com.google.appengine.api.datastore.Transaction Java Examples

protected static void deleteTempDataInTx(DatastoreService ds, Entity entity, Class<? extends TempData> type) {
    Transaction txn = ds.beginTransaction(TransactionOptions.Builder.withXG(true));
    try {
        TempData data = type.newInstance();
        data.fromProperties(entity.getProperties());
        data.preDelete(ds);
        ds.delete(txn, entity.getKey());
        data.postDelete(ds);
        txn.commit();
    } catch (Exception e) {
        throw new IllegalStateException(e);
    } finally {
        if (txn.isActive()) {
            txn.rollback();
        }
    }
}
 

@Test
public void testAncestorIsMandatoryInQueriesInsideTransaction() {
    Transaction tx = service.beginTransaction();
    try {

        service.prepare(new Query("test"));         // no tx, ancestor not necessary
        service.prepare(null, new Query("test"));   // no tx, ancestor not necessary
        service.prepare(tx, new Query("test").setAncestor(KeyFactory.createKey("some_kind", "some_id"))); // tx + ancestor

        try {
            service.prepare(tx, new Query("test")); // tx, but no ancestor
            fail("Expected IllegalArgumentException");
        } catch (IllegalArgumentException e) {
            // pass
        }
    } finally {
        tx.rollback();
    }
}
 

protected void deleteSessionWithValue(String varName, String varValue) {
  Transaction transaction = datastore.beginTransaction();
  try {
    Query query = new Query(SESSION_KIND)
        .setFilter(new FilterPredicate(varName, FilterOperator.EQUAL, varValue));
    Iterator<Entity> results = datastore.prepare(transaction, query).asIterator();
    while (results.hasNext()) {
      Entity stateEntity = results.next();
      datastore.delete(transaction, stateEntity.getKey());
    }
    transaction.commit();
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

/**
 * Delete a value stored in the project's datastore.
 * @param sessionId Request from which the session is extracted.
 */
protected void deleteSessionVariables(String sessionId, String... varNames) {
  if (sessionId.equals("")) {
    return;
  }
  Key key = KeyFactory.createKey(SESSION_KIND, sessionId);
  Transaction transaction = datastore.beginTransaction();
  try {
    Entity stateEntity = datastore.get(transaction, key);
    for (String varName : varNames) {
      stateEntity.removeProperty(varName);
    }
    datastore.put(transaction, stateEntity);
    transaction.commit();
  } catch (EntityNotFoundException e) {
    // Ignore - if there's no session, there's nothing to delete.
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

/**
 * Delete a value stored in the project's datastore.
 * @param sessionId Request from which the session is extracted.
 */
protected void deleteSessionVariables(String sessionId, String... varNames) {
  if (sessionId.equals("")) {
    return;
  }
  Key key = KeyFactory.createKey(SESSION_KIND, sessionId);
  Transaction transaction = datastore.beginTransaction();
  try {
    Entity stateEntity = datastore.get(transaction, key);
    for (String varName : varNames) {
      stateEntity.removeProperty(varName);
    }
    datastore.put(transaction, stateEntity);
    transaction.commit();
  } catch (EntityNotFoundException e) {
    // Ignore - if there's no session, there's nothing to delete.
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

protected void deleteSessionWithValue(String varName, String varValue) {
  Transaction transaction = datastore.beginTransaction();
  try {
    Query query = new Query(SESSION_KIND)
        .setFilter(new FilterPredicate(varName, FilterOperator.EQUAL, varValue));
    Iterator<Entity> results = datastore.prepare(transaction, query).asIterator();
    while (results.hasNext()) {
      Entity stateEntity = results.next();
      datastore.delete(transaction, stateEntity.getKey());
    }
    transaction.commit();
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

