Merge remote-tracking branch 'Baeldung/master' into active_mq

# Conflicts: # .gitignore # LICENSE # README.md # core-java-modules/README.md # core-java-modules/core-java-11/README.md # core-java-modules/core-java-11/pom.xml # core-java-modules/core-java-8/README.md # core-java-modules/core-java-8/pom.xml # core-java-modules/core-java-8/src/main/resources/logback.xml # core-java-modules/core-java-annotations/README.md # core-java-modules/core-java-annotations/pom.xml # core-java-modules/core-java-collections-2/README.md # core-java-modules/core-java-collections-2/pom.xml # core-java-modules/core-java-collections-3/README.md # core-java-modules/core-java-collections-3/pom.xml # core-java-modules/core-java-collections-conversions-2/README.md # core-java-modules/core-java-collections-conversions-2/pom.xml # core-java-modules/core-java-collections-conversions/README.md # core-java-modules/core-java-collections-conversions/pom.xml # core-java-modules/core-java-collections-list/README.md # core-java-modules/core-java-collections-list/pom.xml # core-java-modules/core-java-collections/pom.xml # core-java-modules/core-java-datetime-conversion/README.md # core-java-modules/core-java-datetime-conversion/pom.xml # core-java-modules/core-java-datetime-conversion/src/test/java/com/baeldung/datetime/ConvertInstantToTimestampUnitTest.java # core-java-modules/core-java-io-2/pom.xml # core-java-modules/core-java-io/README.md # core-java-modules/core-java-io/pom.xml # core-java-modules/core-java-io/src/test/resources/fileTest.txt # core-java-modules/core-java-io/src/test/resources/sampleTextFile.txt # core-java-modules/core-java-lambdas/README.md # core-java-modules/core-java-lambdas/pom.xml # core-java-modules/core-java-serialization/pom.xml # core-java-modules/core-java-streams/README.md # core-java-modules/core-java-streams/pom.xml # core-java-modules/core-java-strings/README.md # core-java-modules/core-java-strings/pom.xml # core-java-modules/core-java-strings/src/test/resources/stringtoolong.txt # core-java-modules/core-java-uuid/README.md # core-java-modules/core-java-uuid/pom.xml # core-java-modules/pom.xml # image-processing/README.md # image-processing/pom.xml # image-processing/src/main/java/com/baeldung/imageprocessing/addingtext/AddText.java # image-processing/src/main/java/com/baeldung/imageprocessing/opencv/CameraStream.java # jackson-modules/jackson-annotations/README.md # jackson-modules/jackson-annotations/pom.xml # jackson-modules/jackson-conversions-2/README.md # jackson-modules/jackson-conversions-2/pom.xml # jackson-modules/jackson-conversions/README.md # jackson-modules/jackson-conversions/pom.xml # jackson-modules/jackson-custom-conversions/README.md # jackson-modules/jackson-custom-conversions/pom.xml # jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/defaultserializercustomserializer/CallingDefaultSerializerUnitTest.java # jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/deserialization/CustomDeserializationUnitTest.java # jackson-modules/jackson-exceptions/README.md # jackson-modules/jackson-exceptions/pom.xml # jackson-modules/jackson-exceptions/src/test/java/com/baeldung/exceptions/JacksonExceptionsUnitTest.java # jackson-modules/jackson-exceptions/src/test/java/com/baeldung/mappingexception/JacksonMappingExceptionUnitTest.java # jackson-modules/pom.xml # parent-boot-1/pom.xml # parent-boot-2/pom.xml # parent-boot-3/pom.xml # patterns-modules/design-patterns-architectural/pom.xml # patterns-modules/design-patterns-architectural/src/main/java/com/baeldung/repositoryvsdaopattern/UserDaoImpl.java # patterns-modules/design-patterns-behavioral-2/README.md # patterns-modules/design-patterns-behavioral-2/pom.xml # patterns-modules/design-patterns-creational-2/README.md # patterns-modules/design-patterns-creational-2/pom.xml # patterns-modules/design-patterns-singleton/README.md # patterns-modules/design-patterns-structural/src/main/resources/log4jstructuraldp.properties # patterns-modules/enterprise-patterns/pom.xml # patterns-modules/intercepting-filter/pom.xml # patterns-modules/pom.xml # persistence-modules/activejdbc/pom.xml # persistence-modules/hibernate5/README.md # persistence-modules/hibernate5/pom.xml # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/interceptors/CustomInterceptor.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/interceptors/entity/User.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/namingstrategy/CustomPhysicalNamingStrategy.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/persistjson/Customer.