Merge remote-tracking branch 'upstream/master' into JAVA-2305

algorithms-searching/src/main/java/com/baeldung/algorithms/kthsmallest/KthSmallest.java

@@ -0,0 +1,126 @@
+package com.baeldung.algorithms.kthsmallest;
+
+import java.util.Arrays;
+import java.util.NoSuchElementException;
+
+import static java.lang.Math.max;
+import static java.lang.Math.min;
+
+public class KthSmallest {
+
+    public static int findKthSmallestElement(int k, int[] list1, int[] list2)  throws NoSuchElementException, IllegalArgumentException {
+
+        checkInput(k, list1, list2);
+
+        // we are looking for the minimum value
+        if(k == 1) {
+            return min(list1[0], list2[0]);
+        }
+
+        // we are looking for the maximum value
+        if(list1.length + list2.length == k) {
+            return max(list1[list1.length-1], list2[list2.length-1]);
+        }
+
+        // swap lists if needed to make sure we take at least one element from list1
+        if(k <= list2.length && list2[k-1] < list1[0]) {
+            int[] list1_ = list1;
+            list1 = list2;
+            list2 = list1_;
+        }
+
+        // correct left boundary if k is bigger than the size of list2
+        int left = k < list2.length ? 0 : k - list2.length - 1;
+
+        // the inital right boundary cannot exceed the list1
+        int right = min(k-1, list1.length - 1);
+
+        int nElementsList1, nElementsList2;
+
+        // binary search
+        do {
+            nElementsList1 = ((left + right) / 2) + 1;
+            nElementsList2 = k - nElementsList1;
+
+            if(nElementsList2 > 0) {
+                if (list1[nElementsList1 - 1] > list2[nElementsList2 - 1]) {
+                    right = nElementsList1 - 2;
+                } else {
+                    left = nElementsList1;
+                }
+            }
+        } while(!kthSmallesElementFound(list1, list2, nElementsList1, nElementsList2));
+
+        return nElementsList2 == 0 ? list1[nElementsList1-1] : max(list1[nElementsList1-1], list2[nElementsList2-1]);
+    }
+
+    private static boolean kthSmallesElementFound(int[] list1, int[] list2, int nElementsList1, int nElementsList2) {
+
+        // we do not take any element from the second list
+        if(nElementsList2 < 1) {
+            return true;
+        }
+
+        if(list1[nElementsList1-1] == list2[nElementsList2-1]) {
+            return true;
+        }
+
+        if(nElementsList1 == list1.length) {
+            return list1[nElementsList1-1] <= list2[nElementsList2];
+        }
+
+        if(nElementsList2 == list2.length) {
+            return list2[nElementsList2-1] <= list1[nElementsList1];
+        }
+
+        return list1[nElementsList1-1] <= list2[nElementsList2] && list2[nElementsList2-1] <= list1[nElementsList1];
+    }
+
+
+    private static void checkInput(int k, int[] list1, int[] list2) throws NoSuchElementException, IllegalArgumentException {
+
+        if(list1 == null || list2 == null || k < 1) {
+            throw new IllegalArgumentException();
+        }
+
+        if(list1.length == 0 || list2.length == 0) {
+            throw new IllegalArgumentException();
+        }
+
+        if(k > list1.length + list2.length) {
+            throw new NoSuchElementException();
+        }
+    }
+
+    public static int getKthElementSorted(int[] list1, int[] list2, int k) {
+
+        int length1 = list1.length, length2 = list2.length;
+        int[] combinedArray = new int[length1 + length2];
+        System.arraycopy(list1, 0, combinedArray, 0, list1.length);
+        System.arraycopy(list2, 0, combinedArray, list1.length, list2.length);
+        Arrays.sort(combinedArray);
+
+        return combinedArray[k-1];
+    }
+
+    public static int getKthElementMerge(int[] list1, int[] list2, int k) {
+
+        int i1 = 0, i2 = 0;
+
+        while(i1 < list1.length && i2 < list2.length && (i1 + i2) < k) {
+            if(list1[i1] < list2[i2]) {
+                i1++;
+            } else {
+                i2++;
+            }
+        }
+
+        if((i1 + i2) < k) {
+            return i1 < list1.length ? list1[k - i2 - 1] : list2[k - i1 - 1];
+        } else if(i1 > 0 && i2 > 0) {
+            return Math.max(list1[i1-1], list2[i2-1]);
+        } else {
+            return i1 == 0 ? list2[i2-1] : list1[i1-1];
+        }
+    }
+}

algorithms-searching/src/test/java/com/baeldung/algorithms/kthsmallest/KthSmallestUnitTest.java

@@ -0,0 +1,288 @@
+package com.baeldung.algorithms.kthsmallest;
+
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.function.Executable;
+
+import java.util.*;
+
+import static com.baeldung.algorithms.kthsmallest.KthSmallest.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+public class KthSmallestUnitTest {
+
+    @Nested
+    class Exceptions {
+
+        @Test
+        public void when_at_least_one_list_is_null_then_an_exception_is_thrown() {
+
+            Executable executable1 = () -> findKthSmallestElement(1, null, null);
+            Executable executable2 = () -> findKthSmallestElement(1, new int[]{2}, null);
+            Executable executable3 = () -> findKthSmallestElement(1, null, new int[]{2});
+
+            assertThrows(IllegalArgumentException.class, executable1);
+            assertThrows(IllegalArgumentException.class, executable2);
+            assertThrows(IllegalArgumentException.class, executable3);
+        }
+
+        @Test
+        public void when_at_least_one_list_is_empty_then_an_exception_is_thrown() {
+
+            Executable executable1 = () -> findKthSmallestElement(1, new int[]{}, new int[]{2});
+            Executable executable2 = () -> findKthSmallestElement(1, new int[]{2}, new int[]{});
+            Executable executable3 = () -> findKthSmallestElement(1, new int[]{}, new int[]{});
+
+            assertThrows(IllegalArgumentException.class, executable1);
+            assertThrows(IllegalArgumentException.class, executable2);
+            assertThrows(IllegalArgumentException.class, executable3);
+        }
+
+        @Test
+        public void when_k_is_smaller_than_0_then_an_exception_is_thrown() {
+            Executable executable1 = () -> findKthSmallestElement(-1, new int[]{2}, new int[]{2});
+            assertThrows(IllegalArgumentException.class, executable1);
+        }
+
+        @Test
+        public void when_k_is_smaller_than_1_then_an_exception_is_thrown() {
+            Executable executable1 = () -> findKthSmallestElement(0, new int[]{2}, new int[]{2});
+            assertThrows(IllegalArgumentException.class, executable1);
+        }
+
+        @Test
+        public void when_k_bigger_then_the_two_lists_then_an_exception_is_thrown() {
+            Executable executable1 = () -> findKthSmallestElement(6, new int[]{1, 5, 6}, new int[]{2, 5});
+            assertThrows(NoSuchElementException.class, executable1);
+        }
+
+    }
+
+    @Nested
+    class K_is_smaller_than_the_size_of_list1_and_the_size_of_list2 {
+
+        @Test
+        public void when_k_is_1_then_the_smallest_element_is_returned_from_list1() {
+            int result = findKthSmallestElement(1, new int[]{2, 7}, new int[]{3, 5});
+            assertEquals(2, result);
+        }
+
+        @Test
+        public void when_k_is_1_then_the_smallest_element_is_returned_list2() {
+            int result = findKthSmallestElement(1, new int[]{3, 5}, new int[]{2, 7});
+            assertEquals(2, result);
+        }
+
+        @Test
+        public void when_kth_element_is_smallest_element_and_occurs_in_both_lists() {
+            int[] list1 = new int[]{1, 2, 3};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(1, list1, list2);
+            assertEquals(1, result);
+        }
+
+        @Test
+        public void when_kth_element_is_smallest_element_and_occurs_in_both_lists2() {
+            int[] list1 = new int[]{1, 2, 3};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(2, list1, list2);
+            assertEquals(1, result);
+        }
+
+        @Test
+        public void when_kth_element_is_largest_element_and_occurs_in_both_lists_1() {
+            int[] list1 = new int[]{1, 2, 3};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(5, list1, list2);
+            assertEquals(3, result);
+        }
+
+        @Test
+        public void when_kth_element_is_largest_element_and_occurs_in_both_lists_2() {
+            int[] list1 = new int[]{1, 2, 3};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(6, list1, list2);
+            assertEquals(3, result);
+        }
+
+        @Test
+        public void when_kth_element_and_occurs_in_both_lists() {
+            int[] list1 = new int[]{1, 2, 3};
+            int[] list2 = new int[]{0, 2, 3};
+            int result = findKthSmallestElement(3, list1, list2);
+            assertEquals(2, result);
+        }
+
+        @Test
+        public void and_kth_element_is_in_first_list() {
+            int[] list1 = new int[]{1,2,3,4};
+            int[] list2 = new int[]{1,3,4,5};
+            int result = findKthSmallestElement(3,  list1, list2);
+            assertEquals(2, result);
+        }
+
+        @Test
+        public void and_kth_is_in_second_list() {
+            int[] list1 = new int[]{1,3,4,4};
+            int[] list2 = new int[]{1,2,4,5};
+            int result = findKthSmallestElement(3,  list1, list2);
+            assertEquals(2, result);
+        }
+
+        @Test
+        public void and_elements_in_first_list_are_all_smaller_than_second_list() {
+            int[] list1 = new int[]{1,3,7,9};
+            int[] list2 = new int[]{11,12,14,15};
+            int result = findKthSmallestElement(3,  list1, list2);
+            assertEquals(7, result);
+        }
+
+        @Test
+        public void and_elements_in_first_list_are_all_smaller_than_second_list2() {
+            int[] list1 = new int[]{1,3,7,9};
+            int[] list2 = new int[]{11,12,14,15};
+            int result = findKthSmallestElement(4,  list1, list2);
+            assertEquals(9, result);
+        }
+
+        @Test
+        public void and_only_elements_from_second_list_are_part_of_result() {
+            int[] list1 = new int[]{11,12,14,15};
+            int[] list2 = new int[]{1,3,7,9};
+            int result = findKthSmallestElement(3,  list1, list2);
+            assertEquals(7, result);
+        }
+
+        @Test
+        public void and_only_elements_from_second_list_are_part_of_result2() {
+            int[] list1 = new int[]{11,12,14,15};
+            int[] list2 = new int[]{1,3,7,9};
+            int result = findKthSmallestElement(4,  list1, list2);
+            assertEquals(9, result);
+        }
+    }
+
+    @Nested
+    class K_is_bigger_than_the_size_of_at_least_one_of_the_lists {
+
+        @Test
+        public void k_is_smaller_than_list1_and_bigger_than_list2() {
+            int[] list1 = new int[]{1, 2, 3, 4, 7, 9};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(5, list1, list2);
+            assertEquals(3, result);
+        }
+
+        @Test
+        public void k_is_bigger_than_list1_and_smaller_than_list2() {
+            int[] list1 = new int[]{1, 2, 3};
+            int[] list2 = new int[]{1, 2, 3, 4, 7, 9};
+            int result = findKthSmallestElement(5, list1, list2);
+            assertEquals(3, result);
+        }
+
+        @Test
+        public void when_k_is_bigger_than_the_size_of_both_lists_and_elements_in_second_list_are_all_smaller_than_first_list() {
+            int[] list1 = new int[]{9, 11, 13, 55};
+            int[] list2 = new int[]{1, 2, 3, 7};
+            int result = findKthSmallestElement(6, list1, list2);
+            assertEquals(11, result);
+        }
+
+        @Test
+        public void when_k_is_bigger_than_the_size_of_both_lists_and_elements_in_second_list_are_all_bigger_than_first_list() {
+            int[] list1 = new int[]{1, 2, 3, 7};
+            int[] list2 = new int[]{9, 11, 13, 55};
+            int result = findKthSmallestElement(6, list1, list2);
+            assertEquals(11, result);
+        }
+
+        @Test
+        public void when_k_is_bigger_than_the_size_of_both_lists() {
+            int[] list1 = new int[]{3, 7, 9, 11, 55};
+            int[] list2 = new int[]{1, 2, 3, 7, 13};
+            int result = findKthSmallestElement(7, list1, list2);
+            assertEquals(9, result);
+        }
+
+        @Test
+        public void when_k_is_bigger_than_the_size_of_both_lists_and_list1_has_more_elements_than_list2() {
+            int[] list1 = new int[]{3, 7, 9, 11, 55, 77, 100, 200};
+            int[] list2 = new int[]{1, 2, 3, 7, 13};
+            int result = findKthSmallestElement(11, list1, list2);
+            assertEquals(77, result);
+        }
+
+        @Test
+        public void max_test() {
+            int[] list1 = new int[]{100, 200};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(4, list1, list2);
+            assertEquals(100, result);
+        }
+
+        @Test
+        public void max_test2() {
+            int[] list1 = new int[]{100, 200};
+            int[] list2 = new int[]{1, 2, 3};
+            int result = findKthSmallestElement(5, list1, list2);
+            assertEquals(200, result);
+        }
+
+        @Test
+        public void when_k_is_smaller_than_the_size_of_both_lists_and_kth_element_in_list2() {
+            int[] list1 = new int[]{1, 2, 5};
+            int[] list2 = new int[]{1, 3, 4, 7};
+            int result = findKthSmallestElement(4, list1, list2);
+            assertEquals(3, result);
+        }
+
+        @Test
+        public void when_k_is_smaller_than_the_size_of_both_lists_and_kth_element_is_smallest_in_list2() {
+            int[] list1 = new int[]{1, 2, 5};
+            int[] list2 = new int[]{3, 4, 7};
+            int result = findKthSmallestElement(3, list1, list2);
+            assertEquals(3, result);
+        }
+
+        @Test
+        public void when_k_is_smaller_than_the_size_of_both_lists_and_kth_element_is_smallest_in_list23() {
+            int[] list1 = new int[]{3, 11, 27, 53, 90};
+            int[] list2 = new int[]{4, 20, 21, 100};
+            int result = findKthSmallestElement(5, list1, list2);
+            assertEquals(21, result);
+        }
+    }
+
+//    @Test
+//    public void randomTests() {
+//        IntStream.range(1, 100000).forEach(i -> random());
+//    }
+
+    private void random() {
+
+        Random random = new Random();
+        int length1 = (Math.abs(random.nextInt())) % 1000 + 1;
+        int length2 = (Math.abs(random.nextInt())) % 1000 + 1;
+
+        int[] list1 = sortedRandomIntArrayOfLength(length1);
+        int[] list2 = sortedRandomIntArrayOfLength(length2);
+
+        int k = (Math.abs(random.nextInt()) % (length1 + length2)) + 1 ;
+
+        int result = findKthSmallestElement(k,  list1, list2);
+
+        int result2 = getKthElementSorted(list1, list2, k);
+
+        int result3 = getKthElementMerge(list1, list2, k);
+
+        assertEquals(result2, result);
+        assertEquals(result2, result3);
+    }
+
+    private int[] sortedRandomIntArrayOfLength(int length) {
+        int[] intArray = new Random().ints(length).toArray();
+        Arrays.sort(intArray);
+        return intArray;
+    }
+}

