我在下面有一个 DAO,每个实体和批处理都有一个事务删除。一次删除一个实体就可以了。
批量删除没有任何效果:下面的代码是简单明了的 IMO,但是对deleteMyObjects(Long[] ids)的调用——它调用了Objectify的delete(Iterable keysOrEntities) ——没有效果!
public class MyObjectDao {
private ObjectifyOpts transactional = new ObjectifyOpts().setBeginTransaction(true);
private ObjectifyOpts nonTransactional = new ObjectifyOpts().setBeginTransaction(false);
private String namespace = null;
public MyObjectDao(String namespace) {
Preconditions.checkNotNull(namespace, "Namespace cannot be NULL");
this.namespace = namespace;
}
/**
* set namespace and get a non-transactional instance of Objectify
*
* @return
*/
protected Objectify nontxn() {
NamespaceManager.set(namespace);
return ObjectifyService.factory().begin(nonTransactional);
}
/**
* set namespace and get a transactional instance of Objectify
*
* @return
*/
protected Objectify txn() {
NamespaceManager.set(namespace);
Objectify txn = ObjectifyService.factory().begin(transactional);
log.log(Level.FINE, "transaction <" + txn.getTxn().getId() + "> started");
return txn;
}
protected void commit(Objectify txn) {
if (txn != null && txn.getTxn().isActive()) {
txn.getTxn().commit();
log.log(Level.FINE, "transaction <" + txn.getTxn().getId() + "> committed");
} else {
log.log(Level.WARNING, "commit NULL transaction");
}
}
protected void rollbackIfNeeded(Objectify txn) {
if (txn != null && txn.getTxn() != null && txn.getTxn().isActive()) {
log.log(Level.WARNING, "transaction <" + txn.getTxn().getId() + "> rolling back");
txn.getTxn().rollback();
} else if (txn == null || txn.getTxn() == null) {
log.log(Level.WARNING, "finalizing NULL transaction, not rolling back");
} else if (!txn.getTxn().isActive()) {
log.log(Level.FINEST, "transaction <" + txn.getTxn().getId() + "> NOT rolling back");
}
}
public void deleteMyObject(Long id) {
Objectify txn = null;
try {
txn = txn();
txn.delete(new Key<MyObject>(MyObject.class, id));
commit(txn);
} finally {
rollbackIfNeeded(txn);
}
}
public void deleteMyObjects(Long[] ids) {
Objectify txn = null;
List<Key<? extends MyObject>> keys = new ArrayList<Key<? extends MyObject>>();
for (long id : ids) {
keys.add(new Key<MyObject>(MyObject.class, id));
}
try {
txn = txn();
txn.delete(keys);
commit(txn);
} finally {
rollbackIfNeeded(txn);
}
}
}
当我调用 deleteMyObjects(Long[] ) 时,我在下面的日志中看不到任何可疑之处。事务提交得很好,没有错误。但数据不受影响。循环遍历相同的 Id 列表并一次删除一个对象,效果很好。
Feb 29, 2012 8:37:42 AM com.test.MyObjectDao txn
FINE: transaction <6> started
Feb 29, 2012 8:37:42 AM com.test.MyObjectDao commit
FINE: transaction <6> committed
Feb 29, 2012 8:37:42 AM com.test.MyObjectDao rollbackIfNeeded
FINEST: transaction <6> NOT rolling back
但是数据没有改变并存在于数据存储中!?!?!
欢迎任何帮助。
更新
进入 Objectify 代码,我想知道这是否与命名空间有关?在 objectify 代码中:
@Override
public Result<Void> delete(Iterable<?> keysOrEntities)
{
// We have to be careful here, objs could contain raw Keys or Keys or entity objects or both!
List<com.google.appengine.api.datastore.Key> keys = new ArrayList<com.google.appengine.api.datastore.Key>();
for (Object obj: keysOrEntities)
keys.add(this.factory.getRawKey(obj));
return new ResultAdapter<Void>(this.ads.delete(this.txn, keys));
}
当我在调试中检查this.factory.getRawKey(obj)时,我注意到键的命名空间是空的。但是NamespaceManager.get()返回正确的命名空间!?