1 篇博文 含有标签「JDK21」

public class VirtualThreadDemo {
    public static void main(String[] args) throws Exception {
        // 创建单个虚拟线程
        Thread vThread = Thread.startVirtualThread(() -> {
            System.out.println("在虚拟线程中运行");
        });
        
        // 使用虚拟线程执行器
        try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
            // 提交大量任务
            IntStream.range(0, 10_000).forEach(i -> {
                executor.submit(() -> {
                    // 模拟数据库操作
                    processDatabase(i);
                    return i;
                });
            });
        }
        
        // 使用结构化并发
        try (var scope = new StructuredTaskScope.ShutdownOnFailure()) {
            // 并行执行多个微服务调用
            Future<String> service1 = scope.fork(() -> callMicroservice("service1"));
            Future<String> service2 = scope.fork(() -> callMicroservice("service2"));
            Future<String> service3 = scope.fork(() -> callMicroservice("service3"));
            
            try {
                scope.join();           // 等待所有任务完成
                scope.throwIfFailed();  // 如果有任务失败则抛出异常
                
                // 处理结果
                processResults(
                    service1.resultNow(),
                    service2.resultNow(),
                    service3.resultNow()
                );
            } catch (Exception e) {
                System.err.println("服务调用失败：" + e.getMessage());
                throw e;
            }
        }
    }
    
    // 模拟数据库操作
    private static void processDatabase(int id) {
        try {
            // 模拟网络延迟
            Thread.sleep(Duration.ofMillis(100));
            System.out.printf("处理数据库记录 %d%n", id);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(e);
        }
    }
    
    // 模拟微服务调用
    private static String callMicroservice(String name) throws Exception {
        // 模拟网络延迟
        Thread.sleep(Duration.ofMillis(200));
        return name + " 响应";
    }
    
    // 处理微服务结果
    private static void processResults(String... results) {
        System.out.println("处理服务响应：" + String.join(", ", results));
    }
    
    // 展示虚拟线程与平台线程的区别
    static void threadComparison() throws Exception {
        // 使用平台线程
        try (var executor = Executors.newFixedThreadPool(100)) {
            // 提交任务...
        }
        
        // 使用虚拟线程
        try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
            // 提交任务...
        }
        
        // 虚拟线程的线程本地变量
        ThreadLocal<String> threadLocal = new ThreadLocal<>();
        Thread.startVirtualThread(() -> {
            threadLocal.set("虚拟线程的值");
            System.out.println(threadLocal.get());
        }).join();
    }
}