Merge branch 'eugenp:master' into master

algorithms-modules/algorithms-miscellaneous-7/README.md

@@ -12,4 +12,6 @@
 - [Count the Number of Unique Digits in an Integer using Java](https://www.baeldung.com/java-int-count-unique-digits)
 - [Generate Juggler Sequence in Java](https://www.baeldung.com/java-generate-juggler-sequence)
 - [Finding the Parent of a Node in a Binary Search Tree with Java](https://www.baeldung.com/java-find-parent-node-binary-search-tree)
+- [Check if a Number Is a Happy Number in Java](https://www.baeldung.com/java-happy-sad-number-test)
+- [Find the Largest Number Possible After Removing k Digits of a Number](https://www.baeldung.com/java-find-largest-number-remove-k-digits)
 - More articles: [[<-- prev]](/algorithms-miscellaneous-6)

algorithms-modules/algorithms-miscellaneous-7/src/test/java/com/baeldung/algorithms/happynumber/HappyNumberUnitTest.java

@@ -0,0 +1,82 @@
+package com.baeldung.algorithms.happynumber;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+class HappyNumberDecider {
+
+    public static boolean isHappyNumber(int n) {
+        Set<Integer> checkedNumbers = new HashSet<>();
+        while (true) {
+            n = sumDigitsSquare(n);
+            if (n == 1) {
+                return true;
+            }
+            if (checkedNumbers.contains(n)) {
+                return false;
+            }
+            checkedNumbers.add(n);
+        }
+    }
+
+    public static boolean isHappyNumberFloyd(int n) {
+        int slow = n;
+        int fast = n;
+        do {
+            slow = sumDigitsSquare(slow);
+            fast = sumDigitsSquare(sumDigitsSquare(fast));
+        } while (slow != fast);
+
+        return slow == 1;
+    }
+
+    private static int sumDigitsSquare(int n) {
+        int squareSum = 0;
+        while (n != 0) {
+            squareSum += (n % 10) * (n % 10);
+            n /= 10;
+        }
+        return squareSum;
+    }
+}
+
+public class HappyNumberUnitTest {
+
+    @Test
+    void whenUsingIsHappyNumber_thenGetTheExpectedResult() {
+        assertTrue(HappyNumberDecider.isHappyNumber(7));
+        assertTrue(HappyNumberDecider.isHappyNumber(10));
+        assertTrue(HappyNumberDecider.isHappyNumber(13));
+        assertTrue(HappyNumberDecider.isHappyNumber(19));
+        assertTrue(HappyNumberDecider.isHappyNumber(23));
+
+        assertFalse(HappyNumberDecider.isHappyNumber(4));
+        assertFalse(HappyNumberDecider.isHappyNumber(6));
+        assertFalse(HappyNumberDecider.isHappyNumber(11));
+        assertFalse(HappyNumberDecider.isHappyNumber(15));
+        assertFalse(HappyNumberDecider.isHappyNumber(20));
+
+    }
+
+    @Test
+    void whenUsingIsHappyNumber2_thenGetTheExpectedResult() {
+        assertTrue(HappyNumberDecider.isHappyNumberFloyd(7));
+        assertTrue(HappyNumberDecider.isHappyNumberFloyd(10));
+        assertTrue(HappyNumberDecider.isHappyNumberFloyd(13));
+        assertTrue(HappyNumberDecider.isHappyNumberFloyd(19));
+        assertTrue(HappyNumberDecider.isHappyNumberFloyd(23));
+
+        assertFalse(HappyNumberDecider.isHappyNumberFloyd(4));
+        assertFalse(HappyNumberDecider.isHappyNumberFloyd(6));
+        assertFalse(HappyNumberDecider.isHappyNumberFloyd(11));
+        assertFalse(HappyNumberDecider.isHappyNumberFloyd(15));
+        assertFalse(HappyNumberDecider.isHappyNumberFloyd(20));
+
+    }
+
+}

apache-kafka-3/README.md

@@ -6,4 +6,5 @@ This module contains articles about Apache Kafka.
 You can build the project from the command line using: *mvn clean install*, or in an IDE.
 
 ### Relevant Articles:
+- [Commit Offsets in Kafka](https://www.baeldung.com/kafka-commit-offsets)
 

aws-modules/aws-reactive/pom.xml

@@ -87,6 +87,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring.version}</version>
             </plugin>
         </plugins>
     </build>

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

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

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

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

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

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

core-java-modules/core-java-collections-list-6/src/test/java/com/baeldung/addtoimmutablelist/AddElementsToImmutableListUnitTest.java

@@ -0,0 +1,49 @@
+package com.baeldung.addtoimmutablelist;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+public class AddElementsToImmutableListUnitTest {
+
+    public static <T> List<T> appendAnElement(List<T> immutableList, T element) {
+        List<T> tmpList = new ArrayList<>(immutableList);
+        tmpList.add(element);
+        return Collections.unmodifiableList(tmpList);
+    }
+
+    @SafeVarargs
+    public static <T> List<T> appendElements(List<T> immutableList, T... elements) {
+        List<T> tmpList = new ArrayList<>(immutableList);
+        tmpList.addAll(Arrays.asList(elements));
+        return Collections.unmodifiableList(tmpList);
+    }
+
+    @Test
+    void whenCallingAppendAnElement_thenGetExpectedResult() {
+        List<String> myList = List.of("A", "B", "C", "D", "E");
+        List<String> expected = List.of("A", "B", "C", "D", "E", "F");
+        List<String> result = appendAnElement(myList, "F");
+        assertThat(result).isEqualTo(expected)
+            .isUnmodifiable();
+    }
+
+    @Test
+    void whenCallingAppendElements_thenGetExpectedResult() {
+        List<String> myList = List.of("A", "B", "C", "D", "E");
+        List<String> expected1 = List.of("A", "B", "C", "D", "E", "F");
+        List<String> result1 = appendElements(myList, "F");
+        assertThat(result1).isEqualTo(expected1)
+            .isUnmodifiable();
+
+        List<String> expected2 = List.of("A", "B", "C", "D", "E", "F", "G", "H", "I");
+        List<String> result2 = appendElements(myList, "F", "G", "H", "I");
+        assertThat(result2).isEqualTo(expected2)
+            .isUnmodifiable();
+    }
+}

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

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

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

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

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

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

core-java-modules/core-java-io-5/src/main/java/com/baeldung/usinggzipInputstream/Main.java

@@ -0,0 +1,73 @@
+package com.baeldung.usinggzipInputstream;
+
+import java.io.*;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Consumer;
+import java.util.stream.Stream;
+import java.util.zip.GZIPInputStream;
+
+import static java.util.stream.Collectors.toList;
+
+public class Main {
+    static String filePath = Objects.requireNonNull(Main.class.getClassLoader().getResource("myFile.gz")).getFile();
+
+    public static void main(String[] args) throws IOException {
+        // Test readGZipFile method
+        List<String> fileContents = readGZipFile(filePath);
+        System.out.println("Contents of GZIP file:");
+        fileContents.forEach(System.out::println);
+
+        // Test findInZipFile method
+        String searchTerm = "Line 1 content";
+        List<String> foundLines = findInZipFile(filePath, searchTerm);
+        System.out.println("Lines containing '" + searchTerm + "' in GZIP file:");
+        foundLines.forEach(System.out::println);
+
+
+        // Test useContentsOfZipFile method
+        System.out.println("Using contents of GZIP file with consumer:");
+        useContentsOfZipFile(filePath, linesStream -> {
+            linesStream.filter(line -> line.length() > 10).forEach(System.out::println);
+        });
+    }
+
+
+    public static List<String> readGZipFile(String filePath) throws IOException {
+        List<String> lines = new ArrayList<>();
+        try (InputStream inputStream = new FileInputStream(filePath);
+             GZIPInputStream gzipInputStream = new GZIPInputStream(inputStream);
+             InputStreamReader inputStreamReader = new InputStreamReader(gzipInputStream);
+             BufferedReader bufferedReader = new BufferedReader(inputStreamReader)) {
+
+            String line;
+            while ((line = bufferedReader.readLine()) != null) {
+                lines.add(line);
+            }
+        }
+
+        return lines;
+    }
+
+    public static List<String> findInZipFile(String filePath, String toFind) throws IOException {
+        try (InputStream inputStream = new FileInputStream(filePath);
+             GZIPInputStream gzipInputStream = new GZIPInputStream(inputStream);
+             InputStreamReader inputStreamReader = new InputStreamReader(gzipInputStream);
+             BufferedReader bufferedReader = new BufferedReader(inputStreamReader)) {
+
+            return bufferedReader.lines().filter(line -> line.contains(toFind)).collect(toList());
+        }
+    }
+
+    public static void useContentsOfZipFile(String filePath, Consumer<Stream<String>> consumer) throws IOException {
+        try (InputStream inputStream = new FileInputStream(filePath);
+             GZIPInputStream gzipInputStream = new GZIPInputStream(inputStream);
+             InputStreamReader inputStreamReader = new InputStreamReader(gzipInputStream);
+             BufferedReader bufferedReader = new BufferedReader(inputStreamReader)) {
+
+            consumer.accept(bufferedReader.lines());
+        }
+    }
+
+}

core-java-modules/core-java-io-5/src/test/java/com/baeldung/usinggzipInputstream/ReadingGZIPUsingGZIPInputStreamUnitTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.usinggzipInputstream;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.*;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.junit.Assert.assertEquals;
+
+public class ReadingGZIPUsingGZIPInputStreamUnitTest {
+    String testFilePath = Objects.requireNonNull(ReadingGZIPUsingGZIPInputStreamUnitTest.class.getClassLoader().getResource("myFile.gz")).getFile();
+    List<String> expectedFilteredLines = Arrays.asList("Line 1 content", "Line 2 content", "Line 3 content");
+
+    @Test
+    void givenGZFile_whenUsingGZIPInputStream_thenReadLines() throws IOException {
+        try (Stream<String> lines = Main.readGZipFile(testFilePath).stream()) {
+            List<String> result = lines
+                    .filter(expectedFilteredLines::contains)
+                    .collect(Collectors.toList());
+
+            assertEquals(expectedFilteredLines, result);
+        }
+    }
+
+    @Test
+    void givenGZFile_whenUsingtestFindInZipFile_thenReadLines() throws IOException {
+        String toFind = "Line 1 content";
+
+        List<String> result = Main.findInZipFile(testFilePath, toFind);
+
+        assertEquals("Line 1 content", result.get(0));
+
+    }
+
+    @Test
+    void givenGZFile_whenUsingContentsOfZipFile_thenReadLines() throws IOException {
+        AtomicInteger count = new AtomicInteger(0);
+
+        Main.useContentsOfZipFile(testFilePath, linesStream -> {
+            linesStream.filter(line -> line.length() > 10).forEach(line -> count.incrementAndGet());
+        });
+
+        assertEquals(3, count.get());
+    }
+}