@Override
public T deleteEntity(T demoEntity) {
  Utils.assertTrue(demoEntity != null, "entity cannot be null");
  DemoEntityNoSql entityNoSql = downCastEntity(demoEntity);
  DatastoreService ds = getDatastoreService();
  Transaction txn = ds.beginTransaction();
  try {
    if (checkEntityForDelete(ds, entityNoSql)) {
      ds.delete(entityNoSql.getEntity().getKey());
      txn.commit();
      logger.info("entity deleted.");
      return demoEntity;
    }
  } catch (Exception e) {
    logger.severe("Failed to delete entity from datastore:" + e.getMessage());
  } finally {
    if (txn.isActive()) {
      txn.rollback();
    }
  }
  return null;
}
 

@Test
public void testGetWithDifferentAncestorsInsideSameTransactionAreNotAllowed() {
    service.put(new Entity("foo", "1"));
    service.put(new Entity("foo", "2"));

    Transaction tx = service.beginTransaction();
    try {
        service.get(Arrays.asList(KeyFactory.createKey("foo", "1")));

        try {
            service.get(Arrays.asList(KeyFactory.createKey("foo", "2")));
            fail("Expected IllegalArgumentException");
        } catch (IllegalArgumentException e) {
            // pass
        }
    } finally {
        tx.rollback();
    }
}
 

@Test
public void testMiscOps() throws Exception {
    AsyncDatastoreService service = DatastoreServiceFactory.getAsyncDatastoreService();

    DatastoreAttributes attributes = waitOnFuture(service.getDatastoreAttributes());
    Assert.assertNotNull(attributes);
    Assert.assertNotNull(attributes.getDatastoreType());

    Map<Index, Index.IndexState> indexes = waitOnFuture(service.getIndexes());
    Assert.assertNotNull(indexes);

    Transaction tx = waitOnFuture(service.beginTransaction());
    try {
        String txId = tx.getId();
        Assert.assertNotNull(txId);
        Assert.assertEquals(txId, tx.getId());

        String appId = tx.getApp();
        Assert.assertNotNull(appId);
        Assert.assertEquals(appId, tx.getApp());
    } finally {
        tx.rollback();
    }
}
 

@Test
public void testQueriesWithDifferentAncestorsInsideSameTransactionNoUsage() {
    Transaction tx = service.beginTransaction();
    try {
        Key a1 = KeyFactory.createKey("ancestor", "1");
        prepareQueryWithAncestor(tx, a1).asIterator();

        Key a2 = KeyFactory.createKey("ancestor", "2");
        prepareQueryWithAncestor(tx, a2).asList(FetchOptions.Builder.withDefaults());

        Key a3 = KeyFactory.createKey("ancestor", "3");
        prepareQueryWithAncestor(tx, a3).asIterable();

        Key a4 = KeyFactory.createKey("ancestor", "4");
        prepareQueryWithAncestor(tx, a4).asQueryResultIterable();

        Key a5 = KeyFactory.createKey("ancestor", "5");
        prepareQueryWithAncestor(tx, a5).asQueryResultIterator();

        Key a6 = KeyFactory.createKey("ancestor", "6");
        prepareQueryWithAncestor(tx, a6).asQueryResultList(FetchOptions.Builder.withDefaults());
    } finally {
        tx.rollback();
    }
}
 

@Test
public void testMultipleEntityGroupsInSingleTransactionAreNotAllowed() {
    Transaction tx = service.beginTransaction();
    try {
        Entity person = new Entity("Person", "tom");
        service.put(person);

        try {
            Entity photoNotAChild = new Entity("Photo");
            photoNotAChild.setProperty("photoUrl", "http://domain.com/path/to/photo.jpg");
            service.put(photoNotAChild);
            fail("put should have thrown IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // pass
        }
    } finally {
        tx.rollback();
    }
}
 

protected void deleteSessionWithValue(String varName, String varValue) {
  Transaction transaction = datastore.beginTransaction();
  try {
    Query query = new Query(SESSION_KIND)
        .setFilter(new FilterPredicate(varName, FilterOperator.EQUAL, varValue));
    Iterator<Entity> results = datastore.prepare(transaction, query).asIterator();
    while (results.hasNext()) {
      Entity stateEntity = results.next();
      datastore.delete(transaction, stateEntity.getKey());
    }
    transaction.commit();
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

