParseException {
  
          int incr = 0;
          int i = skipWhiteSpace(pos, s);
          if (i >= s.length()) {
              return i;
          }
          char c = s.charAt(i);
          if ((c >= 'A') && (c <= 'Z') && (!s.equals("L")) && (!s.equals("LW")) && (!s.matches("^L-[0-9]*[W]?"))) {
              String sub = s.substring(i, i + 3);
              int sval = -1;
              int eval = -1;
              if (type == MONTH) {
                  sval = getMonthNumber(sub) + 1;
                  if (sval <= 0) {
                      throw new ParseException("Invalid Month value: '" + sub + "'", i);
                  }
                  if (s.length() > i + 3) {
                      c = s.charAt(i + 3);
                      if (c == Symbol.C_MINUS) {
                          i += 4;
                          sub = s.substring(i, i + 3);
                          eval = getMonthNumber(sub) + 1;
                          if (eval <= 0) {
                              throw new ParseException("Invalid Month value: '" + sub + "'", i);
                          }
                      }
                  }
              } else if (type == DAY_OF_WEEK) {
                  sval = getDayOfWeekNumber(sub);
                  if (sval < 0) {
                      throw new ParseException("Invalid Day-of-Week value: '" + sub + "'", i);
                  }
                  if (s.length() > i + 3) {
                      c = s.charAt(i + 3);
                      if (c == Symbol.C_MINUS) {
                          i += 4;
                          sub = s.substring(i, i + 3);
                          eval = getDayOfWeekNumber(sub);
                          if (eval < 0) {
                              throw new ParseException("Invalid Day-of-Week value: '" + sub + "'", i);
                          }
                      } else if (c == Symbol.C_HASH) {
                          try {
                              i += 4;
                              nthdayOfWeek = Integer.parseInt(s.substring(i));
                              if (nthdayOfWeek < 1 || nthdayOfWeek > 5) {
                                  throw new Exception();
                              }
                          } catch (Exception e) {
                              throw new ParseException("A numeric value between 1 and 5 must follow the '#' option", i);
                          }
                      } else if (c == 'L') {
                          lastdayOfWeek = true;
                          i++;
                      }
                  }
  
              } else {
                  throw new ParseException("Illegal characters for this position: '" + sub + "'", i);
              }
              if (eval != -1) {
                  incr = 1;
              }
              addToSet(sval, eval, incr, type);
              return (i + 3);
          }
  
          if (c == Symbol.C_QUESTION_MARK) {
              i++;
              if ((i + 1) < s.length() && (s.charAt(i) != Symbol.C_SPACE && s.charAt(i + 1) != Symbol.C_HT)) {
                  throw new ParseException("Illegal character after '?': " + s.charAt(i), i);
              }
              if (type != DAY_OF_WEEK && type != DAY_OF_MONTH) {
                  throw new ParseException("'?' can only be specified for Day-of-Month or Day-of-Week.", i);
              }
              if (type == DAY_OF_WEEK && !lastdayOfMonth) {
                  int val = daysOfMonth.last();
                  if (val == NO_SPEC_INT) {
                      throw new ParseException("'?' can only be specified for Day-of-Month -OR- Day-of-Week.", i);
                  }
              }
  
              addToSet(NO_SPEC_INT, -1, 0, type);
              return i;
          }
  
          if (c == Symbol.C_STAR || c == Symbol.C_SLASH) {
              if (c == Symbol.C_STAR && (i + 1) >= s.length()) {
                  addToSet(ALL_SPEC_INT, -1, incr, type);
                  return i + 1;
              } else if (c == Symbol.C_SLASH
                      && ((i + 1) >= s.length() || s.charAt(i + 1) == Symbol.C_SPACE || s.charAt(i + 1) == Symbol.C_HT)) {
                  throw new ParseException("'/' must be followed by an integer.", i);
              } else if (c == Symbol.C_STAR) {
                  i++;
              }
              c = s.charAt(i);
              if (c == Symbol.C_SLASH) { // is an increment specified?
                  i++;
                  if (i >= s.length()) {
                      throw new ParseException("Unexpected end of string.", i);
                  }
  
                  incr = getNumericValue(s, i);
  
                  i++;
                  if (incr > 10) {
                      i++;
                  }
                  checkIncrementRange(incr, type, i);
              } else {
                  incr = 1;
              }
  