apache-cxf/README.md

@@ -7,4 +7,3 @@ This module contains articles about Apache CXF
 - [Apache CXF Support for RESTful Web Services](https://www.baeldung.com/apache-cxf-rest-api)
 - [A Guide to Apache CXF with Spring](https://www.baeldung.com/apache-cxf-with-spring)
 - [Introduction to Apache CXF](https://www.baeldung.com/introduction-to-apache-cxf)
-- [Server-Sent Events (SSE) In JAX-RS](https://www.baeldung.com/java-ee-jax-rs-sse)

apache-cxf/sse-jaxrs/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Server-Sent Events (SSE) In JAX-RS](https://www.baeldung.com/java-ee-jax-rs-sse)

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

@@ -31,6 +31,6 @@ public class UseDateTimeFormatterUnitTest {
     public void givenALocalDate_whenFormattingWithStyleAndLocale_thenPass() {
         String result = subject.formatWithStyleAndLocale(localDateTime, FormatStyle.MEDIUM, Locale.UK);
 
-        assertThat(result).isEqualTo("25 Jan 2015, 06:30:00");
+        assertThat(result).isEqualTo("25-Jan-2015 06:30:00");
     }
 }

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

@@ -3,6 +3,7 @@ package com.baeldung.datetime;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.time.LocalDateTime;
+import java.time.ZoneId;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.GregorianCalendar;
@@ -24,10 +25,11 @@ public class UseToInstantUnitTest {
 
     @Test
     public void givenADate_whenConvertingToLocalDate_thenAsExpected() {
-        Date givenDate = new Date(1465817690000L);
+        LocalDateTime currentDateTime = LocalDateTime.now();
+        Date givenDate = Date.from(currentDateTime.atZone(ZoneId.systemDefault()).toInstant());
 
         LocalDateTime localDateTime = subject.convertDateToLocalDate(givenDate);
 
-        assertThat(localDateTime).isEqualTo("2016-06-13T13:34:50");
+        assertThat(localDateTime).isEqualTo(currentDateTime);
     }
 }

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

@@ -54,7 +54,7 @@ public class UseZonedDateTimeUnitTest {
     @Test
     public void givenAStringWithTimeZone_whenParsing_thenEqualsExpected() {
         ZonedDateTime resultFromString = zonedDateTime.getZonedDateTimeUsingParseMethod("2015-05-03T10:15:30+01:00[Europe/Paris]");
-        ZonedDateTime resultFromLocalDateTime = ZonedDateTime.of(2015, 5, 3, 11, 15, 30, 0, ZoneId.of("Europe/Paris"));
+        ZonedDateTime resultFromLocalDateTime = ZonedDateTime.of(2015, 5, 3, 10, 15, 30, 0, ZoneId.of("Europe/Paris"));
 
         assertThat(resultFromString.getZone()).isEqualTo(ZoneId.of("Europe/Paris"));
         assertThat(resultFromLocalDateTime.getZone()).isEqualTo(ZoneId.of("Europe/Paris"));

core-java-modules/core-java-9-new-features/README.md

@@ -14,3 +14,4 @@ This module contains articles about core Java features that have been introduced
 - [Java 9 Reactive Streams](https://www.baeldung.com/java-9-reactive-streams)
 - [Multi-Release JAR Files with Maven](https://www.baeldung.com/maven-multi-release-jars)
 - [The Difference between RxJava API and the Java 9 Flow API](https://www.baeldung.com/rxjava-vs-java-flow-api)
+- [How to Get a Name of a Method Being Executed?](https://www.baeldung.com/java-name-of-executing-method)

core-java-modules/core-java-collections-2/src/test/java/com/baeldung/collections/sorting/JavaSortingUnitTest.java

@@ -5,7 +5,16 @@ import org.apache.commons.lang3.ArrayUtils;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
 import java.util.Map.Entry;
 
 import static org.junit.Assert.assertTrue;
@@ -138,7 +147,7 @@ public class JavaSortingUnitTest {
         HashSet<Integer> descSortedIntegersSet = new LinkedHashSet<>(Arrays.asList(255, 200, 123, 89, 88, 66, 7, 5, 1));
 
         ArrayList<Integer> list = new ArrayList<>(integersSet);
-        list.sort((i1, i2) -> i2 - i1);
+        list.sort(Comparator.reverseOrder());
         integersSet = new LinkedHashSet<>(list);
 
         assertTrue(Arrays.equals(integersSet.toArray(), descSortedIntegersSet.toArray()));

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

@@ -21,6 +21,12 @@
             <artifactId>commons-collections4</artifactId>
             <version>${commons-collections4.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+            <scope>compile</scope>
+        </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>

core-java-modules/core-java-collections-list-3/src/test/java/com/baeldung/list/difference/FindDifferencesBetweenListsUnitTest.java

@@ -0,0 +1,96 @@
+package com.baeldung.list.difference;
+
+import com.google.common.collect.Sets;
+import org.apache.commons.collections4.CollectionUtils;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.assertj.core.api.Assertions.*;
+
+public class FindDifferencesBetweenListsUnitTest {
+
+    private static final List<String> listOne = Arrays.asList("Jack", "Tom", "Sam", "John", "James", "Jack");
+    private static final List<String> listTwo = Arrays.asList("Jack", "Daniel", "Sam", "Alan", "James", "George");
+
+    @Test
+    public void givenLists_whenUsingPlainJavaImpl_thenDifferencesAreFound() {
+        List<String> differences = new ArrayList<>(listOne);
+        differences.removeAll(listTwo);
+        assertEquals(2, differences.size());
+        assertThat(differences).containsExactly("Tom", "John");
+    }
+
+    @Test
+    public void givenReverseLists_whenUsingPlainJavaImpl_thenDifferencesAreFound() {
+        List<String> differences = new ArrayList<>(listTwo);
+        differences.removeAll(listOne);
+        assertEquals(3, differences.size());
+        assertThat(differences).containsExactly("Daniel", "Alan", "George");
+    }
+
+    @Test
+    public void givenLists_whenUsingJavaStreams_thenDifferencesAreFound() {
+        List<String> differences = listOne.stream()
+                .filter(element -> !listTwo.contains(element))
+                .collect(Collectors.toList());
+        assertEquals(2, differences.size());
+        assertThat(differences).containsExactly("Tom", "John");
+    }
+
+    @Test
+    public void givenReverseLists_whenUsingJavaStreams_thenDifferencesAreFound() {
+        List<String> differences = listTwo.stream()
+                .filter(element -> !listOne.contains(element))
+                .collect(Collectors.toList());
+        assertEquals(3, differences.size());
+        assertThat(differences).containsExactly("Daniel", "Alan", "George");
+    }
+
+    @Test
+    public void givenLists_whenUsingGoogleGuava_thenDifferencesAreFound() {
+        List<String> differences = new ArrayList<>(Sets.difference(Sets.newHashSet(listOne), Sets.newHashSet(listTwo)));
+        assertEquals(2, differences.size());
+        assertThat(differences).containsExactlyInAnyOrder("Tom", "John");
+    }
+
+    @Test
+    public void givenReverseLists_whenUsingGoogleGuava_thenDifferencesAreFound() {
+        List<String> differences = new ArrayList<>(Sets.difference(Sets.newHashSet(listTwo), Sets.newHashSet(listOne)));
+        assertEquals(3, differences.size());
+        assertThat(differences).containsExactlyInAnyOrder("Daniel", "Alan", "George");
+    }
+
+    @Test
+    public void givenLists_whenUsingApacheCommons_thenDifferencesAreFound() {
+        List<String> differences = new ArrayList<>((CollectionUtils.removeAll(listOne, listTwo)));
+        assertEquals(2, differences.size());
+        assertThat(differences).containsExactly("Tom", "John");
+    }
+
+    @Test
+    public void givenReverseLists_whenUsingApacheCommons_thenDifferencesAreFound() {
+        List<String> differences = new ArrayList<>((CollectionUtils.removeAll(listTwo, listOne)));
+        assertEquals(3, differences.size());
+        assertThat(differences).containsExactly("Daniel", "Alan", "George");
+    }
+
+    @Test
+    public void givenLists_whenUsingPlainJavaImpl_thenDifferencesWithDuplicatesAreFound() {
+        List<String> differences = new ArrayList<>(listOne);
+        listTwo.forEach(differences::remove);
+        assertThat(differences).containsExactly("Tom", "John", "Jack");
+    }
+
+    @Test
+    public void givenLists_whenUsingApacheCommons_thenDifferencesWithDuplicatesAreFound() {
+        List<String> differences = new ArrayList<>(CollectionUtils.subtract(listOne, listTwo));
+        assertEquals(3, differences.size());
+        assertThat(differences).containsExactly("Tom", "John", "Jack");
+    }
+
+}

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

@@ -21,20 +21,15 @@
             <version>${eclipse-collections.version}</version>
         </dependency>
         <dependency>
-            <groupId>net.sf.trove4j</groupId>
+            <groupId>com.carrotsearch</groupId>
-            <artifactId>trove4j</artifactId>
+            <artifactId>hppc</artifactId>
-            <version>${trove4j.version}</version>
+            <version>${hppc.version}</version>
         </dependency>
         <dependency>
             <groupId>it.unimi.dsi</groupId>
             <artifactId>fastutil</artifactId>
             <version>${fastutil.version}</version>
         </dependency>
-        <dependency>
-            <groupId>colt</groupId>
-            <artifactId>colt</artifactId>
-            <version>${colt.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
@@ -69,9 +64,8 @@
         <commons-collections4.version>4.1</commons-collections4.version>
         <avaitility.version>1.7.0</avaitility.version>
         <eclipse-collections.version>8.2.0</eclipse-collections.version>
-        <trove4j.version>3.0.2</trove4j.version>
+        <hppc.version>0.7.2</hppc.version>
         <fastutil.version>8.1.0</fastutil.version>
-        <colt.version>1.2.0</colt.version>
         <assertj.version>3.11.1</assertj.version>
     </properties>
 

core-java-modules/core-java-collections-maps-2/src/main/java/com/baeldung/map/primitives/PrimitiveMaps.java

