Merge pull request #1 from eugenp/master

pull

algorithms-miscellaneous-3/README.md

@@ -4,3 +4,4 @@
 - [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)
 - [Converting Between Roman and Arabic Numerals in Java](http://www.baeldung.com/java-convert-roman-arabic)
 - [Practical Java Examples of the Big O Notation](http://www.baeldung.com/java-algorithm-complexity)
+- [Checking If a List Is Sorted in Java](https://www.baeldung.com/java-check-if-list-sorted)

algorithms-miscellaneous-3/pom.xml

@@ -18,6 +18,18 @@
             <version>${org.assertj.core.version}</version>
             <scope>test</scope>
         </dependency>
+        
+        <dependency>
+        	<groupId>org.apache.commons</groupId>
+        	<artifactId>commons-collections4</artifactId>
+        	<version>${commons-collections4.version}</version>
+        </dependency>
+        
+        <dependency>
+        	<groupId>com.google.guava</groupId>
+        	<artifactId>guava</artifactId>
+        	<version>${guava.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -34,6 +46,7 @@
 
     <properties>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
+        <commons-collections4.version>4.3</commons-collections4.version>
+        <guava.version>28.0-jre</guava.version>
     </properties>
-
 </project>

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/checksortedlist/Employee.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.checksortedlist;
+
+public class Employee {
+
+    long id;
+
+    String name;
+
+    public Employee() {
+    }
+
+    public Employee(long id, String name) {
+        super();
+        this.id = id;
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/checksortedlist/SortedListChecker.java

@@ -0,0 +1,87 @@
+package com.baeldung.algorithms.checksortedlist;
+
+import static org.apache.commons.collections4.CollectionUtils.isEmpty;
+
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+
+import com.google.common.collect.Comparators;
+import com.google.common.collect.Ordering;;
+
+public class SortedListChecker {
+
+    private SortedListChecker() {
+        throw new AssertionError();
+    }
+
+    public static boolean checkIfSortedUsingIterativeApproach(List<String> listOfStrings) {
+        if (isEmpty(listOfStrings) || listOfStrings.size() == 1) {
+            return true;
+        }
+
+        Iterator<String> iter = listOfStrings.iterator();
+        String current, previous = iter.next();
+        while (iter.hasNext()) {
+            current = iter.next();
+            if (previous.compareTo(current) > 0) {
+                return false;
+            }
+            previous = current;
+        }
+        return true;
+    }
+
+    public static boolean checkIfSortedUsingIterativeApproach(List<Employee> employees, Comparator<Employee> employeeComparator) {
+        if (isEmpty(employees) || employees.size() == 1) {
+            return true;
+        }
+
+        Iterator<Employee> iter = employees.iterator();
+        Employee current, previous = iter.next();
+        while (iter.hasNext()) {
+            current = iter.next();
+            if (employeeComparator.compare(previous, current) > 0) {
+                return false;
+            }
+            previous = current;
+        }
+        return true;
+    }
+
+    public static boolean checkIfSortedUsingRecursion(List<String> listOfStrings) {
+        return isSortedRecursive(listOfStrings, listOfStrings.size());
+    }
+
+    public static boolean isSortedRecursive(List<String> listOfStrings, int index) {
+        if (index < 2) {
+            return true;
+        } else if (listOfStrings.get(index - 2)
+            .compareTo(listOfStrings.get(index - 1)) > 0) {
+            return false;
+        } else {
+            return isSortedRecursive(listOfStrings, index - 1);
+        }
+    }
+
+    public static boolean checkIfSortedUsingOrderingClass(List<String> listOfStrings) {
+        return Ordering.<String> natural()
+            .isOrdered(listOfStrings);
+    }
+
+    public static boolean checkIfSortedUsingOrderingClass(List<Employee> employees, Comparator<Employee> employeeComparator) {
+        return Ordering.from(employeeComparator)
+            .isOrdered(employees);
+    }
+
+    public static boolean checkIfSortedUsingOrderingClassHandlingNull(List<String> listOfStrings) {
+        return Ordering.<String> natural()
+            .nullsLast()
+            .isOrdered(listOfStrings);
+    }
+
+    public static boolean checkIfSortedUsingComparators(List<String> listOfStrings) {
+        return Comparators.isInOrder(listOfStrings, Comparator.<String> naturalOrder());
+    }
+
+}

algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/checksortedlist/SortedListCheckerUnitTest.java

