multithreading - Java : Running transaction in multithreaded environment

Question

我们正在启动一个网站，该网站在短时间内的交易量非常大。它基本上是在给票。该代码是用Java，Spring和Hibernate编写的。我想通过产生多个线程并尝试使用JUnit测试用例来获取票证来模仿高容量。问题在于，在我的DAO类中，代码只是在我开始交易后就消失了。我的意思是在日志文件或类似的文件中没有错误跟踪。让我对我的代码的方式给出一些想法。

DAO代码:

@Repository("customerTicketDAO")
public class CustomerTicketDAO extends BaseDAOImpl {// BaseDAOImpl extends HibernateDaoSupport

public void saveCustomerTicketUsingJDBC(String customerId) {
  try{
      getSession().getTransaction().begin(); //NOTHING HAPPENS AFTER THIS LINE OF CODE
      // A select query
      Query query1 = getSession().createSQLQuery("my query omitted on purpose");
      .
      .
      // An update query
      Query query2 = getSession().createSQLQuery("my query omitted on purpose");
      getSession().getTransaction().commite();
   } catch (Exception e) {
   }
}

可运行的代码:

public class InsertCustomerTicketRunnable implements Runnable {

@Autowired
private CustomerTicketDAO customerTicketDAO;    

 public InsertCustomerTicketRunnable(String customerId) {
    this.customerId = customerId;
}     

 @Override
public void run() {
    if (customerTicketDAO != null) {
        customerTicketDAO.saveCustomerTicketUsingJDBC(customerId); 
    }
}
}

JUnit方法:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"file:src/test/resources/applicationContext-test.xml"})
public class DatabaseTest {
  @Before
public void init() {
    sessionFactory = (SessionFactory)applicationContext.getBean("sessionFactory");
    Session session = SessionFactoryUtils.getSession(sessionFactory, true);
    TransactionSynchronizationManager.bindResource(sessionFactory, new SessionHolder(session));

    customerTicketDAO = (CustomerTicketDAO)applicationContext.getBean("customerTicketDAO");
}

@After
public void end() throws Exception {
    SessionHolder sessionHolder = (SessionHolder) TransactionSynchronizationManager.unbindResource(sessionFactory);
    SessionFactoryUtils.closeSession(session);
  }

  @Test
public void saveCustomerTicketInMultipleThreads () throws Exception  {
    ExecutorService executor = Executors.newFixedThreadPool(NTHREDS);

    for (int i=0; i<1000; i++) {
        executor.submit(new InsertCustomerTicketRunnable(i));
    }

    // This will make the executor accept no new threads
    // and finish all existing threads in the queue
    executor.shutdown();
    // Wait until all threads are finish
    executor.awaitTermination(1, TimeUnit.SECONDS);
}

我看不到将数据插入数据库中。有人可以指出我要去哪里吗？

谢谢
拉吉

Answer 1

SessionFactory是线程安全的，但Session不是线程安全的。所以我的猜测是，您需要在每个线程中调用SessionFactoryUtils.getSession()，以便每个线程都有自己的实例。您当前正在从主线程调用它，因此所有子线程都尝试共享同一实例。