@@ -1,29 +1,68 @@
 package com.baeldung.map.primitives;
 
-import cern.colt.map.AbstractIntDoubleMap;
+import com.carrotsearch.hppc.IntLongHashMap;
-import cern.colt.map.OpenIntDoubleHashMap;
+import com.carrotsearch.hppc.IntLongScatterMap;
-import gnu.trove.map.TDoubleIntMap;
+import com.carrotsearch.hppc.IntObjectHashMap;
-import gnu.trove.map.hash.TDoubleIntHashMap;
+import com.carrotsearch.hppc.IntObjectMap;
+import com.carrotsearch.hppc.IntObjectScatterMap;
+
 import it.unimi.dsi.fastutil.ints.Int2BooleanMap;
+import it.unimi.dsi.fastutil.ints.Int2BooleanMaps;
 import it.unimi.dsi.fastutil.ints.Int2BooleanOpenHashMap;
 import it.unimi.dsi.fastutil.ints.Int2BooleanSortedMap;
 import it.unimi.dsi.fastutil.ints.Int2BooleanSortedMaps;
+import it.unimi.dsi.fastutil.objects.ObjectIterator;
+
 import org.eclipse.collections.api.map.primitive.ImmutableIntIntMap;
 import org.eclipse.collections.api.map.primitive.MutableIntIntMap;
 import org.eclipse.collections.api.map.primitive.MutableObjectDoubleMap;
 import org.eclipse.collections.impl.factory.primitive.IntIntMaps;
 import org.eclipse.collections.impl.factory.primitive.ObjectDoubleMaps;
 
+import static java.lang.String.format;
+
+import java.math.BigDecimal;
+
 public class PrimitiveMaps {
 
     public static void main(String[] args) {
 
+        hppcMap();
         eclipseCollectionsMap();
-        troveMap();
-        coltMap();
         fastutilMap();
     }
 
+    private static void hppcMap() {
+        //Regular maps
+        IntLongHashMap intLongHashMap = new IntLongHashMap();
+        intLongHashMap.put(25,1L);
+        intLongHashMap.put(150,Long.MAX_VALUE);
+        intLongHashMap.put(1,0L);
+        
+        intLongHashMap.get(150);
+
+        IntObjectMap<BigDecimal> intObjectMap = new IntObjectHashMap<BigDecimal>();
+        intObjectMap.put(1, BigDecimal.valueOf(1));
+        intObjectMap.put(2, BigDecimal.valueOf(2500));
+
+        BigDecimal value = intObjectMap.get(2);
+
+        //Scatter maps
+        IntLongScatterMap intLongScatterMap = new IntLongScatterMap();
+        intLongScatterMap.put(1, 1L);
+        intLongScatterMap.put(2, -2L);
+        intLongScatterMap.put(1000,0L);    
+
+        intLongScatterMap.get(1000);
+
+        IntObjectScatterMap<BigDecimal> intObjectScatterMap = new IntObjectScatterMap<BigDecimal>();
+        intObjectScatterMap.put(1, BigDecimal.valueOf(1));
+        intObjectScatterMap.put(2, BigDecimal.valueOf(2500));
+
+        value = intObjectScatterMap.get(2);
+    }
+
+
     private static void fastutilMap() {
         Int2BooleanMap int2BooleanMap = new Int2BooleanOpenHashMap();
         int2BooleanMap.put(1, true);
@@ -32,13 +71,19 @@ public class PrimitiveMaps {
 
         boolean value = int2BooleanMap.get(1);
 
-        Int2BooleanSortedMap int2BooleanSorted = Int2BooleanSortedMaps.EMPTY_MAP;
+        //Lambda style iteration
-    }
+        Int2BooleanMaps.fastForEach(int2BooleanMap, entry -> {
+            System.out.println(String.format("Key: %d, Value: %b",entry.getIntKey(),entry.getBooleanValue()));
+        });
+
+        //Iterator based loop
+        ObjectIterator<Int2BooleanMap.Entry> iterator = Int2BooleanMaps.fastIterator(int2BooleanMap);
+        while(iterator.hasNext()) {
+            Int2BooleanMap.Entry entry = iterator.next();
+            System.out.println(String.format("Key: %d, Value: %b",entry.getIntKey(),entry.getBooleanValue()));
+
+        }
 
-    private static void coltMap() {
-        AbstractIntDoubleMap map = new OpenIntDoubleHashMap();
-        map.put(1, 4.5);
-        double value = map.get(1);
     }
 
     private static void eclipseCollectionsMap() {
@@ -53,17 +98,5 @@ public class PrimitiveMaps {
         dObject.addToValue("stability", 0.8);
     }
 
-    private static void troveMap() {
-        double[] doubles = new double[] {1.2, 4.5, 0.3};
-        int[] ints = new int[] {1, 4, 0};
 
-        TDoubleIntMap doubleIntMap = new TDoubleIntHashMap(doubles, ints);
-
-        doubleIntMap.put(1.2, 22);
-        doubleIntMap.put(4.5, 16);
-
-        doubleIntMap.adjustValue(1.2, 1);
-        doubleIntMap.adjustValue(4.5, 4);
-        doubleIntMap.adjustValue(0.3, 7);
-    }
 }

core-java-modules/core-java-concurrency-advanced/src/main/java/com/baeldung/threadlocal/ThreadLocalAwareThreadPool.java

@@ -0,0 +1,25 @@
+package com.baeldung.threadlocal;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+public class ThreadLocalAwareThreadPool extends ThreadPoolExecutor {
+
+    public ThreadLocalAwareThreadPool(int corePoolSize,
+      int maximumPoolSize,
+      long keepAliveTime,
+      TimeUnit unit,
+      BlockingQueue<Runnable> workQueue,
+      ThreadFactory threadFactory,
+      RejectedExecutionHandler handler) {
+        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, handler);
+    }
+
+    @Override
+    protected void afterExecute(Runnable r, Throwable t) {
+        // Call remove on each ThreadLocal
+    }
+}

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

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+    <groupId>com.baeldung.exceptions</groupId>
+    <artifactId>core-java-exceptions-3</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-exceptions-3</name>
+    <packaging>jar</packaging>
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../</relativePath>
+    </parent>
+
+    <dependencies>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <!-- testing -->
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+
+</project>

core-java-modules/core-java-exceptions-3/src/main/java/com/baeldung/exceptions/nosuchmethoderror/MainMenu.java

@@ -0,0 +1,11 @@
+package com.baeldung.exceptions.nosuchmethoderror;
+
+public class MainMenu {
+    public static void main(String[] args) {
+        System.out.println("Today's Specials: " + getSpecials());
+    }
+
+    public static String getSpecials() {
+        return SpecialToday.getDesert();
+    }
+}

core-java-modules/core-java-exceptions-3/src/main/java/com/baeldung/exceptions/nosuchmethoderror/SpecialToday.java

@@ -0,0 +1,8 @@
+package com.baeldung.exceptions.nosuchmethoderror;
+public class SpecialToday {
+    private static String desert = "Chocolate Cake";
+
+    public static String getDesert() {
+        return desert;
+    }
+}

core-java-modules/core-java-exceptions-3/src/test/java/com/baeldung/exceptions/nosuchmethoderror/MainMenuUnitTest.java

@@ -0,0 +1,13 @@
+package com.baeldung.exceptions.nosuchmethoderror;
+
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.jupiter.api.Test;
+
+class MainMenuUnitTest {
+
+    @Test
+    void whenGetSpecials_thenNotNull() {
+        assertNotNull(MainMenu.getSpecials());
+    }
+}

core-java-modules/core-java-io-3/src/test/java/com/baeldung/copydirectory/ApacheCommonsUnitTest.java

@@ -16,10 +16,10 @@ import org.junit.jupiter.api.Test;
 
 public class ApacheCommonsUnitTest {
 
-    private final String sourceDirectoryLocation = "src/test/resources/sourceDirectory";
+    private final String sourceDirectoryLocation = "src/test/resources/sourceDirectory3";
     private final String subDirectoryName = "/childDirectory";
     private final String fileName = "/file.txt";
-    private final String destinationDirectoryLocation = "src/test/resources/destinationDirectory";
+    private final String destinationDirectoryLocation = "src/test/resources/destinationDirectory3";
 
     @BeforeEach
     public void createDirectoryWithSubdirectoryAndFile() throws IOException {

core-java-modules/core-java-io-3/src/test/java/com/baeldung/copydirectory/CoreOldUnitTest.java

@@ -16,10 +16,10 @@ import org.junit.jupiter.api.Test;
 
 public class CoreOldUnitTest {
 
-    private final String sourceDirectoryLocation = "src/test/resources/sourceDirectory";
+    private final String sourceDirectoryLocation = "src/test/resources/sourceDirectory1";
     private final String subDirectoryName = "/childDirectory";
     private final String fileName = "/file.txt";
-    private final String destinationDirectoryLocation = "src/test/resources/destinationDirectory";
+    private final String destinationDirectoryLocation = "src/test/resources/destinationDirectory1";
 
     @BeforeEach
     public void createDirectoryWithSubdirectoryAndFile() throws IOException {

core-java-modules/core-java-io-3/src/test/java/com/baeldung/copydirectory/JavaNioUnitTest.java

@@ -16,10 +16,10 @@ import org.junit.jupiter.api.Test;
 
 public class JavaNioUnitTest {
 
-    private final String sourceDirectoryLocation = "src/test/resources/sourceDirectory";
+    private final String sourceDirectoryLocation = "src/test/resources/sourceDirectory2";
     private final String subDirectoryName = "/childDirectory";
     private final String fileName = "/file.txt";
-    private final String destinationDirectoryLocation = "src/test/resources/destinationDirectory";
+    private final String destinationDirectoryLocation = "src/test/resources/destinationDirectory2";
 
     @BeforeEach
     public void createDirectoryWithSubdirectoryAndFile() throws IOException {

core-java-modules/core-java-jvm-2/src/main/java/com/baeldung/loadedclasslisting/Launcher.java

@@ -0,0 +1,19 @@
+package com.baeldung.loadedclasslisting;
+
+import java.util.Arrays;
+
+public class Launcher {
+
+    public static void main(String[] args) {
+        printClassesLoadedBy("BOOTSTRAP");
+        printClassesLoadedBy("SYSTEM");
+        printClassesLoadedBy("EXTENSION");
+    }
+
+    private static void printClassesLoadedBy(String classLoaderType) {
+        System.out.println(classLoaderType + " ClassLoader : ");
+        Class<?>[] classes = ListLoadedClassesAgent.listLoadedClasses(classLoaderType);
+        Arrays.asList(classes)
+            .forEach(clazz -> System.out.println(clazz.getCanonicalName()));
+    }
+}

core-java-modules/core-java-jvm-2/src/main/java/com/baeldung/loadedclasslisting/ListLoadedClassesAgent.java

@@ -0,0 +1,40 @@
+package com.baeldung.loadedclasslisting;
+
+import java.lang.instrument.Instrumentation;
+
+public class ListLoadedClassesAgent {
+
+    private static Instrumentation instrumentation;
+
+    public static void premain(String agentArgs, Instrumentation instrumentation) {
+        ListLoadedClassesAgent.instrumentation = instrumentation;
+    }
+
+    public static Class<?>[] listLoadedClasses(String classLoaderType) {
+        if (instrumentation == null) {
+            throw new IllegalStateException(
+              "ListLoadedClassesAgent is not initialized.");
+        }
+        return instrumentation.getInitiatedClasses(
+          getClassLoader(classLoaderType));
+    }
+
+    private static ClassLoader getClassLoader(String classLoaderType) {
+        ClassLoader classLoader = null;
+        switch (classLoaderType) {
+        case "SYSTEM":
+            classLoader = ClassLoader.getSystemClassLoader();
+            break;
+        case "EXTENSION":
+            classLoader = ClassLoader.getSystemClassLoader().getParent();
+            break;
+        // passing a null value to the Instrumentation : getInitiatedClasses method
+        // defaults to the bootstrap class loader
+        case "BOOTSTRAP":
+            break;
+        default:
+            break;
+        }
+        return classLoader;
+    }
+}

core-java-modules/core-java-jvm-2/src/main/java/com/baeldung/loadedclasslisting/MANIFEST.MF