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

@@ -96,4 +96,5 @@
     <properties>
         <junit-jupiter-version>5.9.3</junit-jupiter-version>
     </properties>
-</project>
+
+</project>

core-java-modules/core-java-io-apis-2/src/test/java/com/baeldung/inputstreamreader/InputStreamReaderUnitTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.inputstreamreader;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+public class InputStreamReaderUnitTest {
+    @Test
+    public void givenAStringWrittenToAFile_whenReadByInputStreamReader_thenShouldMatchWhenRead(@TempDir Path tempDir) throws IOException {
+        String sampleTxt = "Good day. This is just a test. Good bye.";
+        Path sampleOut = tempDir.resolve("sample-out.txt");
+        List<String> lines = Arrays.asList(sampleTxt);
+        Files.write(sampleOut, lines);
+        String absolutePath = String.valueOf(sampleOut.toAbsolutePath());
+        try (InputStreamReader reader = new InputStreamReader(new FileInputStream(absolutePath), StandardCharsets.UTF_8)) {
+            boolean isMatched = false;
+            int b;
+            StringBuilder sb = new StringBuilder();
+            while ((b = reader.read()) != -1) {
+                sb.append((char) b);
+                if (sb.toString().contains(sampleTxt)) {
+                    isMatched = true;
+                    break;
+                }
+            }
+            assertThat(isMatched).isTrue();
+        }
+    }
+}

core-java-modules/core-java-lang-math-4/README.md

@@ -1,3 +1,4 @@
 =========
 
 ### Relevant articles:
+- [Calculate Percentiles in Java](https://www.baeldung.com/java-compute-percentiles)

core-java-modules/core-java-lang-oop-constructors-2/src/main/java/com/baeldung/objectcreation/constructorversussettermethod/Product.java

@@ -0,0 +1,26 @@
+package com.baeldung.constructorversussettermethod;
+
+public class Product {
+    private String name;
+    private double price;
+    private String category;
+
+    public Product(String name, double price, String category) {
+        this.name = name;
+        this.price = price;
+        this.category = category;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public String getCategory() {
+        return category;
+    }
+}
+

core-java-modules/core-java-lang-oop-constructors-2/src/main/java/com/baeldung/objectcreation/constructorversussettermethod/User.java

@@ -0,0 +1,31 @@
+package com.baeldung.constructorversussettermethod;
+
+public class User {
+    private String username;
+    private String password;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        if (username.matches("[a-zA-Z0-9_]+")) {
+            this.username = username;
+        } else {
+            throw new IllegalArgumentException("Invalid username format");
+        }
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        if (password.length() >= 8) {
+            this.password = password;
+        } else {
+            throw new IllegalArgumentException("Password must be at least 8 characters long");
+        }
+    }
+}
+

core-java-modules/core-java-lang-oop-constructors-2/src/test/java/com/baeldung/objectcreation/constructorversussettermethod/ConstructorsVersusSetterMethodsUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.constructorversussettermethod;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class ConstructorsVersusSetterMethodsUnitTest {
+    @Test
+    public void givenNewUser_whenSettingUsername_thenUsernameIsSet() {
+        User user = new User();
+        user.setUsername("john_doe");
+        assertEquals("john_doe", user.getUsername());
+    }
+
+    @Test
+    public void givenNewUser_whenSettingPassword_thenPasswordIsSet() {
+        User user = new User();
+        user.setPassword("strongPassword123");
+        assertEquals("strongPassword123", user.getPassword());
+    }
+
+    @Test
+    public void givenProductDetails_whenCreatingProductWithConstructor_thenProductHasCorrectAttributes() {
+        Product product = new Product("Smartphone", 599.99, "Electronics");
+        assertEquals("Smartphone", product.getName());
+        assertEquals(599.99, product.getPrice(), 0.001);
+        assertEquals("Electronics", product.getCategory());
+    }
+}
+

core-java-modules/core-java-lang-oop-others/src/main/java/com/baeldung/statementsbeforesuper/Child.java

@@ -0,0 +1,14 @@
+package com.baeldung.statementsbeforesuper;
+
+class Child extends Parent {
+    Child() {
+        super(); // Or super(10); Correct placements
+        System.out.println("Child constructor");
+        additionalInitialization();
+        // super(); Compilation error: Constructor call must be the first statement in a constructor
+    }
+
+    private void additionalInitialization() {
+        System.out.println("Additional initialization in Child");
+    }
+}

core-java-modules/core-java-lang-oop-others/src/main/java/com/baeldung/statementsbeforesuper/Parent.java

@@ -0,0 +1,11 @@
+package com.baeldung.statementsbeforesuper;
+
+public class Parent {
+    public Parent(int id) {
+        System.out.println("Parametrized Parent constructor");
+    }
+
+    public Parent() {
+        System.out.println("Parent constructor");
+    }
+}

core-java-modules/core-java-lang-operators-2/README.md

@@ -12,3 +12,4 @@ This module contains articles about Java operators
 - [What Does “––>” Mean in Java?](https://www.baeldung.com/java-minus-minus-greaterthan)
 - [All the Ways Java Uses the Colon Character](https://www.baeldung.com/java-colon)
 - [Convert Infix to Postfix Expressions in Java](https://www.baeldung.com/java-convert-infix-to-postfix-expressions)
+- [Representation of Integers at a Bit Level in Java](https://www.baeldung.com/java-integer-bit-representation)

core-java-modules/core-java-networking-2/src/test/java/com/baeldung/url/UrlCheckerIntegrationTest.java

@@ -6,7 +6,7 @@ import java.io.IOException;
 
 import org.junit.Test;
 
-public class UrlCheckerUnitTest {
+public class UrlCheckerIntegrationTest {
 
     @Test
     public void givenValidUrl_WhenUsingHEAD_ThenReturn200() throws IOException {
@@ -18,7 +18,7 @@ public class UrlCheckerUnitTest {
     @Test
     public void givenInvalidIUrl_WhenUsingHEAD_ThenReturn404() throws IOException {
         UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com/unkownurl");
+        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com/xyz");
         assertEquals(404, responseCode);
     }
     
@@ -32,7 +32,7 @@ public class UrlCheckerUnitTest {
     @Test
     public void givenInvalidIUrl_WhenUsingGET_ThenReturn404() throws IOException {
         UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURL("http://www.example.com/unkownurl");
+        int responseCode = tester.getResponseCodeForURL("http://www.example.com/xyz");
         assertEquals(404, responseCode);
     }
     

core-java-modules/core-java-networking-4/README.md

@@ -8,4 +8,5 @@
 - [Normalize a URL in Java](https://www.baeldung.com/java-url-normalization)
 - [Translating Space Characters in URLEncoder](https://www.baeldung.com/java-urlencoder-translate-space-characters)
 - [Creating a Custom URL Connection](https://www.baeldung.com/java-custom-url-connection)
-- [[<-- Prev]](/core-java-modules/core-java-networking-3)
+- [Obtaining the Last Path Segment of a URI in Java](https://www.baeldung.com/java-uri-get-last-path-segment)
+- [[<-- Prev]](/core-java-modules/core-java-networking-3)

core-java-modules/core-java-numbers-2/README.md

@@ -13,4 +13,5 @@ This module contains articles about numbers in Java.
 - [Binary Numbers in Java](https://www.baeldung.com/java-binary-numbers)
 - [Finding the Least Common Multiple in Java](https://www.baeldung.com/java-least-common-multiple)
 - [Binary Numbers in Java](https://www.baeldung.com/java-binary-numbers)
+- [RGB Representation as an Integer in Java](https://www.baeldung.com/java-rgb-color-representation)
 - More articles: [[<-- prev]](../core-java-numbers) [[next -->]](../core-java-numbers-3)

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

@@ -49,7 +49,7 @@
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
-                <version>0.8.8</version>
+                <version>${jacoco-maven-plugin.version}</version>
                 <executions>
                     <execution>
                         <goals>
@@ -73,6 +73,7 @@
         <source.version>1.8</source.version>
         <target.version>1.8</target.version>
         <spring.version>5.3.4</spring.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
     </properties>
 
 </project>

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

@@ -49,7 +49,7 @@
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
-                <version>0.8.8</version>
+                <version>${jacoco-maven-plugin.version}</version>
                 <executions>
                     <execution>
                         <goals>
@@ -73,6 +73,7 @@
         <source.version>1.8</source.version>
         <target.version>1.8</target.version>
         <spring.version>5.3.4</spring.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
     </properties>
 