@@ -0,0 +1,106 @@
+package com.baeldung.algorithms.checksortedlist;
+
+import static com.baeldung.algorithms.checksortedlist.SortedListChecker.checkIfSortedUsingComparators;
+import static com.baeldung.algorithms.checksortedlist.SortedListChecker.checkIfSortedUsingIterativeApproach;
+import static com.baeldung.algorithms.checksortedlist.SortedListChecker.checkIfSortedUsingOrderingClass;
+import static com.baeldung.algorithms.checksortedlist.SortedListChecker.checkIfSortedUsingRecursion;
+import static java.util.Arrays.asList;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class SortedListCheckerUnitTest {
+
+    private List<String> sortedListOfString;
+    private List<String> unsortedListOfString;
+    private List<String> singletonList;
+
+    private List<Employee> employeesSortedByName;
+    private List<Employee> employeesNotSortedByName;
+
+    @Before
+    public void setUp() {
+        sortedListOfString = asList("Canada", "HK", "LA", "NJ", "NY");
+        unsortedListOfString = asList("LA", "HK", "NJ", "NY", "Canada");
+        singletonList = Collections.singletonList("NY");
+
+        employeesSortedByName = asList(new Employee(1L, "John"), new Employee(2L, "Kevin"), new Employee(3L, "Mike"));
+        employeesNotSortedByName = asList(new Employee(1L, "Kevin"), new Employee(2L, "John"), new Employee(3L, "Mike"));
+    }
+
+    @Test
+    public void givenSortedList_whenUsingIterativeApproach_thenReturnTrue() {
+        assertThat(checkIfSortedUsingIterativeApproach(sortedListOfString)).isTrue();
+    }
+
+    @Test
+    public void givenSingleElementList_whenUsingIterativeApproach_thenReturnTrue() {
+        assertThat(checkIfSortedUsingIterativeApproach(singletonList)).isTrue();
+    }
+
+    @Test
+    public void givenUnsortedList_whenUsingIterativeApproach_thenReturnFalse() {
+        assertThat(checkIfSortedUsingIterativeApproach(unsortedListOfString)).isFalse();
+    }
+
+    @Test
+    public void givenSortedListOfEmployees_whenUsingIterativeApproach_thenReturnTrue() {
+        assertThat(checkIfSortedUsingIterativeApproach(employeesSortedByName, Comparator.comparing(Employee::getName))).isTrue();
+    }
+
+    @Test
+    public void givenUnsortedListOfEmployees_whenUsingIterativeApproach_thenReturnFalse() {
+        assertThat(checkIfSortedUsingIterativeApproach(employeesNotSortedByName, Comparator.comparing(Employee::getName))).isFalse();
+    }
+
+    @Test
+    public void givenSortedList_whenUsingRecursion_thenReturnTrue() {
+        assertThat(checkIfSortedUsingRecursion(sortedListOfString)).isTrue();
+    }
+
+    @Test
+    public void givenSingleElementList_whenUsingRecursion_thenReturnTrue() {
+        assertThat(checkIfSortedUsingRecursion(singletonList)).isTrue();
+    }
+
+    @Test
+    public void givenUnsortedList_whenUsingRecursion_thenReturnFalse() {
+        assertThat(checkIfSortedUsingRecursion(unsortedListOfString)).isFalse();
+    }
+
+    @Test
+    public void givenSortedList_whenUsingGuavaOrdering_thenReturnTrue() {
+        assertThat(checkIfSortedUsingOrderingClass(sortedListOfString)).isTrue();
+    }
+
+    @Test
+    public void givenUnsortedList_whenUsingGuavaOrdering_thenReturnFalse() {
+        assertThat(checkIfSortedUsingOrderingClass(unsortedListOfString)).isFalse();
+    }
+
+    @Test
+    public void givenSortedListOfEmployees_whenUsingGuavaOrdering_thenReturnTrue() {
+        assertThat(checkIfSortedUsingOrderingClass(employeesSortedByName, Comparator.comparing(Employee::getName))).isTrue();
+    }
+
+    @Test
+    public void givenUnsortedListOfEmployees_whenUsingGuavaOrdering_thenReturnFalse() {
+        assertThat(checkIfSortedUsingOrderingClass(employeesNotSortedByName, Comparator.comparing(Employee::getName))).isFalse();
+    }
+
+    @Test
+    public void givenSortedList_whenUsingGuavaComparators_thenReturnTrue() {
+        assertThat(checkIfSortedUsingComparators(sortedListOfString)).isTrue();
+    }
+
+    @Test
+    public void givenUnsortedList_whenUsingGuavaComparators_thenReturnFalse() {
+        assertThat(checkIfSortedUsingComparators(unsortedListOfString)).isFalse();
+    }
+
+}