              addToSet(ALL_SPEC_INT, -1, incr, type);
              return i;
          } else if (c == 'L') {
              i++;
              if (type == DAY_OF_MONTH) {
                  lastdayOfMonth = true;
              }
              if (type == DAY_OF_WEEK) {
                  addToSet(7, 7, 0, type);
              }
              if (type == DAY_OF_MONTH && s.length() > i) {
                  c = s.charAt(i);
                  if (c == Symbol.C_MINUS) {
                      ValueSet vs = getValue(0, s, i + 1);
                      lastdayOffset = vs.value;
                      if (lastdayOffset > 30)
                          throw new ParseException("Offset from last day must be <= 30", i + 1);
                      i = vs.pos;
                  }
                  if (s.length() > i) {
                      c = s.charAt(i);
                      if (c == 'W') {
                          nearestWeekday = true;
                          i++;
                      }
                  }
              }
              return i;
          } else if (c >= '0' && c <= '9') {
              int val = Integer.parseInt(String.valueOf(c));
              i++;
              if (i >= s.length()) {
                  addToSet(val, -1, -1, type);
              } else {
                  c = s.charAt(i);
                  if (c >= '0' && c <= '9') {
                      ValueSet vs = getValue(val, s, i);
                      val = vs.value;
                      i = vs.pos;
                  }
                  i = checkNext(i, s, val, type);
                  return i;
              }
          } else {
              throw new ParseException("Unexpected character: " + c, i);
          }
  
          return i;
      }
  
      private void checkIncrementRange(int incr, int type, int idxPos) throws ParseException {
          if (incr > 59 && (type == SECOND || type == MINUTE)) {
              throw new ParseException("Increment > 60 : " + incr, idxPos);
          } else if (incr > 23 && (type == HOUR)) {
              throw new ParseException("Increment > 24 : " + incr, idxPos);
          } else if (incr > 31 && (type == DAY_OF_MONTH)) {
              throw new ParseException("Increment > 31 : " + incr, idxPos);
          } else if (incr > 7 && (type == DAY_OF_WEEK)) {
              throw new ParseException("Increment > 7 : " + incr, idxPos);
          } else if (incr > 12 && (type == MONTH)) {
              throw new ParseException("Increment > 12 : " + incr, idxPos);
          }
      }
  
      protected int checkNext(int pos, String s, int val, int type) throws ParseException {
  
          int end = -1;
          int i = pos;
  
          if (i >= s.length()) {
              addToSet(val, end, -1, type);
              return i;
          }
  
          char c = s.charAt(pos);
  
          if (c == 'L') {
              if (type == DAY_OF_WEEK) {
                  if (val < 1 || val > 7)
                      throw new ParseException("Day-of-Week values must be between 1 and 7", -1);
                  lastdayOfWeek = true;
              } else {
                  throw new ParseException("'L' option is not valid here. (pos=" + i + ")", i);
              }
              TreeSet<Integer> set = getSet(type);
              set.add(val);
              i++;
              return i;
          }
  
          if (c == 'W') {
              if (type == DAY_OF_MONTH) {
                  nearestWeekday = true;
              } else {
                  throw new ParseException("'W' option is not valid here. (pos=" + i + ")", i);
              }
              if (val > 31)
                  throw new ParseException(
                          "The 'W' option does not make sense with values larger than 31 (max number of days in a month)",
                          i);
              TreeSet<Integer> set = getSet(type);
              set.add(val);
              i++;
              return i;
          }
  
          if (c == Symbol.C_HASH) {
              if (type != DAY_OF_WEEK) {
                  throw new ParseException("'#' option is not valid here. (pos=" + i + ")", i);
              }
              i++;
              try {
                  nthdayOfWeek = Integer.parseInt(s.substring(i));
                  if (nthdayOfWeek < 1 || nthdayOfWeek > 5) {
                      throw new Exception();
                  }
              } catch (Exception e) {
                  throw new ParseException("A numeric value between 1 and 5 must follow the '#' option", i);
              }
  
              TreeSet<Integer> set = getSet(type);
              set.add(val);
              i++;
              return i;
          }
  
          if (c == Symbol.C_MINUS) {
              i++;
              c = s.charAt(i);
              int v = Integer.parseInt(String.valueOf(c));
              end = v;
              i++;
              if (i >= s.length()) {
                  addToSet(val, end, 1, type);
                  return i;
              }
              c = s.charAt(i);
              if (c >= '0' && c <= '9') {
                  ValueSet vs = getValue(v, s, i);
                  end = vs.value;
                  i = vs.pos;
              }
              if (i < s.length() && ((c = s.charAt(i)) == Symbol.C_SLASH)) {
                  i++;
                  c = s.charAt(i);
                  int v2 = Integer.parseInt(String.valueOf(c));
                  i++;
                  if (i >= s.length()) {
                      addToSet(val, end, v2, type);
                      return i;
                  }
                  c = s.charAt(i);
                  if (c >= '0' && c <= '9') {
                      ValueSet vs = getValue(v2, s, i);
                      int v3 = vs.value;
                      addToSet(val, end, v3, type);
                      i = vs.pos;
                      return i;
                  } else {
                      addToSet(val, end, v2, type);
                      return i;
                  }
              } else {
                  addToSet(val, end, 1, type);
                  return i;
              }
          }
  
