[Java 11502] (#12625)

* [JAVA-11502] Added vavr-modules (parent) * [JAVA-11502] Added vavr(submodule) to vavr-modules(parent) * [JAVA-11502] Added vavr-2(submodule) to vavr-modules(parent) * [JAVA-11502] Added java-vavr-stream(submodule) to vavr-modules(parent) * [JAVA-11502] deleted modules that were moved + cleanup Co-authored-by: panagiotiskakos <[email protected]> Co-authored-by: Dhawal Kapil <[email protected]>
2022-08-25 21:17:55 +05:30
parent 18d1cb40dc
commit 3ce04cafd5
40 changed files with 239 additions and 206 deletions
@@ -0,0 +1,3 @@
+## VAVR
+
+This module contains modules about vavr.
@@ -0,0 +1,8 @@
+## Vavr Streams
+
+This module contains articles about streams in Vavr.
+
+### Relevant Articles:
+
+- [Java Streams vs Vavr Streams](https://www.baeldung.com/vavr-java-streams)
+
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.samples</groupId>
+    <artifactId>java-vavr-stream</artifactId>
+    <version>1.0</version>
+    <name>java-vavr-stream</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>vavr-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.vavr</groupId>
+            <artifactId>vavr</artifactId>
+            <version>${io.vavr.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <io.vavr.version>0.9.2</io.vavr.version>
+    </properties>
+
+</project>
@@ -0,0 +1,98 @@
+package com.baeldung.samples.java.vavr;
+
+import io.vavr.collection.Stream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.IntStream;
+
+/**
+ *
+ * @author baeldung
+ */
+public class VavrSampler {
+
+    static int[] intArray = new int[]{1, 2, 4};
+    static List<Integer> intList = new ArrayList<Integer>();
+    static int[][] intOfInts = new int[][]{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
+
+    public static void main(String[] args) {
+        vavrStreamElementAccess();
+        System.out.println("====================================");
+        vavrParallelStreamAccess();
+        System.out.println("====================================");
+        jdkFlatMapping();
+        System.out.println("====================================");
+        vavrStreamManipulation();
+        System.out.println("====================================");
+        vavrStreamDistinct();
+    }
+
+    public static void vavrStreamElementAccess() {
+        System.out.println("Vavr Element Access");
+        System.out.println("====================================");
+        Stream<Integer> vavredStream = Stream.ofAll(intArray);
+        System.out.println("Vavr index access: " + vavredStream.get(2));
+        System.out.println("Vavr head element access: " + vavredStream.get());
+
+        Stream<String> vavredStringStream = Stream.of("foo", "bar", "baz");
+        System.out.println("Find foo " + vavredStringStream.indexOf("foo"));
+    }
+
+    public static void vavrParallelStreamAccess() {
+        try {
+            System.out.println("Vavr Stream Concurrent Modification");
+            System.out.println("====================================");
+            Stream<Integer> vavrStream = Stream.ofAll(intList);
+            intList.add(5);
+            vavrStream.forEach(i -> System.out.println("in a Vavr Stream: " + i));
+        } catch (Exception ex) {
+            ex.printStackTrace();
+        }
+        
+        Stream<Integer> wrapped = Stream.ofAll(intArray);
+        intArray[2] = 5;
+        wrapped.forEach(i -> System.out.println("Vavr looped " + i));
+    }
+
+    public static void jdkFlatMapping() {
+        System.out.println("JDK FlatMap -> Uncomment line 68 to test");
+        System.out.println("====================================");
+        int[][] intOfInts = new int[][]{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
+
+        IntStream mapToInt = Arrays.stream(intOfInts)
+                .map(intArr -> Arrays.stream(intArr))
+                .flatMapToInt(val -> val.map(n -> {
+            return n * n;
+        }))
+                .peek(n -> System.out.println("Peeking at " + n));
