Merge branch 'master' into BAEL-6421-PrintWriter-write-vs-print

core-java-modules/core-java-8-datetime-2/README.md

@@ -13,4 +13,5 @@
 - [Format LocalDate to ISO 8601 With T and Z](https://www.baeldung.com/java-format-localdate-iso-8601-t-z)
 - [Check if Two Date Ranges Overlap](https://www.baeldung.com/java-check-two-date-ranges-overlap)
 - [Difference between ZoneOffset.UTC and ZoneId.of(“UTC”)](https://www.baeldung.com/java-zoneoffset-utc-zoneid-of)
+- [Check if a Given Time Lies Between Two Times Regardless of Date](https://www.baeldung.com/java-check-between-two-times)
 - [[<-- Prev]](/core-java-modules/core-java-datetime-java8-1)

core-java-modules/core-java-8-datetime-2/src/test/java/com/baeldung/checkiftimebetweentwotimes/CheckIfTimeBetweenTwoTimesUnitTest.java

@@ -0,0 +1,45 @@
+package com.baeldung.checkiftimebetweentwotimes;
+
+import org.junit.Test;
+
+import java.time.LocalTime;
+import java.util.Calendar;
+import java.util.Date;
+
+import static org.junit.Assert.assertTrue;
+
+public class CheckIfTimeBetweenTwoTimesUnitTest {
+    private LocalTime startTime = LocalTime.parse("09:00:00");
+    private LocalTime endTime = LocalTime.parse("17:00:00");
+    private LocalTime targetTime = LocalTime.parse("12:30:00");
+
+    @Test
+    public void givenLocalTime_whenUsingIsAfterIsBefore_thenTimeIsBetween() {
+        assertTrue(!targetTime.isBefore(startTime) && !targetTime.isAfter(endTime));
+    }
+
+    @Test
+    public void givenLocalTime_whenUsingCompareTo_thenTimeIsBetween() {
+        assertTrue(targetTime.compareTo(startTime) >= 0 && targetTime.compareTo(endTime) <= 0);
+    }
+
+    @Test
+    public void givenDate_whenUsingAfterBefore_thenTimeIsBetween() {
+        Calendar startCalendar = Calendar.getInstance();
+        startCalendar.set(Calendar.HOUR_OF_DAY, 9);
+        startCalendar.set(Calendar.MINUTE, 0);
+        Date startTime = startCalendar.getTime();
+
+        Calendar endCalendar = Calendar.getInstance();
+        endCalendar.set(Calendar.HOUR_OF_DAY, 17);
+        endCalendar.set(Calendar.MINUTE, 0);
+        Date endTime = endCalendar.getTime();
+
+        Calendar targetCalendar = Calendar.getInstance();
+        targetCalendar.set(Calendar.HOUR_OF_DAY, 12);
+        targetCalendar.set(Calendar.MINUTE, 30);
+        Date targetTime = targetCalendar.getTime();
+
+        assertTrue(!targetTime.before(startTime) && !targetTime.after(endTime));
+    }
+}

core-java-modules/core-java-arrays-convert/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-convert</artifactId>
-    <name>core-java-arrays-convert</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-convert</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>
@@ -20,4 +20,5 @@
             <version>${commons-lang3.version}</version>
         </dependency>
     </dependencies>
+
 </project>

core-java-modules/core-java-arrays-guides/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-guides</artifactId>
-    <name>core-java-arrays-guides</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-guides</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-arrays-multidimensional/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-multidimensional</artifactId>
-    <name>core-java-arrays-multidimensional</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-multidimensional</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-arrays-operations-advanced-2/README.md

@@ -2,3 +2,4 @@
 - [Find the Middle Element of an Array in Java](https://www.baeldung.com/java-array-middle-item)
 - [Find the Equilibrium Indexes of an Array in Java](https://www.baeldung.com/java-equilibrium-index-array)
 - [Moves Zeros to the End of an Array in Java](https://www.baeldung.com/java-array-sort-move-zeros-end)
+- [Finding the Majority Element of an Array in Java](https://www.baeldung.com/java-array-find-majority-element)

