BAEL-3375 Working with Dates before Java 8

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/legacy/sqlpackage/DateUtils.java

@@ -1,4 +1,4 @@
-package com.baeldung.sql;
+package com.baeldung.legacy.sqlpackage;
 
 import java.sql.Date;
 import java.text.ParseException;

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/legacy/sqlpackage/TimeUtils.java

@@ -1,4 +1,4 @@
-package com.baeldung.sql;
+package com.baeldung.legacy.sqlpackage;
 
 import java.sql.Time;
 import java.text.ParseException;

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/legacy/sqlpackage/TimestampUtils.java

@@ -1,4 +1,4 @@
-package com.baeldung.sql;
+package com.baeldung.legacy.sqlpackage;
 
 import java.sql.Timestamp;
 import java.text.ParseException;

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/legacy/utilpackage/CalendarUtils.java

@@ -0,0 +1,15 @@
+package com.baeldung.legacy.utilpackage;
+
+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-date-operations/src/main/java/com/baeldung/legacy/utilpackage/DateUtils.java

@@ -0,0 +1,20 @@
+package com.baeldung.legacy.utilpackage;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+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-date-operations/src/test/java/com/baeldung/legacy/sqlpackage/DateUtilsUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.sql;
+package com.baeldung.legacy.sqlpackage;
 
 import static org.junit.Assert.assertEquals;
 

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/legacy/sqlpackage/TimeUtilsUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.sql;
+package com.baeldung.legacy.sqlpackage;
 
 import static org.junit.Assert.assertEquals;
 

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/legacy/sqlpackage/TimestampUtilsUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.sql;
+package com.baeldung.legacy.sqlpackage;
 
 import static org.junit.Assert.assertEquals;
 
@@ -11,7 +11,7 @@ public class TimestampUtilsUnitTest {
 
     @Test
     public void givenCurrentTimestamp_thenNowIsReturned() {
-        assertEquals(TimestampUtils.getNow().toInstant(), new Date().toInstant());
+        assertEquals(TimestampUtils.getNow().getTime(), new Date().getTime());
     }
 
     @Test(expected = IllegalArgumentException.class)

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/legacy/utilpackage/CalendarUtilsUnitTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.legacy.utilpackage;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.util.Date;
+
+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-date-operations/src/test/java/com/baeldung/legacy/utilpackage/DateUtilsUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.legacy.utilpackage;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.util.Date;
+
+public class DateUtilsUnitTest {
+
+    @Test
+    public void givenTimeMillis_thenDateIsReturned() {
+        Date now = DateUtils.getNow();
+        assertEquals(DateUtils.getDate(now.getTime()), now);
+    }
+
+    @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/pom.xml

@@ -19,6 +19,7 @@
         <module>core-java-lang-operators</module>
         <module>core-java-networking-2</module>
         <module>core-java-security-manager</module>
+        <module>core-java-date-operations</module>
     </modules>
     
 </project>