+        //Uncomment to execute pipeline
+        //mapToInt.forEach(n -> System.out.println("FlatMapped Result "+n));
+    }
+
+    public static void vavrStreamManipulation() {
+        System.out.println("Vavr Stream Manipulation");
+        System.out.println("====================================");
+        List<String> stringList = new ArrayList<>();
+        stringList.add("foo");
+        stringList.add("bar");
+        stringList.add("baz");
+        Stream<String> vavredStream = Stream.ofAll(stringList);
+        vavredStream.forEach(item -> System.out.println("Vavr Stream item: " + item));
+        Stream<String> vavredStream2 = vavredStream.insert(2, "buzz");
+        vavredStream2.forEach(item -> System.out.println("Vavr Stream item after stream addition: " + item));
+        stringList.forEach(item -> System.out.println("List item after stream addition: " + item));
+        Stream<String> deletionStream = vavredStream.remove("bar");
+        deletionStream.forEach(item -> System.out.println("Vavr Stream item after stream item deletion: " + item));
+
+    }
+
+    public static void vavrStreamDistinct() {
+        Stream<String> vavredStream = Stream.of("foo", "bar", "baz", "buxx", "bar", "bar", "foo");
+        Stream<String> distinctVavrStream = vavredStream.distinctBy((y, z) -> {
+            return y.compareTo(z);
+        });
+        distinctVavrStream.forEach(item -> System.out.println("Vavr Stream item after distinct query " + item));
+
+    }
+}
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
@@ -0,0 +1,33 @@
+<?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>vavr-modules</artifactId>
+    <name>vavr-modules</name>
+    <packaging>pom</packaging>
+
+    <parent>
+        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <modules>
+        <module>vavr</module>
+        <module>vavr-2</module>
+        <module>java-vavr-stream</module>
+    </modules>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-maven-plugin</artifactId>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+
+</project>
@@ -0,0 +1,8 @@
+## Vavr
+
+This module contains articles about Vavr.
+
+### Relevant Articles:
+- [Introduction to Vavr’s Either](https://www.baeldung.com/vavr-either)
+- [Interoperability Between Java and Vavr](https://www.baeldung.com/java-vavr)
+- [[<-- prev]](/vavr)
@@ -0,0 +1,27 @@
+<?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>vavr-2</artifactId>
+    <name>vavr-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>vavr-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <dependencies>
+        <dependency>
+            <groupId>io.vavr</groupId>
+            <artifactId>vavr-test</artifactId>
+            <version>${vavr.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <vavr.version>0.9.1</vavr.version>
+    </properties>
+
+</project>
@@ -0,0 +1,37 @@
+package com.baeldung.vavr.either;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import io.vavr.control.Either;
+
+public class EitherDemo {
+
+	public static Object[] computeWithoutEitherUsingArray(int marks) {
+		Object[] results = new Object[2];
+		if (marks < 85) {
+			results[0] = "Marks not acceptable";
+		} else {
+			results[1] = marks;
+		}
+		return results;
+	}
+
+	public static Map<String, Object> computeWithoutEitherUsingMap(int marks) {
+		Map<String, Object> results = new HashMap<>();
+		if (marks < 85) {
+			results.put("FAILURE", "Marks not acceptable");
+		} else {
+			results.put("SUCCESS", marks);
+		}
+		return results;
+	}
+
+	static Either<String, Integer> computeWithEither(int marks) {
+		if (marks < 85) {
+			return Either.left("Marks not acceptable");
+		} else {
+			return Either.right(marks);
+		}
+	}
+}
@@ -0,0 +1,38 @@
+package com.baeldung.vavr.either;
+
+import io.vavr.control.Either;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class EitherUnitTest {
+
+    @Test
+    public void givenMarks_whenPassNumber_thenExpectNumber() {