core-java-modules/core-java-arrays-operations-advanced-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-operations-advanced-2</artifactId>
-    <name>core-java-arrays-operations-advanced-2</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-operations-advanced-2</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-arrays-operations-advanced/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-operations-advanced</artifactId>
-    <name>core-java-arrays-operations-advanced</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-operations-advanced</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-arrays-operations-basic-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-operations-basic-2</artifactId>
-    <name>core-java-arrays-operations-basic-2</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-operations-basic-2</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-arrays-operations-basic/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-operations-basic</artifactId>
-    <name>core-java-arrays-operations-basic</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-operations-basic</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-arrays-sorting/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-arrays-sorting</artifactId>
-    <name>core-java-arrays-sorting</name>
     <packaging>jar</packaging>
+    <name>core-java-arrays-sorting</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-booleans/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-booleans</artifactId>
-    <name>core-java-booleans</name>
     <packaging>jar</packaging>
+    <name>core-java-booleans</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-char/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-char</artifactId>
-    <name>core-java-char</name>
     <packaging>jar</packaging>
+    <name>core-java-char</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-2</artifactId>
-    <name>core-java-collections-2</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-3</artifactId>
-    <name>core-java-collections-3</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-4/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-4</artifactId>
-    <name>core-java-collections-4</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-4</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-5/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-5</artifactId>
-    <name>core-java-collections-5</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-5</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-array-list-2/README.md

@@ -4,3 +4,4 @@ This module contains articles about the Java ArrayList collection
 
 ### Relevant Articles:
 - [Create an ArrayList with Multiple Object Types](https://www.baeldung.com/java-arraylist-multiple-object-types)
+- [Finding the Peak Elements of a List](https://www.baeldung.com/java-list-find-peak)

core-java-modules/core-java-collections-array-list-2/pom.xml

@@ -3,8 +3,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-array-list-2</artifactId>
-    <name>core-java-collections-array-list-2</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-array-list-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/MultiplePeakFinder.java

@@ -0,0 +1,40 @@
+package com.baeldung.peakelements;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MultiplePeakFinder {
+
+    public static List<Integer> findPeaks(int[] arr) {
+
+        List<Integer> peaks = new ArrayList<>();
+
+        if (arr == null || arr.length == 0) {
+            return peaks;
+        }
+        findPeakElements(arr, 0, arr.length - 1, peaks, arr.length);
+        return peaks;
+    }
+
+    private static void findPeakElements(int[] arr, int low, int high, List<Integer> peaks, int length) {
+
+        if (low > high) {
+            return;
+        }
+
+        int mid = low + (high - low) / 2;
+
+        boolean isPeak = (mid == 0 || arr[mid] > arr[mid - 1]) && (mid == length - 1 || arr[mid] > arr[mid + 1]);
+        boolean isFirstInSequence = mid > 0 && arr[mid] == arr[mid - 1] && arr[mid] > arr[mid + 1];
+
+        if (isPeak || isFirstInSequence) {
+
+            if (!peaks.contains(arr[mid])) {
+                peaks.add(arr[mid]);
+            }
+        }
+
+        findPeakElements(arr, low, mid - 1, peaks, length);
+        findPeakElements(arr, mid + 1, high, peaks, length);
+    }
+}

core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/PeakElementFinder.java

@@ -0,0 +1,44 @@
+package com.baeldung.peakelements;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PeakElementFinder {
+    public List<Integer> findPeakElements(int[] arr) {
+        int n = arr.length;
+        List<Integer> peaks = new ArrayList<>();
+
+        if (n == 0) {
+            return peaks;
+        }
+
+        for (int i = 0; i < n; i++) {
+            if (isPeak(arr, i, n)) {
+                peaks.add(arr[i]);
+            }
+
+            while (i < n - 1 && arr[i] == arr[i + 1]) {
+                i++;
+            }
+        }
+
+        return peaks;
+    }
+
+    private boolean isPeak(int[] arr, int index, int n) {
+        if (index == 0) {
+            return n > 1 ? arr[index] >= arr[index + 1] : true;
+        } else if (index == n - 1) {
+            return arr[index] >= arr[index - 1];
+        } else if (arr[index] == arr[index + 1] && arr[index] > arr[index - 1]) {
+            int i = index;
+
+            while (i < n - 1 && arr[i] == arr[i + 1]) {
+                i++;
+            }
+            return i == n - 1 || arr[i] > arr[i + 1];
+        } else {
+            return arr[index] >= arr[index - 1] && arr[index] >= arr[index + 1];
+        }
+    }
+}