 </project>

core-java-modules/core-java-streams-maps/src/test/java/com/baeldung/streams/mapstreamtomap/MapStreamToMapUnitTest.java

@@ -0,0 +1,143 @@
+package com.baeldung.streams.mapstreamtomap;
+
+import static java.lang.Math.max;
+import static java.util.stream.Collectors.flatMapping;
+import static java.util.stream.Collectors.groupingBy;
+import static java.util.stream.Collectors.mapping;
+import static java.util.stream.Collectors.reducing;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.Test;
+
+public class MapStreamToMapUnitTest {
+
+    Map<String, Integer> playerMap1 = new HashMap<String, Integer>() {{
+        put("Kai", 92);
+        put("Liam", 100);
+    }};
+    Map<String, Integer> playerMap2 = new HashMap<String, Integer>() {{
+        put("Eric", 42);
+        put("Kevin", 77);
+    }};
+    Map<String, Integer> playerMap3 = new HashMap<String, Integer>() {{
+        put("Saajan", 35);
+    }};
+    Map<String, Integer> playerMap4 = new HashMap<String, Integer>() {{
+        put("Kai", 76);
+    }};
+    Map<String, Integer> playerMap5 = new HashMap<String, Integer>() {{
+        put("Kai", null);
+        put("Jerry", null);
+    }};
+
+    @Test
+    void givenMapsStream_whenUsingFlatMapAndToMap_thenMultipleMapsMergedIntoOneMap() {
+
+        Map<String, Integer> expectedMap = new HashMap<String, Integer>() {{
+            put("Saajan", 35);
+            put("Liam", 100);
+            put("Kai", 92);
+            put("Eric", 42);
+            put("Kevin", 77);
+        }};
+
+        Map<String, Integer> mergedMap = Stream.of(playerMap1, playerMap2, playerMap3)
+            .flatMap(map -> map.entrySet()
+                .stream())
+            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+
+        assertEquals(expectedMap, mergedMap);
+    }
+
+    @Test
+    void givenMapsWithDuplicateKeys_whenUsingFlatMapAndToMap_thenMultipleMapsMergedIntoOneMap() {
+
+        Map<String, Integer> expectedMap = new HashMap<String, Integer>() {{
+            put("Saajan", 35);
+            put("Liam", 100);
+            put("Kai", 92); // max of 76 and 92
+            put("Eric", 42);
+            put("Kevin", 77);
+        }};
+
+        assertThrows(IllegalStateException.class, () -> Stream.of(playerMap1, playerMap2, playerMap3, playerMap4)
+            .flatMap(map -> map.entrySet()
+                .stream())
+            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)), "Duplicate key Kai (attempted merging values 92 and 76)");
+
+        Map<String, Integer> mergedMap = Stream.of(playerMap1, playerMap2, playerMap3, playerMap4)
+            .flatMap(map -> map.entrySet()
+                .stream())
+            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, Integer::max));
+
+        assertEquals(expectedMap, mergedMap);
+    }
+
+    private Integer maxInteger(Integer int1, Integer int2) {
+        if (int1 == null) {
+            return int2;
+        }
+        if (int2 == null) {
+            return int1;
+        }
+        return max(int1, int2);
+    }
+
+    @Test
+    void givenMapsWithDuplicateKeysAndNullValues_whenUsingFlatMapWithForEach_thenMultipleMapsMergedIntoOneMap() {
+
+        Map<String, Integer> expectedMap = new HashMap<String, Integer>() {{
+            put("Saajan", 35);
+            put("Liam", 100);
+            put("Kai", 92); // max of 92, 76, and null
+            put("Eric", 42);
+            put("Kevin", 77);
+            put("Jerry", null);
+        }};
+
+        assertThrows(NullPointerException.class, () -> Stream.of(playerMap1, playerMap2, playerMap3, playerMap4, playerMap5)
+            .flatMap(map -> map.entrySet()
+                .stream())
+            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, Integer::max)));
+
+        Map<String, Integer> mergedMap = new HashMap<>();
+        Stream.of(playerMap1, playerMap2, playerMap3, playerMap4, playerMap5)
+            .flatMap(map -> map.entrySet()
+                .stream())
+            .forEach(entry -> {
+                String k = entry.getKey();
+                Integer v = entry.getValue();
+                if (mergedMap.containsKey(k)) {
+                    mergedMap.put(k, maxInteger(mergedMap.get(k), v));
+                } else {
+                    mergedMap.put(k, v);
+                }
+            });
+        assertEquals(expectedMap, mergedMap);
+
+    }
+
+    @Test
+    void givenMapsWithDuplicateKeysAndNullValues_whenUsingReduce_thenMultipleMapsMergedIntoOneMap() {
+
+        Map<String, Integer> expectedMap = new HashMap<String, Integer>() {{
+            put("Saajan", 35);
+            put("Liam", 100);
+            put("Kai", 92); // max of 92, 76, and null
+            put("Eric", 42);
+            put("Kevin", 77);
+            put("Jerry", null);
+        }};
+        Map<String, Integer> mergedMap = Stream.of(playerMap1, playerMap2, playerMap3, playerMap4, playerMap5)
+            .flatMap(x -> x.entrySet()
+                .stream())
+            .collect(groupingBy(Map.Entry::getKey, mapping(Map.Entry::getValue, reducing(null, this::maxInteger))));
+        assertEquals(expectedMap, mergedMap);
+    }
+}

core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/UTF8ToISO/UTF8ToISOUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.UTF8ToISO;
+
+import org.junit.jupiter.api.Test;
+
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class UTF8ToISOUnitTest {
+    String string = "âabcd";
+    byte[] expectedBytes = new byte[]{(byte) 0xE2, 0x61, 0x62, 0x63, 0x64};
+
+    @Test
+    public void givenUtf8String_whenUsingGetByte_thenIsoBytesShouldBeEqual() {
+        byte[] iso88591bytes = string.getBytes(StandardCharsets.ISO_8859_1);
+        assertArrayEquals(expectedBytes, iso88591bytes);
+    }
+
+    @Test
+    public void givenString_whenUsingByteBufferCharBufferConvertToIso_thenBytesShouldBeEqual() {
+        ByteBuffer inputBuffer = ByteBuffer.wrap(string.getBytes(StandardCharsets.UTF_8));
+        CharBuffer data = StandardCharsets.UTF_8.decode(inputBuffer);
+        ByteBuffer outputBuffer = StandardCharsets.ISO_8859_1.encode(data);
+        byte[] outputData = new byte[outputBuffer.remaining()];
+        outputBuffer.get(outputData);
+        assertArrayEquals(expectedBytes, outputData);
+    }
+}

dozer/README.md

@@ -1,7 +0,0 @@
-## Dozer
-
-This module contains articles about Dozer
-
-### Relevant Articles:
-
-- [A Guide to Mapping With Dozer](https://www.baeldung.com/dozer)

dozer/pom.xml

@@ -1,32 +0,0 @@
-<?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/maven-v4_0_0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <artifactId>dozer</artifactId>
-    <name>dozer</name>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-    </parent>
-
-    <dependencies>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>${commons-lang3.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>net.sf.dozer</groupId>
-            <artifactId>dozer</artifactId>
-            <version>${dozer.version}</version>
-        </dependency>
-    </dependencies>
-
-    <properties>
-        <dozer.version>5.5.1</dozer.version>
-    </properties>
-
-</project>

jhipster-6/bookstore-monolith/pom.xml

@@ -1168,7 +1168,7 @@
         <maven-war-plugin.version>3.2.2</maven-war-plugin.version>
         <jib-maven-plugin.version>0.9.11</jib-maven-plugin.version>
         <frontend-maven-plugin.version>1.7.6</frontend-maven-plugin.version>
-        <jacoco-maven-plugin.version>0.8.2</jacoco-maven-plugin.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
         <lifecycle-mapping.version>1.0.0</lifecycle-mapping.version>
         <scala-maven-plugin.version>3.4.2</scala-maven-plugin.version>
         <sonar-maven-plugin.version>3.5.0.1254</sonar-maven-plugin.version>

jhipster-modules/jhipster-microservice/car-app/pom.xml

@@ -24,7 +24,7 @@
         <hazelcast-hibernate52.version>1.2</hazelcast-hibernate52.version>
         <hibernate.version>5.2.8.Final</hibernate.version>
         <hikaricp.version>5.1.0</hikaricp.version>
-        <jacoco-maven-plugin.version>0.7.9</jacoco-maven-plugin.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
         <java.version>1.8</java.version>
         <javassist.version>3.21.0-GA</javassist.version>
         <jcache.version>1.0.0</jcache.version>

jhipster-modules/jhipster-microservice/dealer-app/pom.xml

@@ -24,7 +24,7 @@
         <hazelcast-hibernate52.version>1.2</hazelcast-hibernate52.version>
         <hibernate.version>5.2.8.Final</hibernate.version>
         <hikaricp.version>5.1.0</hikaricp.version>
-        <jacoco-maven-plugin.version>0.7.9</jacoco-maven-plugin.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
         <javassist.version>3.21.0-GA</javassist.version>
         <jcache.version>1.0.0</jcache.version>
         <jhipster.server.version>1.1.0</jhipster.server.version>

jhipster-modules/jhipster-microservice/gateway-app/pom.xml

@@ -27,7 +27,7 @@
         <hazelcast-hibernate52.version>1.2</hazelcast-hibernate52.version>
         <hibernate.version>5.2.8.Final</hibernate.version>
         <hikaricp.version>5.1.0</hikaricp.version>
-        <jacoco-maven-plugin.version>0.7.9</jacoco-maven-plugin.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
         <javassist.version>3.21.0-GA</javassist.version>
         <jcache.version>1.0.0</jcache.version>
         <jhipster.server.version>1.1.0</jhipster.server.version>

jhipster-modules/jhipster-monolithic/pom.xml

@@ -893,7 +893,7 @@
         <gatling.version>2.2.3</gatling.version>
         <hibernate.version>5.2.8.Final</hibernate.version>
         <hikaricp.version>5.1.0</hikaricp.version>
-        <jacoco-maven-plugin.version>0.7.9</jacoco-maven-plugin.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
         <javassist.version>3.21.0-GA</javassist.version>
         <jcache.version>1.0.0</jcache.version>
         <jhipster.server.version>1.1.0</jhipster.server.version>

json-modules/json-conversion/src/main/java/com/baeldung/includenullinjson/Customer.java