          if (c == Symbol.C_SLASH) {
              if ((i + 1) >= s.length() || s.charAt(i + 1) == Symbol.C_SPACE || s.charAt(i + 1) == Symbol.C_HT) {
                  throw new ParseException("'/' must be followed by an integer.", i);
              }
  
              i++;
              c = s.charAt(i);
              int v2 = Integer.parseInt(String.valueOf(c));
              i++;
              if (i >= s.length()) {
                  checkIncrementRange(v2, type, i);
                  addToSet(val, end, v2, type);
                  return i;
              }
              c = s.charAt(i);
              if (c >= '0' && c <= '9') {
                  ValueSet vs = getValue(v2, s, i);
                  int v3 = vs.value;
                  checkIncrementRange(v3, type, i);
                  addToSet(val, end, v3, type);
                  i = vs.pos;
                  return i;
              } else {
                  throw new ParseException("Unexpected character '" + c + "' after '/'", i);
              }
          }
  
          addToSet(val, end, 0, type);
          i++;
          return i;
      }
  
      public String getCronExpression() {
          return cronExpression;
      }
  
      public String getExpressionSummary() {
          StringBuilder buf = new StringBuilder();
  
          buf.append("seconds: ");
          buf.append(getExpressionSetSummary(seconds));
          buf.append(Symbol.LF);
          buf.append("minutes: ");
          buf.append(getExpressionSetSummary(minutes));
          buf.append(Symbol.LF);
          buf.append("hours: ");
          buf.append(getExpressionSetSummary(hours));
          buf.append(Symbol.LF);
          buf.append("daysOfMonth: ");
          buf.append(getExpressionSetSummary(daysOfMonth));
          buf.append(Symbol.LF);
          buf.append("months: ");
          buf.append(getExpressionSetSummary(months));
          buf.append(Symbol.LF);
          buf.append("daysOfWeek: ");
          buf.append(getExpressionSetSummary(daysOfWeek));
          buf.append(Symbol.LF);
          buf.append("lastdayOfWeek: ");
          buf.append(lastdayOfWeek);
          buf.append(Symbol.LF);
          buf.append("nearestWeekday: ");
          buf.append(nearestWeekday);
          buf.append(Symbol.LF);
          buf.append("NthDayOfWeek: ");
          buf.append(nthdayOfWeek);
          buf.append(Symbol.LF);
          buf.append("lastdayOfMonth: ");
          buf.append(lastdayOfMonth);
          buf.append(Symbol.LF);
          buf.append("years: ");
          buf.append(getExpressionSetSummary(years));
          buf.append(Symbol.LF);
  
          return buf.toString();
      }
  
      protected String getExpressionSetSummary(java.util.Set<Integer> set) {
  
          if (set.contains(NO_SPEC)) {
              return Symbol.QUESTION_MARK;
          }
          if (set.contains(ALL_SPEC)) {
              return Symbol.STAR;
          }
  
          StringBuilder buf = new StringBuilder();
  
          Iterator<Integer> itr = set.iterator();
          boolean first = true;
          while (itr.hasNext()) {
              Integer iVal = itr.next();
              String val = iVal.toString();
              if (!first) {
                  buf.append(Symbol.COMMA);
              }
              buf.append(val);
              first = false;
          }
  
          return buf.toString();
      }
  
      protected String getExpressionSetSummary(java.util.ArrayList<Integer> list) {
  
          if (list.contains(NO_SPEC)) {
              return Symbol.QUESTION_MARK;
          }
          if (list.contains(ALL_SPEC)) {
              return Symbol.STAR;
          }
  
          StringBuilder buf = new StringBuilder();
  
          Iterator<Integer> itr = list.iterator();
          boolean first = true;
          while (itr.hasNext()) {
              Integer iVal = itr.next();
              String val = iVal.toString();
              if (!first) {
                  buf.append(Symbol.COMMA);
              }
              buf.append(val);
              first = false;
          }
  
          return buf.toString();
      }
  
      protected int skipWhiteSpace(int i, String s) {
          for (; i < s.length() && (s.charAt(i) == Symbol.C_SPACE || s.charAt(i) == Symbol.C_HT); i++) {
          }
  
          return i;
      }
  
      protected int findNextWhiteSpace(int i, String s) {
          for (; i < s.length() && (s.charAt(i) != Symbol.C_SPACE || s.charAt(i) != Symbol.C_HT); i++) {
          }
  
          return i;
      }
  
      protected void addToSet(int val, int end, int incr, int type) throws ParseException {
  