core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/SinglePeakFinder.java

@@ -0,0 +1,30 @@
+package com.baeldung.peakelements;
+
+import java.util.OptionalInt;
+
+public class SinglePeakFinder {
+    public static OptionalInt findSinglePeak(int[] arr) {
+        int n = arr.length;
+
+        if (n < 2) {
+            return n == 0 ? OptionalInt.empty() : OptionalInt.of(arr[0]);
+        }
+
+        if (arr[0] >= arr[1]) {
+            return OptionalInt.of(arr[0]);
+        }
+
+        for (int i = 1; i < n - 1; i++) {
+            if (arr[i] >= arr[i - 1] && arr[i] >= arr[i + 1]) {
+                return OptionalInt.of(arr[i]);
+            }
+        }
+
+        if (arr[n - 1] >= arr[n - 2]) {
+            return OptionalInt.of(arr[n - 1]);
+        }
+
+        return OptionalInt.empty();
+    }
+}
+

core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/MultiplePeakFinderUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.peakelements;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class MultiplePeakFinderUnitTest {
+
+    @Test
+    void findPeaks_givenArrayOfIntegers_whenValidInput_thenReturnsCorrectPeaks() {
+        MultiplePeakFinder finder = new MultiplePeakFinder();
+        int[] array = {1, 13, 7, 0, 4, 1, 4, 45, 50};
+        List<Integer> peaks = finder.findPeaks(array);
+
+        assertEquals(3, peaks.size());
+        assertTrue(peaks.contains(4));
+        assertTrue(peaks.contains(13));
+        assertTrue(peaks.contains(50));
+    }
+}
+

core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/PeakElementFinderUnitTest.java

@@ -0,0 +1,46 @@
+package com.baeldung.peakelements;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class PeakElementFinderUnitTest {
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenValidInput_thenReturnsCorrectPeak() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {1, 2, 3, 2, 1};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(1, peaks.size());
+        assertTrue(peaks.contains(3));
+    }
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenNoPeaks_thenReturnsEmptyList() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(0, peaks.size());
+    }
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenPeaksAtExtremes_thenReturnsCorrectPeak() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {5, 2, 1, 3, 4};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(2, peaks.size());
+        assertTrue(peaks.contains(5));
+        assertTrue(peaks.contains(4));
+    }
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenPlateaus_thenReturnsCorrectPeak() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {1, 2, 2, 2, 3, 4, 5};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(1, peaks.size());
+        assertTrue(peaks.contains(5));
+    }
+}

core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/SinglePeakFinderUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.peakelements;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.OptionalInt;
+
+public class SinglePeakFinderUnitTest {
+
+    @Test
+    void findSinglePeak_givenArrayOfIntegers_whenValidInput_thenReturnsCorrectPeak() {
+        int[] arr = {0, 10, 2, 4, 5, 1};
+        OptionalInt peak = SinglePeakFinder.findSinglePeak(arr);
+        assertTrue(peak.isPresent());
+        assertEquals(10, peak.getAsInt());
+    }
+
+    @Test
+    void findSinglePeak_givenEmptyArray_thenReturnsEmptyOptional() {
+        int[] arr = {};
+        OptionalInt peak = SinglePeakFinder.findSinglePeak(arr);
+        assertTrue(peak.isEmpty());
+    }
+
+    @Test
+    void findSinglePeak_givenEqualElementArray_thenReturnsCorrectPeak() {
+        int[] arr = {-2, -2, -2, -2, -2};
+        OptionalInt peak = SinglePeakFinder.findSinglePeak(arr);
+        assertTrue(peak.isPresent());
+        assertEquals(-2, peak.getAsInt());
+    }
+}

core-java-modules/core-java-collections-array-list/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-array-list</artifactId>
-    <name>core-java-collections-array-list</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-array-list</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-conversions-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-conversions-2</artifactId>
-    <name>core-java-collections-conversions-2</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-conversions-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-conversions-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-conversions-3</artifactId>
-    <name>core-java-collections-conversions-3</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-conversions-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-conversions/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-conversions</artifactId>
-    <name>core-java-collections-conversions</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-conversions</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-list-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-list-2</artifactId>
-    <name>core-java-collections-list-2</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-list-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-list-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-list-3</artifactId>
-    <name>core-java-collections-list-3</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-list-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-list-4/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-list-4</artifactId>
-    <name>core-java-collections-list-4</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-list-4</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-list-5/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-list-5</artifactId>
-    <name>core-java-collections-list-5</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-list-5</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-list-6/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-list-6</artifactId>
-    <name>core-java-collections-list-6</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-list-6</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-list/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-list</artifactId>
-    <name>core-java-collections-list</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-list</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-maps-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-maps-2</artifactId>
-    <name>core-java-collections-maps-2</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-maps-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-maps-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-maps-3</artifactId>
-    <name>core-java-collections-maps-3</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-maps-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-maps-4/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-maps-4</artifactId>
-    <name>core-java-collections-maps-4</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-maps-4</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-maps-5/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-maps-5</artifactId>
-    <name>core-java-collections-maps-5</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-maps-5</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-maps-6/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-maps-6</artifactId>
-    <name>core-java-collections-maps-6</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-maps-6</name>
 