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/persistjson/HashMapConverter.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntryIdClass.java # persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntryPK.java # persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/IdentifiersIntegrationTest.java # persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/bootstrap/BootstrapAPIIntegrationTest.java # persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/proxy/HibernateProxyUnitTest.java # persistence-modules/hibernate5/src/test/resources/hibernate-interceptors.properties # persistence-modules/hibernate5/src/test/resources/hibernate-lifecycle.properties # persistence-modules/hibernate5/src/test/resources/hibernate-namingstrategy.properties # persistence-modules/hibernate5/src/test/resources/hibernate-persistjson.properties # persistence-modules/hibernate5/src/test/resources/hibernate.properties # persistence-modules/pom.xml # persistence-modules/spring-data-jpa-crud/pom.xml # persistence-modules/spring-data-jpa-crud/src/main/java/com/baeldung/repository/FruitRepository.java # persistence-modules/spring-data-jpa-repo-2/README.md # persistence-modules/spring-data-jpa-repo-2/pom.xml # persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/customrepository/model/User.java # persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/customrepository/repository/CustomUserRepositoryImpl.java # persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/saveperformance/Book.java # persistence-modules/spring-data-jpa-repo-2/src/main/resources/application.properties # persistence-modules/spring-data-mongodb-reactive/pom.xml # persistence-modules/spring-data-redis/README.md # persistence-modules/spring-data-redis/pom.xml # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/reactive/redis/config/RedisConfig.java # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/config/RedisConfig.java # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/model/Student.java # persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/queue/RedisMessageSubscriber.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/reactive/redis/template/RedisKeyCommandsManualTest.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/reactive/redis/template/RedisTemplateListOpsManualTest.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/reactive/redis/template/RedisTemplateValueOpsManualTest.java # persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/redis/repo/StudentRepositoryManualTest.java # pom.xml # testing-modules/assertion-libraries/README.md # testing-modules/assertion-libraries/pom.xml # testing-modules/junit-5-basics/README.md # testing-modules/junit-5-basics/pom.xml # testing-modules/mockito-2/src/main/java/com/baeldung/nullmatcher/Helper.java # testing-modules/mockito-2/src/main/java/com/baeldung/nullmatcher/Main.java # testing-modules/mockito-2/src/main/java/com/baeldung/wantedbutnotinvocked/Helper.java # testing-modules/mockito-2/src/main/java/com/baeldung/wantedbutnotinvocked/Main.java # testing-modules/mockito-2/src/test/java/com/baeldung/nullmatcher/MainUnitTest.java # testing-modules/mockito-2/src/test/java/com/baeldung/wantedbutnotinvocked/MainUnitTest.java # testing-modules/pom.xml # testing-modules/spring-mockito/pom.xml # web-modules/dropwizard/pom.xml # web-modules/jakarta-ee/README.md # web-modules/jakarta-ee/pom.xml # web-modules/jakarta-ee/src/test/java/com/baeldung/eclipse/krazo/UserControllerUnitTest.java # web-modules/java-lite/pom.xml # web-modules/javax-servlets-2/README.md # web-modules/javax-servlets-2/pom.xml # web-modules/javax-servlets/pom.xml # web-modules/jee-7/pom.xml # web-modules/jooby/pom.xml # web-modules/ninja/pom.xml # web-modules/pom.xml # web-modules/ratpack/pom.xml # web-modules/resteasy/pom.xml # web-modules/restx/pom.xml # web-modules/spark-java/pom.xml # web-modules/vraptor/pom.xml # xml/README.md # xml/pom.xml # xml/src/main/resources/customer-binding.xml # xml/src/main/resources/sax/baeldung.xml # xml/src/test/resources/example_default_parser.xml # xml/src/test/resources/example_dom4j.xml # xml/src/test/resources/example_jaxb.xml # xml/src/test/resources/example_jaxen.xml # xml/src/test/resources/example_jdom.xml # xml/src/test/resources/example_stax.xml # xml/src/test/resources/sax/baeldung.xml # xml/src/test/resources/xml/websites.xml # xml/src/test/resources/xml/xee_attribute.xml
2024-04-30 12:23:19 -04:00
parent c18eb6d2ed 8cabe509a5
commit a51b7b55d9
27985 changed files with 1584039 additions and 0 deletions
