Concurrency

<?xml version="1.0" encoding="UTF-8"?>
        <project xmlns="http://maven.apache.org/POM/4.0.0"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
            <modelVersion>4.0.0</modelVersion>
            <parent>
                <groupId>at.aydin.academy</groupId>
                <artifactId>16concurrency-pair</artifactId>
                <version>1.0.0</version>
                <relativePath>../pom.xml</relativePath>
            </parent>
            <artifactId>concurrency-modern</artifactId>
            <packaging>jar</packaging>
            <name>Concurrency Modern</name>

            <dependencies>

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <scope>test</scope>
</dependency>

            </dependencies>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-compiler-plugin</artifactId>
                    </plugin>

                </plugins>
            </build>
        </project>

package at.aydin.lab.concurrency.modern;

import java.util.*;
import java.util.concurrent.*;

// Design Pattern: Task Executor
// Zweck: Ein Virtual Thread pro blockierender Aufgabe vereinfacht skalierbare Nebenläufigkeit.
public final class VirtualThreadTaskRunner {
    public List<String> run(List<Callable<String>> tasks) {
        try (ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor()) {
            List<Future<String>> futures = tasks.stream().map(executor::submit).toList();
            List<String> result = new ArrayList<>(futures.size());
            for (Future<String> future : futures) result.add(future.get());
            return List.copyOf(result);
        } catch (InterruptedException ex) {
            Thread.currentThread().interrupt();
            throw new IllegalStateException(ex);
        } catch (ExecutionException ex) {
            throw new IllegalStateException(ex.getCause());
        }
    }
}

package at.aydin.lab.concurrency.modern;

import org.junit.jupiter.api.Test;
import java.util.*;
import static org.junit.jupiter.api.Assertions.*;

class VirtualThreadTaskRunnerTest {
    @Test
    void usesVirtualThreads() {
        var runner = new VirtualThreadTaskRunner();
        assertEquals(List.of("A", "B"), runner.run(List.of(() -> Thread.currentThread().isVirtual() ? "A" : "X", () -> "B")));
    }
}