     <parent>
         <artifactId>core-java-modules</artifactId>

core-java-modules/core-java-collections-maps/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-maps</artifactId>
-    <name>core-java-collections-maps</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-maps</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-set-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-set-2</artifactId>
-    <name>core-java-collections-set-2</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-set-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections-set/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections-set</artifactId>
-    <name>core-java-collections-set</name>
     <packaging>jar</packaging>
+    <name>core-java-collections-set</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-collections/README.md

@@ -13,4 +13,5 @@ This module contains articles about Java collections
 - [Guide to the Java Queue Interface](https://www.baeldung.com/java-queue)
 - [An Introduction to Synchronized Java Collections](https://www.baeldung.com/java-synchronized-collections)
 - [Convert an Array of Primitives to a List](https://www.baeldung.com/java-primitive-array-to-list)
+- [Adding Elements to a Collection During Iteration](https://www.baeldung.com/java-add-elements-collection)
 - More articles: [[next -->]](/core-java-modules/core-java-collections-2)

core-java-modules/core-java-collections/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-collections</artifactId>
-    <name>core-java-collections</name>
     <packaging>jar</packaging>
+    <name>core-java-collections</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-compiler/pom.xml

@@ -5,8 +5,8 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-compiler</artifactId>
     <version>0.1.0-SNAPSHOT</version>
-    <name>core-java-compiler</name>
     <packaging>jar</packaging>
+    <name>core-java-compiler</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-2</artifactId>
-    <name>core-java-concurrency-2</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-advanced-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-advanced-2</artifactId>
-    <name>core-java-concurrency-advanced-2</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-advanced-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-advanced-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-advanced-3</artifactId>
-    <name>core-java-concurrency-advanced-3</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-advanced-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-advanced-4/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-advanced-4</artifactId>
-    <name>core-java-concurrency-advanced-4</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-advanced-4</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-advanced-5/README.md

@@ -4,3 +4,4 @@
 - [Working with Exceptions in Java CompletableFuture](https://www.baeldung.com/java-exceptions-completablefuture)
 - [CountDownLatch vs. Semaphore](https://www.baeldung.com/java-countdownlatch-vs-semaphore)
 - [Callbacks in ListenableFuture and CompletableFuture](https://www.baeldung.com/java-callbacks-listenablefuture-completablefuture)
+- [Guide to ExecutorService vs. CompletableFuture](https://www.baeldung.com/java-executorservice-vs-completablefuture)

core-java-modules/core-java-concurrency-advanced-5/pom.xml

@@ -2,11 +2,10 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-advanced-5</artifactId>
-    <name>core-java-concurrency-advanced-5</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-advanced-5</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>
@@ -29,8 +28,8 @@
     </build>
 
     <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>9</maven.compiler.source>
+        <maven.compiler.target>9</maven.compiler.target>
     </properties>
 
 </project>

core-java-modules/core-java-concurrency-advanced-5/src/main/java/com/baeldung/executorservicevscompletablefuture/CompletableFutureDemo.java