@@ -0,0 +1,10 @@
+package com.baeldung.anonymousclass;
+
+public class EmailSenderService implements SenderService {
+
+    @Override
+    public String callSender(Sender sender) {
+        return sender.send("Email Notification");
+    }
+
+}
@@ -0,0 +1,7 @@
+package com.baeldung.anonymousclass;
+
+public interface Sender {
+
+    String send(final String message);
+
+}
@@ -0,0 +1,7 @@
+package com.baeldung.anonymousclass;
+
+public interface SenderService {
+
+    String callSender(Sender sender);
+
+}
@@ -0,0 +1,10 @@
+package com.baeldung.anonymousclass;
+
+public class SmsSenderService implements SenderService {
+
+    @Override
+    public String callSender(Sender sender) {
+        return sender.send("SMS Notification");
+    }
+
+}
@@ -0,0 +1,85 @@
+package com.baeldung.doublecolon;
+
+public class Computer {
+
+    private Integer age;
+    private String color;
+    private Integer healty;
+
+    Computer(final int age, final String color) {
+        this.age = age;
+        this.color = color;
+    }
+
+    Computer(final Integer age, final String color, final Integer healty) {
+        this.age = age;
+        this.color = color;
+        this.healty = healty;
+    }
+
+    public Computer() {
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    public void setAge(final Integer age) {
+        this.age = age;
+    }
+
+    String getColor() {
+        return color;
+    }
+
+    public void setColor(final String color) {
+        this.color = color;
+    }
+
+    Integer getHealty() {
+        return healty;
+    }
+
+    void setHealty(final Integer healty) {
+        this.healty = healty;
+    }
+
+    public void turnOnPc() {
+        System.out.println("Computer turned on");
+    }
+
+    public void turnOffPc() {
+        System.out.println("Computer turned off");
+    }
+
+    public Double calculateValue(Double initialValue) {
+        return initialValue / 1.50;
+    }
+
+    @Override
+    public String toString() {
+        return "Computer{" + "age=" + age + ", color='" + color + '\'' + ", healty=" + healty + '}';
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        final Computer computer = (Computer) o;
+
+        return (age != null ? age.equals(computer.age) : computer.age == null) && (color != null ? color.equals(computer.color) : computer.color == null);
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = age != null ? age.hashCode() : 0;
+        result = 31 * result + (color != null ? color.hashCode() : 0);
+        return result;
+    }
+}
@@ -0,0 +1,27 @@
+package com.baeldung.doublecolon;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.baeldung.doublecolon.function.ComputerPredicate;
+
+public class ComputerUtils {
+
+    static final ComputerPredicate after2010Predicate = (c) -> (c.getAge() > 2010);
+    static final ComputerPredicate blackPredicate = (c) -> "black".equals(c.getColor());
+
+    public static List<Computer> filter(final List<Computer> inventory, final ComputerPredicate p) {
+
+        final List<Computer> result = new ArrayList<>();
+        inventory.stream().filter(p::filter).forEach(result::add);
+
+        return result;
+    }
+
+    static void repair(final Computer computer) {
+        if (computer.getHealty() < 50) {
+            computer.setHealty(100);
+        }
+    }
+
+}
@@ -0,0 +1,39 @@
+package com.baeldung.doublecolon;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.function.Function;
+
+public class MacbookPro extends Computer {
+
+    private static final Logger LOG = LoggerFactory.getLogger(MacbookPro.class);
+
+    public MacbookPro(int age, String color) {
+        super(age, color);
+    }
+
+    MacbookPro(Integer age, String color, Integer healty) {
+        super(age, color, healty);
+    }
+
+    @Override
+    public void turnOnPc() {
+        LOG.debug("MacbookPro turned on");
+    }
+
+    @Override
+    public void turnOffPc() {
+        LOG.debug("MacbookPro turned off");
+    }
+
+    @Override
+    public Double calculateValue(Double initialValue) {
+
+        Function<Double, Double> function = super::calculateValue;
+        final Double pcValue = function.apply(initialValue);
+        LOG.debug("First value is:" + pcValue);
+        return pcValue + (initialValue / 10);
+
+    }
+}
@@ -0,0 +1,10 @@
+package com.baeldung.doublecolon.function;
+
+import com.baeldung.doublecolon.Computer;
+
+@FunctionalInterface
+public interface ComputerPredicate {
+
+    boolean filter(Computer c);
+
+}
@@ -0,0 +1,15 @@
