Java ObjectifyService.beginTransaction方法代码示例

import com.googlecode.objectify.ObjectifyService; //导入方法依赖的package包/类
public synchronized Key<TrainNode> addTrainNode(TrainNode tn) {
	String functionName = "addTrainNode()";
	Key<TrainNode> resKey = null;
	Objectify ofy = ObjectifyService.beginTransaction();
	try {
		Query<TrainNode> q = ofy.query(TrainNode.class).filter("uniqueName",  tn.getUniqueName()).ancestor(Dao.getRootEntityTrain());
		List<TrainNode> samestation = q.list();
		if(samestation.size() > 0) {
			if(Utils.distanceBetweenGeoCells(samestation.get(0).getGeoCell(), tn.getGeoCell()) <= 10) {
				tn.setGeoCell(samestation.get(0).getGeoCell());
				Logger.getLogger(location).log(Level.WARNING, functionName + ": joined/moved station " + tn.getUniqueName() + " for " + tn.getLineKey());
			} else {
				Logger.getLogger(location).log(Level.SEVERE, functionName + ": did not move station " + tn.getUniqueName() + " for " + tn.getLineKey() + " because distance is too big: " + Utils.distanceBetweenGeoCells(samestation.get(0).getGeoCell(), tn.getGeoCell()));
			}
		}
		resKey = ofy.put(tn);
		ofy.getTxn().commit();
	} finally {
		if (ofy.getTxn().isActive()) {
	        ofy.getTxn().rollback();
	        removeLine(Dao.getInstance().getLineByKey(tn.getLineKey(), ObjectifyService.begin()), ObjectifyService.begin());
	        Logger.getLogger(location).log(Level.SEVERE, functionName + ": Transaction failed for Line: " + tn.getLineKey());
		}
	}
	return resKey;
}
 

import com.googlecode.objectify.ObjectifyService; //导入方法依赖的package包/类
/**
 * Call job.run() in a transaction and commit the transaction if no exceptions
 * occur. If we get a {@link java.util.ConcurrentModificationException}
 * or {@link com.google.appinventor.server.storage.ObjectifyException}
 * we will retry the job (at most {@code MAX_JOB_RETRIES times}).
 * Any other exception will cause the job to fail immediately.
 * @param job
 * @throws ObjectifyException
 */
@VisibleForTesting
void runJobWithRetries(JobRetryHelper job) throws ObjectifyException {
  int tries = 0;
  while (tries <= MAX_JOB_RETRIES) {
    Objectify datastore = ObjectifyService.beginTransaction();
    try {
      job.run(datastore);
      datastore.getTxn().commit();
      break;
    } catch (ConcurrentModificationException ex) {
      job.onNonFatalError();
      LOG.log(Level.WARNING, "Optimistic concurrency failure", ex);
    } catch (ObjectifyException oe) {
      // maybe this should be a fatal error? I think the only thing
      // that creates this exception (other than this method) is uploadToBlobstore
      job.onNonFatalError();
    } finally {
      if (datastore.getTxn().isActive()) {
        try {
          datastore.getTxn().rollback();
        } catch (RuntimeException e) {
          LOG.log(Level.WARNING, "Transaction rollback failed", e);
        }
      }
    }
    tries++;
  }
  if (tries > MAX_JOB_RETRIES) {
    throw new ObjectifyException("Couldn't commit job after max retries.");
  }
}
 

import com.googlecode.objectify.ObjectifyService; //导入方法依赖的package包/类
public static ShardedCounter getOrCreateCounter(String name, int numShards) {
    ShardedCounter shardedCounter = new ShardedCounter(name);
    Objectify trans = ObjectifyService.beginTransaction();
    int tries = 3;
    while (true) {
        try {
            EntityCounter counter = trans.find(new Key<EntityCounter>(
                    EntityCounter.class, name));
            if (counter == null) {
                // create new counter
                counter = new EntityCounter(name);
                trans.put(counter);
                trans.getTxn().commit();
                shardedCounter.addShards(numShards);
            }

            break;
        } catch (ConcurrentModificationException e) {
            if (tries == 0) {
                throw e;
            }
            --tries;
        } finally {
            if (trans.getTxn().isActive()) {
                trans.getTxn().rollback();
            }
        }
    }
    return shardedCounter;
}
 

import com.googlecode.objectify.ObjectifyService; //导入方法依赖的package包/类
public static ShardedCounter createCounter(String name, int numShards) {
    ShardedCounter shardedCounter = new ShardedCounter(name);
    Objectify trans = ObjectifyService.beginTransaction();
    int tries = 3;
    while (true) {
        try {
            EntityCounter counter = trans.find(new Key<EntityCounter>(
                    EntityCounter.class, name));
            if (counter == null) {
                // create new counter
                counter = new EntityCounter(name);
                trans.put(counter);
                trans.getTxn().commit();
                shardedCounter.addShards(numShards);
            } else {
                throw new IllegalArgumentException("A counter with name " +
                         name + " does already exist!");
            }

            break;
        } catch (ConcurrentModificationException e) {
            if (tries == 0) {
                throw e;
            }
            --tries;
        } finally {
            if (trans.getTxn().isActive()) {
                trans.getTxn().rollback();
            }
        }
    }
    return shardedCounter;
}
 

import com.googlecode.objectify.ObjectifyService; //导入方法依赖的package包/类
public synchronized void updateTrainNode(TrainNode tn) {
	String functionName = "updateTrainNode";
	Objectify ofy = ObjectifyService.beginTransaction();
	try {
		ofy.put(tn);
		ofy.getTxn().commit();
	} finally {
		if (ofy.getTxn().isActive()) {
	        ofy.getTxn().rollback();
	        removeLine(Dao.getInstance().getLineByKey(tn.getLineKey(), ObjectifyService.begin()), ObjectifyService.begin());
	        Logger.getLogger(location).log(Level.SEVERE, functionName + ": Transaction failed for Line: " + tn.getLineKey());
		}
	}
}
 

import com.googlecode.objectify.ObjectifyService; //导入方法依赖的package包/类
public void doUpgrade(String userId) {
  if (!conversionEnabled)     // Unless conversion is enabled...
    return;                   // shouldn't really ever happen but...
  Objectify datastore = ObjectifyService.begin();
  UserData userData = datastore.find(userKey(userId));
  if ((userData.upgradedGCS && useGcs) ||
    (!userData.upgradedGCS && !useGcs))
    return;                   // All done, another task did it!
  List<Long> projectIds = getProjects(userId);
  boolean anyFailed = false;
  for (long projectId : projectIds) {
    for (FileData fd : datastore.query(FileData.class).ancestor(projectKey(projectId))) {
      if (fd.isBlob) {
        if (useGcs) {         // Let's convert by just reading it!
          downloadRawFile(userId, projectId, fd.fileName);
        }
      } else if (isTrue(fd.isGCS)) {
        if (!useGcs) {        // Let's downgrade by just reading it!
          downloadRawFile(userId, projectId, fd.fileName);
        }
      }
    }
  }

  /*
   * If we are running low on time, we may have not moved all files
   * so exit now without marking the user as having been finished
   */
  if (ApiProxy.getCurrentEnvironment().getRemainingMillis() <= 5000)
    return;

  /* If anything failed, also return without marking user */
  if (anyFailed)
    return;

  datastore = ObjectifyService.beginTransaction();
  userData = datastore.find(userKey(userId));
  userData.upgradedGCS = useGcs;
  datastore.put(userData);
  datastore.getTxn().commit();
}