異步線程池配置：

/*** 啟動異步線程-并配置線程池*/
@Configuration
@EnableAsync
public class AsyncConfig {@Bean(name = "taskExecutor")public Executor taskExecutor() {ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();executor.setCorePoolSize(2); // 核心線程數executor.setMaxPoolSize(5); // 最大線程數executor.setQueueCapacity(500); // 隊列容量executor.setThreadNamePrefix("Async-"); // 線程名稱前綴executor.initialize();return executor;}
}

異步線程服務

/*** 異步線程服務** @author Lance* @since 2024-07-11 10:07*/
@Component
public class AsyncTaskService {private static final Logger logger = LoggerFactory.getLogger(AsyncTaskService.class);// 默認最大重試次數private static final int DEFAULT_MAX_ATTEMPTS = 3;// 默認重試間隔時間private static final long DEFAULT_DELAY_BETWEEN_ATTEMPTS = 1000;/*** 啟動一個異步任務，并使用重試機制** @param task 待執行的任務* @param <T>  類型* @return 返回結果*/@Asyncpublic <T> CompletableFuture<T> executeAsyncTaskWithRetry(Callable<T> task) {return executeAsyncTaskWithRetry(task, DEFAULT_MAX_ATTEMPTS, DEFAULT_DELAY_BETWEEN_ATTEMPTS);}/*** 啟動一個異步任務，并使用重試機制** @param task         待執行的任務* @param maxAttempts  最大重試次數* @param initialDelay 重試間隔時間* @param <T>          類型* @return 返回結果*/@Asyncpublic <T> CompletableFuture<T> executeAsyncTaskWithRetry(Callable<T> task, int maxAttempts, long initialDelay) {CompletableFuture<T> future = new CompletableFuture<>();ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);executeTaskWithRetry(task, maxAttempts, initialDelay, future, scheduler, 0, new ArrayList<>());return future;}private <T> void executeTaskWithRetry(Callable<T> task, int maxAttempts, long initialDelay, CompletableFuture<T> future, ScheduledExecutorService scheduler, int attempt, List<Exception> exceptions) {if (attempt >= maxAttempts) {RuntimeException exception = new RuntimeException("任務失敗，已達最大重試次數: " + maxAttempts);exceptions.forEach(exception::addSuppressed);future.completeExceptionally(exception);scheduler.shutdown();logger.error("任務失敗，已達最大重試次數: {}", maxAttempts, exception); // 添加這行來打印錯誤信息return;}CompletableFuture<T> attemptFuture = CompletableFuture.supplyAsync(() -> {try {return task.call();} catch (Exception e) {throw new CompletionException(e);}});attemptFuture.whenComplete((result, throwable) -> {if (throwable == null) {future.complete(result);scheduler.shutdown();} else {// 指數退避策略來計算重試間隔 延遲時間是初始延遲initialDelay乘以2的attempt次方long delay = (long) (initialDelay * Math.pow(2, attempt));logger.info("任務失敗，將在 {} 毫秒后重試，嘗試第：{} 次", delay, attempt + 1);exceptions.add((Exception) throwable.getCause());scheduler.schedule(() -> executeTaskWithRetry(task, maxAttempts, initialDelay, future, scheduler, attempt + 1, exceptions), delay, TimeUnit.MILLISECONDS);}});}/*** 啟動一個無返回的異步任務** @param task 待執行的任務*/@Asyncpublic void executeAsyncRunnableTask(Runnable task) {task.run();}
}

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執行測試：

@RestController
public class AsyncController {@Resourceprivate AsyncTaskService genericAsyncService;@GetMapping("/startAsyncTask")@ApiOperation("執行異步任務")public String startAsyncTask() {genericAsyncService.executeAsyncTaskWithRetry(() -> {System.out.println("執行異步任務: " + Thread.currentThread().getName());Thread.sleep(5000); // 模擬長時間運行的任務System.out.println("異步任務完成: " + Thread.currentThread().getName());return "任務結果";});return "異步任務已啟動";}@GetMapping("/startAsyncRunnableTask")@ApiOperation("不需要返回值的操作的任務")public String startAsyncRunnableTask() {genericAsyncService.executeAsyncRunnableTask(() -> {System.out.println("執行異步Runnable任務: " + Thread.currentThread().getName());// 執行一些不需要返回值的操作// 例如，發送電子郵件、更新數據庫、日志記錄等System.out.println("異步Runnable任務完成: " + Thread.currentThread().getName());});return "異步Runnable任務已啟動";}private static final Random RANDOM = new Random();@GetMapping("/executeTask")@ApiOperation("執行異步任務[重試]")public ResponseEntity<CompletableFuture<String>> executeTask() {// 創建一個Callable任務Callable<String> myTask = () -> {// 隨機生成一個0到9之間的數字int randomNumber = RANDOM.nextInt(10);System.out.println("我是任務 ====== 隨機數" + randomNumber);// 如果隨機數小于5，則拋出異常，模擬任務失敗if (randomNumber < 5) {System.out.println("隨機數: " + randomNumber + "，任務將失敗。");throw new Exception("隨機失敗");}return "Task executed successfully";};// 調用executeAsyncTaskWithRetry方法CompletableFuture<String> resultFuture = genericAsyncService.executeAsyncTaskWithRetry(myTask);// 返回CompletableFuture作為響應return new ResponseEntity<>(resultFuture, HttpStatus.OK);}}

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