          TreeSet<Integer> set = getSet(type);
  
          if (type == SECOND || type == MINUTE) {
              if ((val < 0 || val > 59 || end > 59) && (val != ALL_SPEC_INT)) {
                  throw new ParseException("Minute and Second values must be between 0 and 59", -1);
              }
          } else if (type == HOUR) {
              if ((val < 0 || val > 23 || end > 23) && (val != ALL_SPEC_INT)) {
                  throw new ParseException("Hour values must be between 0 and 23", -1);
              }
          } else if (type == DAY_OF_MONTH) {
              if ((val < 1 || val > 31 || end > 31) && (val != ALL_SPEC_INT) && (val != NO_SPEC_INT)) {
                  throw new ParseException("Day of month values must be between 1 and 31", -1);
              }
          } else if (type == MONTH) {
              if ((val < 1 || val > 12 || end > 12) && (val != ALL_SPEC_INT)) {
                  throw new ParseException("Month values must be between 1 and 12", -1);
              }
          } else if (type == DAY_OF_WEEK) {
              if ((val == 0 || val > 7 || end > 7) && (val != ALL_SPEC_INT) && (val != NO_SPEC_INT)) {
                  throw new ParseException("Day-of-Week values must be between 1 and 7", -1);
              }
          }
  
          if ((incr == 0 || incr == -1) && val != ALL_SPEC_INT) {
              if (val != -1) {
                  set.add(val);
              } else {
                  set.add(NO_SPEC);
              }
  
              return;
          }
  
          int startAt = val;
          int stopAt = end;
  
          if (val == ALL_SPEC_INT && incr <= 0) {
              incr = 1;
              set.add(ALL_SPEC); // put in a marker, but also fill values
          }
  
          if (type == SECOND || type == MINUTE) {
              if (stopAt == -1) {
                  stopAt = 59;
              }
              if (startAt == -1 || startAt == ALL_SPEC_INT) {
                  startAt = 0;
              }
          } else if (type == HOUR) {
              if (stopAt == -1) {
                  stopAt = 23;
              }
              if (startAt == -1 || startAt == ALL_SPEC_INT) {
                  startAt = 0;
              }
          } else if (type == DAY_OF_MONTH) {
              if (stopAt == -1) {
                  stopAt = 31;
              }
              if (startAt == -1 || startAt == ALL_SPEC_INT) {
                  startAt = 1;
              }
          } else if (type == MONTH) {
              if (stopAt == -1) {
                  stopAt = 12;
              }
              if (startAt == -1 || startAt == ALL_SPEC_INT) {
                  startAt = 1;
              }
          } else if (type == DAY_OF_WEEK) {
              if (stopAt == -1) {
                  stopAt = 7;
              }
              if (startAt == -1 || startAt == ALL_SPEC_INT) {
                  startAt = 1;
              }
          } else if (type == YEAR) {
              if (stopAt == -1) {
                  stopAt = MAX_YEAR;
              }
              if (startAt == -1 || startAt == ALL_SPEC_INT) {
                  startAt = 1970;
              }
          }
  
          // if the end of the range is before the start, then we need to overflow into
          // the next day, month etc. This is done by adding the maximum amount for that
          // type, and using modulus max to determine the value being added.
          int max = -1;
          if (stopAt < startAt) {
              switch (type) {
                  case SECOND:
                      max = 60;
                      break;
  
                  case MINUTE:
                      max = 60;
                      break;
  
                  case HOUR:
                      max = 24;
                      break;
  
                  case MONTH:
                      max = 12;
                      break;
  
                  case DAY_OF_WEEK:
                      max = 7;
                      break;
  
                  case DAY_OF_MONTH:
                      max = 31;
                      break;
  
                  case YEAR:
                      throw new IllegalArgumentException("Start year must be less than stop year");
  
                  default:
                      throw new IllegalArgumentException("Unexpected type encountered");
              }
              stopAt += max;
          }
  
          for (int i = startAt; i <= stopAt; i += incr) {
              if (max == -1) {
                  // ie: there's no max to overflow over
                  set.add(i);
              } else {
                  // take the modulus to get the real value
                  int i2 = i % max;
  
