add months between and hostname util

hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java

@@ -21,13 +21,7 @@ import java.time.Year;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.TemporalAccessor;
 
-import java.util.Calendar;
+import java.util.*;
-import java.util.Date;
-import java.util.GregorianCalendar;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.TimeZone;
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 
@@ -1389,6 +1383,30 @@ public class DateUtil extends CalendarUtil {
 		return new DateBetween(beginDate, endDate).betweenMonth(isReset);
 	}
 
+	/**
+	 * 获取两个日期之间所有的月份
+	 * @param start 开始时间
+	 * @param end 结束时间
+	 * @return List<String> 格式为yyyMM格式的月份列表 包含收尾</>
+	 * @since 5.4.4
+	 */
+	public static List<String> getBetweenMonths(Date start, Date end) {
+		List<String> result = new ArrayList<>();
+		SimpleDateFormat sdf = new SimpleDateFormat("yyyyMM");
+		Calendar tempStart = Calendar.getInstance();
+		tempStart.setTime(start);
+		// 加一个月，保证开始和结束同步时返回当月
+		tempStart.add(Calendar.MONTH, 1);
+		Calendar tempEnd = Calendar.getInstance();
+		tempEnd.setTime(end);
+		result.add(sdf.format(start));
+		while (tempStart.before(tempEnd) || tempStart.equals(tempEnd)) {
+			result.add(sdf.format(tempStart.getTime()));
+			tempStart.add(Calendar.MONTH, 1);
+		}
+		return result;
+	}
+
 	/**
 	 * 计算两个日期相差年数<br>
 	 * 在非重置情况下，如果起始日期的月小于结束日期的月，年数要少算1（不足1年）

hutool-core/src/main/java/cn/hutool/core/net/NetUtil.java

@@ -42,6 +42,7 @@ import java.util.TreeSet;
 public class NetUtil {
 
 	public final static String LOCAL_IP = "127.0.0.1";
+	public static String LOCAL_HOSTNAME = "";
 
 	/**
 	 * 默认最小端口，1024
@@ -533,6 +534,23 @@ public class NetUtil {
 		return null;
 	}
 
+	/**
+	 * 获取主机名称
+	 * @return 主机名称
+	 * @since 5.4.4
+	 */
+	public static String getLocalHostName() {
+		try {
+			if (StrUtil.isNotBlank(LOCAL_HOSTNAME)) {
+				return LOCAL_HOSTNAME;
+			}
+			LOCAL_HOSTNAME = InetAddress.getLocalHost().getHostName();
+		} catch (UnknownHostException e) {
+			LOCAL_HOSTNAME = getLocalhostStr();
+		}
+		return LOCAL_HOSTNAME;
+	}
+
 	/**
 	 * 创建 {@link InetSocketAddress}
 	 *

hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java

@@ -819,4 +819,12 @@ public class DateUtilTest {
 		final DateTime parse = DateUtil.parse(dt);
 		Assert.assertEquals("2020-06-03 12:32:12", parse.toString());
 	}
+
+	@Test
+	public void getBetweenMonthsTest() {
+		List<String> months1 = DateUtil.getBetweenMonths(new Date(), new Date());
+		Assert.assertEquals(1, months1.size());
+		List<String> months = DateUtil.getBetweenMonths(DateUtil.parse("2020-05-08 3:12:3"), new Date());
+		Assert.assertEquals(5, months.size());
+	}
 }

hutool-core/src/test/java/cn/hutool/core/net/NetUtilTest.java

@@ -74,4 +74,9 @@ public class NetUtilTest {
 		Assert.assertEquals("/", httpCookie.getPath());
 		Assert.assertEquals("cookiedomain.com", httpCookie.getDomain());
 	}
+
+	@Test
+	public void getLocalHostNameTest() {
+		System.out.println(NetUtil.getLocalHostName());
+	}
 }