@@ -0,0 +1,27 @@
+package com.baeldung.includenullinjson;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class Customer {
+    @JsonProperty
+    private final String name;
+    @JsonProperty
+    private final String address;
+    @JsonProperty
+    private final int age;
+
+    public Customer(String name, String address, int age) {
+        this.name = name;
+        this.address = address;
+        this.age = age;
+    }
+
+    @Override
+    public String toString() {
+        return "Customer{" +
+                "name='" + name + '\'' +
+                ", address='" + address + '\'' +
+                ", age=" + age +
+                '}';
+    }
+}

json-modules/json-conversion/src/test/java/com/baeldung/includenullinjson/IncludeNullValuesInJsonUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.includenullinjson;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class IncludeNullValuesInJsonUnitTest {
+    String expectedJson = "{\"name\":\"John\",\"address\":null,\"age\":25}";
+    Customer obj = new Customer("John", null, 25);
+
+    @Test
+    public void givenObjectWithNullField_whenJacksonUsed_thenIncludesNullValue() throws JsonProcessingException {
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.setSerializationInclusion(JsonInclude.Include.ALWAYS);
+        String json = mapper.writeValueAsString(obj);
+        assertEquals(expectedJson, json);
+    }
+
+    @Test
+    public void givenObjectWithNullField_whenGsonUsed_thenIncludesNullValue() {
+        Gson gson = new GsonBuilder().serializeNulls().create();
+        String json = gson.toJson(obj);
+        assertEquals(expectedJson, json);
+    }
+}

jsoup/README.md

@@ -6,6 +6,7 @@ This module contains articles about jsoup.
 - [Parsing HTML in Java with Jsoup](https://www.baeldung.com/java-with-jsoup)
 - [How to Add Proxy Support to Jsoup?](https://www.baeldung.com/java-jsoup-proxy)
 - [Preserving Line Breaks When Using Jsoup](https://www.baeldung.com/jsoup-line-breaks)
+- [Parsing HTML Table in Java With Jsoup](https://www.baeldung.com/java-jsoup-parse-html-table)
 
 ### Build the Project
 

libraries-cli/README.md

@@ -6,4 +6,5 @@ This module contains articles about cli libraries.
 
 - [Create a Java Command Line Program with Picocli](https://www.baeldung.com/java-picocli-create-command-line-program)
 - [Parsing Command-Line Parameters with JCommander](https://www.baeldung.com/jcommander-parsing-command-line-parameters)
-- [Parsing Command-Line Parameters with Airline](https://www.baeldung.com/java-airline)
+- [Parsing Command-Line Parameters with Airline](https://www.baeldung.com/java-airline)
+- [Intro to the Apache Commons CLI](https://www.baeldung.com/apache-commons-cli)

libraries-data-3/README.md

@@ -12,4 +12,5 @@ This module contains articles about libraries for data processing in Java.
 - [Introduction to Eclipse Collections](https://www.baeldung.com/eclipse-collections)
 - [Introduction to Caffeine](https://www.baeldung.com/java-caching-caffeine)
 - [Guide to Using ModelMapper](https://www.baeldung.com/java-modelmapper)
+- [A Guide to Mapping With Dozer](https://www.baeldung.com/dozer)
 - More articles: [[<-- prev]](/../libraries-data-2)

libraries-data-3/pom.xml

@@ -71,6 +71,17 @@
             <artifactId>modelmapper</artifactId>
             <version>${org.modelmapper.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>net.sf.dozer</groupId>
+            <artifactId>dozer</artifactId>
+            <version>${dozer.version}</version>
+        </dependency>
+
     </dependencies>
 
     <build>
@@ -96,6 +107,7 @@
         <caffeine.version>3.1.8</caffeine.version>
         <findbugs.version>3.0.2</findbugs.version>
         <org.modelmapper.version>3.2.0</org.modelmapper.version>
+        <dozer.version>5.5.1</dozer.version>
     </properties>
 
 </project>

libraries-data-3/src/test/java/com/baeldung/dozer/DozerIntegrationTest.java

@@ -171,7 +171,7 @@ public class DozerIntegrationTest {
         configureMapper("dozer_custom_convertor.xml");
 
         String dateTime = "2007-06-26T21:22:39Z";
-        long timestamp = new Long("1182882159000");
+        long timestamp = Long.parseLong("1182882159000");
 
         Person3 person = new Person3("Rich", dateTime);
         Personne3 person0 = mapper.map(person, Personne3.class);
@@ -182,7 +182,7 @@ public class DozerIntegrationTest {
 
     @Test
     public void givenSrcAndDestWithDifferentFieldTypes_whenAbleToCustomConvertBidirectionally_thenCorrect() {
-        long timestamp = new Long("1182882159000");
+        long timestamp = Long.parseLong("1182882159000");
         Personne3 person = new Personne3("Rich", timestamp);
         configureMapper("dozer_custom_convertor.xml");
 

maven-modules/jacoco-coverage-aggregation/pom.xml

@@ -38,7 +38,7 @@
     </build>
 
     <properties>
-        <jacoco-maven-plugin.version>0.8.8</jacoco-maven-plugin.version>
+        <jacoco-maven-plugin.version>0.8.11</jacoco-maven-plugin.version>
     </properties>
 
 </project>

maven-modules/pom.xml

@@ -84,4 +84,7 @@
         </plugins>
     </build>
 
+    <properties>
+        <maven-resources-plugin.version>3.1.0</maven-resources-plugin.version>
+    </properties>
 </project>

maven-modules/version-overriding-plugins/pom.xml

@@ -30,6 +30,7 @@
         <plugins>
             <plugin>
                 <artifactId>maven-resources-plugin</artifactId>
+                <version>${maven-resources-plugin.version}</version>
                 <configuration>
                     <resources combine.children="append">
                         <resource>

maven-modules/version-overriding-plugins/version-overriding-child-a/pom.xml

@@ -16,6 +16,7 @@
         <plugins>
             <plugin>
                 <artifactId>maven-resources-plugin</artifactId>
+                <version>${maven-resources-plugin.version}</version>
                 <configuration>
                     <resources combine.self="override">
                         <resource>

messaging-modules/java-redpanda/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles: 
+- [Introduction to Redpanda](https://www.baeldung.com/redpanda)

microservices-modules/micronaut/pom.xml

@@ -101,6 +101,7 @@
             <plugin>
                 <groupId>io.micronaut.build</groupId>
                 <artifactId>micronaut-maven-plugin</artifactId>
+                <version>${micronaut-build.version}</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -154,6 +155,7 @@
         <packaging>jar</packaging>
         <compiler.plugin.version>3.12.1</compiler.plugin.version>
         <micronaut.runtime>netty</micronaut.runtime>
+        <micronaut-build.version>3.5.4</micronaut-build.version>
         <shade.plugin.version>3.2.0</shade.plugin.version>
     </properties>
 

microservices-modules/saga-pattern/README.md

@@ -0,0 +1,13 @@
+# Saga Pattern Using Orkes Conductor
+
+This is an example project showing how to build event driven applications using [Conductor](https://github.com/conductor-oss/conductor)
+
+# Pre-requisites
+1. Docker
+2. Running conductor server
+
+**Start the conductor server**
+
+```shell
+docker run --init -p 8080:8080 -p 1234:5000 conductoross/conductor-standalone:3.15.0
+```

microservices-modules/saga-pattern/build.gradle

@@ -0,0 +1,34 @@
+buildscript {
+    dependencies {
+        classpath "org.springframework.boot:spring-boot-gradle-plugin:3.2.3"
+    }
+}
+
+plugins {
+    id 'java'
+    id 'org.springframework.boot' version '3.2.3'
+    id 'io.freefair.lombok' version '8.6'
+}
+
+apply plugin: 'io.spring.dependency-management'
+
+group = 'io.orkes.example'
+version = '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation platform('org.junit:junit-bom:5.9.1')
+    testImplementation 'org.junit.jupiter:junit-jupiter'
+
+    implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'io.orkes.conductor:orkes-conductor-client:2.1.0'
+
+    implementation 'org.xerial:sqlite-jdbc:3.32.3.3'
+}
+
+test {
+    useJUnitPlatform()
+}

microservices-modules/saga-pattern/settings.gradle

@@ -0,0 +1,2 @@
+rootProject.name = 'conductor-examples-food-delivery'
+

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/SagaApplication.java

@@ -0,0 +1,28 @@
+package io.orkes.example.saga;
+
+import io.orkes.example.saga.dao.BaseDAO;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+import lombok.AllArgsConstructor;
+
+
+@AllArgsConstructor
+@SpringBootApplication
+@ComponentScan(basePackages = {"io.orkes"})
+public class SagaApplication {
+
+	private static final BaseDAO db = new BaseDAO("jdbc:sqlite:food_delivery.db");
+
+	public static void main(String[] args) {
+		SpringApplication.run(SagaApplication.class, args);
+		initDB();
+	}
+
+	public static void initDB() {
+		db.createTables("orders");
+		db.createTables("inventory");
+		db.createTables("payments");
+		db.createTables("shipments");
+	}
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/controller/OrderServiceController.java