                  // 1-indexed ranges should not include 0, and should include their max
                  if (i2 == 0 && (type == MONTH || type == DAY_OF_WEEK || type == DAY_OF_MONTH)) {
                      i2 = max;
                  }
  
                  set.add(i2);
              }
          }
      }
  
      TreeSet<Integer> getSet(int type) {
          switch (type) {
              case SECOND:
                  return seconds;
  
              case MINUTE:
                  return minutes;
  
              case HOUR:
                  return hours;
  
              case DAY_OF_MONTH:
                  return daysOfMonth;
  
              case MONTH:
                  return months;
  
              case DAY_OF_WEEK:
                  return daysOfWeek;
  
              case YEAR:
                  return years;
  
              default:
                  return null;
          }
      }
  
      protected ValueSet getValue(int v, String s, int i) {
          char c = s.charAt(i);
          StringBuilder s1 = new StringBuilder(String.valueOf(v));
          while (c >= '0' && c <= '9') {
              s1.append(c);
              i++;
              if (i >= s.length()) {
                  break;
              }
              c = s.charAt(i);
          }
          ValueSet val = new ValueSet();
  
          val.pos = (i < s.length()) ? i : i + 1;
          val.value = Integer.parseInt(s1.toString());
          return val;
      }
  
      protected int getNumericValue(String s, int i) {
          int endOfVal = findNextWhiteSpace(i, s);
          String val = s.substring(i, endOfVal);
          return Integer.parseInt(val);
      }
  
      protected int getMonthNumber(String s) {
          Integer integer = monthMap.get(s);
  
          if (null == integer) {
              return -1;
          }
  
          return integer;
      }
  
      protected int getDayOfWeekNumber(String s) {
          Integer integer = dayMap.get(s);
  
          if (null == integer) {
              return -1;
          }
  
          return integer;
      }
  
      public Date getTimeAfter(Date afterTime) {
  
          // Computation is based on Gregorian year only.
          Calendar cl = new GregorianCalendar(getTimeZone());
  
          // move ahead one second, since we're computing the time *after* the
          // given time
          afterTime = new Date(afterTime.getTime() + 1000);
          // CronTrigger does not deal with milliseconds
          cl.setTime(afterTime);
          cl.set(Calendar.MILLISECOND, 0);
  
          boolean gotOne = false;
          // loop until we've computed the next time, or we've past the endTime
          while (!gotOne) {
              if (cl.get(Calendar.YEAR) > 2999) { // prevent endless loop...
                  return null;
              }
  
              SortedSet<Integer> st;
              int t = 0;
  
              int sec = cl.get(Calendar.SECOND);
              int min = cl.get(Calendar.MINUTE);
  
              // get second.................................................
              st = seconds.tailSet(sec);
              if (null != st && st.size() != 0) {
                  sec = st.first();
              } else {
                  sec = seconds.first();
                  min++;
                  cl.set(Calendar.MINUTE, min);
              }
              cl.set(Calendar.SECOND, sec);
  
              min = cl.get(Calendar.MINUTE);
              int hr = cl.get(Calendar.HOUR_OF_DAY);
              t = -1;
  
              // get minute.................................................
              st = minutes.tailSet(min);
              if (null != st && st.size() != 0) {
                  t = min;
                  min = st.first();
              } else {
                  min = minutes.first();
                  hr++;
              }
              if (min != t) {
                  cl.set(Calendar.SECOND, 0);
                  cl.set(Calendar.MINUTE, min);
                  setCalendarHour(cl, hr);
                  continue;
              }
              cl.set(Calendar.MINUTE, min);
  
              hr = cl.get(Calendar.HOUR_OF_DAY);
              int day = cl.get(Calendar.DAY_OF_MONTH);
              t = -1;
  
              // get hour...................................................
              st = hours.tailSet(hr);
              if (null != st && st.size() != 0) {
                  t = hr;
                  hr = st.first();
              } else {
                  hr = hours.first();
                  day++;
              }
              if (hr != t) {
                  cl.set(Calendar.SECOND, 0);
                  cl.set(Calendar.MINUTE, 0);
                  cl.set(Calendar.DAY_OF_MONTH, day);
                  setCalendarHour(cl, hr);
                  continue;
              }
              cl.set(Calendar.HOUR_OF_DAY, hr);
  
              day = cl.get(Calendar.DAY_OF_MONTH);
              int mon = cl.get(Calendar.MONTH) + 1;
              // '+ 1' because calendar is 0-based for this field, and we are
              // 1-based
              t = -1;
              int tmon = mon;
  