+package com.baeldung.doublecolon.function;
+
+import java.util.Objects;
+import java.util.function.Function;
+
+@FunctionalInterface
+public interface TriFunction<A, B, C, R> {
+
+    R apply(A a, B b, C c);
+
+    default <V> TriFunction<A, B, C, V> andThen(final Function<? super R, ? extends V> after) {
+        Objects.requireNonNull(after);
+        return (final A a, final B b, final C c) -> after.apply(apply(a, b, c));
+    }
+}
@@ -0,0 +1,89 @@
+package com.baeldung.java8.entity;
+
+public class Human {
+    private String name;
+    private int age;
+
+    public Human() {
+        super();
+    }
+
+    public Human(final String name, final int age) {
+        super();
+
+        this.name = name;
+        this.age = age;
+    }
+
+    // API
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(final int age) {
+        this.age = age;
+    }
+
+    // compare
+
+    public static int compareByNameThenAge(final Human lhs, final Human rhs) {
+        if (lhs.name.equals(rhs.name)) {
+            return Integer.compare(lhs.age, rhs.age);
+        } else {
+            return lhs.name.compareTo(rhs.name);
+        }
+    }
+
+    //
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + age;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        final Human other = (Human) obj;
+        if (age != other.age) {
+            return false;
+        }
+        if (name == null) {
+            if (other.name != null) {
+                return false;
+            }
+        } else if (!name.equals(other.name)) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Human [name=").append(name).append(", age=").append(age).append("]");
+        return builder.toString();
+    }
+
+}
@@ -0,0 +1,62 @@
+package com.baeldung.java8.lambda.exceptions;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.function.Consumer;
+
+public class LambdaExceptionWrappers {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(LambdaExceptionWrappers.class);
+
+    public static Consumer<Integer> lambdaWrapper(Consumer<Integer> consumer) {
+        return i -> {
+            try {
+                consumer.accept(i);
+            } catch (ArithmeticException e) {
+                LOGGER.error("Arithmetic Exception occurred.", e);
+            }
+        };
+    }
+
+    static <T, E extends Exception> Consumer<T> consumerWrapper(Consumer<T> consumer, Class<E> clazz) {
+        return i -> {
+            try {
+                consumer.accept(i);
+            } catch (Exception ex) {
+                try {
+                    E exCast = clazz.cast(ex);
+                    LOGGER.error("Exception occurred.", exCast);
+                } catch (ClassCastException ccEx) {
+                    throw ex;
+                }
+            }
+        };
+    }
+
+    public static <T> Consumer<T> throwingConsumerWrapper(ThrowingConsumer<T, Exception> throwingConsumer) {
+        return i -> {
+            try {
+                throwingConsumer.accept(i);
+            } catch (Exception ex) {
+                throw new RuntimeException(ex);
+            }
+        };
+    }
+
+    public static <T, E extends Exception> Consumer<T> handlingConsumerWrapper(ThrowingConsumer<T, E> throwingConsumer, Class<E> exceptionClass) {
+        return i -> {
+            try {
+                throwingConsumer.accept(i);
+            } catch (Exception ex) {
+                try {
+                    E exCast = exceptionClass.cast(ex);
+                    LOGGER.error("Exception occurred.", exCast);
+                } catch (ClassCastException ccEx) {
+                    throw new RuntimeException(ex);
+                }
+            }
+        };
+    }
+
+}
@@ -0,0 +1,8 @@
+package com.baeldung.java8.lambda.exceptions;
+
+@FunctionalInterface
+public interface ThrowingConsumer<T, E extends Exception> {
+
+    void accept(T t) throws E;
+
+}
@@ -0,0 +1,8 @@
+package com.baeldung.java8.lambda.serialization;
+
+public class NotSerializableLambdaExpression {
+    public static Object getLambdaExpressionObject() {
+        Runnable r = () -> System.out.println("please serialize this message");
+        return r;
+    }
+}
@@ -0,0 +1,10 @@
+package com.baeldung.java8.lambda.serialization;
+
+import java.io.Serializable;
+
+public class SerializableLambdaExpression {
+    public static Object getLambdaExpressionObject() {
+        Runnable r = (Runnable & Serializable) () -> System.out.println("please serialize this message");
+        return r;
+    }
+}
@@ -0,0 +1,16 @@
