@SpringBootApplication
@EnableAsync
public class ShopApplication {
    public static void main(String[] args) {
        SpringApplication.run(ShopApplication.class, args);
    }
}

@Service
public class OrderNotifyService {
    // 異步發(fā)送短信通知，不阻塞訂單創(chuàng)建流程
    @Async
    public void sendSms(String phone, String orderNo) {
        // 模擬API調(diào)用耗時(shí)
        try {
            Thread.sleep(1500);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
        System.out.println("短信發(fā)送成功：" + phone + "，訂單號(hào)：" + orderNo);
    }
}

@Service
public class ProductService {
    // 異步獲取商品基本信息
    public CompletableFuture<Product> getProductInfo(Long productId) {
        return CompletableFuture.supplyAsync(() -> {
            // 模擬數(shù)據(jù)庫查詢
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
            return new Product(productId, "無線耳機(jī)", 999.0);
        });
    }

    // 異步獲取庫存信息
    public CompletableFuture<Stock> getStockInfo(Long productId) {
        return CompletableFuture.supplyAsync(() -> {
            // 模擬庫存服務(wù)調(diào)用
            try {
                Thread.sleep(800);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
            return new Stock(productId, 100);
        });
    }

    // 合并結(jié)果：總耗時(shí)約1000ms（取最長(zhǎng)任務(wù)時(shí)間）
    public CompletableFuture<ProductDetail> getProductDetail(Long productId) {
        CompletableFuture<Product> productFuture = getProductInfo(productId);
        CompletableFuture<Stock> stockFuture = getStockInfo(productId);
        
        return productFuture.thenCombine(stockFuture, (product, stock) -> {
            ProductDetail detail = new ProductDetail();
            detail.setProduct(product);
            detail.setStock(stock);
            return detail;
        }).exceptionally(ex -> {
            // 統(tǒng)一異常處理
            log.error("獲取商品詳情失敗", ex);
            return new ProductDetail();
        });
    }
}

@PostMapping("/upload")
public Callable<String> uploadFile(@RequestParam MultipartFile file) {
    return () -> {
        // 異步處理文件上傳
        fileService.process(file);
        return "上傳成功";
    };
}

@PostMapping("/refund")
public WebAsyncTask<String> processRefund(@RequestBody RefundRequest request) {
    Callable<String> task = () -> refundService.handle(request);
    
    // 設(shè)置3秒超時(shí)，超時(shí)/異常/完成時(shí)觸發(fā)回調(diào)
    WebAsyncTask<String> asyncTask = new WebAsyncTask<>(3000, task);
    asyncTask.onTimeout(() -> "退款處理超時(shí)，請(qǐng)稍后重試");
    asyncTask.onError(ex -> "處理失敗：" + ex.getMessage());
    asyncTask.onCompletion(() -> log.info("退款任務(wù)結(jié)束"));
    
    return asyncTask;
}

<!-- Maven依賴 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-cache</artifactId>
</dependency>

@Service
public class UserQueryService {
    // 將結(jié)果緩存至"userCache"，鍵為方法參數(shù)id
    @Cacheable(value = "userCache", key = "#id")
    public UserDTO getUserById(Long id) {
        // 首次調(diào)用執(zhí)行，后續(xù)從緩存獲取
        return userMapper.selectById(id); // 模擬DB查詢，耗時(shí)約500ms
    }

    // 更新用戶信息后清除緩存
    @CacheEvict(value = "userCache", key = "#user.id")
    public void updateUser(User user) {
        userMapper.updateById(user);
    }

    // 批量清除緩存
    @CacheEvict(value = "userCache", allEntries = true)
    public void clearUserCache() {
        // 無需業(yè)務(wù)邏輯，僅觸發(fā)緩存清除
    }
}

java -jar app.jar -Xms4g -Xmx4g -XX:+UseG1GC -XX:MaxGCPauseMillis=100 -XX:G1HeapRegionSize=16m