add methods

hutool-core/src/main/java/org/dromara/hutool/core/date/CalendarUtil.java

@@ -13,6 +13,7 @@
 package org.dromara.hutool.core.date;
 
 import org.dromara.hutool.core.comparator.CompareUtil;
+import org.dromara.hutool.core.lang.Assert;
 import org.dromara.hutool.core.math.ChineseNumberFormatter;
 import org.dromara.hutool.core.date.format.GlobalCustomFormat;
 import org.dromara.hutool.core.date.format.parser.DateParser;
@@ -577,6 +578,20 @@ public class CalendarUtil {
 		return calendar.getActualMaximum(dateField);
 	}
 
+	/**
+	 * 获得日期的某个部分<br>
+	 * 例如获得年的部分，则使用 getField(DatePart.YEAR)
+	 *
+	 * @param calendar {@link Calendar}
+	 * @param field    表示日期的哪个部分的枚举 {@link DateField}
+	 * @return 某个部分的值
+	 * @since 6.0.0
+	 */
+	@SuppressWarnings("MagicConstant")
+	public static int getField(final Calendar calendar, final DateField field) {
+		return Assert.notNull(calendar).get(Assert.notNull(field).getValue());
+	}
+
 	/**
 	 * Calendar{@link Instant}对象
 	 *
@@ -596,6 +611,9 @@ public class CalendarUtil {
 	 * @since 5.0.5
 	 */
 	public static LocalDateTime toLocalDateTime(final Calendar calendar) {
+		if(null == calendar){
+			return null;
+		}
 		return LocalDateTime.ofInstant(calendar.toInstant(), calendar.getTimeZone().toZoneId());
 	}
 

hutool-core/src/main/java/org/dromara/hutool/core/date/DateField.java

@@ -19,7 +19,6 @@ import java.util.Calendar;
  * 与Calendar相应值对应
  *
  * @author Looly
- *
  */
 public enum DateField {
 
@@ -121,6 +120,11 @@ public enum DateField {
 		this.value = value;
 	}
 
+	/**
+	 * 获取{@link Calendar}中对应的值
+	 *
+	 * @return {@link Calendar}中对应的值
+	 */
 	public int getValue() {
 		return this.value;
 	}
@@ -133,38 +137,38 @@ public enum DateField {
 	 */
 	public static DateField of(final int calendarPartIntValue) {
 		switch (calendarPartIntValue) {
-		case Calendar.ERA:
+			case Calendar.ERA:
-			return ERA;
+				return ERA;
-		case Calendar.YEAR:
+			case Calendar.YEAR:
-			return YEAR;
+				return YEAR;
-		case Calendar.MONTH:
+			case Calendar.MONTH:
-			return MONTH;
+				return MONTH;
-		case Calendar.WEEK_OF_YEAR:
+			case Calendar.WEEK_OF_YEAR:
-			return WEEK_OF_YEAR;
+				return WEEK_OF_YEAR;
-		case Calendar.WEEK_OF_MONTH:
+			case Calendar.WEEK_OF_MONTH:
-			return WEEK_OF_MONTH;
+				return WEEK_OF_MONTH;
-		case Calendar.DAY_OF_MONTH:
+			case Calendar.DAY_OF_MONTH:
-			return DAY_OF_MONTH;
+				return DAY_OF_MONTH;
-		case Calendar.DAY_OF_YEAR:
+			case Calendar.DAY_OF_YEAR:
-			return DAY_OF_YEAR;
+				return DAY_OF_YEAR;
-		case Calendar.DAY_OF_WEEK:
+			case Calendar.DAY_OF_WEEK:
-			return DAY_OF_WEEK;
+				return DAY_OF_WEEK;
-		case Calendar.DAY_OF_WEEK_IN_MONTH:
+			case Calendar.DAY_OF_WEEK_IN_MONTH:
-			return DAY_OF_WEEK_IN_MONTH;
+				return DAY_OF_WEEK_IN_MONTH;
-		case Calendar.AM_PM:
+			case Calendar.AM_PM:
-			return AM_PM;
+				return AM_PM;
-		case Calendar.HOUR:
+			case Calendar.HOUR:
-			return HOUR;
+				return HOUR;
-		case Calendar.HOUR_OF_DAY:
+			case Calendar.HOUR_OF_DAY:
-			return HOUR_OF_DAY;
+				return HOUR_OF_DAY;
-		case Calendar.MINUTE:
+			case Calendar.MINUTE:
-			return MINUTE;
+				return MINUTE;
-		case Calendar.SECOND:
+			case Calendar.SECOND:
-			return SECOND;
+				return SECOND;
-		case Calendar.MILLISECOND:
+			case Calendar.MILLISECOND:
-			return MILLISECOND;
+				return MILLISECOND;
-		default:
+			default:
-			return null;
+				return null;
 		}
 	}
 }

hutool-cron/src/main/java/org/dromara/hutool/cron/pattern/PatternUtil.java

@@ -59,9 +59,9 @@ class PatternUtil {
 		final int minute = calendar.get(Calendar.MINUTE);
 		final int hour = calendar.get(Calendar.HOUR_OF_DAY);
 		final int dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH);
-		final int month = calendar.get(Calendar.MONTH) + 1;// 月份从1开始
+		final int monthBase1 = calendar.get(Calendar.MONTH) + 1;// 月份从1开始
-		final int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1; // 星期从0开始，0和7都表示周日
+		final int dayOfWeekBase0 = calendar.get(Calendar.DAY_OF_WEEK) - 1; // 星期从0开始，0和7都表示周日
 		final int year = calendar.get(Calendar.YEAR);
-		return new int[]{second, minute, hour, dayOfMonth, month, dayOfWeek, year};
+		return new int[]{second, minute, hour, dayOfMonth, monthBase1, dayOfWeekBase0, year};
 	}
 }

hutool-cron/src/test/java/org/dromara/hutool/cron/pattern/IssueI92H5HTest.java

@@ -14,6 +14,7 @@ package org.dromara.hutool.cron.pattern;
 
 import org.dromara.hutool.core.date.DateTime;
 import org.dromara.hutool.core.date.DateUtil;
+import org.dromara.hutool.core.lang.Console;
 import org.junit.jupiter.api.Test;
 
 import java.util.Calendar;
@@ -28,6 +29,6 @@ public class IssueI92H5HTest {
 		final CronPattern pattern = new CronPattern("0 0 0 L 2 ?");
 		//noinspection ConstantConditions
 		final Calendar calendar = pattern.nextMatchAfter(date.toCalendar());
-		System.out.println(DateUtil.date(calendar));
+		Console.log(DateUtil.date(calendar));
 	}
 }