@@ -0,0 +1 @@
+Premain-Class: com.baeldung.loadedclasslisting.ListLoadedClassesAgent

core-java-modules/core-java-lambdas/src/main/java/com/baeldung/java8/entity/Human.java

@@ -37,7 +37,7 @@ public class Human {
 
     public static int compareByNameThenAge(final Human lhs, final Human rhs) {
         if (lhs.name.equals(rhs.name)) {
-            return lhs.age - rhs.age;
+            return Integer.compare(lhs.age, rhs.age);
         } else {
             return lhs.name.compareTo(rhs.name);
         }

core-java-modules/core-java-lambdas/src/test/java/com/baeldung/java8/Java8SortUnitTest.java

@@ -54,7 +54,7 @@ public class Java8SortUnitTest {
         final List<Human> humans = Lists.newArrayList(new Human("Sarah", 12), new Human("Sarah", 10), new Human("Zack", 12));
         humans.sort((lhs, rhs) -> {
             if (lhs.getName().equals(rhs.getName())) {
-                return lhs.getAge() - rhs.getAge();
+                return Integer.compare(lhs.getAge(), rhs.getAge());
             } else {
                 return lhs.getName().compareTo(rhs.getName());
             }

core-java-modules/core-java-lang/src/main/java/com/baeldung/comparable/Player.java

@@ -45,7 +45,7 @@ public class Player implements Comparable<Player> {
 
     @Override
     public int compareTo(Player otherPlayer) {
-        return (this.getRanking() - otherPlayer.getRanking());
+        return Integer.compare(getRanking(), otherPlayer.getRanking());
     }
 
 }

core-java-modules/core-java-lang/src/main/java/com/baeldung/comparator/PlayerAgeComparator.java

@@ -6,7 +6,7 @@ public class PlayerAgeComparator implements Comparator<Player> {
 
     @Override
     public int compare(Player firstPlayer, Player secondPlayer) {
-       return (firstPlayer.getAge() - secondPlayer.getAge());
+       return Integer.compare(firstPlayer.getAge(), secondPlayer.getAge());
     }
 
 }

core-java-modules/core-java-lang/src/main/java/com/baeldung/comparator/PlayerRankingComparator.java

@@ -6,7 +6,7 @@ public class PlayerRankingComparator implements Comparator<Player> {
 
     @Override
     public int compare(Player firstPlayer, Player secondPlayer) {
-       return (firstPlayer.getRanking() - secondPlayer.getRanking());
+       return Integer.compare(firstPlayer.getRanking(), secondPlayer.getRanking());
     }
 
 }

core-java-modules/core-java-lang/src/test/java/com/baeldung/comparator/AvoidingSubtractionUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.comparator;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class AvoidingSubtractionUnitTest {
+
+    @Test
+    public void givenTwoPlayers_whenUsingSubtraction_thenOverflow() {
+        Comparator<Player> comparator = (p1, p2) -> p1.getRanking() - p2.getRanking();
+        Player player1 = new Player(59, "John", Integer.MAX_VALUE);
+        Player player2 = new Player(67, "Roger", -1);
+
+        List<Player> players = Arrays.asList(player1, player2);
+        players.sort(comparator);
+        System.out.println(players);
+
+        assertEquals("John", players.get(0).getName());
+        assertEquals("Roger", players.get(1).getName());
+    }
+}

core-java-modules/core-java-lang/src/test/java/com/baeldung/comparator/Java8ComparatorUnitTest.java

@@ -1,14 +1,14 @@
 package com.baeldung.comparator;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.Before;
+import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
-import org.junit.Before;
+import static org.junit.Assert.assertEquals;
-import org.junit.Test;
 
 public class Java8ComparatorUnitTest {
 
@@ -28,7 +28,7 @@ public class Java8ComparatorUnitTest {
     @Test
     public void whenComparing_UsingLambda_thenSorted() {
         System.out.println("************** Java 8 Comaparator **************");
-        Comparator<Player> byRanking = (Player player1, Player player2) -> player1.getRanking() - player2.getRanking();
+        Comparator<Player> byRanking = (Player player1, Player player2) -> Integer.compare(player1.getRanking(), player2.getRanking());
 
         System.out.println("Before Sorting : " + footballTeam);
         Collections.sort(footballTeam, byRanking);

core-java-modules/core-java-nio-2/src/main/java/com/baeldung/selector/EchoServer.java

@@ -49,11 +49,11 @@ public class EchoServer {
         if (new String(buffer.array()).trim().equals(POISON_PILL)) {
             client.close();
             System.out.println("Not accepting client messages anymore");
+        } else {
+            buffer.flip();
+            client.write(buffer);
+            buffer.clear();
         }
-
-        buffer.flip();
-        client.write(buffer);
-        buffer.clear();
     }
 
     private static void register(Selector selector, ServerSocketChannel serverSocket) throws IOException {

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

@@ -1,13 +1,13 @@
 ## Core Java Cookbooks and Examples
 
 ### Relevant Articles: 
-[Getting Started with Java Properties](http://www.baeldung.com/java-properties)
+- [Getting Started with Java Properties](http://www.baeldung.com/java-properties)
-[Java Money and the Currency API](http://www.baeldung.com/java-money-and-currency)
+- [Java Money and the Currency API](http://www.baeldung.com/java-money-and-currency)
-[Introduction to Java Serialization](http://www.baeldung.com/java-serialization)
+- [Introduction to Java Serialization](http://www.baeldung.com/java-serialization)
-[Guide to UUID in Java](http://www.baeldung.com/java-uuid)
+- [Guide to UUID in Java](http://www.baeldung.com/java-uuid)
-[Compiling Java *.class Files with javac](http://www.baeldung.com/javac)
+- [Compiling Java *.class Files with javac](http://www.baeldung.com/javac)
-[Introduction to Javadoc](http://www.baeldung.com/javadoc)
+- [Introduction to Javadoc](http://www.baeldung.com/javadoc)
-[Guide to the Externalizable Interface in Java](http://www.baeldung.com/java-externalizable)
+- [Guide to the Externalizable Interface in Java](http://www.baeldung.com/java-externalizable)
-[What is the serialVersionUID?](http://www.baeldung.com/java-serial-version-uid)
+- [What is the serialVersionUID?](http://www.baeldung.com/java-serial-version-uid)
-[A Guide to the ResourceBundle](http://www.baeldung.com/java-resourcebundle)
+- [A Guide to the ResourceBundle](http://www.baeldung.com/java-resourcebundle)
-[Merging java.util.Properties Objects](https://www.baeldung.com/java-merging-properties)
+- [Merging java.util.Properties Objects](https://www.baeldung.com/java-merging-properties)

core-java-modules/pom.xml

@@ -22,6 +22,7 @@
         <!-- <module>core-java-11</module> --> <!-- We haven't upgraded to java 11. Fixing in BAEL-10841 -->
         <!-- <module>core-java-12</module> --> <!-- We haven't upgraded to java 12. Fixing in BAEL-10841 -->
         <!-- <module>core-java-13</module> --> <!-- We haven't upgraded to java 12. Fixing in BAEL-10841 -->
+        <!-- <module>core-java-14</module> --> <!-- We haven't upgraded to java 14.-->
         <module>core-java-8</module>
         <module>core-java-8-2</module>
 
@@ -59,15 +60,20 @@
         <module>core-java-concurrency-basic</module>
         <module>core-java-concurrency-basic-2</module>
         <module>core-java-concurrency-collections</module>
+        <module>core-java-concurrency-collections-2</module>
+        <module>core-java-console</module>
 
+        <!--<module>core-java-8-datetime</module>--> <!-- unit test case failure -->
+        <module>core-java-8-datetime-2</module>
         <!-- <module>core-java-date-operations-1</module> --> <!-- We haven't upgraded to java 9. Fixing in BAEL-10841 -->
         <module>core-java-date-operations-2</module>
         <!-- We haven't upgraded to java 9. -->
         <!-- <module>core-java-datetime-computations</module> <module>core-java-datetime-conversion</module> <module>core-java-datetime-java8</module> <module>core-java-datetime-string</module> -->
+        <module>core-java-8-datetime</module>
 
         <module>core-java-exceptions</module>
         <module>core-java-exceptions-2</module>
-
+        <module>core-java-exceptions-3</module>
         <module>core-java-function</module>
 
         <module>core-java-io</module>

docker/docker-spring-boot/README.md

@@ -0,0 +1,3 @@
+### Relevant Article:
+
+- [Creating Docker Images with Spring Boot](https://www.baeldung.com/spring-boot-docker-images)

excelformula/README.md

@@ -3,6 +3,3 @@
 This module contains articles about Apache POI
 
 ### Relevant Articles:
-- [Working with Microsoft Excel in Java](https://www.baeldung.com/java-microsoft-excel)
-- [Read Excel Cell Value Rather Than Formula With Apache POI](https://www.baeldung.com/apache-poi-read-cell-value-formula)
-- [Upload and Display Excel Files with Spring MVC](https://www.baeldung.com/spring-mvc-excel-files)

java-collections-conversions/src/test/java/com/baeldung/java/collections/JavaCollectionConversionUnitTest.java

@@ -144,7 +144,7 @@ public class JavaCollectionConversionUnitTest {
         final Map<Integer, String> sourceMap = createMap();
 
         final Collection<String> values = sourceMap.values();
-        final String[] targetArray = values.toArray(new String[values.size()]);
+        final String[] targetArray = values.toArray(new String[0]);
     }
 
     @Test

java-numbers-3/README.md

@@ -4,7 +4,7 @@ This module contains articles about numbers in Java.
 
 ### Relevant Articles:
 
-- [Generating Random Numbers](https://www.baeldung.com/java-generating-random-numbers)
+- [Generating Random Numbers in Java](https://www.baeldung.com/java-generating-random-numbers)
 - [Convert Double to Long in Java](https://www.baeldung.com/java-convert-double-long)
 - [Check for null Before Calling Parse in Double.parseDouble](https://www.baeldung.com/java-check-null-parse-double)
 - [Generating Random Numbers in a Range in Java](https://www.baeldung.com/java-generating-random-numbers-in-range)

jgit/src/main/java/com/baeldung/jgit/porcelain/AddFile.java

@@ -6,6 +6,8 @@ import com.baeldung.jgit.helper.Helper;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.Repository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Simple snippet which shows how to add a file to the index
@@ -14,6 +16,8 @@ import org.eclipse.jgit.lib.Repository;
  */
 public class AddFile {
 
+    private static final Logger logger = LoggerFactory.getLogger(AddFile.class);
+
     public static void main(String[] args) throws IOException, GitAPIException {
         // prepare a new test-repository
         try (Repository repository = Helper.createNewRepository()) {
@@ -29,7 +33,7 @@ public class AddFile {
                         .addFilepattern("testfile")
                         .call();
 
-                System.out.println("Added file " + myfile + " to repository at " + repository.getDirectory());
+                logger.debug("Added file " + myfile + " to repository at " + repository.getDirectory());
             }
         }
     }

jgit/src/main/java/com/baeldung/jgit/porcelain/CommitAll.java

@@ -7,6 +7,8 @@ import com.baeldung.jgit.helper.Helper;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.Repository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Simple snippet which shows how to commit all files
@@ -15,6 +17,8 @@ import org.eclipse.jgit.lib.Repository;
  */
 public class CommitAll {
 
+    private static final Logger logger = LoggerFactory.getLogger(CommitAll.class);
+
     public static void main(String[] args) throws IOException, GitAPIException {
         // prepare a new test-repository
         try (Repository repository = Helper.createNewRepository()) {
@@ -44,7 +48,7 @@ public class CommitAll {
                         .call();
 
 
-                System.out.println("Committed all changes to repository at " + repository.getDirectory());
+                logger.debug("Committed all changes to repository at " + repository.getDirectory());
             }
         }
     }

jgit/src/main/java/com/baeldung/jgit/porcelain/CreateAndDeleteTag.java

@@ -9,6 +9,8 @@ import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Simple snippet which shows how to create a tag
@@ -17,6 +19,8 @@ import org.eclipse.jgit.revwalk.RevWalk;
  */
 public class CreateAndDeleteTag {
 
+    private static final Logger logger = LoggerFactory.getLogger(CreateAndDeleteTag.class);
+
     public static void main(String[] args) throws IOException, GitAPIException {
         // prepare test-repository
         try (Repository repository = Helper.openJGitRepository()) {
@@ -26,7 +30,7 @@ public class CreateAndDeleteTag {
 