+package com.baeldung.java8.lambda.tips;
+
+
+@FunctionalInterface
+public interface Bar {
+
+    String method(String string);
+
+    default String defaultBar() {
+        return "Default String from Bar";
+    }
+
+    default String defaultCommon() {
+        return "Default Common from Bar";
+    }
+}
@@ -0,0 +1,16 @@
+package com.baeldung.java8.lambda.tips;
+
+
+@FunctionalInterface
+public interface Baz {
+
+    String method(String string);
+
+    default String defaultBaz() {
+        return "Default String from Baz";
+    }
+
+    default String defaultCommon(){
+        return "Default Common from Baz";
+    }
+}
@@ -0,0 +1,11 @@
+package com.baeldung.java8.lambda.tips;
+
+
+@FunctionalInterface
+public interface Foo {
+
+    String method(String string);
+
+    default void defaultMethod() {
+    }
+}
@@ -0,0 +1,11 @@
+package com.baeldung.java8.lambda.tips;
+
+
+@FunctionalInterface
+public interface FooExtended extends Baz, Bar {
+
+    @Override
+    default String defaultCommon() {
+        return Bar.super.defaultCommon();
+    }
+}
@@ -0,0 +1,12 @@
+package com.baeldung.java8.lambda.tips;
+
+import java.util.concurrent.Callable;
+import java.util.function.Supplier;
+
+public interface Processor {
+
+    String processWithCallable(Callable<String> c) throws Exception;
+
+    String processWithSupplier(Supplier<String> s);
+
+}
@@ -0,0 +1,20 @@
+package com.baeldung.java8.lambda.tips;
+
+
+import java.util.concurrent.Callable;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+public class ProcessorImpl implements Processor {
+
+    @Override
+    public String processWithCallable(Callable<String> c) throws Exception {
+        return c.call();
+    }
+
+    @Override
+    public String processWithSupplier(Supplier<String> s) {
+        return s.get();
+    }
+}
@@ -0,0 +1,38 @@
+package com.baeldung.java8.lambda.tips;
+
+
+import java.util.function.Function;
+
+public class UseFoo {
+
+    private String value = "Enclosing scope value";
+
+    public String add(final String string, final Foo foo) {
+        return foo.method(string);
+    }
+
+    public String addWithStandardFI(final String string, final Function<String, String> fn) {
+        return fn.apply(string);
+    }
+
+    public String scopeExperiment() {
+        final Foo fooIC = new Foo() {
+            String value = "Inner class value";
+
+            @Override
+            public String method(final String string) {
+                return value;
+            }
+        };
+        final String resultIC = fooIC.method("");
+
+        final Foo fooLambda = parameter -> {
+            final String value = "Lambda value";
+            return this.value;
+        };
+        final String resultLambda = fooLambda.method("");
+
+        return "Results: resultIC = " + resultIC + ", resultLambda = " + resultLambda;
+    }
+
+}
@@ -0,0 +1,88 @@
+package com.baeldung.lambdas;
+
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.function.Supplier;
+import java.util.stream.IntStream;
+
+/**
+ * Class with examples about working with capturing lambdas.
+ */
+public class LambdaVariables {
+
+    private volatile boolean run = true;
+    private int start = 0;
+
+    private ExecutorService executor = Executors.newFixedThreadPool(3);
+
+    public static void main(String[] args) {
+        new LambdaVariables().localVariableMultithreading();
+    }
+
+    Supplier<Integer> incrementer(int start) {
+        return () -> start; // can't modify start parameter inside the lambda
+    }
+
+    Supplier<Integer> incrementer() {
+        return () -> start++;
+    }
+
+    public void localVariableMultithreading() {
+        boolean run = true;
+        executor.execute(() -> {
+            while (run) {
+                // do operation
+            }
+        });
+        // commented because it doesn't compile, it's just an example of non-final local variables in lambdas
+        // run = false;
+    }
+
+    public void instanceVariableMultithreading() {
+        executor.execute(() -> {
+            while (run) {
+                // do operation
+            }
+        });
+
+        run = false;
+    }
+
+    /**
+     * WARNING: always avoid this workaround!!
+     */
+    public void workaroundSingleThread() {
+        int[] holder = new int[] { 2 };
+        IntStream sums = IntStream
+          .of(1, 2, 3)
+          .map(val -> val + holder[0]);
+
+        holder[0] = 0;
+
+        System.out.println(sums.sum());
+    }
+
+    /**
+     * WARNING: always avoid this workaround!!