autovalue/pom.xml

@@ -29,6 +29,12 @@
                 </exclusion>
             </exclusions>
         </dependency>
+        <dependency>
+            <groupId>com.google.auto.service</groupId>
+            <artifactId>auto-service</artifactId>
+            <version>${auto-service.version}</version>
+            <optional>true</optional>
+        </dependency>
 
         <dependency>
             <groupId>com.google.inject</groupId>
@@ -40,6 +46,7 @@
     <properties>
         <auto-value.version>1.3</auto-value.version>
         <auto-factory.version>1.0-beta5</auto-factory.version>
+        <auto-service.version>1.0-rc5</auto-service.version>
         <guice.version>4.2.0</guice.version>
     </properties>
 

autovalue/src/main/java/com/baeldung/autoservice/BingTranslationServiceProvider.java

@@ -0,0 +1,14 @@
+package com.baeldung.autoservice;
+
+import com.google.auto.service.AutoService;
+
+import java.util.Locale;
+
+@AutoService(TranslationService.class)
+public class BingTranslationServiceProvider implements TranslationService {
+    @Override
+    public String translate(String message, Locale from, Locale to) {
+        // implementation details
+        return message + " (translated by Bing)"; 
+    }
+}

autovalue/src/main/java/com/baeldung/autoservice/GoogleTranslationServiceProvider.java

@@ -0,0 +1,14 @@
+package com.baeldung.autoservice;
+
+import com.google.auto.service.AutoService;
+
+import java.util.Locale;
+
+@AutoService(TranslationService.class)
+public class GoogleTranslationServiceProvider implements TranslationService {
+    @Override
+    public String translate(String message, Locale from, Locale to) {
+        // implementation details
+        return message + " (translated by Google)"; 
+    }
+}

autovalue/src/main/java/com/baeldung/autoservice/TranslationService.java

@@ -0,0 +1,7 @@
+package com.baeldung.autoservice;
+
+import java.util.Locale;
+
+public interface TranslationService {
+    String translate(String message, Locale from, Locale to);
+}

autovalue/src/test/java/com/baeldung/autoservice/TranslationServiceUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.autoservice;
+
+import com.baeldung.autoservice.TranslationService;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.ServiceLoader;
+import java.util.stream.StreamSupport;
+
+import static org.junit.Assert.assertEquals;
+
+public class TranslationServiceUnitTest {
+
+    private ServiceLoader<TranslationService> loader;
+
+    @Before
+    public void setUp() {
+        loader = ServiceLoader.load(TranslationService.class);
+    }
+
+    @Test
+    public void whenServiceLoaderLoads_thenLoadsAllProviders() {
+        long count = StreamSupport.stream(loader.spliterator(), false).count();
+        assertEquals(2, count);
+    }
+
+    @Test
+    public void whenServiceLoaderLoadsGoogleService_thenGoogleIsLoaded() {
+        TranslationService googleService = StreamSupport.stream(loader.spliterator(), false)
+          .filter(p -> p.getClass().getSimpleName().equals("GoogleTranslationServiceProvider"))
+          .findFirst()
+          .get();
+		
+        String message = "message";
+        assertEquals(message + " (translated by Google)", googleService.translate(message, null, null));
+    }
+}