                 // set it on the current HEAD
                 Ref tag = git.tag().setName("tag_for_testing").call();
-                System.out.println("Created/moved tag " + tag + " to repository at " + repository.getDirectory());
+                logger.debug("Created/moved tag " + tag + " to repository at " + repository.getDirectory());
 
                 // remove the tag again
                 git.tagDelete().setTags("tag_for_testing").call();
@@ -36,14 +40,14 @@ public class CreateAndDeleteTag {
                 try (RevWalk walk = new RevWalk(repository)) {
                     RevCommit commit = walk.parseCommit(id);
                     tag = git.tag().setObjectId(commit).setName("tag_for_testing").call();
-                    System.out.println("Created/moved tag " + tag + " to repository at " + repository.getDirectory());
+                    logger.debug("Created/moved tag " + tag + " to repository at " + repository.getDirectory());
 
                     // remove the tag again
                     git.tagDelete().setTags("tag_for_testing").call();
 
                     // create an annotated tag
                     tag = git.tag().setName("tag_for_testing").setAnnotated(true).call();
-                    System.out.println("Created/moved tag " + tag + " to repository at " + repository.getDirectory());
+                    logger.debug("Created/moved tag " + tag + " to repository at " + repository.getDirectory());
 
                     // remove the tag again
                     git.tagDelete().setTags("tag_for_testing").call();

jgit/src/main/java/com/baeldung/jgit/porcelain/Log.java

@@ -7,6 +7,9 @@ import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * Simple snippet which shows how to get the commit-ids for a file to provide log information.
  *
@@ -14,6 +17,8 @@ import org.eclipse.jgit.revwalk.RevCommit;
  */
 public class Log {
 
+    private static final Logger logger = LoggerFactory.getLogger(Log.class);
+
     @SuppressWarnings("unused")
     public static void main(String[] args) throws IOException, GitAPIException {
         try (Repository repository = Helper.openJGitRepository()) {
@@ -22,30 +27,30 @@ public class Log {
                         .call();
                 int count = 0;
                 for (RevCommit rev : logs) {
-                    //System.out.println("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
+                    logger.trace("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
                     count++;
                 }
-                System.out.println("Had " + count + " commits overall on current branch");
+                logger.debug("Had " + count + " commits overall on current branch");
 
                 logs = git.log()
                         .add(repository.resolve(git.getRepository().getFullBranch()))
                         .call();
                 count = 0;
                 for (RevCommit rev : logs) {
-                    System.out.println("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
+                    logger.trace("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
                     count++;
                 }
-                System.out.println("Had " + count + " commits overall on "+git.getRepository().getFullBranch());
+                logger.debug("Had " + count + " commits overall on "+git.getRepository().getFullBranch());
 
                 logs = git.log()
                         .all()
                         .call();
                 count = 0;
                 for (RevCommit rev : logs) {
-                    //System.out.println("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
+                    logger.trace("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
                     count++;
                 }
-                System.out.println("Had " + count + " commits overall in repository");
+                logger.debug("Had " + count + " commits overall in repository");
 
                 logs = git.log()
                         // for all log.all()
@@ -53,10 +58,10 @@ public class Log {
                         .call();
                 count = 0;
                 for (RevCommit rev : logs) {
-                    //System.out.println("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
+                    logger.trace("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
                     count++;
                 }
-                System.out.println("Had " + count + " commits on README.md");
+                logger.debug("Had " + count + " commits on README.md");
 
                 logs = git.log()
                         // for all log.all()
@@ -64,10 +69,10 @@ public class Log {
                         .call();
                 count = 0;
                 for (RevCommit rev : logs) {
-                    //System.out.println("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
+                    logger.trace("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
                     count++;
                 }
-                System.out.println("Had " + count + " commits on pom.xml");
+                logger.debug("Had " + count + " commits on pom.xml");
             }
         }
     }

jgit/src/test/java/com/baeldung/jgit/porcelain/PorcelainUnitTest.java

@@ -13,5 +13,6 @@ public class PorcelainUnitTest {
         CreateAndDeleteTag.main(null);
 
         Log.main(null);
+
     }
 }

jhipster-5/bookstore-monolith/pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
 
     <groupId>com.baeldung.jhipster5</groupId>
-    <artifactId>bookstore</artifactId>
+    <artifactId>bookstore-monolith</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>
     <name>Bookstore</name>

jib/pom.xml

@@ -40,6 +40,6 @@
     </build>
 
     <properties>
-        <jib-maven-plugin.version>0.9.10</jib-maven-plugin.version>
+        <jib-maven-plugin.version>2.5.0</jib-maven-plugin.version>
     </properties>
 </project>

libraries-5/pom.xml

@@ -32,12 +32,6 @@
             <artifactId>pact-jvm-consumer-junit_2.11</artifactId>
             <version>${pact.version}</version>
             <scope>test</scope>
-            <exclusions>
-                <exclusion>
-                    <groupId>org.codehaus.groovy</groupId>
-                    <artifactId>groovy-all</artifactId>
-                </exclusion>
-            </exclusions>
         </dependency>
 
         <!-- https://mvnrepository.com/artifact/com.typesafe.akka/akka-actor -->
@@ -53,10 +47,10 @@
             <scope>test</scope>
 
         </dependency>
-                <dependency>
+        <dependency>
-                    <groupId>one.util</groupId>
+            <groupId>one.util</groupId>
-                    <artifactId>streamex</artifactId>
+            <artifactId>streamex</artifactId>
-                    <version>${streamex.version}</version>
+            <version>${streamex.version}</version>
         </dependency>
         <dependency>
             <groupId>net.bytebuddy</groupId>

libraries-5/src/test/java/com/baeldung/pact/PactConsumerDrivenContractUnitTest.java

@@ -5,8 +5,6 @@ import au.com.dius.pact.consumer.PactProviderRuleMk2;
 import au.com.dius.pact.consumer.PactVerification;
 import au.com.dius.pact.consumer.dsl.PactDslWithProvider;
 import au.com.dius.pact.model.RequestResponsePact;
-
-import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.springframework.http.HttpEntity;
@@ -28,15 +26,30 @@ public class PactConsumerDrivenContractUnitTest {
 
     @Pact(consumer = "test_consumer")
     public RequestResponsePact createPact(PactDslWithProvider builder) {
-        Map<String, String> headers = new HashMap<String, String>();
+        Map<String, String> headers = new HashMap<>();
         headers.put("Content-Type", "application/json");
 
-        return builder.given("test GET").uponReceiving("GET REQUEST").path("/pact").method("GET").willRespondWith().status(200).headers(headers).body("{\"condition\": true, \"name\": \"tom\"}").given("test POST").uponReceiving("POST REQUEST").method("POST")
+        return builder
-                .headers(headers).body("{\"name\": \"Michael\"}").path("/pact").willRespondWith().status(201).toPact();
+          .given("test GET")
+            .uponReceiving("GET REQUEST")
+            .path("/pact")
+            .method("GET")
+          .willRespondWith()
+            .status(200)
+            .headers(headers)
+            .body("{\"condition\": true, \"name\": \"tom\"}")
+          .given("test POST")
+            .uponReceiving("POST REQUEST")
+            .method("POST")
+            .headers(headers)
+            .body("{\"name\": \"Michael\"}")
+            .path("/pact")
+          .willRespondWith()
+            .status(201)
+          .toPact();
     }
 
     @Test
-    @Ignore
     @PactVerification()
     public void givenGet_whenSendRequest_shouldReturn200WithProperHeaderAndBody() {
         // when

libraries-testing/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    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">
+    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>libraries-testing</artifactId>
     <name>libraries-testing</name>
@@ -158,6 +158,13 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>com.tngtech.archunit</groupId>
+            <artifactId>archunit-junit5</artifactId>
+            <version>${archunit.version}</version>
+            <scope>test</scope>
+        </dependency>
+
     </dependencies>
 
     <build>
@@ -193,7 +200,7 @@
 
     <properties>
         <asciidoctor.version>1.5.7.1</asciidoctor.version>
-		<serenity.version>1.9.9</serenity.version>
+        <serenity.version>1.9.9</serenity.version>
         <serenity.jbehave.version>1.9.0</serenity.jbehave.version>
         <serenity.jira.version>1.9.0</serenity.jira.version>
         <serenity.plugin.version>1.9.27</serenity.plugin.version>
@@ -210,6 +217,7 @@
         <maven-compiler-plugin.target>1.8</maven-compiler-plugin.target>
         <maven-compiler-plugin.source>1.8</maven-compiler-plugin.source>
         <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
+        <archunit.version>0.14.1</archunit.version>
     </properties>
 
 </project>

libraries-testing/src/main/java/com/baeldung/archunit/smurfs/persistence/SmurfsRepository.java

@@ -0,0 +1,38 @@
+package com.baeldung.archunit.smurfs.persistence;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.TreeMap;
+
+import com.baeldung.archunit.smurfs.persistence.domain.Smurf;
+
+import static java.util.stream.Collectors.toList;
+
+public class SmurfsRepository {
+    
+    private static Map<String,Smurf> smurfs = Collections.synchronizedMap(new TreeMap<>());
+    
+    static {
+        // Just a few here. A full list can be found 
+        // at https://smurfs.fandom.com/wiki/List_of_Smurf_characters
+        smurfs.put("Papa", new Smurf("Papa", true, true));
+        smurfs.put("Actor", new Smurf("Actor", true, true));
+        smurfs.put("Alchemist", new Smurf("Alchemist", true, true));
+        smurfs.put("Archeologist", new Smurf("Archeologist", true, true));
+        smurfs.put("Architect", new Smurf("Architect", true, true));
+        smurfs.put("Baby", new Smurf("Baby", true, true));
+        smurfs.put("Baker", new Smurf("Baker", true, true));
+        smurfs.put("Baker", new Smurf("Baker", true, true));
+    }
+
+    public List<Smurf> findAll() {
+       return Collections.unmodifiableList(smurfs.values().stream().collect(toList()));
+    }
+    
+    public Optional<Smurf> findByName(String name) {
+        return Optional.of(smurfs.get(name));
+    }
+
+}

libraries-testing/src/main/java/com/baeldung/archunit/smurfs/persistence/domain/Smurf.java

@@ -0,0 +1,39 @@
+package com.baeldung.archunit.smurfs.persistence.domain;
+
+public class Smurf {
+    private String name;
+    private boolean comic;
+    private boolean cartoon;
+
+    public Smurf() {}
+
+    public Smurf(String name, boolean comic, boolean cartoon) {
+        this.name = name;
+        this.comic = comic;
+        this.cartoon = cartoon;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public boolean isComic() {
+        return comic;
+    }
+
+    public void setCommic(boolean comic) {
+        this.comic = comic;
+    }
+
+    public boolean isCartoon() {
+        return cartoon;
+    }
+
+    public void setCartoon(boolean cartoon) {
+        this.cartoon = cartoon;
+    }
+}

libraries-testing/src/main/java/com/baeldung/archunit/smurfs/presentation/SmurfsController.java

@@ -0,0 +1,27 @@
+package com.baeldung.archunit.smurfs.presentation;
+
+import java.util.List;
+
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.archunit.smurfs.service.SmurfsService;
+import com.baeldung.archunit.smurfs.service.dto.SmurfDTO;
+
+@RequestMapping(value = "/smurfs", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
+@RestController
+public class SmurfsController {
+    
+    private SmurfsService smurfs;
+    
+    public SmurfsController(SmurfsService smurfs) {
+        this.smurfs = smurfs;
+    }
+
+    @GetMapping
+    public List<SmurfDTO> getSmurfs() {
+        return smurfs.findAll();
+    }
+}

libraries-testing/src/main/java/com/baeldung/archunit/smurfs/service/SmurfsService.java

@@ -0,0 +1,35 @@
+
+package com.baeldung.archunit.smurfs.service;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.springframework.stereotype.Component;
+
+import com.baeldung.archunit.smurfs.persistence.SmurfsRepository;
+import com.baeldung.archunit.smurfs.persistence.domain.Smurf;
+import com.baeldung.archunit.smurfs.service.dto.SmurfDTO;
+
+@Component
+public class SmurfsService {
+    
+    private SmurfsRepository repository;
+    
+    public SmurfsService(SmurfsRepository repository) {
+        this.repository = repository;
+    }
+    
+    public List<SmurfDTO> findAll() {
+        
+        return repository.findAll()
+          .stream()
+          .map(SmurfsService::toDTO)
+          .collect(Collectors.toList());
+    }
+    
+    
+    public static SmurfDTO toDTO(Smurf smurf) {
+        return new SmurfDTO(smurf.getName(),smurf.isComic(), smurf.isCartoon());
+    }
+
+}

libraries-testing/src/main/java/com/baeldung/archunit/smurfs/service/dto/SmurfDTO.java