@@ -0,0 +1,64 @@
+package com.baeldung.executorservicevscompletablefuture;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.TimeUnit;
+
+public class CompletableFutureDemo {
+
+    public static void completableFutureMethod() {
+        CompletableFuture<Integer> future = CompletableFuture.supplyAsync(() -> {
+            return 42;
+        });
+
+        System.out.println(future.join());
+    }
+
+    public static void chainingTaskExample() {
+        CompletableFuture<Integer> firstTask = CompletableFuture.supplyAsync(() -> {
+            return 42;
+        });
+
+        CompletableFuture<String> secondTask = firstTask.thenApply(result -> {
+            return "Result based on Task 1: " + result;
+        });
+
+        System.out.println(secondTask.join());
+    }
+
+    public static void exceptionHandlingExample() {
+        CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
+                // Simulate a task that might throw an exception
+                if (true) {
+                    throw new RuntimeException("Something went wrong!");
+                }
+                return "Success";
+            })
+            .exceptionally(ex -> {
+                System.err.println("Error in task: " + ex.getMessage());
+                // Can optionally return a default value
+                return "Error occurred";
+            });
+
+        future.thenAccept(result -> System.out.println("Result: " + result));
+    }
+
+    public static void timeoutExample() {
+        CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
+            try {
+                Thread.sleep(5000);
+            } catch (InterruptedException e) {
+                System.err.println("Task execution timed out!");
+            }
+            return "Task completed";
+        });
+
+        CompletableFuture<String> timeoutFuture = future.completeOnTimeout("Timed out!", 2, TimeUnit.SECONDS);
+        String result = timeoutFuture.join();
+        System.out.println("Result: " + result);
+    }
+
+    public static void main(String[] args) {
+        timeoutExample();
+    }
+}

core-java-modules/core-java-concurrency-advanced-5/src/main/java/com/baeldung/executorservicevscompletablefuture/ExecutorServiceDemo.java

@@ -0,0 +1,98 @@
+package com.baeldung.executorservicevscompletablefuture;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+public class ExecutorServiceDemo {
+
+    public static void executorServiceMethod() throws ExecutionException, InterruptedException {
+        ExecutorService executor = Executors.newFixedThreadPool(3);
+        Future<Integer> future = executor.submit(() -> {
+            return 42;
+        });
+
+        System.out.println(future.get());
+    }
+
+    public static void chainingTaskExample() {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+        Future<Integer> firstTask = executor.submit(() -> {return 42;});
+
+        Future<String> secondTask = executor.submit(() -> {
+            try {
+                Integer result = firstTask.get();
+                return "Result based on Task 1: " + result;
+            } catch (InterruptedException | ExecutionException e) {
+                // Handle exception
+                System.err.println("Error occured: " + e.getMessage());
+            }
+            return null;
+        });
+        executor.shutdown();
+
+        try {
+            // Wait for the second task to complete and retrieve the result
+            String result = secondTask.get();
+            System.out.println(result); // Output: Result based on Task 1: 42
+        } catch (InterruptedException | ExecutionException e) {
+            // Handle exception
+            System.err.println("Error occured: " + e.getMessage());
+        }
+    }
+
+    public static void exceptionHandlingExample() {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+        Future<String> future = executor.submit(() -> {
+            // Simulate a task that might throw an exception
+            if (true) {
+                throw new RuntimeException("Something went wrong!");
+            }
+            return "Success";
+        });
+
+        try {
+            // This might block the main thread if the task throws an exception
+            String result = future.get();
+            System.out.println("Result: " + result);
+        } catch (InterruptedException | ExecutionException e) {
+            // Handle exceptions thrown by the task or during retrieval
+            System.err.println("Error occured: " + e.getMessage());
+        } finally {
+            executor.shutdown();
+        }
+    }
+
+    public static void timeoutExample() {
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+        Future<String> future = executor.submit(() -> {
+            try {
+                System.out.println("Start");
+                Thread.sleep(5000);
+                System.out.println("End");
+            } catch (InterruptedException e) {
+                System.err.println("Error occured: " + e.getMessage());
+            }
+            return "Task completed";
+        });
+
+        try {
+            String result = future.get(2, TimeUnit.SECONDS);
+            System.out.println("Result: " + result);
+        } catch (TimeoutException e) {
+            System.err.println("Task execution timed out!");
+            future.cancel(true);
+        } catch (Exception e) {
+            System.err.println("Error occured: " + e.getMessage());
+        } finally {
+            executor.shutdown();
+        }
+    }
+
+    public static void main(String[] args) throws ExecutionException, InterruptedException {
+        timeoutExample();
+    }
+}

core-java-modules/core-java-concurrency-advanced/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-advanced</artifactId>
-    <name>core-java-concurrency-advanced</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-advanced</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-basic-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-basic-2</artifactId>
-    <name>core-java-concurrency-basic-2</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-basic-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-basic-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-basic-3</artifactId>
-    <name>core-java-concurrency-basic-3</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-basic-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-basic/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-basic</artifactId>
-    <name>core-java-concurrency-basic</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-basic</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-collections-2/pom.xml

