App Engine雲端點單元測試，數據核問題，有可能嗎？

Question

我們已經使用Google App Engine Cloud Endpoints構建了一個基本的RESTful API，並且我們正在尋找單元測試我們編寫的一些代碼，以檢查插入和更新是否符合我們所期望的一切。

我查看了Google提供的Local Unit Testing documentation，並實現了它所建議的所有內容，但在調用EntityManager.close()時仍然崩潰。我添加了4個.jar文件，並在我的測試文件中使用LocalServiceTestHelper。

我希望有人能夠解決這個問題，我假設我所需要做的就是改變persistance.xml中的一個值，以允許DataNucleus在本地單元測試中運行，或者可能是.jar我失蹤的文件？

我希望有人能幫忙，Google App Engine的衆多用戶之一！我可以提供代碼，但所有我真正要做的是EntityManager.persist(Obj); ... EntityManager.close();

相關問題的控制檯輸出爲：

Jan 17, 2014 12:08:04 PM org.datanucleus.transaction.Transaction rollback

SEVERE: Operation rollback failed on resource: com.google.appengine.datanucleus.DatastoreXAResource@556afa8, error code UNKNOWN and transaction: [DataNucleus Transaction, ID=Xid=, enlisted resources=[com.google.appengine.datanucleus.DatastoreXAResource@556afa8]]

指向DataNucleus將問題。堆棧跟蹤

javax.persistence.PersistenceException: Illegal argument at org.datanucleus.api.jpa.NucleusJPAHelper.getJPAExceptionForNucleusException(NucleusJPAHelper.java:298) at org.datanucleus.api.jpa.JPAEntityManager.close(JPAEntityManager.java:197) at com.multipie.snapture.HashtagEndpoint.insertHashtag(HashtagEndpoint.java:124) at com.multipie.snapture.tests.HashtagTest.testInsertHashtag(HashtagTest.java:30) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at junit.framework.TestCase.runTest(TestCase.java:176) at junit.framework.TestCase.runBare(TestCase.java:141) at junit.framework.TestResult$1.protect(TestResult.java:122) at junit.framework.TestResult.runProtected(TestResult.java:142) at junit.framework.TestResult.run(TestResult.java:125) at junit.framework.TestCase.run(TestCase.java:129) at junit.framework.TestSuite.runTest(TestSuite.java:255) at junit.framework.TestSuite.run(TestSuite.java:250) at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:84) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Caused by: java.lang.IllegalArgumentException: transactions on multiple entity groups only allowed in High Replication applications at com.google.appengine.api.datastore.DatastoreApiHelper.translateError(DatastoreApiHelper.java:39) at com.google.appengine.api.datastore.DatastoreApiHelper$1.convertException(DatastoreApiHelper.java:76) at com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:94) at com.google.appengine.api.datastore.FutureHelper.getInternal(FutureHelper.java:71) at com.google.appengine.api.datastore.FutureHelper.quietGet(FutureHelper.java:32) at com.google.appengine.api.datastore.TransactionImpl.getHandle(TransactionImpl.java:97) at com.google.appengine.api.datastore.TransactionImpl.getId(TransactionImpl.java:190) at com.google.appengine.api.datastore.BaseDatastoreServiceImpl.localTxnToRemoteTxn(BaseDatastoreServiceImpl.java:130) at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.doBatchPut(AsyncDatastoreServiceImpl.java:532) at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.put(AsyncDatastoreServiceImpl.java:490) at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.put(AsyncDatastoreServiceImpl.java:444) at com.google.appengine.api.datastore.DatastoreServiceImpl.put(DatastoreServiceImpl.java:86) at com.google.appengine.datanucleus.WrappedDatastoreService.put(WrappedDatastoreService.java:112) at com.google.appengine.datanucleus.EntityUtils.putEntitiesIntoDatastore(EntityUtils.java:766) at com.google.appengine.datanucleus.DatastorePersistenceHandler.insertObjectsInternal(DatastorePersistenceHandler.java:314) at com.google.appengine.datanucleus.DatastorePersistenceHandler.insertObject(DatastorePersistenceHandler.java:218) at org.datanucleus.state.JDOStateManager.internalMakePersistent(JDOStateManager.java:2381) at org.datanucleus.state.JDOStateManager.flush(JDOStateManager.java:3778) at org.datanucleus.ObjectManagerImpl.flushInternalWithOrdering(ObjectManagerImpl.java:3888) at org.datanucleus.ObjectManagerImpl.flushInternal(ObjectManagerImpl.java:3811) at org.datanucleus.ObjectManagerImpl.flush(ObjectManagerImpl.java:3751) at org.datanucleus.ObjectManagerImpl.preCommit(ObjectManagerImpl.java:4141) at org.datanucleus.ObjectManagerImpl.transactionPreCommit(ObjectManagerImpl.java:428) at org.datanucleus.TransactionImpl.internalPreCommit(TransactionImpl.java:398) at org.datanucleus.TransactionImpl.commit(TransactionImpl.java:287) at org.datanucleus.ObjectManagerImpl.close(ObjectManagerImpl.java:1090) at org.datanucleus.api.jpa.JPAEntityManager.close(JPAEntityManager.java:193) ... 21 more

Answer 1

好，碰到一個谷歌代碼項目，它幫了我 - datanucleus-appengine-test。

設置LocalServiceTestHelper時，需要在LocalDatastoreServiceTestConfig上設置一些特殊參數。代碼如下：

 // Create High-Replication-Datastore simulation 
     LocalDatastoreServiceTestConfig config = new LocalDatastoreServiceTestConfig(); 
     config.setDefaultHighRepJobPolicyUnappliedJobPercentage(1); // Can't be <1 and still have 
                    // multi-XG txns 
     config.setStoreDelayMs(0); 
     helper = new LocalServiceTestHelper(config); 
     helper.setUp(); 

Answer 2

在this answer，有1％的機會，一個數據存儲操作將是最終一致，可能會導致測試失敗。如果它設置爲0％，則LocalService將引發異常。有一個更好的解決方案。

該配置允許您設置自定義高複製策略。您可以通過設置一個策略來解決這個問題，這樣您的寫入將始終適用。

static final class ConsistentHighRepPolicy implements HighRepJobPolicy { 
    @Override 
    public boolean shouldRollForwardExistingJob(Key key) { 
     return true; 
    } 

    @Override 
    public boolean shouldApplyNewJob(Key key) { 
     return true; 
    } 
} 


Config config = new LocalDatastoreServiceTestConfig() 
         .setAlternateHighRepJobPolicyClass(ConsistentHighRepPolicy.class);