core-groovy-2/README.md

@@ -5,4 +5,5 @@
 - [String Matching in Groovy](http://www.baeldung.com/)
 - [Template Engines in Groovy](https://www.baeldung.com/groovy-template-engines)
 - [Groovy def Keyword](https://www.baeldung.com/groovy-def-keyword)
-- [Pattern Matching in Strings in Groovy](https://www.baeldung.com/groovy-pattern-matching)
+- [Pattern Matching in Strings in Groovy](https://www.baeldung.com/groovy-pattern-matching)
+- [Working with XML in Groovy](https://www.baeldung.com/groovy-xml)

core-java-modules/core-java-8-2/src/main/java/com/baeldung/forEach/ReverseList.java

@@ -0,0 +1,84 @@
+package com.baeldung.forEach;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.function.Consumer;
+
+class ReverseList extends ArrayList<String> {
+
+    List<String> list = Arrays.asList("A", "B", "C", "D");
+
+    Consumer<String> removeElement = s -> {
+        System.out.println(s + " " + list.size());
+        if (s != null && s.equals("A")) {
+            list.remove("D");
+        }
+    };
+
+    @Override
+    public Iterator<String> iterator() {
+
+        final int startIndex = this.size() - 1;
+        final List<String> list = this;
+        return new Iterator<String>() {
+
+            int currentIndex = startIndex;
+
+            @Override
+            public boolean hasNext() {
+                return currentIndex >= 0;
+            }
+
+            @Override
+            public String next() {
+                String next = list.get(currentIndex);
+                currentIndex--;
+                return next;
+            }
+
+            @Override
+            public void remove() {
+                throw new UnsupportedOperationException();
+            }
+        };
+    }
+
+    public void forEach(Consumer<? super String> action) {
+        for (String s : this) {
+            action.accept(s);
+        }
+    }
+
+    public void iterateParallel() {
+        list.forEach(System.out::print);
+        System.out.print(" ");
+        list.parallelStream().forEach(System.out::print);
+    }
+
+    public void iterateReverse() {
+        List<String> myList = new ReverseList();
+        myList.addAll(list);
+        myList.forEach(System.out::print);
+        System.out.print(" ");
+        myList.stream().forEach(System.out::print);
+    }
+
+    public void removeInCollectionForEach() {
+        list.forEach(removeElement);
+    }
+
+    public void removeInStreamForEach() {
+        list.stream().forEach(removeElement);
+    }
+
+    public static void main(String[] argv) {
+
+        ReverseList collectionForEach = new ReverseList();
+        collectionForEach.iterateParallel();
+        collectionForEach.iterateReverse();
+        collectionForEach.removeInCollectionForEach();
+        collectionForEach.removeInStreamForEach();
+    }
+}

core-java-modules/core-java-8-2/src/main/java/com/baeldung/stream/SkipLimitComparison.java

@@ -0,0 +1,46 @@
+package com.baeldung.stream;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class SkipLimitComparison {
+
+    public static void main(String[] args) {
+        skipExample();
+        limitExample();
+        limitInfiniteStreamExample();
+        getEvenNumbers(10, 10).stream()
+            .forEach(System.out::println);
+    }
+
+    public static void skipExample() {
+        Stream.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+            .filter(i -> i % 2 == 0)
+            .skip(2)
+            .forEach(i -> System.out.print(i + " "));
+    }
+
+    public static void limitExample() {
+        Stream.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+            .filter(i -> i % 2 == 0)
+            .limit(2)
+            .forEach(i -> System.out.print(i + " "));
+    }
+
+    public static void limitInfiniteStreamExample() {
+        Stream.iterate(0, i -> i + 1)
+            .filter(i -> i % 2 == 0)
+            .limit(10)
+            .forEach(System.out::println);
+    }
+
+    private static List<Integer> getEvenNumbers(int offset, int limit) {
+        return Stream.iterate(0, i -> i + 1)
+            .filter(i -> i % 2 == 0)
+            .skip(offset)
+            .limit(limit)
+            .collect(Collectors.toList());
+    }
+
+}