              // get day...................................................
              boolean dayOfMSpec = !daysOfMonth.contains(NO_SPEC);
              boolean dayOfWSpec = !daysOfWeek.contains(NO_SPEC);
              if (dayOfMSpec && !dayOfWSpec) { // get day by day of month rule
                  st = daysOfMonth.tailSet(day);
                  if (lastdayOfMonth) {
                      if (!nearestWeekday) {
                          t = day;
                          day = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
                          day -= lastdayOffset;
                          if (t > day) {
                              mon++;
                              if (mon > 12) {
                                  mon = 1;
                                  tmon = 3333; // ensure test of mon != tmon further below fails
                                  cl.add(Calendar.YEAR, 1);
                              }
                              day = 1;
                          }
                      } else {
                          t = day;
                          day = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
                          day -= lastdayOffset;
  
                          Calendar tcal = Calendar.getInstance(getTimeZone());
                          tcal.set(Calendar.SECOND, 0);
                          tcal.set(Calendar.MINUTE, 0);
                          tcal.set(Calendar.HOUR_OF_DAY, 0);
                          tcal.set(Calendar.DAY_OF_MONTH, day);
                          tcal.set(Calendar.MONTH, mon - 1);
                          tcal.set(Calendar.YEAR, cl.get(Calendar.YEAR));
  
                          int ldom = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
                          int dow = tcal.get(Calendar.DAY_OF_WEEK);
  
                          if (dow == Calendar.SATURDAY && day == 1) {
                              day += 2;
                          } else if (dow == Calendar.SATURDAY) {
                              day -= 1;
                          } else if (dow == Calendar.SUNDAY && day == ldom) {
                              day -= 2;
                          } else if (dow == Calendar.SUNDAY) {
                              day += 1;
                          }
  
                          tcal.set(Calendar.SECOND, sec);
                          tcal.set(Calendar.MINUTE, min);
                          tcal.set(Calendar.HOUR_OF_DAY, hr);
                          tcal.set(Calendar.DAY_OF_MONTH, day);
                          tcal.set(Calendar.MONTH, mon - 1);
                          Date nTime = tcal.getTime();
                          if (nTime.before(afterTime)) {
                              day = 1;
                              mon++;
                          }
                      }
                  } else if (nearestWeekday) {
                      t = day;
                      day = daysOfMonth.first();
  
                      Calendar tcal = Calendar.getInstance(getTimeZone());
                      tcal.set(Calendar.SECOND, 0);
                      tcal.set(Calendar.MINUTE, 0);
                      tcal.set(Calendar.HOUR_OF_DAY, 0);
                      tcal.set(Calendar.DAY_OF_MONTH, day);
                      tcal.set(Calendar.MONTH, mon - 1);
                      tcal.set(Calendar.YEAR, cl.get(Calendar.YEAR));
  
                      int ldom = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
                      int dow = tcal.get(Calendar.DAY_OF_WEEK);
  
                      if (dow == Calendar.SATURDAY && day == 1) {
                          day += 2;
                      } else if (dow == Calendar.SATURDAY) {
                          day -= 1;
                      } else if (dow == Calendar.SUNDAY && day == ldom) {
                          day -= 2;
                      } else if (dow == Calendar.SUNDAY) {
                          day += 1;
                      }
  
                      tcal.set(Calendar.SECOND, sec);
                      tcal.set(Calendar.MINUTE, min);
                      tcal.set(Calendar.HOUR_OF_DAY, hr);
                      tcal.set(Calendar.DAY_OF_MONTH, day);
                      tcal.set(Calendar.MONTH, mon - 1);
                      Date nTime = tcal.getTime();
                      if (nTime.before(afterTime)) {
                          day = daysOfMonth.first();
                          mon++;
                      }
                  } else if (null != st && st.size() != 0) {
                      t = day;
                      day = st.first();
                      // make sure we don't over-run a short month, such as february
                      int lastDay = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
                      if (day > lastDay) {
                          day = daysOfMonth.first();
                          mon++;
                      }
                  } else {
                      day = daysOfMonth.first();
                      mon++;
                  }
  
                  if (day != t || mon != tmon) {
                      cl.set(Calendar.SECOND, 0);
                      cl.set(Calendar.MINUTE, 0);
                      cl.set(Calendar.HOUR_OF_DAY, 0);
                      cl.set(Calendar.DAY_OF_MONTH, day);
                      cl.set(Calendar.MONTH, mon - 1);
                      // '- 1' because calendar is 0-based for this field, and we
                      // are 1-based
                      continue;
                  }
              } else if (dayOfWSpec && !dayOfMSpec) { // get day by day of week rule
                  if (lastdayOfWeek) { // are we looking for the last XXX day of
                      // the month?
                      int dow = daysOfWeek.first(); // desired
                      // d-o-w
                      int cDow = cl.get(Calendar.DAY_OF_WEEK); // current d-o-w
                      int daysToAdd = 0;
                      if (cDow < dow) {
                          daysToAdd = dow - cDow;
                      }
                      if (cDow > dow) {
                          daysToAdd = dow + (7 - cDow);
                      }
  