public static Key putTempData(TempData data) {
    DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
    Transaction txn = ds.beginTransaction(TransactionOptions.Builder.withXG(true));
    try {
        Class<? extends TempData> type = data.getClass();
        String kind = getKind(type);
        Entity entity = new Entity(kind);
        for (Map.Entry<String, Object> entry : data.toProperties(ds).entrySet()) {
            entity.setProperty(entry.getKey(), entry.getValue());
        }
        entity.setProperty(TEMP_DATA_READ_PROPERTY, false);
        data.prePut(ds);
        Key key = ds.put(txn, entity);
        data.postPut(ds);
        txn.commit();
        return key;
    } catch (Exception e) {
        throw new IllegalStateException(e);
    } finally {
        if (txn.isActive()) {
            txn.rollback();
        }
    }
}
 

/**
 * Delete a value stored in the project's datastore.
 * @param sessionId Request from which the session is extracted.
 */
protected void deleteSessionVariables(String sessionId, String... varNames) {
  if (sessionId.equals("")) {
    return;
  }
  Key key = KeyFactory.createKey(SESSION_KIND, sessionId);
  Transaction transaction = datastore.beginTransaction();
  try {
    Entity stateEntity = datastore.get(transaction, key);
    for (String varName : varNames) {
      stateEntity.removeProperty(varName);
    }
    datastore.put(transaction, stateEntity);
    transaction.commit();
  } catch (EntityNotFoundException e) {
    // Ignore - if there's no session, there's nothing to delete.
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

protected void deleteSessionWithValue(String varName, String varValue) {
  Transaction transaction = datastore.beginTransaction();
  try {
    Query query = new Query(SESSION_KIND)
        .setFilter(new FilterPredicate(varName, FilterOperator.EQUAL, varValue));
    Iterator<Entity> results = datastore.prepare(transaction, query).asIterator();
    while (results.hasNext()) {
      Entity stateEntity = results.next();
      datastore.delete(transaction, stateEntity.getKey());
    }
    transaction.commit();
  } finally {
    if (transaction.isActive()) {
      transaction.rollback();
    }
  }
}
 

private void assertRollbackSucceedsWhenResultFetchedWith(ResultFetcher resultFetcher) throws EntityNotFoundException {
    String methodName = "assertRollbackSucceedsWhenResultFetchedWith";
    Entity entity = createTestEntityWithUniqueMethodNameKey(TRANSACTION_TEST_ENTITY, methodName);
    Key parentKey = entity.getKey();
    entity.setProperty("name", "original");
    Key key = service.put(entity);
    try {
        Transaction tx = service.beginTransaction();
        PreparedQuery preparedQuery = service.prepare(new Query(TRANSACTION_TEST_ENTITY).setAncestor(parentKey));
        Entity entity2 = resultFetcher.fetchResult(preparedQuery);
        entity2.setProperty("name", "modified");
        service.put(tx, entity2);
        tx.rollback();

        Entity entity3 = service.get(key);
        assertEquals("original", entity3.getProperty("name"));
    } finally {
        service.delete(entity.getKey());
    }
}
 

@Test
public void creatingAnEntityInASpecificEntityGroup() throws Exception {
  String boardName = "my-message-board";

  // [START creating_an_entity_in_a_specific_entity_group]
  DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();

  String messageTitle = "Some Title";
  String messageText = "Some message.";
  Date postDate = new Date();

  Key messageBoardKey = KeyFactory.createKey("MessageBoard", boardName);

  Entity message = new Entity("Message", messageBoardKey);
  message.setProperty("message_title", messageTitle);
  message.setProperty("message_text", messageText);
  message.setProperty("post_date", postDate);