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

@@ -1,26 +1,35 @@
 <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.exception.numberformat</groupId>
-    <artifactId>core-java-exceptions</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
-    <name>core-java-exceptions</name>
+	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.exception.numberformat</groupId>
+	<artifactId>core-java-exceptions</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>core-java-exceptions</name>
 
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../parent-java</relativePath>
-    </parent>
+	<parent>
+		<groupId>com.baeldung</groupId>
+		<artifactId>parent-java</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+		<relativePath>../../parent-java</relativePath>
+	</parent>
 
-    <dependencies>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.12</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+	<properties>
+		<commons-lang3.version>3.9</commons-lang3.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<version>4.12</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-lang3</artifactId>
+			<version>${commons-lang3.version}</version>
+		</dependency>
+	</dependencies>
 
 </project>

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exception/error/ErrorGeneratorUnitTest.java

@@ -1,7 +1,6 @@
-package com.baeldung.error;
+package com.baeldung.exception.error;
 
 import org.junit.Assert;
-import org.junit.Before;
 import org.junit.Test;
 
 public class ErrorGeneratorUnitTest {

core-java-modules/core-java-lambdas/README.MD

@@ -1,3 +0,0 @@
-### Relevant Articles
-
-- [Why Do Local Variables Used in Lambdas Have to Be Final or Effectively Final?](https://www.baeldung.com/java-lambda-effectively-final-local-variables)

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/rawtype/RawTypeDemo.java

@@ -0,0 +1,25 @@
+package com.baeldung.rawtype;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class RawTypeDemo {
+
+	public static void main(String[] args) {
+		RawTypeDemo rawTypeDemo = new RawTypeDemo();
+		rawTypeDemo.methodA();
+	}
+
+	public void methodA() {
+		// parameterized type
+		List<String> listStr = new ArrayList<>();
+		listStr.add("Hello Folks!");
+		methodB(listStr);
+		String s = listStr.get(1); // ClassCastException at run time
+	}
+
+	public void methodB(List rawList) { // Inexpressive raw type
+		rawList.add(1); // Unsafe operation
+	}
+
+}

core-java-modules/core-java-lang-syntax/src/main/java/com/baeldung/breakloop/LoopBreaking.java

@@ -0,0 +1,47 @@
+package com.baeldung.breakloop;
+
+public class LoopBreaking {
+
+    public String simpleBreak() {
+        String result = "";
+        for (int outerCounter = 0; outerCounter < 2; outerCounter++) {
+            result += "outer" + outerCounter;
+            for (int innerCounter = 0; innerCounter < 2; innerCounter++) {
+                result += "inner" + innerCounter;
+                if (innerCounter == 0) {
+                    break;
+                }
+            }
+        }
+        return result;
+    }
+
+    public String labelBreak() {
+        String result = "";
+        myBreakLabel:
+        for (int outerCounter = 0; outerCounter < 2; outerCounter++) {
+            result += "outer" + outerCounter;
+            for (int innerCounter = 0; innerCounter < 2; innerCounter++) {
+                result += "inner" + innerCounter;
+                if (innerCounter == 0) {
+                    break myBreakLabel;
+                }
+            }
+        }
+        return result;
+    }
+
+    public String usingReturn() {
+        String result = "";
+        for (int outerCounter = 0; outerCounter < 2; outerCounter++) {
+            result += "outer" + outerCounter;
+            for (int innerCounter = 0; innerCounter < 2; innerCounter++) {
+                result += "inner" + innerCounter;
+                if (innerCounter == 0) {
+                    return result;
+                }
+            }
+        }
+        return "failed";
+    }
+}