+     */
+    public void workaroundMultithreading() {
+        int[] holder = new int[] { 2 };
+        Runnable runnable = () -> System.out.println(IntStream
+          .of(1, 2, 3)
+          .map(val -> val + holder[0])
+          .sum());
+
+        new Thread(runnable).start();
+
+        // simulating some processing
+        try {
+            Thread.sleep(new Random().nextInt(3) * 1000L);
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        holder[0] = 0;
+    }
+
+}
@@ -0,0 +1,59 @@
+package com.baeldung.suppliercallable.data;
+
+import java.time.LocalDate;
+
+public class User {
+
+    private String name;
+    private String surname;
+    private LocalDate birthDate;
+    private Integer age;
+    private Boolean canDriveACar = false;
+
+    public User(String name, String surname, LocalDate birthDate) {
+        this.name = name;
+        this.surname = surname;
+        this.birthDate = birthDate;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getSurname() {
+        return surname;
+    }
+
+    public void setSurname(String surname) {
+        this.surname = surname;
+    }
+
+    public LocalDate getBirthDate() {
+        return birthDate;
+    }
+
+    public void setBirthDate(LocalDate birthDate) {
+        this.birthDate = birthDate;
+    }
+
+    public void setAge(Integer age) {
+        this.age = age;
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    public Boolean getCanDriveACar() {
+        return canDriveACar;
+    }
+
+    public void setCanDriveACar(Boolean canDriveACar) {
+        this.canDriveACar = canDriveACar;
+    }
+
+}
@@ -0,0 +1,8 @@
+package com.baeldung.suppliercallable.service;
+
+import com.baeldung.suppliercallable.data.User;
+
+public interface Service {
+
+    User execute(User user);
+}
@@ -0,0 +1,20 @@
+package com.baeldung.suppliercallable.service.callable;
+
+import java.time.LocalDate;
+import java.time.Period;
+import java.util.concurrent.Callable;
+
+public class AgeCalculatorCallable implements Callable<Integer> {
+
+    private final LocalDate birthDate;
+
+    @Override
+    public Integer call() throws Exception {
+        return Period.between(birthDate, LocalDate.now())
+          .getYears();
+    }
+
+    public AgeCalculatorCallable(LocalDate birthDate) {
+        this.birthDate = birthDate;
+    }
+}
@@ -0,0 +1,31 @@
+package com.baeldung.suppliercallable.service.callable;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import com.baeldung.suppliercallable.data.User;
+import com.baeldung.suppliercallable.service.Service;
+
+public class CallableServiceImpl implements Service {
+
+    @Override
+    public User execute(User user) {
+        ExecutorService executorService = Executors.newCachedThreadPool();
+
+        try {
+            Future<Integer> ageFuture = executorService.submit(new AgeCalculatorCallable(user.getBirthDate()));
+            Integer age = ageFuture.get();
+            Future<Boolean> canDriveACarFuture = executorService.submit(new CarDriverValidatorCallable(age));
+            Boolean canDriveACar = canDriveACarFuture.get();
+            user.setAge(age);
+            user.setCanDriveACar(canDriveACar);
+        } catch (ExecutionException | InterruptedException e) {
+            throw new RuntimeException(e.getCause());
+        }
+
+        return user;
+    }
+
+}
@@ -0,0 +1,17 @@
+package com.baeldung.suppliercallable.service.callable;
+
+import java.util.concurrent.Callable;
+
+public class CarDriverValidatorCallable implements Callable<Boolean> {
+
+    private final Integer age;
+
+    @Override
+    public Boolean call() throws Exception {
+        return age > 18;
+    }
+
+    public CarDriverValidatorCallable(Integer age) {
+        this.age = age;
+    }
+}
@@ -0,0 +1,26 @@
+package com.baeldung.suppliercallable.service.supplier;
+
+import java.time.LocalDate;
+import java.time.Period;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import com.baeldung.suppliercallable.data.User;
+import com.baeldung.suppliercallable.service.Service;
+
+public class SupplierServiceImpl implements Service {
+    @Override
+    public User execute(User user) {
+        ExecutorService executorService = Executors.newCachedThreadPool();
+        CompletableFuture<Integer> ageFut = CompletableFuture.supplyAsync(() -> Period.between(user.getBirthDate(), LocalDate.now())
+          .getYears(), executorService)
+          .exceptionally((throwable -> null));
+        CompletableFuture<Boolean> canDriveACarFut = ageFut.thenComposeAsync(age -> CompletableFuture.supplyAsync(() -> age > 18, executorService))
+          .exceptionally((ex) -> false);
+        user.setAge(ageFut.join());
+        user.setCanDriveACar(canDriveACarFut.join());
+        return user;
+    }
+
+}