@@ -0,0 +1,27 @@
+package io.orkes.example.saga.controller;
+
+import io.orkes.example.saga.pojos.FoodDeliveryRequest;
+import io.orkes.example.saga.pojos.OrderRequest;
+import io.orkes.example.saga.service.WorkflowService;
+
+import lombok.AllArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+@Slf4j
+@AllArgsConstructor
+@RestController
+public class OrderServiceController {
+
+    private final WorkflowService workflowService;
+
+    @PostMapping(value = "/triggerFoodDeliveryFlow", produces = "application/json")
+    public ResponseEntity<Map<String, Object>> triggerFoodDeliveryFlow(@RequestBody FoodDeliveryRequest foodDeliveryRequest) {
+        return ResponseEntity.ok(workflowService.startFoodDeliveryWorkflow(foodDeliveryRequest));
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/dao/BaseDAO.java

@@ -0,0 +1,221 @@
+package io.orkes.example.saga.dao;
+
+import java.sql.*;
+
+public class BaseDAO {
+
+    private String url;
+
+    public BaseDAO(String url) {
+        this.url = url;
+    }
+
+    protected Connection connect() {
+        Connection conn = null;
+        try {
+            conn = DriverManager.getConnection(this.url);
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+        return conn;
+    }
+
+    protected Boolean execute(String sql) {
+        try (Connection conn = DriverManager.getConnection(this.url); Statement stmt = conn.createStatement()) {
+            stmt.execute(sql);
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            return false;
+        }
+        return true;
+    }
+
+    public void createTables(String service) {
+        switch (service) {
+            case "orders":
+                createOrdersTable();
+                createOrderDetailsTable();
+                createCustomerTable();
+                break;
+            case "inventory":
+                createRestaurantsTable();
+                break;
+            case "shipments":
+                createDriversTable();
+                createShipmentTable();
+                break;
+            case "payments":
+                createPaymentsTable();
+                break;
+            default:
+                System.out.println("Service name not recognized");
+        }
+    }
+
+    private void createOrdersTable() {
+        if (!tableExists("orders")) {
+
+            String sql = "CREATE TABLE orders (\n"
+                    + "	orderId text PRIMARY KEY,\n"
+                    + "	customerId integer NOT NULL,\n"
+                    + "	restaurantId integer NOT NULL,\n"
+                    + "	deliveryAddress text NOT NULL,\n"
+                    + "	createdAt TIMESTAMP NOT NULL,\n"
+                    + "	status text NOT NULL\n"
+                    + ");";
+
+            execute(sql);
+        }
+    }
+
+    private void createOrderDetailsTable() {
+        if (!tableExists("orders_details")) {
+            String sql = "CREATE TABLE orders_details (\n"
+                    + "	orderId text PRIMARY KEY,\n"
+                    + "	items text NOT NULL,\n"
+                    + "	notes text\n"
+                    + ");";
+
+            execute(sql);
+        }
+    }
+
+    private void createCustomerTable() {
+        if (tableExists("customers")) {
+            return;
+        }
+
+        String sql = "CREATE TABLE customers (\n"
+                + "	id integer PRIMARY KEY AUTOINCREMENT,\n"
+                + "	email text NOT NULL,\n"
+                + "	name text NOT NULL,\n"
+                + "	contact text\n"
+                + ");";
+
+        if(execute(sql)) {
+            seedCustomers();
+        }
+    }
+
+    private void createRestaurantsTable() {
+        if (!tableExists("restaurants")) {
+            String sql = "CREATE TABLE restaurants (\n"
+                    + "	id integer PRIMARY KEY AUTOINCREMENT,\n"
+                    + "	name text NOT NULL,\n"
+                    + "	address text NOT NULL,\n"
+                    + "	contact text NOT NULL\n"
+                    + ");";
+
+            if (execute(sql)) {
+                seedRestaurants();
+            }
+        }
+    }
+
+
+    private void createPaymentsTable() {
+        if (tableExists("payments")) {
+            return;
+        }
+
+        String sql = "CREATE TABLE payments (\n"
+                + "	paymentId text PRIMARY KEY,\n"
+                + "	orderId text NOT NULL,\n"
+                + "	amount number NOT NULL,\n"
+                + "	method text,\n"
+                + "	status text,\n"
+                + "	createdAt TIMESTAMP NOT NULL\n"
+                + ");";
+
+        execute(sql);
+    }
+
+    private void createDriversTable() {
+        if (tableExists("drivers")) {
+            return;
+        }
+
+        String sql = "CREATE TABLE drivers (\n"
+                + "	id integer PRIMARY KEY AUTOINCREMENT,\n"
+                + "	name text NOT NULL,\n"
+                + "	contact text\n"
+                + ");";
+
+        if(execute(sql)) {
+            seedDrivers();
+        }
+    }
+    private void createShipmentTable() {
+        if (tableExists("shipments")) {
+            return;
+        }
+
+        String sql = "CREATE TABLE shipments (\n"
+                + "	id integer PRIMARY KEY AUTOINCREMENT,\n"
+                + "	orderId text NOT NULL,\n"
+                + "	driverId number NOT NULL,\n"
+                + "	address text NOT NULL,\n"
+                + "	instructions text,\n"
+                + "	status text NOT NULL,\n"
+                + "	createdAt TIMESTAMP NOT NULL\n"
+                + ");";
+
+        execute(sql);
+    }
+
+    private void seedCustomers() {
+        String[] queries = {
+                "INSERT INTO customers(email, name, contact) VALUES('John Smith','john.smith@example.com','+12126781345');",
+                "INSERT INTO customers(email, name, contact) VALUES('Mike Ross','mike.ross@example.com','+15466711147');",
+                "INSERT INTO customers(email, name, contact) VALUES('Martha Williams','martha.williams@example.com','+12790581941');"
+        };
+
+        for (String query : queries) {
+            execute(query);
+        }
+    }
+
+    private void seedRestaurants() {
+        String[] add = {
+                "5331 Redford Court, Montgomery AL 36116",
+                "43 West 4th Street, New York NY 10024",
+                "1693 Alice Court, Annapolis MD 21401"
+        };
+        String[] queries = {
+                "INSERT INTO restaurants(name, address, contact) VALUES('Mikes','+12121231345','" + add[0] + "');",
+                "INSERT INTO restaurants(name, address, contact) VALUES('Tamarind','+12412311147','" + add[1] + "');",
+                "INSERT INTO restaurants(name, address, contact) VALUES('Thai Place','+14790981941','" + add[2] + "');",
+        };
+
+        for (String query : queries) {
+            execute(query);
+        }
+    }
+
+    private void seedDrivers() {
+        String[] queries = {
+                "INSERT INTO drivers(name,contact) VALUES('Wayne Stevens','+12520711467');",
+                "INSERT INTO drivers(name,contact) VALUES('Jim Willis','+16466281981');",
+                "INSERT INTO drivers(name,contact) VALUES('Steven Carroll','+12612590430');",
+                "INSERT INTO drivers(name,contact) VALUES('Tom Cruise','+18659581430');"
+        };
+
+        for (String query : queries) {
+            execute(query);
+        }
+    }
+
+    boolean tableExists(String tableName) {
+        try {
+            Connection conn = DriverManager.getConnection(this.url);
+            DatabaseMetaData meta = conn.getMetaData();
+            ResultSet resultSet = meta.getTables(null, null, tableName, new String[] {"TABLE"});
+            boolean exists = resultSet.next();
+            conn.close();
+            return exists;
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+        return false;
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/dao/InventoryDAO.java

@@ -0,0 +1,33 @@
+package io.orkes.example.saga.dao;
+
+import io.orkes.example.saga.pojos.Order;
+import io.orkes.example.saga.pojos.Restaurant;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class InventoryDAO extends BaseDAO {
+
+    public InventoryDAO(String url) {
+        super(url);
+    }
+
+    public void readRestaurant(int restaurantId, Restaurant restaurant) {
+        String sql = "SELECT name, address, contact FROM restaurants WHERE id = ?";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setInt(1, restaurantId);
+            ResultSet rs = pstmt.executeQuery();
+            while (rs.next()) {
+                restaurant.setName(rs.getString("name"));
+                restaurant.setAddress(rs.getString("address"));
+                restaurant.setContact(rs.getString("contact"));
+            }
+
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/dao/OrdersDAO.java

