在哪里使用 JDO/Google App Engine 设置 TransactionOptions？

Posted 2023-04-18

【中文标题】在哪里使用 JDO/Google App Engine 设置 TransactionOptions？

【英文标题】：Where do I set TransactionOptions with JDO / Google App Engine?

【发布时间】：2013-10-28 03:50:05

【问题描述】：

我在 GAE 中使用 JDO 使用以下方法批量持久化对象：

public void makePersistent(PersistenceManager pm,
        List<Regeling> makePersistent)         
    Transaction tx = pm.currentTransaction(); 
    try 
        // Start the transaction
        tx.begin();
        // Persist to the datastore
        // pm.makePersistentAll(makePersistent);
        for (int i = 0; i < makePersistent.size(); i += BATCH_SIZE) 
            int last = i + BATCH_SIZE;
            last = last > makePersistent.size() ? makePersistent.size()
                    : last;
            pm.makePersistentAll(makePersistent.subList(i, last));
            pm.flush();
            System.out.println("Made "+last+" items persistent.");
        
        // Commit the transaction, flushing the object to the datastore
        tx.commit();
     catch (Exception e) 
        e.printStackTrace();
     finally 
        if (tx.isActive()) 
            // Error occurred so rollback the transaction
            System.out.println("Rolling back transaction");
            tx.rollback();
        
        pm.close();
    

这会中断：

javax.jdo.JDOUserException: One or more instances could not be made persistent
    at org.datanucleus.api.jdo.JDOPersistenceManager.makePersistentAll(JDOPersistenceManager.java:791)
    ...
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
NestedThrowablesStackTrace:

java.lang.IllegalArgumentException: cross-group transaction need to be explicitly specified, see TransactionOptions.Builder.withXGfound both

 Element 
  type: "PersistentServiceResultaat$RegelingInfoLijst$Regeling"
  name: "BWBR0001821"

 and 

 Element 
  type: "PersistentServiceResultaat$RegelingInfoLijst$Regeling"
  name: "BWBR0001822"

所以我尝试设置这些选项：

TransactionOptions ops = TransactionOptions.Builder.withXG(true);

但我找不到采用TransactionOptions 对象的方法。我可以在哪里设置这些选项？

【问题讨论】：

想解释一下为什么有人投了反对票？

【参考方案1】：

设置在jdoconfig.xml:

<property name="datanucleus.appengine.datastoreEnableXGTransactions" value="true" />