+        Either<String, Integer> result = EitherDemo.computeWithEither(100);
+        int marks = result.right()
+          .getOrElseThrow(x -> new IllegalStateException());
+
+        assertEquals(100, marks);
+    }
+
+    @Test
+    public void givenMarks_whenFailNumber_thenExpectErrorMesssage() {
+        Either<String, Integer> result = EitherDemo.computeWithEither(50);
+        String error = result.left()
+          .getOrNull();
+
+        assertEquals("Marks not acceptable", error);
+    }
+
+    @Test
+    public void givenPassMarks_whenModified_thenExpectNumber() {
+        Either<String, Integer> result = EitherDemo.computeWithEither(90);
+        int marks = result.right()
+          .map(x -> x * 2)
+          .get();
+
+        assertEquals(180, marks);
+    }
+
+}
@@ -0,0 +1,93 @@
+package com.baeldung.vavr.interoperability;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.Optional;
+
+import org.junit.Test;
+
+import io.vavr.collection.HashMap;
+import io.vavr.collection.LinkedHashSet;
+import io.vavr.collection.List;
+import io.vavr.collection.Map;
+import io.vavr.collection.Set;
+import io.vavr.collection.Stream;
+
+public class CollectionsInteroperabilityUnitTest {
+
+  @Test
+  public void givenParams_whenVavrList_thenReturnJavaList() {
+    List<String> vavrStringList = List.of("JAVA", "Javascript", "Scala");
+
+    java.util.List<String> javaStringList = vavrStringList.toJavaList();
+    assertTrue(javaStringList instanceof java.util.List);
+  }
+
+  @Test
+  public void givenParams_whenVavrStream_thenReturnJavaStream() {
+    Stream<String> vavrStream = Stream.of("JAVA", "Javascript", "Scala");
+
+    java.util.stream.Stream<String> javaParallelStream = vavrStream.toJavaParallelStream();
+    assertTrue(javaParallelStream instanceof java.util.stream.Stream);
+
+    java.util.List<String> javaStringList = vavrStream.toJavaList();
+    assertTrue(javaStringList instanceof java.util.List);
+  }
+
+  @Test
+  public void givenParams_whenVavrMap_thenReturnJavaMap() {
+    Map<String, String> vavrMap = HashMap.of("1", "a", "2", "b", "3", "c");
+
+    java.util.Map<String, String> javaMap = vavrMap.toJavaMap();
+    assertTrue(javaMap instanceof java.util.Map);
+  }
+
+  @Test
+  public void givenParams_whenJavaList_thenReturnVavrListUsingOfAll() {
+    java.util.List<String> javaList = Arrays.asList("Java", "Haskell", "Scala");
+    List<String> vavrList = List.ofAll(javaList);
+    assertTrue(vavrList instanceof io.vavr.collection.List);
+  }
+
+  @Test
+  public void givenParams_whenJavaStream_thenReturnVavrListUsingOfAll() {
+    java.util.stream.Stream<String> javaStream = Arrays.asList("Java", "Haskell", "Scala")
+      .stream();
+    Stream<String> vavrStream = Stream.ofAll(javaStream);
+    assertTrue(vavrStream instanceof io.vavr.collection.Stream);
+  }
+
+  @Test(expected = UnsupportedOperationException.class)
+  public void givenParams_whenVavrListConverted_thenException() {
+    java.util.List<String> javaList = List.of("Java", "Haskell", "Scala")
+      .asJava();
+    javaList.add("Python");
+    assertEquals(4, javaList.size());
+  }
+
+  @Test
+  public void givenParams_whenVavrListConvertedToMutable_thenRetunMutableList() {
+    java.util.List<String> javaList = List.of("Java", "Haskell", "Scala")
+      .asJavaMutable();
+    javaList.add("Python");
+    assertEquals(4, javaList.size());
+  }
+
+  @Test
+  public void givenParams_WhenVavarListConvertedToLinkedSet_thenReturnLinkedSet() {
+    List<String> vavrList = List.of("Java", "Haskell", "Scala", "Java");
+    Set<String> linkedSet = vavrList.toLinkedSet();
+    assertEquals(3, linkedSet.size());
+    assertTrue(linkedSet instanceof LinkedHashSet);
+  }
+
+  @Test
+  public void givenParams_WhenVavrList_thenReturnJavaOptional() {
+    List<String> vavrList = List.of("Java");
+    Optional<String> optional = vavrList.toJavaOptional();
+    assertEquals("Java", optional.get());
+  }
+
+}
@@ -0,0 +1,16 @@
+## Vavr
+
+This module contains articles about Vavr.