@@ -0,0 +1,135 @@
+package io.orkes.example.saga.dao;
+
+import io.orkes.example.saga.pojos.Customer;
+import io.orkes.example.saga.pojos.Order;
+
+import java.sql.*;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.TimeZone;
+import java.util.Date;
+
+public class OrdersDAO extends BaseDAO {
+
+    public OrdersDAO(String url) {
+        super(url);
+    }
+
+    public String insertOrder(Order order) {
+        Date date = new Date();
+        Timestamp nowAsTS = new Timestamp(date.getTime());
+
+        String itemsStr = String.join("", order.getOrderDetails().getItems().toString());
+
+        String notesStr = null;
+
+        if(!order.getOrderDetails().getNotes().isEmpty()) {
+            notesStr = String.join("", order.getOrderDetails().getNotes().toString());
+        } else {
+            notesStr = "";
+        }
+
+        String sql = "INSERT INTO orders(orderId,customerId,restaurantId,deliveryAddress,createdAt,status) VALUES(?,?,?,?,?,?)";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, order.getOrderId());
+            pstmt.setInt(2, order.getCustomer().getId());
+            pstmt.setInt(3, order.getRestaurantId());
+            pstmt.setString(4, order.getDeliveryAddress());
+            pstmt.setTimestamp(5, nowAsTS);
+            pstmt.setString(6, order.getStatus().name());
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            return e.getMessage();
+        }
+
+        sql = "INSERT INTO orders_details(orderId,items,notes) VALUES(?,?,?)";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, order.getOrderId());
+            pstmt.setString(2, itemsStr);
+            pstmt.setString(3, notesStr);
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            return e.getMessage();
+        }
+
+        return "";
+    }
+
+    public void updateOrder(Order order) {
+        String sql = "UPDATE orders SET restaurantId=?,deliveryAddress=?,status=? WHERE orderId=?";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setInt(1, order.getRestaurantId());
+            pstmt.setString(2, order.getDeliveryAddress());
+            pstmt.setString(3, order.getStatus().name());
+            pstmt.setString(4, order.getOrderId());
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+    public void readOrder(String orderId, Order order) {
+        String sql = "SELECT orderId, customerId, restaurantId, deliveryAddress, createdAt, status FROM orders WHERE orderId = ?";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, orderId);
+            ResultSet rs = pstmt.executeQuery();
+            while (rs.next()) {
+                order.setOrderId(rs.getString("orderId"));
+                Customer customer = new Customer();
+                customer.setId(rs.getInt("customerId"));
+                order.setCustomer(customer);
+                order.setRestaurantId(rs.getInt("restaurantId"));
+                order.setDeliveryAddress(rs.getString("deliveryAddress"));
+                order.setCreatedAt(rs.getLong("createdAt"));
+                order.setStatus(Order.Status.valueOf(rs.getString("status")));
+            }
+
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+    public int insertCustomer(Customer customer) {
+        int id = 0;
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement("SELECT id FROM customers WHERE email = ?")) {
+            pstmt.setString(1, customer.getEmail());
+            ResultSet rs = pstmt.executeQuery();
+            if (rs.next()) {
+                id = rs.getInt("id");
+            }
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+
+        if (id > 0) {
+            return id;
+        }
+
+        String sql = "INSERT INTO customers(email,name,contact) VALUES(?,?,?)";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, customer.getEmail());
+            pstmt.setString(2, customer.getName());
+            pstmt.setString(3, customer.getContact());
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement("SELECT id FROM customers WHERE email = ?")) {
+            pstmt.setString(1, customer.getEmail());
+            ResultSet rs = pstmt.executeQuery();
+            id = rs.getInt("id");
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+        return id;
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/dao/PaymentsDAO.java

@@ -0,0 +1,65 @@
+package io.orkes.example.saga.dao;
+
+import io.orkes.example.saga.pojos.Payment;
+
+import java.sql.*;
+import java.util.Date;
+
+public class PaymentsDAO extends BaseDAO {
+
+    public PaymentsDAO(String url) {
+        super(url);
+    }
+
+    public String insertPayment(Payment payment) {
+        Date date = new Date();
+        Timestamp nowAsTS = new Timestamp(date.getTime());
+
+        String sql = "INSERT INTO payments(paymentId, orderId, amount, method, createdAt, status) VALUES(?,?,?,?,?,?);";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, payment.getPaymentId());
+            pstmt.setString(2, payment.getOrderId());
+            pstmt.setDouble(3, payment.getAmount());
+            pstmt.setString(4, payment.getPaymentMethod().toString());
+            pstmt.setTimestamp(5, nowAsTS);
+            pstmt.setString(6, payment.getStatus().name());
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            return e.getMessage();
+        }
+        return "";
+    }
+
+    public void updatePaymentStatus(Payment payment) {
+        String sql = "UPDATE payments SET status=? WHERE paymentId=?;";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, payment.getStatus().name());
+            pstmt.setString(2, payment.getPaymentId());
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+    public void readPayment(String orderId, Payment payment) {
+        String sql = "SELECT paymentId, orderId, amount, method, createdAt, status FROM payments WHERE orderId = ?";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, orderId);
+            ResultSet rs = pstmt.executeQuery();
+            while (rs.next()) {
+                payment.setPaymentId(rs.getString("paymentId"));
+                payment.setOrderId(rs.getString("orderId"));
+                payment.setAmount(rs.getDouble("amount"));
+                payment.setCreatedAt(rs.getLong("createdAt"));
+                payment.setStatus(Payment.Status.valueOf(rs.getString("status")));
+            }
+
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/dao/ShipmentDAO.java

@@ -0,0 +1,75 @@
+package io.orkes.example.saga.dao;
+
+import io.orkes.example.saga.pojos.Driver;
+import io.orkes.example.saga.pojos.Shipment;
+
+import java.sql.*;
+import java.util.Date;
+
+public class ShipmentDAO extends BaseDAO {
+
+    public ShipmentDAO(String url) {
+        super(url);
+    }
+
+    public boolean insertShipment(Shipment shipment) {
+        Date date = new Date();
+        Timestamp nowAsTS = new Timestamp(date.getTime());
+
+        String sql = "INSERT INTO shipments(orderId,driverId,address,instructions,createdAt,status) VALUES(?,?,?,?,?,?)";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, shipment.getOrderId());
+            pstmt.setInt(2, shipment.getDriverId());
+            pstmt.setString(3, shipment.getDeliveryAddress());
+            pstmt.setString(4, shipment.getDeliveryInstructions());
+            pstmt.setTimestamp(5, nowAsTS);
+            pstmt.setString(6, Shipment.Status.SCHEDULED.name());
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+            return false;
+        }
+        return true;
+    }
+    public void cancelShipment(String orderId) {
+        String sql = "UPDATE shipments SET status=? WHERE orderId=?;";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, Shipment.Status.CANCELED.name());
+            pstmt.setString(2, orderId);
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+    public void confirmShipment(String orderId) {
+        String sql = "UPDATE shipments SET status=? WHERE orderId=?;";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setString(1, Shipment.Status.CONFIRMED.name());
+            pstmt.setString(2, orderId);
+            pstmt.executeUpdate();
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+    public void readDriver(int driverId, Driver driver) {
+        String sql = "SELECT name, contact FROM drivers WHERE id = ?";
+
+        try (Connection conn = this.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
+            pstmt.setInt(1, driverId);
+            ResultSet rs = pstmt.executeQuery();
+            while (rs.next()) {
+                driver.setId(driverId);
+                driver.setName(rs.getString("name"));
+                driver.setContact(rs.getString("contact"));
+            }
+
+        } catch (SQLException e) {
+            System.out.println(e.getMessage());
+        }
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/CancelRequest.java

@@ -0,0 +1,8 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class CancelRequest {
+    private String orderId;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/CheckInventoryRequest.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+
+import lombok.Data;
+import java.util.ArrayList;
+
+@Data
+public class CheckInventoryRequest {
+    private int restaurantId;
+    private ArrayList<FoodItem> items;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/Customer.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class Customer {
+    private int id;
+    private String email;
+    private String name;
+    private String contact;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/Driver.java

@@ -0,0 +1,10 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class Driver {
+    int id;
+    String name;
+    String contact;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/DriverNotificationRequest.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class DriverNotificationRequest {
+    int driverId;
+    String dropOff;
+    String pickUp;
+    String orderId;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/FoodDeliveryRequest.java

@@ -0,0 +1,19 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+import java.util.ArrayList;
+
+@Data
+public class FoodDeliveryRequest {
+    private String customerEmail;
+    private String customerName;
+    private String customerContact;
+    private int restaurantId;
+    private ArrayList<Object> foodItems;
+    private ArrayList<String> additionalNotes;
+    private String address;
+    private String deliveryInstructions;
+    private double paymentAmount;
+    private Object paymentMethod;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/FoodItem.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+import lombok.ToString;
+
+@Data
+@ToString
+public class FoodItem {
+    private String item;
+    private int quantity;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/Order.java

@@ -0,0 +1,24 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+import java.util.EnumMap;
+
+@Data
+public class Order {
+
+    public enum Status {
+        PENDING,
+        ASSIGNED,
+        CONFIRMED,
+        CANCELLED
+    }
+
+    private String orderId;
+    private Customer customer;
+    private int restaurantId;
+    private String deliveryAddress;
+    private long createdAt;
+    private Status status;
+    private OrderDetails orderDetails;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/OrderDetails.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+import java.util.ArrayList;
+
+@Data
+public class OrderDetails {
+    private String orderId;
+    private ArrayList<FoodItem> items;
+    private ArrayList<String> notes;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/OrderRequest.java

@@ -0,0 +1,18 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+import java.util.ArrayList;
+
+@Data
+public class OrderRequest {
+    private String OrderRequestId;
+    private String customerEmail;
+    private String customerName;
+    private String customerContact;
+    private int restaurantId;
+    private ArrayList<FoodItem> items;
+    private ArrayList<String> notes;
+    private String deliveryAddress;
+    private String deliveryInstructions;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/Payment.java

@@ -0,0 +1,20 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class Payment {
+    public enum Status {
+        PENDING,
+        FAILED,
+        SUCCESSFUL,
+        CANCELED
+    }
+    private String paymentId;
+    private String orderId;
+    private double amount;
+    private PaymentMethod paymentMethod;
+    private Status status;
+    private long createdAt;
+    private String errorMsg;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/PaymentDetails.java

