public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier);
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier, Executor executor);

public static CompletableFuture<Void> runAsync(Runnable runnable);
public static CompletableFuture<Void> runAsync(Runnable runnable, Executor executor);

// 使线程串行执行，无入参，无返回值
public CompletableFuture<Void> thenRun(Runnable action);
public CompletableFuture<Void> thenRunAsync(Runnable action);
public CompletableFuture<Void> thenRunAsync(Runnable action, Executor executor);

// 使线程串行执行，有入参，无返回值
public CompletableFuture<Void> thenAccept(Consumer<? super T> action);
public CompletableFuture<Void> thenAcceptAsync(Consumer<? super T> action);
public CompletableFuture<Void> thenAcceptAsync(Consumer<? super T> action, Executor executor);

// 使线程串行执行，有入参，有返回值
public <U> CompletableFuture<U> thenApply(Function<? super T,? extends U> fn);
public <U> CompletableFuture<U> thenApplyAsync(Function<? super T,? extends U> fn);
public <U> CompletableFuture<U> thenApplyAsync(Function<? super T,? extends U> fn, Executor executor);

public static CompletableFuture<Void> allOf(CompletableFuture<?>... cfs);

public class CompletableFutureTest5 {

    @SneakyThrows
    public static void main(String[] args) {
        //动态获取服务器核数
        int processors = Runtime.getRuntime().availableProcessors();
        ThreadPoolExecutor executor = new ThreadPoolExecutor(
                processors+1, // 核心线程个数 io:2n ,cpu: n+1  n:内核数据
                processors+1,
                0,
                TimeUnit.SECONDS,
                new ArrayBlockingQueue<>(10),
                Executors.defaultThreadFactory(),
                new ThreadPoolExecutor.AbortPolicy()
        );

        CompletableFuture<String> future01 = CompletableFuture.supplyAsync(() -> "任务1", executor);
        CompletableFuture<String> future02 = CompletableFuture.supplyAsync(() -> "任务2", executor);
        CompletableFuture<String> future03 = CompletableFuture.supplyAsync(() -> {
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return "任务3";
        }, executor);

        // 串联起若干个线程任务, 没有返回值
        CompletableFuture<Void> all = CompletableFuture.allOf(future01, future02, future03);
        // 等待所有线程执行完成
        // .join()和.get()都会阻塞并获取线程的执行情况
        // .join()会抛出未经检查的异常，不会强制开发者处理异常 .get()会抛出检查异常，需要开发者处理
        all.join();
        all.get();
    }
}  

curl -fsSL https://pgp.mongodb.com/server-7.0.asc | \
   sudo gpg -o /usr/share/keyrings/mongodb-server-7.0.gpg \
   --dearmor

@Tag(name = "测试接口")  
@RestController  
@RequestMapping("/order/test")  
public class TestController {  
  
    @Autowired  
    private TestService testService;  
  
    @GetMapping("testLock")  
    public Result testLock() {  
        testService.testLock();  
        return Result.ok();  
    }  
}

public class ClassA {
    private ClassB classB;
    // 构造方法、getter 和 setter 等
}

public class ClassB {
    private ClassA classA;
    // 构造方法、getter 和 setter 等
}