+
+### Relevant Articles:
+- [Introduction to Vavr](https://www.baeldung.com/vavr)
+- [Guide to Try in Vavr](https://www.baeldung.com/vavr-try)
+- [Guide to Pattern Matching in Vavr](https://www.baeldung.com/vavr-pattern-matching)
+- [Property Testing Example With Vavr](https://www.baeldung.com/vavr-property-testing)
+- [Exceptions in Lambda Expression Using Vavr](https://www.baeldung.com/exceptions-using-vavr)
+- [Vavr Support in Spring Data](https://www.baeldung.com/spring-vavr)
+- [Introduction to Vavr’s Validation API](https://www.baeldung.com/vavr-validation-api)
+- [Guide to Collections API in Vavr](https://www.baeldung.com/vavr-collections)
+- [Collection Factory Methods for Vavr](https://www.baeldung.com/vavr-collection-factory-methods)
+- [Introduction to Future in Vavr](https://www.baeldung.com/vavr-future)
+- [[next -->]](/vavr-2)
@@ -0,0 +1,49 @@
+<?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>vavr</artifactId>
+    <version>1.0</version>
+    <name>vavr</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.vavr</groupId>
+            <artifactId>vavr-test</artifactId>
+            <version>${vavr.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${awaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <vavr.version>0.9.1</vavr.version>
+        <awaitility.version>3.0.0</awaitility.version>
+    </properties>
+
+</project>
@@ -0,0 +1,11 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}
@@ -0,0 +1,18 @@
+package com.baeldung.repositories;
+
+import org.springframework.data.repository.Repository;
+
+import com.baeldung.vavr.User;
+
+import io.vavr.collection.Seq;
+import io.vavr.control.Option;
+
+public interface VavrUserRepository extends Repository<User, Long> {
+
+    Option<User> findById(long id);
+
+    Seq<User> findByName(String name);
+
+    User save(User user);
+
+}
@@ -0,0 +1,99 @@
+package com.baeldung.samples.java.vavr;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import io.vavr.collection.Stream;
+
+/**
+ *
+ * @author baeldung
+ */
+public class VavrSampler {
+
+    static int[] intArray = new int[] { 1, 2, 4 };
+    static List<Integer> intList = new ArrayList<>();
+    static int[][] intOfInts = new int[][] { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
+
+    public static void main(String[] args) {
+        vavrStreamElementAccess();
+        System.out.println("====================================");
+        vavrParallelStreamAccess();
+        System.out.println("====================================");
+        vavrFlatMapping();
+        System.out.println("====================================");
+        vavrStreamManipulation();
+        System.out.println("====================================");
+        vavrStreamDistinct();
+    }
+
+    public static void vavrStreamElementAccess() {
+        System.out.println("Vavr Element Access");
+        System.out.println("====================================");
+        Stream<Integer> vavredStream = Stream.ofAll(intArray);
+        System.out.println("Vavr index access: " + vavredStream.get(2));
+        System.out.println("Vavr head element access: " + vavredStream.get());
+
+        Stream<String> vavredStringStream = Stream.of("foo", "bar", "baz");
+        System.out.println("Find foo " + vavredStringStream.indexOf("foo"));
+    }
+
+    public static void vavrParallelStreamAccess() {
+
+        System.out.println("Vavr Stream Concurrent Modification");
+        System.out.println("====================================");
+        Stream<Integer> vavrStream = Stream.ofAll(intList);
+        // intList.add(5);