  Transaction txn = datastore.beginTransaction();
  datastore.put(txn, message);

  txn.commit();
  // [END creating_an_entity_in_a_specific_entity_group]
}
 

@Test
public void crossGroupTransactions() throws Exception {
  // [START cross-group_XG_transactions_using_the_Java_low-level_API]
  DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
  TransactionOptions options = TransactionOptions.Builder.withXG(true);
  Transaction txn = datastore.beginTransaction(options);

  Entity a = new Entity("A");
  a.setProperty("a", 22);
  datastore.put(txn, a);

  Entity b = new Entity("B");
  b.setProperty("b", 11);
  datastore.put(txn, b);

  txn.commit();
  // [END cross-group_XG_transactions_using_the_Java_low-level_API]
}
 

@Override
public Photo deactivePhoto(String userId, long id) {
  Utils.assertTrue(userId != null, "user id cannot be null");
  DatastoreService ds = getDatastoreService();
  Transaction txn = ds.beginTransaction();
  try {
    Entity entity = getDatastoreEntity(ds, createPhotoKey(userId, id));
    if (entity != null) {
      PhotoNoSql photo = new PhotoNoSql(entity);
      if (photo.isActive()) {
        photo.setActive(false);
        ds.put(entity);
      }
      txn.commit();

      return photo;
    }
  } catch (Exception e) {
    logger.severe("Failed to delete entity from datastore:" + e.getMessage());
  } finally {
    if (txn.isActive()) {
      txn.rollback();
    }
  }
  return null;
}
 

@ApiMethod(name = "storeTask")
public void storeTask(TaskBean taskBean) {
    DatastoreService datastoreService = DatastoreServiceFactory.getDatastoreService();
    Transaction txn = datastoreService.beginTransaction();
    try {
        Key taskBeanParentKey = KeyFactory.createKey("TaskBeanParent", "todo.txt");
        Entity taskEntity = new Entity("TaskBean", taskBean.getId(), taskBeanParentKey);
        taskEntity.setProperty("data", taskBean.getData());
        datastoreService.put(taskEntity);
        txn.commit();
    } finally {
        if (txn.isActive()) {
            txn.rollback();
        }
    }
}
 

@ApiMethod(name = "clearTasks")
public void clearTasks() {
    DatastoreService datastoreService = DatastoreServiceFactory.getDatastoreService();
    Transaction txn = datastoreService.beginTransaction();
    try {
        Key taskBeanParentKey = KeyFactory.createKey("TaskBeanParent", "todo.txt");
        Query query = new Query(taskBeanParentKey);
        List<Entity> results = datastoreService.prepare(query).asList(FetchOptions.Builder.withDefaults());
        for (Entity result : results) {
            datastoreService.delete(result.getKey());
        }
        txn.commit();
    } finally {
        if (txn.isActive()) {
            txn.rollback();
        }
    }
}
 

@Test
public void testCommitTx() throws Exception {
    AsyncDatastoreService service = DatastoreServiceFactory.getAsyncDatastoreService();
    Transaction tx = waitOnFuture(service.beginTransaction(TransactionOptions.Builder.withDefaults()));
    Key key;
    try {
        Future<Key> fKey = service.put(tx, new Entity("AsyncTx"));
        key = waitOnFuture(fKey);
        waitOnFuture(tx.commitAsync());
    } catch (Exception e) {
        waitOnFuture(tx.rollbackAsync());
        throw e;
    }

    if (key != null) {
        Assert.assertNotNull(getSingleEntity(service, key));
    }
}
 

@Test
public void testRollbackTx() throws Exception {
    AsyncDatastoreService service = DatastoreServiceFactory.getAsyncDatastoreService();
    Transaction tx = waitOnFuture(service.beginTransaction(TransactionOptions.Builder.withDefaults()));
    Key key = null;
    try {
        Future<Key> fKey = service.put(tx, new Entity("AsyncTx"));
        key = waitOnFuture(fKey);
    } finally {
        waitOnFuture(tx.rollbackAsync());
    }

    if (key != null) {
        Assert.assertNull(getSingleEntity(service, key));
    }
}
 