@@ -3,8 +3,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-collections-2</artifactId>
-    <name>core-java-concurrency-collections-2</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-collections-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-collections/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-collections</artifactId>
-    <name>core-java-concurrency-collections</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-collections</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-concurrency-simple/pom.xml

@@ -3,8 +3,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-concurrency-simple</artifactId>
-    <name>core-java-concurrency-simple</name>
     <packaging>jar</packaging>
+    <name>core-java-concurrency-simple</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-conditionals/pom.xml

@@ -5,8 +5,8 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-conditionals</artifactId>
     <version>0.1.0-SNAPSHOT</version>
-    <name>core-java-conditionals</name>
     <packaging>jar</packaging>
+    <name>core-java-conditionals</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-console/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-console</artifactId>
-    <name>core-java-console</name>
     <packaging>jar</packaging>
+    <name>core-java-console</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-date-operations-1/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-date-operations-1</artifactId>
-    <name>core-java-date-operations-1</name>
     <packaging>jar</packaging>
+    <name>core-java-date-operations-1</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-date-operations-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-date-operations-2</artifactId>
-    <name>core-java-date-operations-2</name>
     <packaging>jar</packaging>
+    <name>core-java-date-operations-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-date-operations-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-date-operations-3</artifactId>
-    <name>core-java-date-operations-3</name>
     <packaging>jar</packaging>
+    <name>core-java-date-operations-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-date-operations-4/README.md

@@ -5,3 +5,4 @@ This module contains articles about date operations in Java.
 - [Calculate Number of Weekdays Between Two Dates in Java](https://www.baeldung.com/java-count-weekdays-between-two-dates)
 - [Convert Long to Date in Java](https://www.baeldung.com/java-long-date-conversion)
 - [Convert Date to Unix Timestamp in Java](https://www.baeldung.com/java-convert-date-unix-timestamp)
+- [Checking if a Date Object Equals Yesterday](https://www.baeldung.com/java-date-check-yesterday)

core-java-modules/core-java-date-operations-4/pom.xml

@@ -4,8 +4,15 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-date-operations-4</artifactId>
+    <packaging>jar</packaging>
     <name>core-java-date-operations-4</name>
 
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
     <build>
         <plugins>
             <plugin>
@@ -18,13 +25,6 @@
             </plugin>
         </plugins>
     </build>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>core-java-modules</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-    </parent>
 
     <dependencies>
         <dependency>

core-java-modules/core-java-date-operations-4/src/test/java/com/baeldung/compareyesterday/CompareYesterdayUnitTest.java

