Add additional AssertJ examples

core-java-8/pom.xml

@@ -63,6 +63,12 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.4.1</version>
+        </dependency>
+
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>

core-java-8/src/main/java/com/baeldung/date_migration/NewApi.java

@@ -1,54 +0,0 @@
-package com.baeldung.date_migration;
-
-import java.text.ParseException;
-import java.time.*;
-import java.time.format.DateTimeFormatter;
-import java.time.temporal.ChronoUnit;
-
-public class NewApi {
-    public void currentTime() {
-        ZonedDateTime now = ZonedDateTime.now();
-    }
-
-    public void specificTime() {
-        LocalDate birthDay = LocalDate.of(1990, Month.DECEMBER, 15);
-    }
-
-    public void extractMonth() {
-        Month month = LocalDateTime.now().getMonth();
-    }
-
-    public void subtractTime() {
-        LocalDateTime fiveHoursBefore = LocalDateTime.now().minusHours(5);
-    }
-
-    public void alterField() {
-        LocalDateTime inJune = LocalDateTime.now().withMonth(Month.JUNE.getValue());
-    }
-
-    public void truncate() {
-        LocalTime truncated = LocalTime.now().truncatedTo(ChronoUnit.HOURS);
-    }
-
-    public void convertTimeZone() {
-        ZonedDateTime centralEastern = LocalDateTime.now().atZone(ZoneId.of("CET"));
-    }
-
-    public void getTimeSpan() {
-        LocalDateTime now = LocalDateTime.now();
-        LocalDateTime hourLater = LocalDateTime.now().plusHours(1);
-        Duration span = Duration.between(now, hourLater);
-    }
-
-    public void formatAndParse() throws ParseException {
-        LocalDate now = LocalDate.now();
-        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
-        String formattedDate = now.format(formatter);
-        LocalDate parsedDate = LocalDate.parse(formattedDate, formatter);
-    }
-
-    public void daysInMonth() {
-        int daysInMonth = YearMonth.of(1990, 2).lengthOfMonth();
-    }
-
-}

core-java-8/src/main/java/com/baeldung/date_migration/OldApi.java

@@ -1,68 +0,0 @@
-package com.baeldung.date_migration;
-
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.GregorianCalendar;
-import java.util.TimeZone;
-
-public class OldApi {
-    public void currentTime() {
-        Date now = new Date();
-    }
-
-    public void specificTime () {
-        Date birthDay = new GregorianCalendar(1990, Calendar.DECEMBER, 15).getTime();
-    }
-
-    public void extractMonth() {
-        int month = new GregorianCalendar().get(Calendar.MONTH);
-    }
-
-    public void subtractTime() {
-        GregorianCalendar calendar = new GregorianCalendar();
-        calendar.add(Calendar.HOUR_OF_DAY, -5);
-        Date fiveHoursBefore = calendar.getTime();
-    }
-
-    public void alterField() {
-        GregorianCalendar calendar = new GregorianCalendar();
-        calendar.set(Calendar.MONTH, Calendar.JUNE);
-        Date inJune = calendar.getTime();
-    }
-
-    public void truncate() {
-        Calendar now = Calendar.getInstance();
-        now.set(Calendar.MINUTE, 0);
-        now.set(Calendar.SECOND, 0);
-        now.set(Calendar.MILLISECOND, 0);
-        Date truncated = now.getTime();
-    }
-
-    public void convertTimeZone() {
-        GregorianCalendar calendar = new GregorianCalendar();
-        calendar.setTimeZone(TimeZone.getTimeZone("CET"));
-        Date centralEastern = calendar.getTime();
-    }
-
-    public void getTimeSpan() {
-        GregorianCalendar calendar = new GregorianCalendar();
-        Date now = new Date();
-        calendar.add(Calendar.HOUR, 1);
-        Date hourLater = calendar.getTime();
-        long elapsed = hourLater.getTime() - now.getTime();
-    }
-
-    public void formatAndParse() throws ParseException {
-        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
-        Date now = new Date();
-        String formattedDate = dateFormat.format(now);
-        Date parsedDate = dateFormat.parse(formattedDate);
-    }
-
-    public void daysInMonth() {
-        Calendar calendar = new GregorianCalendar(1990, Calendar.FEBRUARY, 20);
-        int daysInMonth = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
-    }
-}

core-java-8/src/test/java/com/baeldung/dateapi/ConversionExample.java

@@ -1,4 +1,4 @@
-package com.baeldung.date_migration;
+package com.baeldung.dateapi;
 
 import java.time.Instant;
 import java.time.ZoneId;
@@ -7,7 +7,7 @@ import java.util.Date;
 import java.util.GregorianCalendar;
 import java.util.TimeZone;
 
-public class Conversion {
+public class ConversionExample {
     public static void main(String[] args) {
         Instant instantFromCalendar = GregorianCalendar.getInstance().toInstant();
         ZonedDateTime zonedDateTimeFromCalendar = new GregorianCalendar().toZonedDateTime();

core-java-8/src/test/java/com/baeldung/dateapi/JavaUtilTimeTest.java

@@ -0,0 +1,89 @@
+package com.baeldung.dateapi;
+
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.time.Duration;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.Month;
+import java.time.YearMonth;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoUnit;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JavaUtilTimeTest {
+
+    @Test
+    public void currentTime() {
+        final LocalDate now = LocalDate.now();
+
+        System.out.println(now);
+        // there is not much to test here
+    }
+
+    @Test
+    public void specificTime() {
+        LocalDate birthDay = LocalDate.of(1990, Month.DECEMBER, 15);
+
+        System.out.println(birthDay);
+        // there is not much to test here
+    }
+
+    @Test
+    public void extractMonth() {
+        Month month = LocalDate.of(1990, Month.DECEMBER, 15).getMonth();
+
+        assertThat(month).isEqualTo(Month.DECEMBER);
+    }
+
+    @Test
+    public void subtractTime() {
+        LocalDateTime fiveHoursBefore = LocalDateTime.of(1990, Month.DECEMBER, 15, 15, 0).minusHours(5);
+
+        assertThat(fiveHoursBefore.getHour()).isEqualTo(10);
+    }
+
+    @Test
+    public void alterField() {
+        LocalDateTime inJune = LocalDateTime.of(1990, Month.DECEMBER, 15, 15, 0).with(Month.JUNE);
+
+        assertThat(inJune.getMonth()).isEqualTo(Month.JUNE);
+    }
+
+    @Test
+    public void truncate() {
+        LocalTime truncated = LocalTime.of(15, 12, 34).truncatedTo(ChronoUnit.HOURS);
+
+        assertThat(truncated).isEqualTo(LocalTime.of(15, 0, 0));
+    }
+
+    @Test
+    public void getTimeSpan() {
+        LocalDateTime now = LocalDateTime.now();
+        LocalDateTime hourLater = now.plusHours(1);
+        Duration span = Duration.between(now, hourLater);
+
+        assertThat(span).isEqualTo(Duration.ofHours(1));
+    }
+
+    @Test
+    public void formatAndParse() throws ParseException {
+        LocalDate someDate = LocalDate.of(2016, 12, 7);
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
+        String formattedDate = someDate.format(formatter);
+        LocalDate parsedDate = LocalDate.parse(formattedDate, formatter);
+
+        assertThat(formattedDate).isEqualTo("2016-12-07");
+        assertThat(parsedDate).isEqualTo(someDate);
+    }
+
+    @Test
+    public void daysInMonth() {
+        int daysInMonth = YearMonth.of(1990, 2).lengthOfMonth();
+
+        assertThat(daysInMonth).isEqualTo(28);
+    }
+}