Merge pull request eugenp#5512 from MrSamMillington/master

[BAEL-2256] Guide to simple date format unit test

Author: CalamarBicefalo

core-java/src/test/java/com/baeldung/simpledateformat/SimpleDateFormatUnitTest.java

@@ -0,0 +1,59 @@
+package com.baeldung;
+
+import org.junit.Test;
+
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+import java.util.logging.Logger;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+
+public class SimpleDateFormatUnitTest {
+
+  private static final Logger logger = Logger.getLogger(SimpleDateFormatUnitTest.class.getName());
+
+  @Test
+  public void givenSpecificDate_whenFormatted_thenCheckFormatCorrect() throws Exception {
+    SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
+    assertEquals("24-05-1977", formatter.format(new Date(233345223232L)));
+  }
+
+  @Test
+  public void givenSpecificDate_whenFormattedUsingDateFormat_thenCheckFormatCorrect() throws Exception {
+    DateFormat formatter = DateFormat.getDateInstance(DateFormat.SHORT);
+    assertEquals("5/24/77", formatter.format(new Date(233345223232L)));
+  }
+
+  @Test
+  public void givenStringDate_whenParsed_thenCheckDateCorrect() throws Exception{
+    SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
+    Date myDate = new Date(233276400000L);
+    Date parsedDate = formatter.parse("24-05-1977");
+    assertEquals(myDate.getTime(), parsedDate.getTime());
+  }
+
+  @Test
+  public void givenFranceLocale_whenFormatted_thenCheckFormatCorrect() throws Exception{
+    SimpleDateFormat franceDateFormatter = new SimpleDateFormat("EEEEE dd-MMMMMMM-yyyy", Locale.FRANCE);
+    Date myWednesday = new Date(1539341312904L);
+    assertTrue(franceDateFormatter.format(myWednesday).startsWith("vendredi"));
+  }
+
+  @Test
+  public void given2TimeZones_whenFormatted_thenCheckTimeDifference() throws Exception {
+    Date now = new Date();
+
+    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE dd-MMM-yy HH:mm:ssZ");
+
+    simpleDateFormat.setTimeZone(TimeZone.getTimeZone("Europe/London"));
+    logger.info(simpleDateFormat.format(now));
+    //change the date format
+    simpleDateFormat.setTimeZone(TimeZone.getTimeZone("America/New_York"));
+    logger.info(simpleDateFormat.format(now));
+  }
+}