@@ -0,0 +1,12 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+import lombok.ToString;
+
+@Data
+@ToString
+public class PaymentDetails {
+    private String number;
+    private String expiry;
+    private int cvv;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/PaymentMethod.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+import lombok.ToString;
+
+@Data
+@ToString
+public class PaymentMethod {
+    private String type;
+    private PaymentDetails details;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/PaymentRequest.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class PaymentRequest {
+    private String orderId;
+    private int customerId;
+    private float amount;
+    private PaymentMethod method;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/Restaurant.java

@@ -0,0 +1,11 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class Restaurant {
+    int id;
+    String name;
+    String address;
+    String contact;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/Shipment.java

@@ -0,0 +1,20 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class Shipment {
+    public enum Status {
+        SCHEDULED,
+        CONFIRMED,
+        DELIVERED,
+        CANCELED
+    }
+    private int id;
+    private String orderId;
+    private int driverId;
+    private String deliveryAddress;
+    private String deliveryInstructions;
+    private long createdAt;
+    private String status;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/pojos/ShippingRequest.java

@@ -0,0 +1,10 @@
+package io.orkes.example.saga.pojos;
+
+import lombok.Data;
+
+@Data
+public class ShippingRequest {
+    private String orderId;
+    private String deliveryAddress;
+    private String deliveryInstructions;
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/service/InventoryService.java

@@ -0,0 +1,23 @@
+package io.orkes.example.saga.service;
+
+import io.orkes.example.saga.dao.InventoryDAO;
+import io.orkes.example.saga.pojos.FoodItem;
+import io.orkes.example.saga.pojos.Restaurant;
+import lombok.extern.slf4j.Slf4j;
+
+import java.util.ArrayList;
+import java.util.Objects;
+
+@Slf4j
+public class InventoryService {
+
+    private static final InventoryDAO inventoryDAO = new InventoryDAO("jdbc:sqlite:food_delivery.db");
+
+    public static boolean checkAvailability(int restaurantId, ArrayList<FoodItem> items) {
+        Restaurant restaurant = new Restaurant();
+        restaurant.setId(restaurantId);
+        restaurant.setName("");
+        inventoryDAO.readRestaurant(restaurantId, restaurant);
+        return !Objects.equals(restaurant.getName(), "");
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/service/OrderService.java

@@ -0,0 +1,72 @@
+package io.orkes.example.saga.service;
+
+import io.orkes.example.saga.dao.OrdersDAO;
+import io.orkes.example.saga.pojos.Customer;
+import io.orkes.example.saga.pojos.Order;
+import io.orkes.example.saga.pojos.OrderDetails;
+import io.orkes.example.saga.pojos.OrderRequest;
+import lombok.AllArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+
+import java.util.UUID;
+
+@Slf4j
+@AllArgsConstructor
+@Service
+public class OrderService {
+
+    private static final OrdersDAO ORDERS_DAO = new OrdersDAO("jdbc:sqlite:food_delivery.db");
+
+    public static String createOrder(OrderRequest orderRequest) {
+        UUID uuid = UUID.randomUUID();
+        String uuidAsString = uuid.toString();
+
+        Order order = new Order();
+        order.setOrderId(uuidAsString);
+
+        Customer customer = new Customer();
+        customer.setEmail(orderRequest.getCustomerEmail());
+        customer.setName(orderRequest.getCustomerName());
+        customer.setContact(orderRequest.getCustomerContact());
+        customer.setId(ORDERS_DAO.insertCustomer(customer));
+
+        log.info("Upsert customer record in DB with id: {}", customer.getId());
+
+        order.setCustomer(customer);
+        order.setRestaurantId(orderRequest.getRestaurantId());
+        order.setDeliveryAddress(orderRequest.getDeliveryAddress());
+        order.setStatus(Order.Status.PENDING);
+
+        OrderDetails orderDetails = new OrderDetails();
+        orderDetails.setOrderId(uuidAsString);
+        orderDetails.setItems(orderRequest.getItems());
+        orderDetails.setNotes(orderRequest.getNotes());
+
+        order.setOrderDetails(orderDetails);
+
+        String error = ORDERS_DAO.insertOrder(order);
+
+        if (error.isEmpty()) {
+            log.info("Created order with id: {}", order.getOrderId());
+        }
+        else {
+            log.error("Order creation failure: {}", error);
+            return null;
+        }
+
+        return uuidAsString;
+    }
+
+    public static Order getOrder(String orderId) {
+        Order order = new Order();
+        ORDERS_DAO.readOrder(orderId, order);
+        return order;
+    }
+
+    public static void cancelOrder(Order order) {
+        order.setStatus(Order.Status.CANCELLED);
+        log.info("Cancelling order {}", order.getOrderId());
+        ORDERS_DAO.updateOrder(order);
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/service/PaymentService.java

@@ -0,0 +1,85 @@
+package io.orkes.example.saga.service;
+
+import io.orkes.example.saga.dao.PaymentsDAO;
+import io.orkes.example.saga.pojos.Payment;
+import io.orkes.example.saga.pojos.PaymentDetails;
+import io.orkes.example.saga.pojos.PaymentMethod;
+import io.orkes.example.saga.pojos.PaymentRequest;
+import lombok.extern.slf4j.Slf4j;
+
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Objects;
+import java.util.UUID;
+
+@Slf4j
+public class PaymentService {
+
+    private static final PaymentsDAO paymentsDAO = new PaymentsDAO("jdbc:sqlite:food_delivery.db");
+
+    public static Payment createPayment(PaymentRequest paymentRequest) {
+        UUID uuid = UUID.randomUUID();
+        String uuidAsString = uuid.toString();
+
+        Payment payment = new Payment();
+        payment.setPaymentId(uuidAsString);
+        payment.setOrderId(paymentRequest.getOrderId());
+        payment.setAmount(paymentRequest.getAmount());
+        payment.setPaymentMethod(paymentRequest.getMethod());
+        payment.setStatus(Payment.Status.PENDING);
+
+        // Check if returned error is non-empty, i.e failure
+        if (!paymentsDAO.insertPayment(payment).isEmpty()) {
+            log.error("Failed to process payment for order {}", paymentRequest.getOrderId());
+            payment.setErrorMsg("Payment creation failure");
+            payment.setStatus(Payment.Status.FAILED);
+        }
+        else {
+            if(makePayment(payment)) {
+                payment.setStatus(Payment.Status.SUCCESSFUL);
+            } else {
+                payment.setStatus(Payment.Status.FAILED);
+            }
+        }
+
+        // Record final status
+        paymentsDAO.updatePaymentStatus(payment);
+        return payment;
+    }
+
+    public static void cancelPayment(String orderId) {
+        // Cancel Payment in DB
+        Payment payment = new Payment();
+        paymentsDAO.readPayment(orderId, payment);
+        payment.setStatus(Payment.Status.CANCELED);
+        paymentsDAO.updatePaymentStatus(payment);
+    }
+
+    private static boolean makePayment(Payment payment) {
+        if (Objects.equals(payment.getPaymentMethod().getType(), "Credit Card")) {
+            PaymentDetails details = payment.getPaymentMethod().getDetails();
+
+            DateFormat dateFormat= new SimpleDateFormat("MM/yyyy");
+            Date expiry = new Date();
+
+            try {
+                expiry = dateFormat.parse(details.getExpiry());
+            } catch (ParseException e) {
+                payment.setErrorMsg("Invalid expiry date:" + details.getExpiry());
+                return false;
+            }
+
+            Date today = new Date();
+            if (today.getTime() > expiry.getTime()) {
+                payment.setErrorMsg("Expired payment method:" + details.getExpiry());
+                return false;
+            }
+
+        }
+        // Ideally an async call would be made with a callback
+        // But, we're skipping that and assuming payment went through
+        return true;
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/service/ShipmentService.java

@@ -0,0 +1,64 @@
+package io.orkes.example.saga.service;
+
+import io.orkes.example.saga.dao.ShipmentDAO;
+import io.orkes.example.saga.pojos.Driver;
+import io.orkes.example.saga.pojos.Shipment;
+import io.orkes.example.saga.pojos.ShippingRequest;
+import lombok.extern.slf4j.Slf4j;
+
+import java.util.Random;
+
+@Slf4j
+public class ShipmentService {
+
+    private static final ShipmentDAO shipmentDAO = new ShipmentDAO("jdbc:sqlite:food_delivery.db");
+
+    public static int createShipment(ShippingRequest shippingRequest) {
+        String orderId = shippingRequest.getOrderId();
+
+        Shipment shipment = new Shipment();
+        shipment.setOrderId(orderId);
+        shipment.setDeliveryAddress(shippingRequest.getDeliveryAddress());
+        shipment.setDeliveryInstructions(shippingRequest.getDeliveryInstructions());
+
+        int driverId = findDriver();
+        shipment.setDriverId(driverId);
+
+        if (!shipmentDAO.insertShipment(shipment)) {
+            log.error("Shipment creation for order {} failed.", orderId);
+            return 0;
+        }
+
+        Driver driver = new Driver();
+        driver.setName("");
+        shipmentDAO.readDriver(driverId, driver);
+
+        if (driver.getName().isBlank()) {
+            log.error("Shipment creation for order {} failed as driver in the area is not available.", orderId);
+            shipmentDAO.cancelShipment(orderId);
+            return 0;
+        }
+        else {
+            log.info("Assigned driver {} to order with id: {}", driverId, orderId);
+            shipmentDAO.confirmShipment(orderId);
+        }
+
+        return driverId;
+    }
+
+    public static void cancelDelivery(String orderId) {
+        shipmentDAO.cancelShipment(orderId);
+    }
+
+    private static int findDriver() {
+        Random random = new Random();
+        int driverId = 0;
+        int counter = 0;
+        while (counter < 10) {
+            driverId = random.nextInt(4);
+            if(driverId !=0) break;
+            counter += 1;
+        }
+        return driverId;
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/service/WorkflowService.java

