Add Date & Calendar extensions (#26)

README.md

@@ -33,9 +33,9 @@ val result = "2021-06-07".parseZonedDateTime()
 ```kotlin
 val result = ZonedDateTimeUtil.new(year = 2021, month = 3, day = 25)
 
-val result = LocalDateTimeUtil.new(Date())
+val result = Date().toLocalDateTime()
 
-val result = LocalDateUtil.new(GregorianCalendar())
+val result = GregorianCalendar().toLocalDate()
 
 val result = LocalTimeUtil.new(hour = 5, minute = 30)
 ```

src/main/kotlin/javatimefun/calendar/extensions/CalendarMutatingExtensions.kt

@@ -0,0 +1,23 @@
+package javatimefun.calendar.extensions
+
+import javatimefun.localdate.LocalDateUtil
+import javatimefun.localdatetime.LocalDateTimeUtil
+import javatimefun.localtime.LocalTimeUtil
+import java.time.*
+import java.util.Calendar
+
+/**
+ * @param useSystemTimeZone  If true, converts to time zone of the device, else leaves as is on calendar.
+ * @return  ZonedDateTime.
+ */
+fun Calendar.toZonedDateTime(): ZonedDateTime =
+    ZonedDateTime.ofInstant(this.toInstant(), ZoneId.of(this.timeZone.id))
+
+fun Calendar.toLocalDateTime(): LocalDateTime =
+    LocalDateTimeUtil.new(this.toInstant().toEpochMilli())
+
+fun Calendar.toLocalDate(): LocalDate =
+    LocalDateUtil.new(this.toInstant().toEpochMilli())
+
+fun Calendar.toLocalTime(): LocalTime =
+    LocalTimeUtil.new(this.toInstant().toEpochMilli())

src/main/kotlin/javatimefun/date/extensions/DateMutatingExtensions.kt

@@ -0,0 +1,36 @@
+package javatimefun.date.extensions
+
+import javatimefun.localdate.LocalDateUtil
+import javatimefun.localdatetime.LocalDateTimeUtil
+import javatimefun.localtime.LocalTimeUtil
+import javatimefun.zoneddatetime.ZonedDateTimeUtil
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.LocalTime
+import java.time.ZonedDateTime
+import java.util.Date
+
+/**
+ * @param useSystemTimeZone  If true, converts to time zone of the device, else leaves as UTC.
+ * @return  ZonedDateTime.
+ */
+fun Date.toZonedDateTime(useSystemTimeZone: Boolean = true): ZonedDateTime =
+    ZonedDateTimeUtil.new(this.toInstant().toEpochMilli(), useSystemTimeZone)
+
+/**
+ * @return  LocalDateTime.
+ */
+fun Date.toLocalDateTime(): LocalDateTime =
+    LocalDateTimeUtil.new(this.toInstant().toEpochMilli())
+
+/**
+ * @return  LocalDate.
+ */
+fun Date.toLocalDate(): LocalDate =
+    LocalDateUtil.new(this.toInstant().toEpochMilli())
+
+/**
+ * @return  LocalTime.
+ */
+fun Date.toLocalTime(): LocalTime =
+    LocalTimeUtil.new(this.toInstant().toEpochMilli())

src/main/kotlin/javatimefun/localdate/LocalDateUtil.kt

@@ -23,19 +23,6 @@ object LocalDateUtil {
      * @param epochMilliseconds  Epoch time, aka Unix time, are seconds elapsed since January 1st 1970 at 00:00:00 UTC.
      * @return  LocalDate.
      */
-    fun new(epochMilliseconds: Long): LocalDate = LocalDate.ofEpochDay(epochMilliseconds / 1000 / 60 / 60 / 24)
-
-    /**
-     * @param date  A wrapper of Epoch time in UTC.
-     * @return  LocalDate.
-     */
-    fun new(date: Date): LocalDate =
-        javatimefun.localdate.LocalDateUtil.new(date.toInstant().toEpochMilli())
-
-    /**
-     * @param calendar  Calendar, a date time variable that supports time zones.
-     * @return  LocalDate.
-     */
-    fun new(calendar: Calendar): LocalDate =
-        javatimefun.localdate.LocalDateUtil.new(calendar.toInstant().toEpochMilli())
+    fun new(epochMilliseconds: Long): LocalDate =
+        LocalDate.ofEpochDay(epochMilliseconds / 1000 / 60 / 60 / 24)
 }

src/main/kotlin/javatimefun/localdatetime/LocalDateTimeUtil.kt

@@ -1,9 +1,10 @@
 package javatimefun.localdatetime
 
+import javatimefun.date.extensions.toLocalDateTime
+import java.time.Instant
 import java.time.LocalDateTime
 import java.time.Month
-import java.time.ZoneId
-import java.util.Calendar
+import java.time.ZoneOffset
 import java.util.Date
 
