diff --git a/core-java-modules/core-java-date-operations-2/README.md b/core-java-modules/core-java-date-operations-2/README.md index 728162ca1a..0f57686fe4 100644 --- a/core-java-modules/core-java-date-operations-2/README.md +++ b/core-java-modules/core-java-date-operations-2/README.md @@ -7,4 +7,5 @@ This module contains articles about date operations in Java. - [Checking If Two Java Dates Are on the Same Day](https://www.baeldung.com/java-check-two-dates-on-same-day) - [Converting Java Date to OffsetDateTime](https://www.baeldung.com/java-convert-date-to-offsetdatetime) - [How to Set the JVM Time Zone](https://www.baeldung.com/java-jvm-time-zone) +- [Extracting the Day of the Week](http://inprogress.baeldung.com/wp-admin/post.php?post=184664&action=edit&classic-editor) - [[<-- Prev]](/core-java-modules/core-java-date-operations-1) diff --git a/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/datetime/dayofweek/DayOfWeekExtractor.java b/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/datetime/dayofweek/DayOfWeekExtractor.java new file mode 100644 index 0000000000..b027790e35 --- /dev/null +++ b/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/datetime/dayofweek/DayOfWeekExtractor.java @@ -0,0 +1,35 @@ +package com.baeldung.datetime.dayofweek; + +import java.text.DateFormat; +import java.text.SimpleDateFormat; +import java.time.DayOfWeek; +import java.time.LocalDate; +import java.time.format.TextStyle; +import java.util.Calendar; +import java.util.Date; +import java.util.Locale; + +public class DayOfWeekExtractor { + + public static int getDayNumberOld(Date date) { + Calendar cal = Calendar.getInstance(); + cal.setTime(date); + return cal.get(Calendar.DAY_OF_WEEK); + } + + public static String getDayStringOld(Date date, Locale locale ) { + DateFormat formatter = new SimpleDateFormat("EEEE", locale); + return formatter.format(date); + } + + public static int getDayNumberNew(LocalDate date) { + DayOfWeek day = date.getDayOfWeek(); + return day.getValue(); + } + + public static String getDayStringNew(LocalDate date, Locale locale ) { + DayOfWeek day = date.getDayOfWeek(); + return day.getDisplayName(TextStyle.FULL, locale); + } + +} diff --git a/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/datetime/dayofweek/DayOfWeekExtractorUnitTest.java b/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/datetime/dayofweek/DayOfWeekExtractorUnitTest.java new file mode 100644 index 0000000000..0dfd50dca2 --- /dev/null +++ b/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/datetime/dayofweek/DayOfWeekExtractorUnitTest.java @@ -0,0 +1,52 @@ +package com.baeldung.datetime.dayofweek; + +import static org.assertj.core.api.Assertions.assertThat; + +import java.text.DateFormat; +import java.text.ParseException; +import java.text.SimpleDateFormat; +import java.time.LocalDate; +import java.util.Calendar; +import java.util.Locale; + +import org.junit.Test; + +public class DayOfWeekExtractorUnitTest { + + private DateFormat oldDateParser = new SimpleDateFormat("yyyy-MM-dd"); + + @Test + public void givenFeb29_2020_thenOldSaturdayNumber() throws ParseException { + assertThat(DayOfWeekExtractor.getDayNumberOld(oldDateParser.parse("2020-02-29")) == Calendar.SATURDAY); + } + + @Test + public void givenFeb29_2020_and_localeUS_thenOldSaturdayText() throws ParseException { + assertThat("Saturday".equals(DayOfWeekExtractor.getDayStringOld(oldDateParser.parse("2020-02-29"), Locale.US)) ); + } + + @Test + public void givenFeb29_2020_and_localeDE_thenOldSaturdayText() throws ParseException { + assertThat("Samstag".equals(DayOfWeekExtractor.getDayStringOld(oldDateParser.parse("2020-02-29"), Locale.GERMANY)) ); + } + + @Test + public void givenFeb29_2020_thenNewSaturdayNumber() throws ParseException { + assertThat(DayOfWeekExtractor.getDayNumberNew(LocalDate.parse("2020-02-29")) == Calendar.SATURDAY); + } + + @Test + public void givenFeb29_2020_and_localeUS_thenNewSaturdayText() throws ParseException { + assertThat("Saturday".equals(DayOfWeekExtractor.getDayStringOld(oldDateParser.parse("2020-02-29"), Locale.US)) ); + } + + @Test + public void givenFeb29_2020_and_localeDE_thenNewSaturdayText() throws ParseException { + assertThat("Samstag".equals(DayOfWeekExtractor.getDayStringOld(oldDateParser.parse("2020-02-29"), Locale.GERMANY)) ); + } + + +} + + +