[BAEL-8456] - Moved Java Date articles into a new module - 'java-dates'

java-dates/src/test/java/com/baeldung/date/DateDiffUnitTest.java

@@ -0,0 +1,70 @@
+package com.baeldung.date;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+
+public class DateDiffUnitTest {
+
+    @Test
+    public void givenTwoDatesBeforeJava8_whenDifferentiating_thenWeGetSix() throws ParseException {
+        SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy", Locale.ENGLISH);
+        Date firstDate = sdf.parse("06/24/2017");
+        Date secondDate = sdf.parse("06/30/2017");
+
+        long diffInMillies = Math.abs(secondDate.getTime() - firstDate.getTime());
+        long diff = TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);
+
+        assertEquals(diff, 6);
+    }
+
+    @Test
+    public void givenTwoDateTimesInJava8_whenDifferentiating_thenWeGetSix() {
+        LocalDateTime now = LocalDateTime.now();
+        LocalDateTime sixMinutesBehind = now.minusMinutes(6);
+
+        Duration duration = Duration.between(now, sixMinutesBehind);
+        long diff = Math.abs(duration.toMinutes());
+
+        assertEquals(diff, 6);
+    }
+
+    @Test
+    public void givenTwoDatesInJodaTime_whenDifferentiating_thenWeGetSix() {
+        org.joda.time.LocalDate now = org.joda.time.LocalDate.now();
+        org.joda.time.LocalDate sixDaysBehind = now.minusDays(6);
+
+        org.joda.time.Period period = new org.joda.time.Period(now, sixDaysBehind);
+        long diff = Math.abs(period.getDays());
+
+        assertEquals(diff, 6);
+    }
+
+    @Test
+    public void givenTwoDateTimesInJodaTime_whenDifferentiating_thenWeGetSix() {
+        org.joda.time.LocalDateTime now = org.joda.time.LocalDateTime.now();
+        org.joda.time.LocalDateTime sixMinutesBehind = now.minusMinutes(6);
+
+        org.joda.time.Period period = new org.joda.time.Period(now, sixMinutesBehind);
+        long diff = Math.abs(period.getDays());
+    }
+
+    @Test
+    public void givenTwoDatesInDate4j_whenDifferentiating_thenWeGetSix() {
+        hirondelle.date4j.DateTime now = hirondelle.date4j.DateTime.now(TimeZone.getDefault());
+        hirondelle.date4j.DateTime sixDaysBehind = now.minusDays(6);
+
+        long diff = Math.abs(now.numDaysFrom(sixDaysBehind));
+
+        assertEquals(diff, 6);
+    }
+}