 /**
@@ -58,21 +59,9 @@ object LocalDateTimeUtil {
      * @param epochMilliseconds  Epoch time, aka Unix time, are seconds elapsed since January 1st 1970 at 00:00:00 UTC.
      * @return  LocalDateTime.
      */
-    fun new(epochMilliseconds: Long): LocalDateTime = new(Date(epochMilliseconds))
-
-    /**
-     * @param date  A wrapper of Epoch time in UTC.
-     * @return  LocalDateTime.
-     */
-    fun new(date: Date): LocalDateTime = LocalDateTime.ofInstant(date.toInstant(), ZoneId.of("UTC"))
-
-    /**
-     * @param calendar  Calendar, a date time variable that supports time zones.
-     * @return  LocalDateTime.
-     */
-    fun new(calendar: Calendar, useSystemTimeZone: Boolean = true): LocalDateTime =
+    fun new(epochMilliseconds: Long): LocalDateTime =
         LocalDateTime.ofInstant(
-            calendar.toInstant(),
-            if (useSystemTimeZone) ZoneId.systemDefault() else ZoneId.of("UTC")
+            Instant.ofEpochMilli(epochMilliseconds),
+            ZoneOffset.UTC
         )
 }

src/main/kotlin/javatimefun/localtime/LocalTimeUtil.kt

@@ -1,9 +1,9 @@
 package javatimefun.localtime
 
-import javatimefun.localdatetime.LocalDateTimeUtil
+import java.time.Instant
+import java.time.LocalDateTime
 import java.time.LocalTime
-import java.util.Date
-import java.util.Calendar
+import java.time.ZoneOffset
 
 /**
  * Contains helper functions that only serve to create new LocalTimes.
@@ -48,17 +48,10 @@ object LocalTimeUtil {
      * @param epochMilliseconds  Epoch time, aka Unix time, are seconds elapsed since January 1st 1970 at 00:00:00 UTC.
      * @return  LocalTime.
      */
-    fun new(epochMilliseconds: Long): LocalTime = LocalDateTimeUtil.new(epochMilliseconds).toLocalTime()
-
-    /**
-     * @param date  A wrapper of Epoch time in UTC.
-     * @return  LocalTime.
-     */
-    fun new(date: Date): LocalTime = LocalDateTimeUtil.new(date).toLocalTime()
-
-    /**
-     * @param calendar  Calendar, a date time variable that supports time zones.
-     * @return  LocalTime.
-     */
-    fun new(calendar: Calendar): LocalTime = LocalDateTimeUtil.new(calendar, useSystemTimeZone = false).toLocalTime()
+    fun new(epochMilliseconds: Long): LocalTime =
+        LocalDateTime.ofInstant(
+            Instant.ofEpochMilli(epochMilliseconds),
+            ZoneOffset.UTC
+        )
+            .toLocalTime()
 }

src/main/kotlin/javatimefun/zoneddatetime/ZonedDateTimeUtil.kt

@@ -1,21 +1,13 @@
 package javatimefun.zoneddatetime
 
-import java.time.Instant
-import java.time.LocalDateTime
-import java.time.Month
-import java.time.ZoneId
-import java.time.ZonedDateTime
-import java.util.Calendar
-import java.util.Date
+import java.time.*
 
 /**
  * Contains helper functions that only serve to create new ZonedDateTimes.
  * Creation methods do not include parsing methods.
  */
 object ZonedDateTimeUtil {
 
-    private val UTC get() = ZoneId.of("UTC")
-
     /**
      * @param year  Year, ie, 2020.
      * @param month  Month with range 1-12, i.e. 1 for January.
@@ -38,7 +30,10 @@ object ZonedDateTimeUtil {
         useSystemTimeZone: Boolean = true
     ): ZonedDateTime {
         val localDateTime = LocalDateTime.of(year, Month.of(month), day, hourIn24, minute, second, nano)
-        return ZonedDateTime.of(localDateTime, if (useSystemTimeZone) ZoneId.systemDefault() else UTC)
+        return ZonedDateTime.of(
+            localDateTime,
+            if (useSystemTimeZone) ZoneId.systemDefault() else ZoneOffset.UTC
+        )
     }
 