                      int lDay = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
  
                      if (day + daysToAdd > lDay) { // did we already miss the
                          // last one?
                          cl.set(Calendar.SECOND, 0);
                          cl.set(Calendar.MINUTE, 0);
                          cl.set(Calendar.HOUR_OF_DAY, 0);
                          cl.set(Calendar.DAY_OF_MONTH, 1);
                          cl.set(Calendar.MONTH, mon);
                          // no '- 1' here because we are promoting the month
                          continue;
                      }
  
                      // find date of last occurrence of this day in this month...
                      while ((day + daysToAdd + 7) <= lDay) {
                          daysToAdd += 7;
                      }
  
                      day += daysToAdd;
  
                      if (daysToAdd > 0) {
                          cl.set(Calendar.SECOND, 0);
                          cl.set(Calendar.MINUTE, 0);
                          cl.set(Calendar.HOUR_OF_DAY, 0);
                          cl.set(Calendar.DAY_OF_MONTH, day);
                          cl.set(Calendar.MONTH, mon - 1);
                          // '- 1' here because we are not promoting the month
                          continue;
                      }
  
                  } else if (nthdayOfWeek != 0) {
                      // are we looking for the Nth XXX day in the month?
                      int dow = daysOfWeek.first(); // desired
                      // d-o-w
                      int cDow = cl.get(Calendar.DAY_OF_WEEK); // current d-o-w
                      int daysToAdd = 0;
                      if (cDow < dow) {
                          daysToAdd = dow - cDow;
                      } else if (cDow > dow) {
                          daysToAdd = dow + (7 - cDow);
                      }
  
                      boolean dayShifted = daysToAdd > 0;
  
                      day += daysToAdd;
                      int weekOfMonth = day / 7;
                      if (day % 7 > 0) {
                          weekOfMonth++;
                      }
  
                      daysToAdd = (nthdayOfWeek - weekOfMonth) * 7;
                      day += daysToAdd;
                      if (daysToAdd < 0 || day > getLastDayOfMonth(mon, cl.get(Calendar.YEAR))) {
                          cl.set(Calendar.SECOND, 0);
                          cl.set(Calendar.MINUTE, 0);
                          cl.set(Calendar.HOUR_OF_DAY, 0);
                          cl.set(Calendar.DAY_OF_MONTH, 1);
                          cl.set(Calendar.MONTH, mon);
                          // no '- 1' here because we are promoting the month
                          continue;
                      } else if (daysToAdd > 0 || dayShifted) {
                          cl.set(Calendar.SECOND, 0);
                          cl.set(Calendar.MINUTE, 0);
                          cl.set(Calendar.HOUR_OF_DAY, 0);
                          cl.set(Calendar.DAY_OF_MONTH, day);
                          cl.set(Calendar.MONTH, mon - 1);
                          // '- 1' here because we are NOT promoting the month
                          continue;
                      }
                  } else {
                      int cDow = cl.get(Calendar.DAY_OF_WEEK); // current d-o-w
                      int dow = daysOfWeek.first(); // desired
                      // d-o-w
                      st = daysOfWeek.tailSet(cDow);
                      if (null != st && st.size() > 0) {
                          dow = st.first();
                      }
  
                      int daysToAdd = 0;
                      if (cDow < dow) {
                          daysToAdd = dow - cDow;
                      }
                      if (cDow > dow) {
                          daysToAdd = dow + (7 - cDow);
                      }
  
                      int lDay = getLastDayOfMonth(mon, cl.get(Calendar.YEAR));
  
                      if (day + daysToAdd > lDay) { // will we pass the end of
                          // the month?
                          cl.set(Calendar.SECOND, 0);
                          cl.set(Calendar.MINUTE, 0);
                          cl.set(Calendar.HOUR_OF_DAY, 0);
                          cl.set(Calendar.DAY_OF_MONTH, 1);
                          cl.set(Calendar.MONTH, mon);
                          // no '- 1' here because we are promoting the month
                          continue;
                      } else if (daysToAdd > 0) { // are we swithing days?
                          cl.set(Calendar.SECOND, 0);
                          cl.set(Calendar.MINUTE, 0);
                          cl.set(Calendar.HOUR_OF_DAY, 0);
                          cl.set(Calendar.DAY_OF_MONTH, day + daysToAdd);
                          cl.set(Calendar.MONTH, mon - 1);
                          // '- 1' because calendar is 0-based for this field,
                          // and we are 1-based
                          continue;
                      }
                  }
              } else { // dayOfWSpec && !dayOfMSpec
                  throw new UnsupportedOperationException(
                          "Support for specifying both a day-of-week AND a day-of-month parameter is not implemented.");
              }
              cl.set(Calendar.DAY_OF_MONTH, day);
  