core-java-modules/core-java-lang-syntax/src/test/java/com/baeldung/breakloop/LoopBreakingUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.breakloop;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class LoopBreakingUnitTest {
+
+    private LoopBreaking loopBreaking = new LoopBreaking();
+
+    @Test
+    void whenUsingBreak_shouldBreakInnerLoop() {
+        assertEquals("outer0inner0outer1inner0", loopBreaking.simpleBreak());
+    }
+
+    @Test
+    void whenUsingLabeledBreak_shouldBreakInnerLoopAndOuterLoop() {
+        assertEquals("outer0inner0", loopBreaking.labelBreak());
+    }
+
+    @Test
+    void whenUsingReturn_shouldBreakInnerLoopAndOuterLoop() {
+        assertEquals("outer0inner0", loopBreaking.usingReturn());
+    }
+}

easy-random/pom.xml

@@ -0,0 +1,23 @@
+<?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>easy-random</artifactId>
+    <name>easy-random</name>
+
+    <parent>
+        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.jeasy</groupId>
+            <artifactId>easy-random-core</artifactId>
+            <version>4.0.0</version>
+        </dependency>
+    </dependencies>
+
+</project>

easy-random/src/main/java/org/baeldung/easy/random/model/Department.java

@@ -0,0 +1,17 @@
+package org.baeldung.easy.random.model;
+
+import java.util.StringJoiner;
+
+public class Department {
+    private String depName;
+
+    public Department(String depName) {
+        this.depName = depName;
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", Department.class.getSimpleName() + "[", "]").add("depName='" + depName + "'")
+            .toString();
+    }
+}

easy-random/src/main/java/org/baeldung/easy/random/model/Employee.java

@@ -0,0 +1,70 @@
+package org.baeldung.easy.random.model;
+
+import java.util.*;
+
+public class Employee {
+
+    private long id;
+    private String firstName;
+    private String lastName;
+    private Department department;
+    private Collection<Employee> coworkers;
+    private Map<YearQuarter, Grade> quarterGrades;
+
+    public Employee(long id, String firstName, String lastName, Department department) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.department = department;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Employee employee = (Employee) o;
+        return id == employee.id;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public Department getDepartment() {
+        return department;
+    }
+
+    public Collection<Employee> getCoworkers() {
+        return Collections.unmodifiableCollection(coworkers);
+    }
+
+    public Map<YearQuarter, Grade> getQuarterGrades() {
+        return Collections.unmodifiableMap(quarterGrades);
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", Employee.class.getSimpleName() + "[", "]").add("id=" + id)
+            .add("firstName='" + firstName + "'")
+            .add("lastName='" + lastName + "'")
+            .add("department=" + department)
+            .add("coworkers size=" + ((coworkers == null) ? 0 : coworkers.size()))
+            .add("quarterGrades=" + quarterGrades)
+            .toString();
+    }
+}

easy-random/src/main/java/org/baeldung/easy/random/model/Grade.java

@@ -0,0 +1,22 @@
+package org.baeldung.easy.random.model;
+
+import java.util.StringJoiner;
+
+public class Grade {
+
+    private int grade;
+
+    public Grade(int grade) {
+        this.grade = grade;
+    }
+
+    public int getGrade() {
+        return grade;
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", Grade.class.getSimpleName() + "[", "]").add("grade=" + grade)
+            .toString();
+    }
+}

easy-random/src/main/java/org/baeldung/easy/random/model/Person.java

@@ -0,0 +1,30 @@
+package org.baeldung.easy.random.model;
+
+import java.util.StringJoiner;
+
+public class Person {
+
+    private String firstName;
+    private String lastName;
+    private Integer age;
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", Person.class.getSimpleName() + "[", "]").add("firstName='" + firstName + "'")
+            .add("lastName='" + lastName + "'")
+            .add("age=" + age)
+            .toString();
+    }
+}