@@ -0,0 +1,61 @@
+package io.orkes.example.saga.service;
+
+import com.netflix.conductor.common.metadata.workflow.StartWorkflowRequest;
+import io.orkes.conductor.client.WorkflowClient;
+import io.orkes.example.saga.pojos.FoodDeliveryRequest;
+import lombok.AllArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.core.env.Environment;
+import org.springframework.stereotype.Service;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Slf4j
+@AllArgsConstructor
+@Service
+public class WorkflowService {
+
+    private final WorkflowClient workflowClient;
+    private final Environment environment;
+
+    public Map<String, Object> startFoodDeliveryWorkflow(FoodDeliveryRequest foodDeliveryRequest) {
+        StartWorkflowRequest request = new StartWorkflowRequest();
+        request.setName("FoodDeliveryWorkflow");
+        request.setVersion(1);
+        request.setCorrelationId("api-triggered");
+
+        String TASK_DOMAIN_PROPERTY = "conductor.worker.all.domain";
+        String domain = environment.getProperty(TASK_DOMAIN_PROPERTY, String.class, "");
+
+        if (!domain.isEmpty()) {
+            Map<String, String> taskToDomain = new HashMap<>();
+            taskToDomain.put("*", domain);
+            request.setTaskToDomain(taskToDomain);
+        }
+
+        Map<String, Object> inputData = new HashMap<>();
+        inputData.put("customerEmail", foodDeliveryRequest.getCustomerEmail());
+        inputData.put("customerName", foodDeliveryRequest.getCustomerName());
+        inputData.put("customerContact", foodDeliveryRequest.getCustomerContact());
+        inputData.put("restaurantId", foodDeliveryRequest.getRestaurantId());
+        inputData.put("foodItems", foodDeliveryRequest.getFoodItems());
+        inputData.put("additionalNotes", foodDeliveryRequest.getAdditionalNotes());
+        inputData.put("address", foodDeliveryRequest.getAddress());
+        inputData.put("deliveryInstructions", foodDeliveryRequest.getDeliveryInstructions());
+        inputData.put("paymentAmount", foodDeliveryRequest.getPaymentAmount());
+        inputData.put("paymentMethod", foodDeliveryRequest.getPaymentMethod());
+        request.setInput(inputData);
+
+        String workflowId = "";
+        try {
+            workflowId = workflowClient.startWorkflow(request);
+            log.info("Workflow id: {}", workflowId);
+        } catch (Exception ex) {
+            ex.printStackTrace(System.out);
+            return Map.of("error", "Order creation failure", "detail", ex.toString());
+        }
+
+        return Map.of("workflowId", workflowId);
+    }
+}

microservices-modules/saga-pattern/src/main/java/io/orkes/example/saga/workers/ConductorWorkers.java

@@ -0,0 +1,130 @@
+package io.orkes.example.saga.workers;
+
+import com.netflix.conductor.common.metadata.tasks.TaskResult;
+import com.netflix.conductor.sdk.workflow.task.WorkerTask;
+import io.orkes.example.saga.pojos.*;
+import io.orkes.example.saga.service.InventoryService;
+import io.orkes.example.saga.service.OrderService;
+import io.orkes.example.saga.service.PaymentService;
+import io.orkes.example.saga.service.ShipmentService;
+import lombok.AllArgsConstructor;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+
+@AllArgsConstructor
+@Component
+@ComponentScan(basePackages = {"io.orkes"})
+public class ConductorWorkers {
+    /**
+     * Note: Using this setting, up to 5 tasks will run in parallel, with tasks being polled every 200ms
+     */
+    @WorkerTask(value = "order_food", threadCount = 3, pollingInterval = 300)
+    public TaskResult orderFoodTask(OrderRequest orderRequest) {
+        String orderId = OrderService.createOrder(orderRequest);
+
+        TaskResult result = new TaskResult();
+        Map<String, Object> output = new HashMap<>();
+
+        if(orderId != null) {
+            output.put("orderId", orderId);
+            result.setOutputData(output);
+            result.setStatus(TaskResult.Status.COMPLETED);
+        } else {
+            output.put("orderId", null);
+            result.setStatus(TaskResult.Status.FAILED);
+        }
+        return result;
+    }
+
+    @WorkerTask(value = "check_inventory", threadCount = 2, pollingInterval = 300)
+    public TaskResult checkInventoryTask(CheckInventoryRequest checkInventoryRequest) {
+        int restaurantId = checkInventoryRequest.getRestaurantId();
+        ArrayList<FoodItem> items = checkInventoryRequest.getItems();
+        boolean availability = InventoryService.checkAvailability(restaurantId, items);
+
+        TaskResult result = new TaskResult();
+
+        if (availability) {
+            result.setStatus(TaskResult.Status.COMPLETED);
+        } else {
+            result.setReasonForIncompletion("Restaurant is closed");
+            result.setStatus(TaskResult.Status.FAILED_WITH_TERMINAL_ERROR);
+        }
+
+        return result;
+    }
+
+    @WorkerTask(value = "make_payment", threadCount = 2, pollingInterval = 300)
+    public TaskResult makePaymentTask(PaymentRequest paymentRequest) {
+        TaskResult result = new TaskResult();
+
+        Payment payment = PaymentService.createPayment(paymentRequest);
+        Map<String, Object> output = new HashMap<>();
+        output.put("orderId", payment.getOrderId());
+        output.put("paymentId", payment.getPaymentId());
+        output.put("paymentStatus", payment.getStatus().name());
+
+        if(payment.getStatus() == Payment.Status.SUCCESSFUL) {
+            result.setStatus(TaskResult.Status.COMPLETED);
+        } else {
+            output.put("error", payment.getErrorMsg());
+            result.setStatus(TaskResult.Status.FAILED_WITH_TERMINAL_ERROR);
+        }
+
+        result.setOutputData(output);
+
+        return result;
+    }
+
+    @WorkerTask(value = "ship_food", threadCount = 2, pollingInterval = 300)
+    public TaskResult shipFoodTask(ShippingRequest shippingRequest) {
+        TaskResult result = new TaskResult();
+        Map<String, Object> output = new HashMap<>();
+        int driverId = ShipmentService.createShipment(shippingRequest);
+        if (driverId != 0) {
+            result.setStatus(TaskResult.Status.COMPLETED);
+        } else {
+            result.setStatus(TaskResult.Status.FAILED);
+        }
+        return result;
+    }
+
+    @WorkerTask(value = "notify_driver", threadCount = 2, pollingInterval = 300)
+    public Map<String, Object> checkForDriverNotifications(DriverNotificationRequest driverNotificationRequest) {
+        Map<String, Object> result = new HashMap<>();
+        return result;
+    }
+
+    @WorkerTask(value = "notify_customer", threadCount = 2, pollingInterval = 300)
+    public Map<String, Object> checkForCustomerNotifications(Order order) {
+        Map<String, Object> result = new HashMap<>();
+        return result;
+    }
+//
+    @WorkerTask(value = "cancel_payment", threadCount = 2, pollingInterval = 300)
+    public Map<String, Object> cancelPaymentTask(CancelRequest cancelRequest) {
+        Map<String, Object> result = new HashMap<>();
+        PaymentService.cancelPayment(cancelRequest.getOrderId());
+        return result;
+    }
+
+    @WorkerTask(value = "cancel_delivery", threadCount = 2, pollingInterval = 300)
+    public Map<String, Object> cancelDeliveryTask(CancelRequest cancelRequest) {
+        Map<String, Object> result = new HashMap<>();
+        ShipmentService.cancelDelivery(cancelRequest.getOrderId());
+        return result;
+    }
+
+    @WorkerTask(value = "cancel_order", threadCount = 2, pollingInterval = 300)
+    public Map<String, Object> cancelOrderTask(CancelRequest cancelRequest) {
+        Map<String, Object> result = new HashMap<>();
+        Order order = OrderService.getOrder(cancelRequest.getOrderId());
+        OrderService.cancelOrder(order);
+        return result;
+    }
+
+}

microservices-modules/saga-pattern/src/main/resources/application.properties

@@ -0,0 +1,32 @@
+
+spring.mvc.pathmatch.matching-strategy=ant_path_matcher
+
+springdoc.swagger-ui.path=/swagger-ui.html
+
+management.endpoints.enabled-by-default=false
+management.endpoint.info.enabled=false
+
+# Local app server port
+server.port=8081
+
+# Playground
+
+# Obtain key and secret by logging into https://play.orkes.io/
+# and navigating to applications menu, create an application and generate key/secret
+conductor.server.url=https://play.orkes.io/api
+conductor.security.client.key-id=<key>
+conductor.security.client.secret=<secret>
+
+
+# Task Domain
+conductor.worker.all.domain=saga
+conductor.worker.all.pollingInterval=22
+
+
+# DB Setup
+spring.jpa.database-platform=com.springboot.sqlite.SQLDialect
+spring.jpa.hibernate.ddl-auto=update
+spring.datasource.url=jdbc:sqlite:food_delivery.db
+spring.datasource.driver-class-name = org.sqlite.JDBC
+spring.datasource.username=admin
+spring.datasource.password=admin

parent-spring-6/pom.xml

@@ -35,7 +35,7 @@
     </dependencies>
 
     <properties>
-        <spring.version>6.1.2</spring.version>
+        <spring.version>6.1.5</spring.version>
         <spring-cloud.version>2023.0.0</spring-cloud.version>
         <spring-boot.version>3.2.1</spring-boot.version>
     </properties>