@@ -0,0 +1,41 @@
+
+package com.baeldung.archunit.smurfs.service.dto;
+
+public class SmurfDTO {
+    private String name;
+    private boolean comic;
+    private boolean cartoon;
+    
+    public SmurfDTO() {}
+    
+    public SmurfDTO(String name, boolean comic, boolean cartoon) {
+        this.name = name;
+        this.comic = comic;
+        this.cartoon = cartoon;
+    }
+    
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+    
+    public boolean isComic() {
+        return comic;
+    }
+
+    public void setCommic(boolean comic) {
+        this.comic = comic;
+    }
+    
+    public boolean isCartoon() {
+        return cartoon;
+    }
+
+    public void setCartoon(boolean cartoon) {
+        this.cartoon = cartoon;
+    }
+    
+}

libraries-testing/src/test/java/com/baeldung/archunit/smurfs/SmurfsArchUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.archunit.smurfs;
+
+
+import com.tngtech.archunit.core.domain.JavaClasses;
+import com.tngtech.archunit.core.importer.ClassFileImporter;
+import com.tngtech.archunit.lang.ArchRule;
+import com.tngtech.archunit.library.Architectures.LayeredArchitecture;
+
+import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.classes;
+import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.noClasses;
+import static com.tngtech.archunit.library.Architectures.layeredArchitecture;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+public class SmurfsArchUnitTest {
+    
+    @Test
+    public void givenPresentationLayerClasses_thenWrongCheckFails() {        
+        JavaClasses jc = new ClassFileImporter().importPackages("com.baeldung.archunit.smurfs");
+        
+        ArchRule r1 = classes()
+          .that()
+          .resideInAPackage("..presentation..")
+          .should().onlyDependOnClassesThat()
+          .resideInAPackage("..service..");
+    
+        assertThrows(AssertionError.class, ()-> r1.check(jc)) ;
+    }
+    
+
+    @Test
+    public void givenPresentationLayerClasses_thenCheckWithFrameworkDependenciesSuccess() {        
+        JavaClasses jc = new ClassFileImporter().importPackages("com.baeldung.archunit.smurfs");
+        
+        ArchRule r1 = classes()
+          .that()
+          .resideInAPackage("..presentation..")
+          .should().onlyDependOnClassesThat()
+          .resideInAnyPackage("..service..", "java..", "javax..", "org.springframework..");
+
+        r1.check(jc);
+    }
+
+    @Test
+    public void givenPresentationLayerClasses_thenNoPersistenceLayerAccess() {        
+        JavaClasses jc = new ClassFileImporter().importPackages("com.baeldung.archunit.smurfs");
+        
+        ArchRule r1 = noClasses()
+          .that()
+          .resideInAPackage("..presentation..")
+          .should().dependOnClassesThat()
+          .resideInAPackage("..persistence..");
+        
+        r1.check(jc);
+    }
+    
+    @Test
+    public void givenApplicationClasses_thenNoLayerViolationsShouldExist() {
+        
+        JavaClasses jc = new ClassFileImporter().importPackages("com.baeldung.archunit.smurfs");
+        
+        LayeredArchitecture arch = layeredArchitecture()
+           // Define layers
+          .layer("Presentation").definedBy("..presentation..")
+          .layer("Service").definedBy("..service..")
+          .layer("Persistence").definedBy("..persistence..")
+          // Add constraints
+          .whereLayer("Presentation").mayNotBeAccessedByAnyLayer()
+          .whereLayer("Service").mayOnlyBeAccessedByLayers("Presentation")
+          .whereLayer("Persistence").mayOnlyBeAccessedByLayers("Service");
+        
+        arch.check(jc);
+    }
+}

libraries-testing/src/test/resources/logback.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <logger name="org.dbunit" level="INFO" />
+</configuration>
+

maven-modules/maven-plugins/maven-enforcer/README.md

@@ -1,3 +0,0 @@
-### Relevant Articles:
-
-- [Maven Enforcer Plugin](https://www.baeldung.com/maven-enforcer-plugin)

maven-modules/maven-profiles/pom.xml

@@ -66,27 +66,29 @@
                 </file>
             </activation>
         </profile>
+        <profile>
+            <id>show-active-profiles</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-help-plugin</artifactId>
+                        <version>${help.plugin.version}</version>
+                        <executions>
+                            <execution>
+                                <id>show-profiles</id>
+                                <phase>compile</phase>
+                                <goals>
+                                    <goal>active-profiles</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
     </profiles>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-help-plugin</artifactId>
-                <version>${help.plugin.version}</version>
-                <executions>
-                    <execution>
-                        <id>show-profiles</id>
-                        <phase>compile</phase>
-                        <goals>
-                            <goal>active-profiles</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
-
     <properties>
        <help.plugin.version>3.2.0</help.plugin.version>
     </properties>

patterns/pom.xml

@@ -21,6 +21,7 @@
         <module>dip</module>
         <module>cqrs-es</module>
         <module>front-controller</module>
+        <module>hexagonal-architecture</module>
         <module>intercepting-filter</module>
         <module>solid</module>
     </modules>

persistence-modules/core-java-persistence/src/main/java/com/baeldung/jdbcmetadata/DatabaseConfig.java

@@ -0,0 +1,49 @@
+package com.baeldung.jdbcmetadata;
+
+import org.apache.log4j.Logger;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+
+public class DatabaseConfig {
+    private static final Logger LOG = Logger.getLogger(DatabaseConfig.class);
+
+    private Connection connection;
+
+    public DatabaseConfig() {
+        try {
+            Class.forName("org.h2.Driver");
+            String url = "jdbc:h2:mem:testdb";
+            connection = DriverManager.getConnection(url, "sa", "");
+        } catch (ClassNotFoundException | SQLException e) {
+            LOG.error(e);
+        }
+    }
+
+    public Connection getConnection() {
+        return connection;
+    }
+
+    public void init() {
+        createTables();
+        createViews();
+    }
+
+    private void createTables() {
+        try {
+            connection.createStatement().executeUpdate("create table CUSTOMER (ID int primary key auto_increment, NAME VARCHAR(45))");
+            connection.createStatement().executeUpdate("create table CUST_ADDRESS (ID VARCHAR(36), CUST_ID int, ADDRESS VARCHAR(45), FOREIGN KEY (CUST_ID) REFERENCES CUSTOMER(ID))");
+        } catch (SQLException e) {
+            LOG.error(e);
+        }
+    }
+
+    private void createViews() {
+        try {
+            connection.createStatement().executeUpdate("CREATE VIEW CUSTOMER_VIEW AS SELECT * FROM CUSTOMER");
+        } catch (SQLException e) {
+            LOG.error(e);
+        }
+    }
+}

persistence-modules/core-java-persistence/src/main/java/com/baeldung/jdbcmetadata/JdbcMetadataApplication.java

@@ -0,0 +1,30 @@
+package com.baeldung.jdbcmetadata;
+
+import org.apache.log4j.Logger;
+
+import java.sql.SQLException;
+
+public class JdbcMetadataApplication {
+
+    private static final Logger LOG = Logger.getLogger(JdbcMetadataApplication.class);
+
+    public static void main(String[] args) {
+        DatabaseConfig databaseConfig = new DatabaseConfig();
+        databaseConfig.init();
+        try {
+            MetadataExtractor metadataExtractor = new MetadataExtractor(databaseConfig.getConnection());
+            metadataExtractor.extractTableInfo();
+            metadataExtractor.extractSystemTables();
+            metadataExtractor.extractViews();
+            String tableName = "CUSTOMER";
+            metadataExtractor.extractColumnInfo(tableName);
+            metadataExtractor.extractPrimaryKeys(tableName);
+            metadataExtractor.extractForeignKeys("CUST_ADDRESS");
+            metadataExtractor.extractDatabaseInfo();
+            metadataExtractor.extractUserName();
+            metadataExtractor.extractSupportedFeatures();
+        } catch (SQLException e) {
+            LOG.error("Error while executing SQL statements", e);
+        }
+    }
+}

persistence-modules/core-java-persistence/src/main/java/com/baeldung/jdbcmetadata/MetadataExtractor.java

@@ -0,0 +1,113 @@
+package com.baeldung.jdbcmetadata;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class MetadataExtractor {
+    private final DatabaseMetaData databaseMetaData;
+
+    public MetadataExtractor(Connection connection) throws SQLException {
+        this.databaseMetaData = connection.getMetaData();
+        DatabaseMetaData databaseMetaData = connection.getMetaData();
+    }
+
+    public void extractTableInfo() throws SQLException {
+        ResultSet resultSet = databaseMetaData.getTables(null, null, "CUST%", new String[] { "TABLE" });
+        while (resultSet.next()) {
+            // Print the names of existing tables
+            System.out.println(resultSet.getString("TABLE_NAME"));
+            System.out.println(resultSet.getString("REMARKS"));
+        }
+    }
+
+    public void extractSystemTables() throws SQLException {
+        ResultSet resultSet = databaseMetaData.getTables(null, null, null, new String[] { "SYSTEM TABLE" });
+        while (resultSet.next()) {
+            // Print the names of system tables
+            System.out.println(resultSet.getString("TABLE_NAME"));
+        }
+    }
+
+    public void extractViews() throws SQLException {
+        ResultSet resultSet = databaseMetaData.getTables(null, null, null, new String[] { "VIEW" });
+        while (resultSet.next()) {
+            // Print the names of existing views
+            System.out.println(resultSet.getString("TABLE_NAME"));
+        }
+    }
+
+    public void extractColumnInfo(String tableName) throws SQLException {
+        ResultSet columns = databaseMetaData.getColumns(null, null, tableName, null);
+
+        while (columns.next()) {
+            String columnName = columns.getString("COLUMN_NAME");
+            String columnSize = columns.getString("COLUMN_SIZE");
+            String datatype = columns.getString("DATA_TYPE");
+            String isNullable = columns.getString("IS_NULLABLE");
+            String isAutoIncrement = columns.getString("IS_AUTOINCREMENT");
+            System.out.println(String.format("ColumnName: %s, columnSize: %s, datatype: %s, isColumnNullable: %s, isAutoIncrementEnabled: %s", columnName, columnSize, datatype, isNullable, isAutoIncrement));
+        }
+    }
+
+    public void extractPrimaryKeys(String tableName) throws SQLException {
+        ResultSet primaryKeys = databaseMetaData.getPrimaryKeys(null, null, tableName);
+        while (primaryKeys.next()) {
+            String primaryKeyColumnName = primaryKeys.getString("COLUMN_NAME");
+            String primaryKeyName = primaryKeys.getString("PK_NAME");
+            System.out.println(String.format("columnName:%s, pkName:%s", primaryKeyColumnName, primaryKeyName));
+        }
+    }
+
+    public void fun() throws SQLException {
+
+    }
+
+    public void extractForeignKeys(String tableName) throws SQLException {
+        ResultSet foreignKeys = databaseMetaData.getImportedKeys(null, null, tableName);
+        while (foreignKeys.next()) {
+            String pkTableName = foreignKeys.getString("PKTABLE_NAME");
+            String fkTableName = foreignKeys.getString("FKTABLE_NAME");
+            String pkColumnName = foreignKeys.getString("PKCOLUMN_NAME");
+            String fkColumnName = foreignKeys.getString("FKCOLUMN_NAME");
+            System.out.println(String.format("pkTableName:%s, fkTableName:%s, pkColumnName:%s, fkColumnName:%s", pkTableName, fkTableName, pkColumnName, fkColumnName));
+        }
+    }
+
+    public void extractDatabaseInfo() throws SQLException {
+        String productName = databaseMetaData.getDatabaseProductName();
+        String productVersion = databaseMetaData.getDatabaseProductVersion();
+
+        String driverName = databaseMetaData.getDriverName();
+        String driverVersion = databaseMetaData.getDriverVersion();
+
+        System.out.println(String.format("Product name:%s, Product version:%s", productName, productVersion));
+        System.out.println(String.format("Driver name:%s, Driver Version:%s", driverName, driverVersion));
+    }
+
+    public void extractUserName() throws SQLException {
+        String userName = databaseMetaData.getUserName();
+        System.out.println(userName);
+        ResultSet schemas = databaseMetaData.getSchemas();
+        while (schemas.next()) {
+            String table_schem = schemas.getString("TABLE_SCHEM");
+            String table_catalog = schemas.getString("TABLE_CATALOG");
+            System.out.println(String.format("Table_schema:%s, Table_catalog:%s", table_schem, table_catalog));
+        }
+    }
+
+    public void extractSupportedFeatures() throws SQLException {
+        System.out.println("Supports scrollable & Updatable Result Set: " + databaseMetaData.supportsResultSetConcurrency(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE));
+        System.out.println("Supports Full Outer Joins: " + databaseMetaData.supportsFullOuterJoins());
+        System.out.println("Supports Stored Procedures: " + databaseMetaData.supportsStoredProcedures());
+        System.out.println("Supports Subqueries in 'EXISTS': " + databaseMetaData.supportsSubqueriesInExists());
+        System.out.println("Supports Transactions: " + databaseMetaData.supportsTransactions());
+        System.out.println("Supports Core SQL Grammar: " + databaseMetaData.supportsCoreSQLGrammar());
+        System.out.println("Supports Batch Updates: " + databaseMetaData.supportsBatchUpdates());
+        System.out.println("Supports Column Aliasing: " + databaseMetaData.supportsColumnAliasing());
+        System.out.println("Supports Savepoints: " + databaseMetaData.supportsSavepoints());
+        System.out.println("Supports Union All: " + databaseMetaData.supportsUnionAll());
+        System.out.println("Supports Union: " + databaseMetaData.supportsUnion());
+    }
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/hilo/RestaurantOrder.java

