add datetime test case (#17865)

Author: wynnteo

core-java-modules/core-java-8-datetime/src/main/java/com/baeldung/datetime/CalendarUtils.java

@@ -0,0 +1,14 @@
+package com.baeldung.datetime;
+
+import java.text.ParseException;
+import java.util.Calendar;
+import java.util.Date;
+
+public class CalendarUtils {
+    public static Calendar getPlusDays(Date date, int amount) throws ParseException {
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+        calendar.add(Calendar.DAY_OF_YEAR, amount);
+        return calendar;
+    }
+}

core-java-modules/core-java-8-datetime/src/main/java/com/baeldung/datetime/DateUtils.java

@@ -0,0 +1,19 @@
+package com.baeldung.datetime;
+
+import java.text.SimpleDateFormat;
+import java.text.ParseException;
+import java.util.Date;
+public class DateUtils {
+
+    public static Date getNow() {
+        return new Date();
+    }
+
+    public static Date getDate(long millis) {
+        return new Date(millis);
+    }
+
+    public static Date getDate(String dateAsString, String pattern) throws ParseException {
+        return new SimpleDateFormat(pattern).parse(dateAsString);
+    }
+}

core-java-modules/core-java-8-datetime/src/main/java/com/baeldung/datetime/sql/DateUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import java.sql.Date;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class DateUtils {
+
+    public static Date getNow() {
+        return new Date(System.currentTimeMillis());
+    }
+
+    public static Date getDate(String dateAsString) {
+        return Date.valueOf(dateAsString);
+    }
+
+    public static Date getDate(String dateAsString, String pattern) throws ParseException {
+        java.util.Date customUtilDate = new SimpleDateFormat(pattern).parse(dateAsString);
+        return new Date(customUtilDate.getTime());
+    }
+}

core-java-modules/core-java-8-datetime/src/main/java/com/baeldung/datetime/sql/TimeUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import java.sql.Time;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class TimeUtils {
+
+    public static Time getNow() {
+        return new Time(System.currentTimeMillis());
+    }
+
+    public static Time getTime(String timeAsString) {
+        return Time.valueOf(timeAsString);
+    }
+
+    public static Time getTime(String dateAsString, String pattern) throws ParseException {
+        java.util.Date customUtilDate = new SimpleDateFormat(pattern).parse(dateAsString);
+        return new Time(customUtilDate.getTime());
+    }
+}

core-java-modules/core-java-8-datetime/src/main/java/com/baeldung/datetime/sql/TimestampUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import java.sql.Timestamp;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class TimestampUtils {
+
+    public static Timestamp getNow() {
+        return new Timestamp(System.currentTimeMillis());
+    }
+
+    public static Timestamp getTimestamp(String timestampAsString) {
+        return Timestamp.valueOf(timestampAsString);
+    }
+
+    public static Timestamp getTimestamp(String dateAsString, String pattern) throws ParseException {
+        java.util.Date customUtilDate = new SimpleDateFormat(pattern).parse(dateAsString);
+        return new Timestamp(customUtilDate.getTime());
+    }
+}

core-java-modules/core-java-8-datetime/src/test/java/com/baeldung/datetime/CalendarUtilsUnitTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.datetime;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.util.Date;
+
+import static org.junit.Assert.assertEquals;
+
+public class CalendarUtilsUnitTest {
+
+    @Test
+    public void givenDateAndDaysToAdd_thenCalendarIsCorrectlyReturned() throws ParseException {
+        Date initialDate = DateUtils.getDate("2020/01/01", "yyyy/MM/dd");
+        Date expectedDate= DateUtils.getDate("2020/01/11", "yyyy/MM/dd");
+        assertEquals(expectedDate, CalendarUtils.getPlusDays(initialDate, 10).getTime());
+    }
+}

core-java-modules/core-java-8-datetime/src/test/java/com/baeldung/datetime/DateUtilsUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.datetime;
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.util.Date;
+
+import static org.junit.Assert.assertEquals;
+public class DateUtilsUnitTest {
+
+    @Test
+    public void givenDateAndPattern_thenDateIsCorrectlyReturned() throws ParseException {
+        long milliseconds = new Date(2020 - 1900, 0, 1).getTime();
+        assertEquals(DateUtils.getDate(milliseconds), DateUtils.getDate("2020/01/01", "yyyy/MM/dd"));
+    }
+}

core-java-modules/core-java-8-datetime/src/test/java/com/baeldung/datetime/sql/DateUtilsUnitTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import static org.junit.Assert.assertEquals;
+
+import java.text.ParseException;
+import java.time.LocalDate;
+
+import org.junit.Test;
+
+public class DateUtilsUnitTest {
+
+    @Test(expected = IllegalArgumentException.class)
+    public void givenDateAsString_whenPatternIsNotRespected_thenExceptionIsThrown() {
+        DateUtils.getDate("2020 01 01");
+    }
+
+    @Test
+    public void givenDateAndPattern_thenDateIsCorrectlyReturned() throws ParseException {
+        assertEquals(DateUtils.getDate("2020-01-01"), DateUtils.getDate("2020/01/01", "yyyy/MM/dd"));
+    }
+}

core-java-modules/core-java-8-datetime/src/test/java/com/baeldung/datetime/sql/TimeUtilsUnitTest.java

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+package com.baeldung.datetime.sql;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.baeldung.datetime.sql.TimeUtils;
+
+import java.text.ParseException;
+
+public class TimeUtilsUnitTest {
+
+    @Test(expected = IllegalArgumentException.class)
+    public void givenTimeAsString_whenPatternIsNotRespected_thenExceptionIsThrown() {
+        TimeUtils.getTime("10 11 12");
+    }
+
+    @Test
+    public void givenTimeAndPattern_thenTimeIsCorrectlyReturned() throws ParseException {
+        assertEquals(TimeUtils.getTime("10:11:12"), TimeUtils.getTime("10 11 12", "hh mm ss"));
+    }
+}

core-java-modules/core-java-8-datetime/src/test/java/com/baeldung/datetime/sql/TimestampUtilsUnitTest.java

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+package com.baeldung.datetime.sql;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+
+import static org.junit.Assert.assertEquals;
+
+public class TimestampUtilsUnitTest {
+
+    @Test(expected = IllegalArgumentException.class)
+    public void givenTimestampAsString_whenPatternIsNotRespected_thenExceptionIsThrown() {
+        TimestampUtils.getTimestamp("2020/01/01 10:11-12");
+    }
+
+    @Test
+    public void givenTimestampAndPattern_thenTimestampIsCorrectlyReturned() throws ParseException {
+        assertEquals(TimestampUtils.getTimestamp("2020-01-01 10:11:12"), TimestampUtils.getTimestamp("2020/01/01 10:11-12", "yyyy/MM/dd hh:mm-ss"));
+    }
+}