@Override
public void run(
    DatastoreService ds, Supplier<Key> keySupplier, Supplier<Entity> entitySupplier) {
  // Put a fresh entity.
  Entity originalEntity = new Entity(getFreshKindName());
  originalEntity.setProperty("prop1", 75L);
  ds.put(originalEntity);
  Key key = originalEntity.getKey();

  // Prepare a new version of it with a different property value.
  Entity mutatedEntity = new Entity(key);
  mutatedEntity.setProperty("prop1", 76L);

  // Test Get/Put within a transaction.
  Transaction txn = ds.beginTransaction();
  assertGetEquals(ds, key, originalEntity);
  ds.put(mutatedEntity); // Write the mutated Entity.
  assertGetEquals(ds, key, originalEntity); // Within a txn, the put is not yet reflected.
  txn.commit();

  // Now that the txn is committed, the mutated entity will show up in Get.
  assertGetEquals(ds, key, mutatedEntity);
}
 

@Test
public void testSingleDefault() throws EntityNotFoundException, InterruptedException {
    clearData(kindName);
    Transaction tx = service.beginTransaction();
    Entity newRec = new Entity(kindName);
    newRec.setProperty("check", "4100331");
    newRec.setProperty("step", "added");
    Key key = service.put(tx, newRec);
    tx.commit();
    Entity qRec = service.get(key);
    assertEquals("4100331", qRec.getProperty("check"));

    tx = service.beginTransaction();
    qRec = service.get(key);
    qRec.setUnindexedProperty("step", "update");
    service.put(tx, newRec);
    tx.rollback();
    qRec = service.get(key);
    assertEquals("added", qRec.getProperty("step"));
}
 

void handleAbandonedTxns(Collection<Transaction> txns) {
  // TODO(user): In the dev appserver, capture a stack trace whenever a
  // transaction is started so we can print it here.
  for (Transaction txn : txns) {
    try {
      logger.warning("Request completed without committing or rolling back transaction with id "
          + txn.getId() + ".  Transaction will be rolled back.");
      txn.rollback();
    } catch (Exception e) {
      // We swallow exceptions so that there is no risk of our cleanup
      // impacting the actual result of the request.
      logger.log(Level.SEVERE, "Swallowing an exception we received while trying to rollback "
          + "abandoned transaction with id " + txn.getId(), e);
    }
  }
}
 

@Override
public boolean deleteObject(GcsFilename filename, long timeoutMillis) throws IOException {
  ensureInitialized();
  Transaction tx = datastore.beginTransaction();
  Key key = makeKey(filename);
  try {
    datastore.get(tx, key);
    datastore.delete(tx, key);
    blobstoreService.delete(getBlobKeyForFilename(filename));
  } catch (EntityNotFoundException ex) {
    return false;
  } finally {
    if (tx.isActive()) {
      tx.commit();
    }
  }

  return true;
}
 

protected <T> T inTx(Action<T> action) throws Exception {
    AsyncDatastoreService ads = DatastoreServiceFactory.getAsyncDatastoreService();
    Transaction tx = ads.beginTransaction().get();
    boolean ok = false;
    try {
        T result = action.run(ads);
        ok = true;
        return result;
    } finally {
        if (ok)
            tx.commitAsync();
        else
            tx.rollbackAsync();

        sync(); // wait for tx to finish
    }
}
 

@Test(expected = IllegalStateException.class)
public void testClosedTx() throws InterruptedException {
    clearData(kindName);
    Transaction tx = service.beginTransaction();
    Entity newRec = new Entity(kindName);
    newRec.setProperty("check", "4100331");
    newRec.setProperty("stamp", new Date());
    service.put(newRec);
    tx.commit();
    service.put(tx, new Entity(kindName));
}
 

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    throws IOException, ServletException {
  try {
    chain.doFilter(request, response);
  } finally {
    Collection<Transaction> txns = datastoreService.getActiveTransactions();
    if (!txns.isEmpty()) {
      handleAbandonedTxns(txns);
    }
  }
}