@@ -0,0 +1,34 @@
+package com.baeldung.hibernate.hilo;
+
+import org.hibernate.annotations.GenericGenerator;
+import org.hibernate.annotations.Parameter;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class RestaurantOrder {
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "hilo_sequence_generator")
+    @GenericGenerator(
+      name = "hilo_sequence_generator",
+      strategy = "sequence",
+      parameters = {
+        @Parameter(name = "sequence_name", value = "hilo_seqeunce"),
+        @Parameter(name = "initial_value", value = "1"),
+        @Parameter(name = "increment_size", value = "3"),
+        @Parameter(name = "optimizer", value = "hilo")
+      }
+    )
+    private Long id;
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+}

persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/hilo/HibernateHiloUnitTest.java

@@ -0,0 +1,99 @@
+package com.baeldung.hibernate.hilo;
+
+import org.apache.log4j.BasicConfigurator;
+import org.apache.log4j.Level;
+import org.apache.log4j.LogManager;
+import org.hibernate.HibernateException;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
+import org.hibernate.boot.Metadata;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.SessionFactoryBuilder;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.service.ServiceRegistry;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Properties;
+
+import static org.junit.Assert.fail;
+
+public class HibernateHiloUnitTest {
+    private Session session;
+
+    @Before
+    public void init() {
+        try {
+            configureLogger();
+
+            ServiceRegistry serviceRegistry = configureServiceRegistry();
+            SessionFactory factory = getSessionFactoryBuilder(serviceRegistry).build();
+            session = factory.openSession();
+        } catch (HibernateException | IOException e) {
+            fail("Failed to initiate Hibernate Session [Exception:" + e.toString() + "]");
+        }
+    }
+
+    private void configureLogger() {
+        BasicConfigurator.configure();
+        LogManager.getLogger("org.hibernate").setLevel(Level.ERROR);
+        LogManager.getLogger("org.hibernate.id.enhanced.SequenceStructure").setLevel(Level.DEBUG);
+        LogManager.getLogger("org.hibernate.event.internal.AbstractSaveEventListener").setLevel(Level.DEBUG);
+        LogManager.getLogger("org.hibernate.SQL").setLevel(Level.DEBUG);
+    }
+
+
+    private static SessionFactoryBuilder getSessionFactoryBuilder(ServiceRegistry serviceRegistry) {
+        MetadataSources metadataSources = new MetadataSources(serviceRegistry);
+        metadataSources.addAnnotatedClass(RestaurantOrder.class);
+        Metadata metadata = metadataSources.buildMetadata();
+
+        return metadata.getSessionFactoryBuilder();
+    }
+
+    private static ServiceRegistry configureServiceRegistry() throws IOException {
+        Properties properties = getProperties();
+
+        return new StandardServiceRegistryBuilder().applySettings(properties)
+          .build();
+    }
+
+    private static Properties getProperties() throws IOException {
+        Properties properties = new Properties();
+        URL propertiesURL = getPropertiesURL();
+
+        try (FileInputStream inputStream = new FileInputStream(propertiesURL.getFile())) {
+            properties.load(inputStream);
+        }
+
+        return properties;
+    }
+
+    private static URL getPropertiesURL() {
+        return Thread.currentThread()
+          .getContextClassLoader()
+          .getResource("hibernate-hilo.properties");
+    }
+
+    @Test
+    public void givenHiLoAlgorithm_when9EntitiesArePersisted_Then3callsToDBForNextValueShouldBeMade() {
+        Transaction transaction = session.beginTransaction();
+
+        for (int i = 0; i < 9; i++) {
+            session.persist(new RestaurantOrder());
+            session.flush();
+        }
+
+        transaction.commit();
+    }
+
+    @After
+    public void cleanup() {
+        session.close();
+    }
+}

persistence-modules/hibernate5/src/test/resources/hibernate-hilo.properties

@@ -0,0 +1,10 @@
+hibernate.connection.driver_class=org.h2.Driver
+hibernate.connection.url=jdbc:h2:mem:hilo_db;DB_CLOSE_DELAY=-1
+hibernate.connection.username=sa
+hibernate.dialect=org.hibernate.dialect.H2Dialect
+hibernate.show_sql=true
+hibernate.hbm2ddl.auto=create-drop
+hibernate.c3p0.min_size=5
+hibernate.c3p0.max_size=20
+hibernate.c3p0.acquire_increment=5
+hibernate.c3p0.timeout=1800

persistence-modules/java-jpa-3/README.md

@@ -0,0 +1,3 @@
+## JPA in Java
+
+This module contains articles about the Java Persistence API (JPA) in Java.

persistence-modules/java-jpa-3/pom.xml

@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>java-jpa-3</artifactId>
+    <name>java-jpa-3</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>persistence-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>${hibernate.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-jpamodelgen</artifactId>
+            <version>${hibernate.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>${h2.version}</version>
+        </dependency>
+
+        <!--Compile time JPA API -->
+        <dependency>
+            <groupId>javax.persistence</groupId>
+            <artifactId>javax.persistence-api</artifactId>
+            <version>${javax.persistence-api.version}</version>
+        </dependency>
+
+        <!--Runtime JPA implementation -->
+        <dependency>
+            <groupId>org.eclipse.persistence</groupId>
+            <artifactId>eclipselink</artifactId>
+            <version>${eclipselink.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>${postgres.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <compilerArgument>-proc:none</compilerArgument>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <hibernate.version>5.4.14.Final</hibernate.version>
+        <eclipselink.version>2.7.4</eclipselink.version>
+        <postgres.version>42.2.5</postgres.version>
+        <javax.persistence-api.version>2.2</javax.persistence-api.version>
+        <assertj.version>3.11.1</assertj.version>
+        <maven-compiler-plugin.version>3.5.1</maven-compiler-plugin.version>
+        <maven-processor-plugin.version>3.3.3</maven-processor-plugin.version>
+        <build-helper-maven-plugin.version>3.0.0</build-helper-maven-plugin.version>
+    </properties>
+
+</project>

persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByBusinessKey.java

@@ -0,0 +1,53 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.*;
+
+@Entity
+public class EqualByBusinessKey {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+
+    private String email;
+
+    public EqualByBusinessKey() {
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    @Override
+    public int hashCode() {
+        return java.util.Objects.hashCode(email);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (obj instanceof EqualByBusinessKey) {
+            if (((EqualByBusinessKey) obj).getEmail() == getEmail()) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualById.java

@@ -0,0 +1,55 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.*;
+
+@Entity
+public class EqualById {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+
+    private String email;
+
+    public EqualById() {
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((id == null) ? 0 : id.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (obj instanceof EqualById) {
+            return ((EqualById) obj).getId().equals(getId());
+        }
+        return false;
+    }
+}

persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByJavaDefault.java

@@ -0,0 +1,36 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.*;
+
+@Entity
+public class EqualByJavaDefault implements Cloneable{
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+
+    private String email;
+
+    public EqualByJavaDefault() {
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public Object clone() throws CloneNotSupportedException {
+        return super.clone();
+    }
+}

persistence-modules/java-jpa-3/src/main/resources/META-INF/persistence.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
+             http://xmlns.jcp.org/xml/ns/persistence/persistence_2_2.xsd"
+	version="2.2">
+	<persistence-unit name="jpa-h2-equality">
+		<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
+		<class>com.baeldung.jpa.equality.EqualByJavaDefault</class>
+		<class>com.baeldung.jpa.equality.EqualById</class>
+		<class>com.baeldung.jpa.equality.EqualByBusinessKey</class>
+		<exclude-unlisted-classes>true</exclude-unlisted-classes>
+		<properties>
+			<property name="javax.persistence.jdbc.driver" value="org.h2.Driver" />
+			<property name="javax.persistence.jdbc.url" value="jdbc:h2:mem:test" />
+			<property name="javax.persistence.jdbc.user" value="sa" />
+			<property name="javax.persistence.jdbc.password" value="" />
+			<property name="javax.persistence.jdbc.driver" value="org.h2.Driver" />
+			<property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect" />
+			<property name="hibernate.hbm2ddl.auto" value="create-drop" />
+			<property name="show_sql" value="false" />
+			<property name="hibernate.temp.use_jdbc_metadata_defaults" value="false" />
+		</properties>
+	</persistence-unit>
+</persistence>

persistence-modules/java-jpa-3/src/main/resources/logback.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT"
+        class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} -
+                %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/equality/EqualityUnitTest.java

@@ -0,0 +1,74 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class EqualityUnitTest {
+
+    private static EntityManagerFactory factory;
+    private static EntityManager entityManager;
+
+    @BeforeClass
+    public static void setup() {
+        factory = Persistence.createEntityManagerFactory("jpa-h2-equality");
+        entityManager = factory.createEntityManager();
+    }
+
+    @Test
+    public void givenObjectBasedEquality_whenUsingEquals_thenEqualIsBasedOnInstance() throws CloneNotSupportedException {
+        EqualByJavaDefault object1 = new EqualByJavaDefault();
+        EqualByJavaDefault object2 = new EqualByJavaDefault();
+
+        object1.setEmail("test.user@domain.com");
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(object1);
+        entityManager.getTransaction().commit();
+
+        object2 = (EqualByJavaDefault) object1.clone();
+
+        Assert.assertNotEquals(object1, object2);
+        Assert.assertEquals(object1.getId(), object2.getId());
+        Assert.assertEquals(object1.getEmail(), object2.getEmail());
+    }
+
+    @Test
+    public void givenIdBasedEquality_whenUsingEquals_thenEqualIsBasedOnId() {
+        EqualById object1 = new EqualById();
+        EqualById object2 = new EqualById();
+
+        object1.setEmail("test.user.1@domain.com");
+        object2.setEmail("test.user.2@domain.com");
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(object1);
+        entityManager.getTransaction().commit();
+
+        object2.setId(object1.getId());
+
+        Assert.assertEquals(object1, object2);
+        Assert.assertEquals(object1.getId(), object2.getId());
+        Assert.assertNotEquals(object1.getEmail(), object2.getEmail());
+    }
+
+    @Test
+    public void givenBusinessKeyBasedEquality_whenUsingEquals_thenEqualIsBasedOnBusinessKey() {
+        EqualByBusinessKey object1 = new EqualByBusinessKey();
+        EqualByBusinessKey object2 = new EqualByBusinessKey();
+
+        object1.setEmail("test.user@test-domain.com");
+        object2.setEmail("test.user@test-domain.com");
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(object1);
+        entityManager.getTransaction().commit();
+
+        Assert.assertEquals(object1, object2);
+        Assert.assertNotEquals(object1.getId(), object2.getId());
+    }
+}

persistence-modules/pom.xml

@@ -19,12 +19,14 @@
         <module>core-java-persistence</module>
         <module>deltaspike</module>
         <module>elasticsearch</module>
+        <module>flyway</module>
         <module>flyway-repair</module>
         <module>hbase</module>
         <module>hibernate5</module>
         <module>hibernate-mapping</module> <!-- long running -->
         <module>hibernate-ogm</module>
         <module>hibernate-annotations</module>
+        <module>hibernate-exceptions</module>
         <module>hibernate-libraries</module>
         <module>hibernate-jpa</module>
         <module>hibernate-queries</module>
@@ -53,6 +55,7 @@
         <module>spring-boot-persistence-mongodb</module>
         <module>spring-data-cassandra</module>
         <module>spring-data-cassandra-reactive</module>
+        <module>spring-data-cosmosdb</module>
         <module>spring-data-couchbase-2</module>
         <module>spring-data-dynamodb</module>
         <module>spring-data-eclipselink</module>
@@ -78,6 +81,7 @@
         <module>spring-hibernate-5</module> <!-- long running -->
         <module>spring-hibernate4</module>
         <module>spring-jpa</module>
+        <module>spring-jpa-2</module>
         <!-- <module>spring-mybatis</module> --> <!-- needs fixing in BAEL-9021 -->
         <module>spring-persistence-simple</module>
         <module>spring-persistence-simple-2</module>

persistence-modules/spring-data-cosmosdb/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-data-cosmosdb</artifactId>
+    <name>spring-data-cosmos-db</name>
+    <description>tutorial for spring-data-cosmosdb</description>
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+    
+    <properties>
+        <java.version>1.8</java.version>
+        <cosmodb.version>2.3.0</cosmodb.version>
+    </properties>
+    
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.microsoft.azure</groupId>
+            <artifactId>spring-data-cosmosdb</artifactId>
+            <version>${cosmodb.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+        </dependency>
+    </dependencies>
+    
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

persistence-modules/spring-data-cosmosdb/src/main/java/com/baeldung/spring/data/cosmosdb/AzureCosmosDbApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung.spring.data.cosmosdb;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class AzureCosmosDbApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(AzureCosmosDbApplication.class, args);
+    }
+}

persistence-modules/spring-data-cosmosdb/src/main/java/com/baeldung/spring/data/cosmosdb/config/AzureCosmosDbConfiguration.java