     /**
@@ -71,28 +66,8 @@ object ZonedDateTimeUtil {
      * @return  ZonedDateTime.
      */
     fun new(epochMilliseconds: Long, useSystemTimeZone: Boolean = true): ZonedDateTime =
-        getZonedDateTimeFromInstant(Instant.ofEpochMilli(epochMilliseconds), useSystemTimeZone)
-
-    /**
-     * @param date  A wrapper of Epoch time in UTC.
-     * @param useSystemTimeZone  If true, converts to time zone of the device, else leaves as UTC.
-     * @return  ZonedDateTime.
-     */
-    fun new(date: Date, useSystemTimeZone: Boolean = true): ZonedDateTime =
-        getZonedDateTimeFromInstant(date.toInstant(), useSystemTimeZone)
-
-    /**
-     * @param calendar  Calendar, a date time variable that supports time zones.
-     * @param useSystemTimeZone  If true, converts to time zone of the device, else leaves as is on calendar.
-     * @return  ZonedDateTime.
-     */
-    fun new(calendar: Calendar, useSystemTimeZone: Boolean = true): ZonedDateTime {
-        if (useSystemTimeZone) {
-            return getZonedDateTimeFromInstant(calendar.toInstant(), true)
-        }
-        return ZonedDateTime.ofInstant(calendar.toInstant(), ZoneId.of(calendar.timeZone.id))
-    }
-
-    private fun getZonedDateTimeFromInstant(instant: Instant, useSystemTimeZone: Boolean): ZonedDateTime =
-        ZonedDateTime.ofInstant(instant, if (useSystemTimeZone) ZoneId.systemDefault() else UTC)
+        ZonedDateTime.ofInstant(
+            Instant.ofEpochMilli(epochMilliseconds),
+            if (useSystemTimeZone) ZoneId.systemDefault() else ZoneOffset.UTC
+        )
 }

src/test/kotlin/localdate/LocalDateUtilTest.kt

@@ -1,5 +1,7 @@
 package localdate
 
+import javatimefun.calendar.extensions.toLocalDate
+import javatimefun.date.extensions.toLocalDate
 import javatimefun.localdate.extensions.getMonthBaseZero
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
@@ -31,7 +33,7 @@ class LocalDateUtilTest {
 
         // when
         val date = Date(epoch)
-        val localDate = javatimefun.localdate.LocalDateUtil.new(date)
+        val localDate = date.toLocalDate()
 
         // then
         assertEquals(2011, localDate.year)
@@ -50,7 +52,7 @@ class LocalDateUtilTest {
             timeZone = TimeZone.getTimeZone("UTC")
             time = date
         }
-        val localDate = javatimefun.localdate.LocalDateUtil.new(calendar)
+        val localDate = calendar.toLocalDate()
 
         // then
         assertEquals(calendar[Calendar.YEAR], localDate.year)

src/test/kotlin/localdatetime/LocalDateTimeUtilTest.kt

@@ -1,5 +1,7 @@
 package localdatetime
 
+import javatimefun.calendar.extensions.toLocalDateTime
+import javatimefun.date.extensions.toLocalDateTime
 import javatimefun.localdatetime.LocalDateTimeUtil
 import javatimefun.localdatetime.extensions.getMonthBaseZero
 import org.junit.jupiter.api.Assertions.assertEquals
@@ -35,7 +37,7 @@ class LocalDateTimeUtilTest {
 
         // when
         val date = Date(epoch)
-        val localDateTime = LocalDateTimeUtil.new(date)
+        val localDateTime = date.toLocalDateTime()
 
         // then
         assertEquals(2011, localDateTime.year)
@@ -57,7 +59,7 @@ class LocalDateTimeUtilTest {
             timeZone = TimeZone.getTimeZone("UTC")
             time = date
         }
-        val localDateTime = LocalDateTimeUtil.new(calendar, useSystemTimeZone = false)
+        val localDateTime = calendar.toLocalDateTime()
 
         // then
         assertEquals(2011, localDateTime.year)

src/test/kotlin/localtime/LocalTimeUtilTest.kt

@@ -1,5 +1,7 @@
 package localtime
 
+import javatimefun.calendar.extensions.toLocalTime
+import javatimefun.date.extensions.toLocalTime
 import javatimefun.localtime.LocalTimeUtil
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
@@ -31,7 +33,7 @@ class LocalTimeUtilTest {
 
         // when
         val date = Date(epoch)
-        val localTime = LocalTimeUtil.new(date)
+        val localTime = date.toLocalTime()
 
         // then
         assertEquals(5, localTime.hour)
@@ -50,7 +52,7 @@ class LocalTimeUtilTest {
             timeZone = TimeZone.getTimeZone("UTC")
             time = date
         }
-        val localTime = LocalTimeUtil.new(calendar)
+        val localTime = calendar.toLocalTime()
 
         // then
         assertEquals(5, localTime.hour)

src/test/kotlin/zoneddatetime/ZonedDateTimeUtilTest.kt

@@ -1,5 +1,6 @@
 package zoneddatetime
 
+import javatimefun.calendar.extensions.toZonedDateTime
 import javatimefun.zoneddatetime.ZonedDateTimeUtil
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
@@ -149,7 +150,7 @@ class ZonedDateTimeTest {
             timeZone = TimeZone.getTimeZone(timeZoneId)
             set(year, month, day, hour, minute, second)
         }
-        val zonedDateTime = ZonedDateTimeUtil.new(calendar, useSystemTimeZone = false)
+        val zonedDateTime = calendar.toZonedDateTime()
 
         // then
         assertEquals(calendar.timeZone.id, zonedDateTime.zone.id)