@@ -0,0 +1,116 @@
+package com.baeldung.compareyesterday;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.joda.time.DateTime;
+import org.junit.jupiter.api.Test;
+
+public class CompareYesterdayUnitTest {
+
+    @Test
+    void givenYesterdayDate_whenCompareWithCalendar_returnTrue() {
+        // To simulate yesterday
+        Date date = new Date(System.currentTimeMillis() - (1000 * 60 * 60 * 24));
+        Calendar expectedCalendar = Calendar.getInstance();
+        expectedCalendar.setTime(date);
+
+        Calendar actualCalendar = Calendar.getInstance();
+        actualCalendar.add(Calendar.DATE, -1);
+
+        boolean isEqualToYesterday = expectedCalendar.get(Calendar.YEAR) == actualCalendar.get(Calendar.YEAR) &&
+            expectedCalendar.get(Calendar.MONTH) == actualCalendar.get(Calendar.MONTH) &&
+            expectedCalendar.get(Calendar.DAY_OF_MONTH) == actualCalendar.get(Calendar.DAY_OF_MONTH);
+        assertTrue(isEqualToYesterday);
+    }
+
+    @Test
+    void givenTodayDate_whenCompareWithCalendar_returnFalse() {
+        Calendar expectedCalendar = Calendar.getInstance();
+
+        Calendar actualCalendar = Calendar.getInstance();
+        actualCalendar.add(Calendar.DATE, -1);
+
+        boolean isEqualToYesterday = expectedCalendar.get(Calendar.YEAR) == actualCalendar.get(Calendar.YEAR) &&
+            expectedCalendar.get(Calendar.MONTH) == actualCalendar.get(Calendar.MONTH) &&
+            expectedCalendar.get(Calendar.DAY_OF_MONTH) == actualCalendar.get(Calendar.DAY_OF_MONTH);
+        assertFalse(isEqualToYesterday);
+    }
+
+    @Test
+    void givenYesterdayDate_whenCompareWithDateMilliseconds_returnTrue() {
+        // Create a Date object representing yesterday
+        Date expectedDate = new Date(System.currentTimeMillis() - (1000 * 60 * 60 * 24));
+        long yesterdayMidnightMillis = Instant.now()
+            .minus(1, ChronoUnit.DAYS)
+            .toEpochMilli();
+
+        boolean isEqualToYesterday = expectedDate.getTime() >= yesterdayMidnightMillis && expectedDate.getTime() < yesterdayMidnightMillis + 86_400_000;
+        assertTrue(isEqualToYesterday);
+    }
+
+    @Test
+    void givenTodayDate_whenCompareWithDateMilliseconds_returnFalse() {
+        // Create a Date object representing yesterday
+        Date expectedDate = new Date();
+        long yesterdayMidnightMillis = Instant.now()
+            .minus(1, ChronoUnit.DAYS)
+            .toEpochMilli();
+
+        boolean isEqualToYesterday = expectedDate.getTime() >= yesterdayMidnightMillis && expectedDate.getTime() < yesterdayMidnightMillis + 86_400_000;
+        assertFalse(isEqualToYesterday);
+    }
+
+    @Test
+    void givenYesterdayDate_whenCompareWithLocalDate_returnTrue() {
+        // To simulate yesterday
+        Date date = new Date(System.currentTimeMillis() - (1000 * 60 * 60 * 24));
+        LocalDate expectedLocalDate = LocalDate.of(date.getYear() + 1900, date.getMonth() + 1, date.getDate());
+
+        LocalDate actualLocalDate = LocalDate.now()
+            .minusDays(1);
+        boolean isEqualToYesterday = expectedLocalDate.equals(actualLocalDate);
+        assertTrue(isEqualToYesterday);
+    }
+
+    @Test
+    void givenTodayDate_whenCompareWithLocalDate_returnFalse() {
+        LocalDate expectedLocalDate = LocalDate.now();
+        LocalDate actualLocalDate = LocalDate.now()
+            .minusDays(1);
+        boolean isEqualToYesterday = expectedLocalDate.equals(actualLocalDate);
+        assertFalse(isEqualToYesterday);
+    }
+
+    @Test
+    void givenYesterdayDate_whenCompareWithJodaTime_returnTrue() {
+        // To simulate yesterday
+        Date date = new Date(System.currentTimeMillis() - (1000 * 60 * 60 * 24));
+        DateTime expectedDateTime = new DateTime(date).withTimeAtStartOfDay();
+
+        DateTime actualDateTime = DateTime.now()
+            .minusDays(1)
+            .withTimeAtStartOfDay();
+
+        boolean isEqualToYesterday = expectedDateTime.equals(actualDateTime);
+        assertTrue(isEqualToYesterday);
+    }
+
+    @Test
+    void givenTodayDate_whenCompareWithJodaTime_returnFalse() {
+        DateTime expectedDateTime = DateTime.now()
+            .withTimeAtStartOfDay();
+        DateTime actualDateTime = DateTime.now()
+            .minusDays(1)
+            .withTimeAtStartOfDay();
+
+        boolean isEqualToYesterday = expectedDateTime.equals(actualDateTime);
+        assertFalse(isEqualToYesterday);
+    }
+}

core-java-modules/core-java-datetime-conversion-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-datetime-conversion-2</artifactId>
-    <name>core-java-datetime-conversion-2</name>
     <packaging>jar</packaging>
+    <name>core-java-datetime-conversion-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>
@@ -29,7 +29,6 @@
             <artifactId>ummalqura-calendar</artifactId>
             <version>${ummalqura-calendar.version}</version>
         </dependency>
-
     </dependencies>
 
     <build>

core-java-modules/core-java-datetime-conversion/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-datetime-conversion</artifactId>
-    <name>core-java-datetime-conversion</name>
     <packaging>jar</packaging>
+    <name>core-java-datetime-conversion</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-datetime-string-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-datetime-string-2</artifactId>
-    <name>core-java-datetime-string-2</name>
     <packaging>jar</packaging>
+    <name>core-java-datetime-string-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-datetime-string/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-datetime-string</artifactId>
-    <name>core-java-datetime-string</name>
     <packaging>jar</packaging>
+    <name>core-java-datetime-string</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-documentation/pom.xml