+        vavrStream.forEach(i -> System.out.println("in a Vavr Stream: " + i));
+
+        // Stream<Integer> wrapped = Stream.ofAll(intArray);
+        // intArray[2] = 5;
+        // wrapped.forEach(i -> System.out.println("Vavr looped " + i));
+    }
+
+    public static void jdkFlatMapping() {
+        System.out.println("Java flatMapping");
+        System.out.println("====================================");
+        java.util.stream.Stream.of(42).flatMap(i -> java.util.stream.Stream.generate(() -> {
+            System.out.println("nested call");
+            return 42;
+        })).findAny();
+    }
+
+    public static void vavrFlatMapping() {
+        System.out.println("Vavr flatMapping");
+        System.out.println("====================================");
+        Stream.of(42)
+                .flatMap(i -> Stream.continually(() -> {
+                    System.out.println("nested call");
+                    return 42;
+                }))
+                .get(0);
+    }
+
+    public static void vavrStreamManipulation() {
+        System.out.println("Vavr Stream Manipulation");
+        System.out.println("====================================");
+        List<String> stringList = new ArrayList<>();
+        stringList.add("foo");
+        stringList.add("bar");
+        stringList.add("baz");
+        Stream<String> vavredStream = Stream.ofAll(stringList);
+        vavredStream.forEach(item -> System.out.println("Vavr Stream item: " + item));
+        Stream<String> vavredStream2 = vavredStream.insert(2, "buzz");
+        vavredStream2.forEach(item -> System.out.println("Vavr Stream item after stream addition: " + item));
+        stringList.forEach(item -> System.out.println("List item after stream addition: " + item));
+        Stream<String> deletionStream = vavredStream.remove("bar");
+        deletionStream.forEach(item -> System.out.println("Vavr Stream item after stream item deletion: " + item));
+
+    }
+
+    public static void vavrStreamDistinct() {
+        Stream<String> vavredStream = Stream.of("foo", "bar", "baz", "buxx", "bar", "bar", "foo");
+        Stream<String> distinctVavrStream = vavredStream.distinctBy((y, z) -> {
+            return y.compareTo(z);
+        });
+        distinctVavrStream.forEach(item -> System.out.println("Vavr Stream item after distinct query " + item));
+
+    }
+}
@@ -0,0 +1,38 @@
+package com.baeldung.vavr;
+
+public class Person {
+    private String name;
+    private int age;
+
+    Person(String name, int age) {
+        super();
+        this.name = name;
+        this.age = age;
+    }
+
+    public Person() {
+        super();
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    @Override
+    public String toString() {
+        return "Person [name=" + name + ", age=" + age + "]";
+    }
+
+}
@@ -0,0 +1,22 @@
+package com.baeldung.vavr;
+
+import io.vavr.collection.Seq;
+import io.vavr.control.Validation;
+
+class PersonValidator {
+    private static final String NAME_ERR = "Invalid characters in name: ";
+    private static final String AGE_ERR = "Age must be at least 0";
+
+    Validation<Seq<String>, Person> validatePerson(String name, int age) {
+        return Validation.combine(validateName(name), validateAge(age)).ap(Person::new);
+    }
+
+    private Validation<String, String> validateName(String name) {
+        String invalidChars = name.replaceAll("[a-zA-Z ]", "");
+        return invalidChars.isEmpty() ? Validation.valid(name) : Validation.invalid(NAME_ERR + invalidChars);
+    }
+
+    private Validation<String, Integer> validateAge(int age) {
