Quarkus中子线程@Transactional注解不生效报错如何解决？

问题根本原因 #

你手动new DataTask()创建的实例不属于Quarkus CDI容器的托管对象，加在run()方法上的@Transactional注解是基于AOP拦截实现的，只有容器托管的Bean调用被注解的方法才会触发事务开启逻辑，自定义实例的注解不会被识别，所以执行persist时没有活跃事务。

解决方案1：将DataTask改为CDI托管Bean（推荐） #

1. 给DataTask类加@Dependent注解，声明为CDI Bean
2. 注入Instance<DataTask>动态获取实例，避免参数传递冲突

修改后的代码示例：

TaskController修改 #

@RequestScoped
@Path("/task/ledger")
public class TaskController {
    // 注入DataTask的实例工厂
    @Inject
    Instance<DataTask> dataTaskInstance;

    ExecutorService threadPool = Executors.newFixedThreadPool(10);

    @Transactional
    @POST
    @Path("/start/{id}")
    public int createLedgerTask(@PathParam("id") String id) {
        LedgerTaskOverview overview = LedgerTaskOverview.findById(id);
        // 从容器获取托管实例，不要自己new
        DataTask task = dataTaskInstance.get();
        // 手动设置参数
        task.init(overview, dnsServer, elasticSearchClient);
        threadPool.execute(task);
        return 0;
    }
}

DataTask修改 #

@Dependent // 声明为CDI托管Bean
public class DataTask implements Runnable {
    private LedgerTaskOverview overview;
    private DNSServer dnsServer;
    private ElasticSearchClient elasticSearchClient;

    // 提供初始化方法设置参数
    public void init(LedgerTaskOverview overview,
                    DNSServer dnsServer,
                    ElasticSearchClient elasticSearchClient) {
        this.overview = overview;
        this.dnsServer = dnsServer;
        this.elasticSearchClient = elasticSearchClient;
    }

    @Transactional
    @Override
    public void run() {
        ManagedContext requestContext = Arc.container().requestContext();
        boolean contextCreated = false;
        if (!requestContext.isActive()) {
            requestContext.activate();
            contextCreated = true;
        }
        try {
            //执行业务逻辑，若提示实体游离可改为 overview.getEntityManager().merge(overview)
            overview.persist();
        } finally {
            // 用完手动销毁请求上下文，避免内存泄漏
            if (contextCreated) {
                requestContext.deactivate();
                requestContext.destroy();
            }
        }
    }
}

解决方案2：使用编程式事务手动控制（无需改Bean托管） #

如果你不想把DataTask改成托管Bean，可以直接在run方法里手动开启/提交事务：

public class DataTask implements Runnable {
    public DataTask(LedgerTaskOverview overview,
                    DNSServer dnsServer,
                    ElasticSearchClient elasticSearchClient) {
        this.overview = overview;
        this.dnsServer = dnsServer;
        this.elasticSearchClient = elasticSearchClient;
    }

    // 不需要@Transactional注解
    @Override
    public void run() {
        ManagedContext requestContext = Arc.container().requestContext();
        boolean contextCreated = false;
        if (!requestContext.isActive()) {
            requestContext.activate();
            contextCreated = true;
        }
        // 手动控制事务
        QuarkusTransaction.begin();
        try {
            // 若提示实体游离可改为 overview.getEntityManager().merge(overview)
            overview.persist();
            QuarkusTransaction.commit();
        } catch (Exception e) {
            QuarkusTransaction.rollback();
            throw new RuntimeException("事务执行失败", e);
        } finally {
            if (contextCreated) {
                requestContext.deactivate();
                requestContext.destroy();
            }
        }
    }
}

内容的提问来源于stack exchange，提问作者庞启荣