#14 -- Add date utils

src/main/java/ru/ulstu/DateUtils.java

@@ -0,0 +1,72 @@
+package ru.ulstu;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.Month;
+import java.time.ZoneId;
+import java.util.Arrays;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.List;
+
+public class DateUtils {
+
+    public static Date clearTime(Date date) {
+        if (date == null) {
+            return null;
+        }
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+        calendar.set(Calendar.HOUR_OF_DAY, 0);
+        calendar.set(Calendar.MINUTE, 0);
+        calendar.set(Calendar.SECOND, 0);
+        calendar.set(Calendar.MILLISECOND, 0);
+        return calendar.getTime();
+    }
+
+    public static Calendar getCalendar(Date date) {
+        Calendar cal = Calendar.getInstance();
+        cal.setTime(date);
+        return cal;
+    }
+
+    public static List<Month> getMonths() {
+        return Arrays.asList(Month.values());
+    }
+
+    public static Date instantToDate(Instant instant) {
+        return Date.from(instant);
+    }
+
+    public static Date localDateToDate(LocalDate localDate) {
+        return Date.from(localDate.atStartOfDay(ZoneId.systemDefault()).toInstant());
+    }
+
+    public static Date localDateTimeToDate(LocalDateTime localDate) {
+        return Date.from(localDate.atZone(ZoneId.systemDefault()).toInstant());
+    }
+
+    public static Date localTimeToDate(LocalTime localTime) {
+        return Date.from(localTime.atDate(LocalDate.now()).atZone(ZoneId.systemDefault()).toInstant());
+    }
+
+    public static Date addDays(Date date, int count) {
+        Calendar cal = getCalendar(date);
+        cal.add(Calendar.DAY_OF_MONTH, count);
+        return cal.getTime();
+    }
+
+    public static Date addYears(Date date, int count) {
+        Calendar cal = getCalendar(date);
+        cal.add(Calendar.YEAR, count);
+        return cal.getTime();
+    }
+
+    public static LocalDate convertToLocalDate(Date dateToConvert) {
+        return dateToConvert.toInstant()
+                .atZone(ZoneId.systemDefault())
+                .toLocalDate();
+    }
+}