+        return age < 0 ? Validation.invalid(AGE_ERR) : Validation.valid(age);
+    }
+}
@@ -0,0 +1,32 @@
+package com.baeldung.vavr;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class User {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+
+    private String 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;
+    }
+}
@@ -0,0 +1,21 @@
+package com.baeldung.vavr.exception.handling;
+
+import com.baeldung.vavr.exception.handling.client.ClientException;
+import com.baeldung.vavr.exception.handling.client.HttpClient;
+import com.baeldung.vavr.exception.handling.client.Response;
+
+public class JavaTryCatch {
+    private HttpClient httpClient;
+
+    public JavaTryCatch(HttpClient httpClient) {
+        this.httpClient = httpClient;
+    }
+
+    public Response getResponse() {
+        try {
+            return httpClient.call();
+        } catch (ClientException e) {
+            return null;
+        }
+    }
+}
@@ -0,0 +1,18 @@
+package com.baeldung.vavr.exception.handling;
+
+
+import com.baeldung.vavr.exception.handling.client.HttpClient;
+import com.baeldung.vavr.exception.handling.client.Response;
+import io.vavr.control.Try;
+
+class VavrTry {
+    private final HttpClient httpClient;
+
+    VavrTry(HttpClient httpClient) {
+        this.httpClient = httpClient;
+    }
+
+    Try<Response> getResponse() {
+        return Try.of(httpClient::call);
+    }
+}
@@ -0,0 +1,8 @@
+package com.baeldung.vavr.exception.handling.client;
+
+
+public class ClientException extends Exception {
+    public ClientException(String message) {
+        super(message);
+    }
+}
@@ -0,0 +1,6 @@
+package com.baeldung.vavr.exception.handling.client;
+
+
+public interface HttpClient {
+    Response call() throws ClientException;
+}
@@ -0,0 +1,9 @@
+package com.baeldung.vavr.exception.handling.client;
+
+public class Response {
+    public final String id;
+
+    public Response(String id) {
+        this.id = id;
+    }
+}
@@ -0,0 +1,17 @@
+package com.baeldung.vavrvalidation.application;
+
+import com.baeldung.vavrvalidation.model.User;
+import com.baeldung.vavrvalidation.validator.UserValidator;
+import io.vavr.collection.Seq;
+import io.vavr.control.Validation;
+
+public class Application {
+
+    public static void main(String[] args) {
+
+        UserValidator userValidator = new UserValidator();
+        Validation<Seq<String>, User> validation = userValidator.validateUser("John", "[email protected]");
+
+        // process validation results here
+    }	
+}
@@ -0,0 +1,18 @@
+package com.baeldung.vavrvalidation.model;
+
+public class User {
+    private String name;
+    private String email;
+    
+    public User(String name, String email) {
+        this.name = name;
+        this.email = email;
+    }
+    
+    @Override
+    public String toString() {
+        return "User [name=" + name + ", email=" + email + "]";
+    }
+    
+    // standard setters and getters
+}
@@ -0,0 +1,29 @@
+package com.baeldung.vavrvalidation.validator;
+
+import com.baeldung.vavrvalidation.model.User;
+import io.vavr.collection.CharSeq;
+import io.vavr.collection.Seq;
+import io.vavr.control.Validation;
+
+public class UserValidator {
+    
+    private static final String NAME_PATTERN = "^[a-zA-Z0-9]+$";
+    private static final String NAME_ERROR = "Name contains invalid characters";
+    private static final String EMAIL_PATTERN =
+        "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
+          + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
+    private static final String EMAIL_ERROR = "Email must be a well-formed email address";
+    