@@ -5,8 +5,8 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-documentation</artifactId>
     <version>0.1.0-SNAPSHOT</version>
-    <name>core-java-documentation</name>
     <packaging>jar</packaging>
+    <name>core-java-documentation</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>
@@ -14,9 +14,6 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
-    <dependencies>
-    </dependencies>
-
     <build>
         <plugins>
             <plugin>

core-java-modules/core-java-exceptions-2/pom.xml

@@ -3,8 +3,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-exceptions-2</artifactId>
-    <name>core-java-exceptions-2</name>
     <packaging>jar</packaging>
+    <name>core-java-exceptions-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-exceptions-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-exceptions-3</artifactId>
-    <name>core-java-exceptions-3</name>
     <packaging>jar</packaging>
+    <name>core-java-exceptions-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-exceptions-4/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-exceptions-4</artifactId>
-    <name>core-java-exceptions-4</name>
     <packaging>jar</packaging>
+    <name>core-java-exceptions-4</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-exceptions/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-exceptions</artifactId>
-    <name>core-java-exceptions</name>
     <packaging>jar</packaging>
+    <name>core-java-exceptions</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-function/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-function</artifactId>
-    <name>core-java-function</name>
     <packaging>jar</packaging>
+    <name>core-java-function</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-functional/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-functional</artifactId>
-    <name>core-java-functional</name>
     <packaging>jar</packaging>
+    <name>core-java-functional</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-hex/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-hex</artifactId>
-    <name>core-java-hex</name>
     <packaging>jar</packaging>
+    <name>core-java-hex</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-httpclient/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-httpclient</artifactId>
-    <name>core-java-httpclient</name>
     <packaging>jar</packaging>
+    <name>core-java-httpclient</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-io-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-2</artifactId>
-    <name>core-java-io-2</name>
     <packaging>jar</packaging>
+    <name>core-java-io-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-3</artifactId>
-    <name>core-java-io-3</name>
     <packaging>jar</packaging>
+    <name>core-java-io-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-4/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-4</artifactId>
-    <name>core-java-io-4</name>
     <packaging>jar</packaging>
+    <name>core-java-io-4</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-5/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-5</artifactId>
-    <name>core-java-io-5</name>
     <packaging>jar</packaging>
+    <name>core-java-io-5</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-apis-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-apis-2</artifactId>
-    <name>core-java-io-apis-2</name>
     <packaging>jar</packaging>
+    <name>core-java-io-apis-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-apis/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-apis</artifactId>
-    <name>core-java-io-apis</name>
     <packaging>jar</packaging>
+    <name>core-java-io-apis</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-conversions-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-conversions-2</artifactId>
-    <name>core-java-io-conversions-2</name>
     <packaging>jar</packaging>
+    <name>core-java-io-conversions-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io-conversions/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io-conversions</artifactId>
-    <name>core-java-io-conversions</name>
     <packaging>jar</packaging>
+    <name>core-java-io-conversions</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-io/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-io</artifactId>
-    <name>core-java-io</name>
     <packaging>jar</packaging>
+    <name>core-java-io</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-ipc/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-ipc</artifactId>
-    <name>core-java-ipc</name>
     <packaging>jar</packaging>
+    <name>core-java-ipc</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-jar/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-jar</artifactId>
-    <name>core-java-jar</name>
     <packaging>jar</packaging>
+    <name>core-java-jar</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-jpms/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-jpms</artifactId>
-    <name>core-java-jpms</name>
     <packaging>pom</packaging>
+    <name>core-java-jpms</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-jvm-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-jvm-2</artifactId>
-    <name>core-java-jvm-2</name>
     <packaging>jar</packaging>
+    <name>core-java-jvm-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-jvm-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-jvm-3</artifactId>
-    <name>core-java-jvm-3</name>
     <packaging>jar</packaging>
+    <name>core-java-jvm-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-jvm/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-jvm</artifactId>
-    <name>core-java-jvm</name>
     <packaging>jar</packaging>
+    <name>core-java-jvm</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-lambdas/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-lambdas</artifactId>
-    <name>core-java-lambdas</name>
     <packaging>jar</packaging>
+    <name>core-java-lambdas</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-lang-2/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-lang-2</artifactId>
-    <name>core-java-lang-2</name>
     <packaging>jar</packaging>
+    <name>core-java-lang-2</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>

core-java-modules/core-java-lang-3/pom.xml

@@ -4,8 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-lang-3</artifactId>
-    <name>core-java-lang-3</name>
     <packaging>jar</packaging>
+    <name>core-java-lang-3</name>
 
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>