@@ -0,0 +1,37 @@
+package com.baeldung.spring.data.cosmosdb.config;
+
+import com.azure.data.cosmos.CosmosKeyCredential;
+import com.microsoft.azure.spring.data.cosmosdb.config.AbstractCosmosConfiguration;
+import com.microsoft.azure.spring.data.cosmosdb.config.CosmosDBConfig;
+import com.microsoft.azure.spring.data.cosmosdb.repository.config.EnableCosmosRepositories;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableCosmosRepositories(basePackages = "com.baeldung.spring.data.cosmosdb.repository")
+public class AzureCosmosDbConfiguration extends AbstractCosmosConfiguration {
+
+    @Value("${azure.cosmosdb.uri}")
+    private String uri;
+
+    @Value("${azure.cosmosdb.key}")
+    private String key;
+
+    @Value("${azure.cosmosdb.secondaryKey}")
+    private String secondaryKey;
+
+    @Value("${azure.cosmosdb.database}")
+    private String dbName;
+
+    private CosmosKeyCredential cosmosKeyCredential;
+
+    @Bean
+    public CosmosDBConfig getConfig() {
+        this.cosmosKeyCredential = new CosmosKeyCredential(key);
+        CosmosDBConfig cosmosdbConfig = CosmosDBConfig.builder(uri, this.cosmosKeyCredential, dbName)
+            .build();
+        return cosmosdbConfig;
+    }
+}

persistence-modules/spring-data-cosmosdb/src/main/java/com/baeldung/spring/data/cosmosdb/controller/ProductController.java

@@ -0,0 +1,53 @@
+package com.baeldung.spring.data.cosmosdb.controller;
+
+import com.baeldung.spring.data.cosmosdb.entity.Product;
+import com.baeldung.spring.data.cosmosdb.service.ProductService;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+import java.util.Optional;
+
+@RestController
+@RequestMapping("/products")
+public class ProductController {
+
+    private ProductService productService;
+
+    @Autowired
+    public ProductController(ProductService productService) {
+        this.productService = productService;
+    }
+
+    @PostMapping
+    @ResponseStatus(HttpStatus.CREATED)
+    public void create(@RequestBody Product product) {
+        productService.saveProduct(product);
+    }
+
+    @GetMapping(value = "/{id}/category/{category}")
+    public Optional<Product> get(@PathVariable String id, @PathVariable String category) {
+        return productService.findById(id, category);
+    }
+
+    @DeleteMapping(value = "/{id}/category/{category}")
+    public void delete(@PathVariable String id, @PathVariable String category) {
+        productService.delete(id, category);
+    }
+
+    @GetMapping
+    public List<Product> getByName(@RequestParam String name) {
+        return productService.findProductByName(name);
+    }
+
+}

persistence-modules/spring-data-cosmosdb/src/main/java/com/baeldung/spring/data/cosmosdb/entity/Product.java

@@ -0,0 +1,26 @@
+package com.baeldung.spring.data.cosmosdb.entity;
+
+import com.microsoft.azure.spring.data.cosmosdb.core.mapping.Document;
+import com.microsoft.azure.spring.data.cosmosdb.core.mapping.PartitionKey;
+
+import org.springframework.data.annotation.Id;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+@Document(collection = "products")
+public class Product {
+
+    @Id
+    private String productid;
+
+    private String productName;
+
+    private double price;
+
+    @PartitionKey
+    private String productCategory;
+
+}

persistence-modules/spring-data-cosmosdb/src/main/java/com/baeldung/spring/data/cosmosdb/repository/ProductRepository.java

@@ -0,0 +1,14 @@
+package com.baeldung.spring.data.cosmosdb.repository;
+
+import com.baeldung.spring.data.cosmosdb.entity.Product;
+import com.microsoft.azure.spring.data.cosmosdb.repository.CosmosRepository;
+
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+
+@Repository
+public interface ProductRepository extends CosmosRepository<Product, String> {
+    List<Product> findByProductName(String productName);
+
+}

persistence-modules/spring-data-cosmosdb/src/main/java/com/baeldung/spring/data/cosmosdb/service/ProductService.java

@@ -0,0 +1,38 @@
+package com.baeldung.spring.data.cosmosdb.service;
+
+import com.azure.data.cosmos.PartitionKey;
+import com.baeldung.spring.data.cosmosdb.entity.Product;
+import com.baeldung.spring.data.cosmosdb.repository.ProductRepository;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.Optional;
+
+@Component
+public class ProductService {
+
+    private ProductRepository repository;
+
+    @Autowired
+    public ProductService(ProductRepository repository) {
+        this.repository = repository;
+    }
+
+    public List<Product> findProductByName(String productName) {
+        return repository.findByProductName(productName);
+    }
+
+    public Optional<Product> findById(String productId, String category) {
+        return repository.findById(productId, new PartitionKey(category));
+    }
+
+    public void saveProduct(Product product) {
+        repository.save(product);
+    }
+
+    public void delete(String productId, String category) {
+        repository.deleteById(productId, new PartitionKey(category));
+    }
+}

persistence-modules/spring-data-cosmosdb/src/main/resources/application.properties

@@ -0,0 +1,4 @@
+azure.cosmosdb.uri=cosmodb-uri
+azure.cosmosdb.key=cosmodb-primary-key
+azure.cosmosdb.secondaryKey=cosmodb-second-key
+azure.cosmosdb.database=cosmodb-name

persistence-modules/spring-data-cosmosdb/src/test/java/com/baeldung/spring/data/cosmosdb/AzureCosmosDbApplicationManualTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.spring.data.cosmosdb;
+
+import com.azure.data.cosmos.PartitionKey;
+import com.baeldung.spring.data.cosmosdb.entity.Product;
+import com.baeldung.spring.data.cosmosdb.repository.ProductRepository;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.util.Assert;
+
+@SpringBootTest
+public class AzureCosmosDbApplicationManualTest {
+
+    @Autowired
+    ProductRepository productRepository;
+
+    @Test
+    public void givenProductIsCreated_whenCallFindById_thenProductIsFound() {
+        Product product = new Product();
+        product.setProductid("1001");
+        product.setProductCategory("Shirt");
+        product.setPrice(110.0);
+        product.setProductName("Blue Shirt");
+
+        productRepository.save(product);
+        Product retrievedProduct = productRepository.findById("1001", new PartitionKey("Shirt"))
+            .orElse(null);
+        Assert.notNull(retrievedProduct, "Retrieved Product is Null");
+
+    }
+
+}

persistence-modules/spring-data-elasticsearch/README.md

@@ -6,7 +6,6 @@
 - [Guide to Elasticsearch in Java](https://www.baeldung.com/elasticsearch-java)
 - [Geospatial Support in ElasticSearch](https://www.baeldung.com/elasticsearch-geo-spatial)
 - [A Simple Tagging Implementation with Elasticsearch](https://www.baeldung.com/elasticsearch-tagging)
-- [Introduction to Spring Data Elasticsearch (evaluation)](https://www.baeldung.com/spring-data-elasticsearch-test-2)
 
 ### Build the Project with Tests Running
 ```

persistence-modules/spring-data-jpa-enterprise/src/main/java/com/baeldung/boot/Application.java

@@ -6,8 +6,8 @@ import org.springframework.boot.autoconfigure.domain.EntityScan;
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 
 @SpringBootApplication
-@EnableJpaRepositories("com.baeldung")
+@EnableJpaRepositories("com.baeldung.boot")
-@EntityScan("com.baeldung")
+@EntityScan("com.baeldung.boot")
 public class Application {
 
     public static void main(String[] args) {

persistence-modules/spring-data-jpa-enterprise/src/main/java/com/baeldung/osiv/model/BasicUser.java

@@ -4,7 +4,7 @@ import javax.persistence.*;
 import java.util.Set;
 
 @Entity
-@Table(name = "users")
+@Table(name = "basic_users")
 public class BasicUser {
 
     @Id

persistence-modules/spring-jpa-2/README.md

@@ -0,0 +1,5 @@
+## Spring JPA (2)
+
+### Relevant Articles: 
+- [Many-To-Many Relationship in JPA](https://www.baeldung.com/jpa-many-to-many)
+- More articles: [[<-- prev]](/spring-jpa)

persistence-modules/spring-jpa-2/pom.xml

@@ -0,0 +1,62 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>spring-jpa-2</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <name>spring-jpa-2</name>
+    <packaging>war</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>persistence-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <!-- Spring -->
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-orm</artifactId>
+            <version>${org.springframework.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <version>${org.springframework.version}</version>
+        </dependency>
+
+        <!-- persistence -->
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-entitymanager</artifactId>
+            <version>${hibernate.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>${h2.version}</version>
+        </dependency>
+
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <version>${org.springframework.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <properties>
+        <!-- Spring -->
+        <org.springframework.version>5.1.5.RELEASE</org.springframework.version>
+    </properties>
+
+</project>

persistence-modules/spring-jpa-2/src/test/java/com/baeldung/manytomany/ManyToManyTestConfiguration.java

@@ -16,7 +16,7 @@ import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
 import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
 
 @Configuration
-@PropertySource("classpath:/manytomany/test.properties")
+@PropertySource("manytomany/test.properties")
 public class ManyToManyTestConfiguration {
 
     @Bean

persistence-modules/spring-jpa/README.md

@@ -1,7 +1,4 @@
-=========
+## Spring JPA (1)
-
-## Spring JPA Example Project
-
 
 ### Relevant Articles: 
 - [The DAO with JPA and Spring](https://www.baeldung.com/spring-dao-jpa)
@@ -10,9 +7,7 @@
 - [Self-Contained Testing Using an In-Memory Database](https://www.baeldung.com/spring-jpa-test-in-memory-database)
 - [A Guide to Spring AbstractRoutingDatasource](https://www.baeldung.com/spring-abstract-routing-data-source)
 - [Obtaining Auto-generated Keys in Spring JDBC](https://www.baeldung.com/spring-jdbc-autogenerated-keys)
-- [Many-To-Many Relationship in JPA](https://www.baeldung.com/jpa-many-to-many)
+- More articles: [[next -->]](/spring-jpa-2)
-- [Spring Persistence (Hibernate and JPA) with a JNDI datasource](https://www.baeldung.com/spring-persistence-hibernate-and-jpa-with-a-jndi-datasource-2)
-
 
 ### Eclipse Config 
 After importing the project into Eclipse, you may see the following error:  

pom.xml

@@ -556,6 +556,7 @@
 				<module>atomikos</module>
 				<module>reactive-systems</module>
 				<module>slack</module>
+				<module>spring-webflux-threads</module>
             </modules>
 
         </profile>
@@ -1067,6 +1068,7 @@
 				<module>atomikos</module>
 				<module>reactive-systems</module>
 				<module>slack</module>
+				<module>spring-webflux-threads</module>
             </modules>
 
         </profile>