+	public Validation<Seq<String>, User> validateUser(String name, String email) {
+        return Validation
+          .combine(validateField(name, NAME_PATTERN, NAME_ERROR)
+              ,validateField(email, EMAIL_PATTERN, EMAIL_ERROR))
+                .ap(User::new);
+    }
+    
+    private Validation<String, String> validateField(String field, String pattern, String error) {
+        return CharSeq.of(field).replaceAll(pattern, "").transform(seq -> seq.isEmpty()
+          ? Validation.valid(field) 
+            : Validation.invalid(error));
+    }
+}
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
@@ -0,0 +1,116 @@
+package com.baeldung.vavr;
+
+import io.vavr.MatchError;
+import io.vavr.control.Option;
+import org.junit.Test;
+
+import static io.vavr.API.$;
+import static io.vavr.API.Case;
+import static io.vavr.API.Match;
+import static io.vavr.API.run;
+import static io.vavr.Predicates.allOf;
+import static io.vavr.Predicates.anyOf;
+import static io.vavr.Predicates.instanceOf;
+import static io.vavr.Predicates.is;
+import static io.vavr.Predicates.isIn;
+import static io.vavr.Predicates.isNotNull;
+import static io.vavr.Predicates.isNull;
+import static io.vavr.Predicates.noneOf;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class PatternMatchingUnitTest {
+    @Test
+    public void whenMatchesDefault_thenCorrect() {
+        int input = 5;
+        String output = Match(input).of(Case($(1), "one"), Case($(2), "two"), Case($(3), "three"), Case($(), "unknown"));
+
+        assertEquals("unknown", output);
+    }
+
+    @Test(expected = MatchError.class)
+    public void givenNoMatchAndNoDefault_whenThrows_thenCorrect() {
+        int input = 5;
+        Match(input).of(Case($(1), "one"), Case($(2), "two"));
+    }
+
+    @Test
+    public void whenMatchWorksWithOption_thenCorrect() {
+        int i = 10;
+        Option<String> s = Match(i).option(Case($(0), "zero"));
+        assertTrue(s.isEmpty());
+        assertEquals("None", s.toString());
+    }
+
+    @Test
+    public void whenMatchWorksWithPredicate_thenCorrect() {
+        int i = 3;
+        String s = Match(i).of(Case($(is(1)), "one"), Case($(is(2)), "two"), Case($(is(3)), "three"), Case($(), "?"));
+        assertEquals("three", s);
+    }
+
+    @Test
+    public void givenInput_whenMatchesClass_thenCorrect() {
+        Object obj = 5;
+        String s = Match(obj).of(Case($(instanceOf(String.class)), "string matched"), Case($(), "not string"));
+        assertEquals("not string", s);
+    }
+
+    @Test
+    public void givenInput_whenMatchesNull_thenCorrect() {
+        Object obj = 5;
+        String s = Match(obj).of(Case($(isNull()), "no value"), Case($(isNotNull()), "value found"));
+        assertEquals("value found", s);
+    }
+
+    @Test
+    public void givenInput_whenContainsWorks_thenCorrect() {
+        int i = 5;
+        String s = Match(i).of(Case($(isIn(2, 4, 6, 8)), "Even Single Digit"), Case($(isIn(1, 3, 5, 7, 9)), "Odd Single Digit"), Case($(), "Out of range"));
+        assertEquals("Odd Single Digit", s);
+    }
+
+    @Test
+    public void givenInput_whenMatchAllWorks_thenCorrect() {
+        Integer i = null;
+        String s = Match(i).of(Case($(allOf(isNotNull(), isIn(1, 2, 3, null))), "Number found"), Case($(), "Not found"));
+        assertEquals("Not found", s);
+    }
+
+    @Test
+    public void givenInput_whenMatchesAnyOfWorks_thenCorrect() {
+        Integer year = 1990;
+        String s = Match(year).of(Case($(anyOf(isIn(1990, 1991, 1992), is(1986))), "Age match"), Case($(), "No age match"));