              mon = cl.get(Calendar.MONTH) + 1;
              // '+ 1' because calendar is 0-based for this field, and we are
              // 1-based
              int year = cl.get(Calendar.YEAR);
              t = -1;
  
              // test for expressions that never generate a valid fire date,
              // but keep looping...
              if (year > MAX_YEAR) {
                  return null;
              }
  
              // get month...................................................
              st = months.tailSet(mon);
              if (null != st && st.size() != 0) {
                  t = mon;
                  mon = st.first();
              } else {
                  mon = months.first();
                  year++;
              }
              if (mon != t) {
                  cl.set(Calendar.SECOND, 0);
                  cl.set(Calendar.MINUTE, 0);
                  cl.set(Calendar.HOUR_OF_DAY, 0);
                  cl.set(Calendar.DAY_OF_MONTH, 1);
                  cl.set(Calendar.MONTH, mon - 1);
                  // '- 1' because calendar is 0-based for this field, and we are
                  // 1-based
                  cl.set(Calendar.YEAR, year);
                  continue;
              }
              cl.set(Calendar.MONTH, mon - 1);
              // '- 1' because calendar is 0-based for this field, and we are
              // 1-based
  
              year = cl.get(Calendar.YEAR);
              t = -1;
  
              // get year...................................................
              st = years.tailSet(year);
              if (null != st && st.size() != 0) {
                  t = year;
                  year = st.first();
              } else {
                  return null; // ran out of years...
              }
  
              if (year != t) {
                  cl.set(Calendar.SECOND, 0);
                  cl.set(Calendar.MINUTE, 0);
                  cl.set(Calendar.HOUR_OF_DAY, 0);
                  cl.set(Calendar.DAY_OF_MONTH, 1);
                  cl.set(Calendar.MONTH, 0);
                  // '- 1' because calendar is 0-based for this field, and we are
                  // 1-based
                  cl.set(Calendar.YEAR, year);
                  continue;
              }
              cl.set(Calendar.YEAR, year);
  
              gotOne = true;
          } // while( !done )
  
          return cl.getTime();
      }
  
      /**
       * Advance the calendar to the particular hour paying particular attention to daylight saving problems.
       *
       * @param cal  the calendar to operate on
       * @param hour the hour to set
       */
      protected void setCalendarHour(Calendar cal, int hour) {
          cal.set(Calendar.HOUR_OF_DAY, hour);
          if (cal.get(Calendar.HOUR_OF_DAY) != hour && hour != 24) {
              cal.set(Calendar.HOUR_OF_DAY, hour + 1);
          }
      }
  
      /**
       * NOT YET IMPLEMENTED: Returns the time before the given time that the <code>CronExpression</code> matches.
       *
       * @param endTime end time
       * @return date
       */
      public Date getTimeBefore(Date endTime) {
          return null;
      }
  
      /**
       * NOT YET IMPLEMENTED: Returns the final time that the <code>CronExpression</code> will match.
       *
       * @return time
       */
      public Date getFinalFireTime() {
          return null;
      }
  
      protected int getLastDayOfMonth(int monthNum, int year) {
  
          switch (monthNum) {
              case 1:
                  return 31;
  
              case 2:
                  return (DateKit.isLeapYear(year)) ? 29 : 28;
  
              case 3:
                  return 31;
  
              case 4:
                  return 30;
  
              case 5:
                  return 31;
  
              case 6:
                  return 30;
  
              case 7:
                  return 31;
  
              case 8:
                  return 31;
  
              case 9:
                  return 30;
  
              case 10:
                  return 31;
  
              case 11:
                  return 30;
  
              case 12:
                  return 31;
  
              default:
                  throw new IllegalArgumentException("Illegal month number: " + monthNum);
          }
      }
  
      private void readObject(java.io.ObjectInputStream stream) throws java.io.IOException, ClassNotFoundException {
  
          stream.defaultReadObject();
          try {
              buildExpression(cronExpression);
          } catch (Exception ignore) {
          }
      }
  
      class ValueSet {
  
          public int value;
  
          public int pos;
      }
  
  }
  