easy-random/src/main/java/org/baeldung/easy/random/model/YearQuarter.java

@@ -0,0 +1,50 @@
+package org.baeldung.easy.random.model;
+
+import java.time.LocalDate;
+import java.util.Objects;
+import java.util.StringJoiner;
+
+public class YearQuarter {
+
+    private LocalDate startDate;
+    private LocalDate endDate;
+
+    public YearQuarter(LocalDate startDate) {
+        this.startDate = startDate;
+        autoAdjustEndDate();
+    }
+
+    private void autoAdjustEndDate() {
+        endDate = startDate.plusMonths(3L);
+    }
+
+    public LocalDate getStartDate() {
+        return startDate;
+    }
+
+    public LocalDate getEndDate() {
+        return endDate;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        YearQuarter quarter = (YearQuarter) o;
+        return Objects.equals(startDate, quarter.startDate) && Objects.equals(endDate, quarter.endDate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(startDate, endDate);
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", YearQuarter.class.getSimpleName() + "[", "]").add("startDate=" + startDate)
+            .add("endDate=" + endDate)
+            .toString();
+    }
+}

easy-random/src/main/java/org/baeldung/easy/random/randomizer/YearQuarterRandomizer.java

@@ -0,0 +1,18 @@
+package org.baeldung.easy.random.randomizer;
+
+import org.baeldung.easy.random.model.YearQuarter;
+import org.jeasy.random.api.Randomizer;
+
+import java.time.LocalDate;
+import java.time.Month;
+
+public class YearQuarterRandomizer implements Randomizer<YearQuarter> {
+
+    private LocalDate date = LocalDate.of(1990, Month.SEPTEMBER, 25);
+
+    @Override
+    public YearQuarter getRandomValue() {
+        date = date.plusMonths(3);
+        return new YearQuarter(date);
+    }
+}

easy-random/src/test/java/org/baeldung/easy/random/EasyRandomUnitTest.java

@@ -0,0 +1,63 @@
+package org.baeldung.easy.random;
+
+import org.baeldung.easy.random.model.Employee;
+import org.baeldung.easy.random.model.Person;
+import org.baeldung.easy.random.model.YearQuarter;
+import org.baeldung.easy.random.randomizer.YearQuarterRandomizer;
+import org.jeasy.random.EasyRandom;
+import org.jeasy.random.EasyRandomParameters;
+import org.jeasy.random.FieldPredicates;
+import org.jeasy.random.TypePredicates;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class EasyRandomUnitTest {
+
+    @Test
+    void givenDefaultConfiguration_thenGenerateSingleObject() {
+        EasyRandom generator = new EasyRandom();
+        Person person = generator.nextObject(Person.class);
+
+        assertNotNull(person.getAge());
+        assertNotNull(person.getFirstName());
+        assertNotNull(person.getLastName());
+    }
+
+    @Test
+    void givenDefaultConfiguration_thenGenerateObjectsList() {
+        EasyRandom generator = new EasyRandom();
+        List<Person> persons = generator.objects(Person.class, 5)
+            .collect(Collectors.toList());
+
+        assertEquals(5, persons.size());
+    }
+
+    @Test
+    void givenCustomConfiguration_thenGenerateSingleEmployee() {
+        EasyRandomParameters parameters = new EasyRandomParameters();
+        parameters.stringLengthRange(3, 3);
+        parameters.collectionSizeRange(5, 5);
+        parameters.excludeField(FieldPredicates.named("lastName").and(FieldPredicates.inClass(Employee.class)));
+        parameters.excludeType(TypePredicates.inPackage("not.existing.pkg"));
+        parameters.randomize(YearQuarter.class, new YearQuarterRandomizer());
+
+        EasyRandom generator = new EasyRandom(parameters);
+        Employee employee = generator.nextObject(Employee.class);
+
+        assertEquals(3, employee.getFirstName().length());
+        assertEquals(5, employee.getCoworkers().size());
+        assertEquals(5, employee.getQuarterGrades().size());
+        assertNotNull(employee.getDepartment());
+
+        assertNull(employee.getLastName());
+
+        for (YearQuarter key : employee.getQuarterGrades().keySet()) {
+            assertEquals(key.getStartDate(), key.getEndDate().minusMonths(3L));
+        }
+    }
+
+}

java-collections-conversions/src/test/java/com/baeldung/convert/iteratortolist/ConvertIteratorToListServiceUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.convertiteratortolist;
+package com.baeldung.convert.iteratortolist;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.collection.IsCollectionWithSize.hasSize;