+        assertEquals("Age match", s);
+    }
+
+    @Test
+    public void givenInput_whenMatchesNoneOfWorks_thenCorrect() {
+        Integer year = 1990;
+        String s = Match(year).of(Case($(noneOf(isIn(1990, 1991, 1992), is(1986))), "Age match"), Case($(), "No age match"));
+        assertEquals("No age match", s);
+    }
+
+    @Test
+    public void whenMatchWorksWithPredicate_thenCorrect2() {
+        int i = 5;
+        String s = Match(i).of(Case($(isIn(2, 4, 6, 8)), "Even Single Digit"), Case($(isIn(1, 3, 5, 7, 9)), "Odd Single Digit"), Case($(), "Out of range"));
+        assertEquals("Odd Single Digit", s);
+    }
+
+    @Test
+    public void whenMatchCreatesSideEffects_thenCorrect() {
+        int i = 4;
+        Match(i).of(Case($(isIn(2, 4, 6, 8)), o -> run(this::displayEven)), Case($(isIn(1, 3, 5, 7, 9)), o -> run(this::displayOdd)), Case($(), o -> run(() -> {
+            throw new IllegalArgumentException(String.valueOf(i));
+        })));
+    }
+
+    private void displayEven() {
+        System.out.println("Input is even");
+    }
+
+    private void displayOdd() {
+        System.out.println("Input is odd");
+    }
+}
@@ -0,0 +1,73 @@
+package com.baeldung.vavr;
+
+import io.vavr.CheckedFunction1;
+import io.vavr.collection.Stream;
+import io.vavr.test.Arbitrary;
+import io.vavr.test.CheckResult;
+import io.vavr.test.Property;
+import org.junit.Test;
+
+import java.util.function.Predicate;
+
+import static io.vavr.API.$;
+import static io.vavr.API.Case;
+import static io.vavr.API.Match;
+
+public class PropertyBasedLongRunningUnitTest {
+
+    private static Predicate<Integer> divisibleByTwo = i -> i % 2 == 0;
+    private static Predicate<Integer> divisibleByFive = i -> i % 5 == 0;
+
+    private Stream<String> stringsSupplier() {
+        return Stream.from(0).map(i -> Match(i).of(
+          Case($(divisibleByFive.and(divisibleByTwo)), "DividedByTwoAndFiveWithoutRemainder"),
+          Case($(divisibleByFive), "DividedByFiveWithoutRemainder"),
+          Case($(divisibleByTwo), "DividedByTwoWithoutRemainder"),
+          Case($(), "")));
+    }
+
+    @Test
+    public void givenArbitrarySeq_whenCheckThatEverySecondElementIsEqualToString_thenTestPass() {
+        //given
+        Arbitrary<Integer> multiplesOf2 = Arbitrary
+          .integer()
+          .filter(i -> i > 0)
+          .filter(i -> i % 2 == 0 && i % 5 != 0);
+
+        //when
+        CheckedFunction1<Integer, Boolean> mustEquals = i -> stringsSupplier()
+          .get(i)
+          .equals("DividedByTwoWithoutRemainder");
+
+        //then
+        CheckResult result = Property
+          .def("Every second element must equal to DividedByTwoWithoutRemainder")
+          .forAll(multiplesOf2)
+          .suchThat(mustEquals)
+          .check(10_000, 100);
+
+        result.assertIsSatisfied();
+    }
+
+    @Test
+    public void givenArbitrarySeq_whenCheckThatEveryFifthElementIsEqualToString_thenTestPass() {
+        //given
+        Arbitrary<Integer> multiplesOf5 = Arbitrary
+          .integer()
+          .filter(i -> i > 0)
+          .filter(i -> i % 5 == 0 && i % 2 == 0);
+
+        //when
+        CheckedFunction1<Integer, Boolean> mustEquals = i -> stringsSupplier()
+          .get(i)
+          .endsWith("DividedByTwoAndFiveWithoutRemainder");
+
+        //then
+        Property
+          .def("Every fifth element must equal to DividedByTwoAndFiveWithoutRemainder")
+          .forAll(multiplesOf5)
+          .suchThat(mustEquals)
+          .check(10_000, 1_000)
+          .assertIsSatisfied();
+    }
+}
--- a/Show More
+++ b/Show More