CODEWITHSUNDEEP
javagoogle-app-enginegoogle-cloud-datastorejdogoogle-eclipse-plugin
Michele Orsi
Michele Orsi

Reputation: 762

Testing GAE datastore with threads

I would like to test my JDO - DAO with multiple threads in order to verify if the persistence layer is aware of synchronization.

Here is my piece of code in a JUnit test 

for(int i=0;i<10;i++) {
    Runnable runnable = new UserAccountLifeCycle(..);
    Thread thread = new Thread(runnable);
    thread.start();
}

.. where UserAccountLifeCycle is a class that extends another business layer class and implements "Runnable" with this code:

@Override
public void run() {
    CategoryBusiness catBusiness = new CategoryBusiness(..);
    Category cat1 = catBusiness.createEntity(..);
    catBusiness.createEntities(..);
    ContentBusiness conBusiness = new ContentBusiness(..);
    conBusiness.createEntities(..);
}

If I run the test I get:

Exception in thread "Thread-6" java.lang.NullPointerException: No API environment is registered for this thread. at com.google.appengine.api.datastore.DatastoreApiHelper.getCurrentAppId(DatastoreApiHelper.java:86) at com.google.appengine.api.datastore.DatastoreAttributes.(DatastoreAttributes.java:28) at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.getDatastoreAttributes(AsyncDatastoreServiceImpl.java:952) at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.getDatastoreType(AsyncDatastoreServiceImpl.java:944) at com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.get(AsyncDatastoreServiceImpl.java:267) at com.google.appengine.api.datastore.DatastoreServiceImpl$1.runInternal(DatastoreServiceImpl.java:78) at com.google.appengine.api.datastore.DatastoreServiceImpl$1.runInternal(DatastoreServiceImpl.java:75) at com.google.appengine.api.datastore.TransactionRunner.runInTransaction(TransactionRunner.java:31) at com.google.appengine.api.datastore.DatastoreServiceImpl.get(DatastoreServiceImpl.java:75) at com.google.appengine.api.datastore.DatastoreServiceImpl.get(DatastoreServiceImpl.java:62) at org.datanucleus.store.appengine.RuntimeExceptionWrappingDatastoreService.get(RuntimeExceptionWrappingDatastoreService.java:56) at org.datanucleus.store.appengine.DatastorePersistenceHandler.get(DatastorePersistenceHandler.java:100) at org.datanucleus.store.appengine.DatastorePersistenceHandler.get(DatastorePersistenceHandler.java:112) at org.datanucleus.store.appengine.DatastorePersistenceHandler.fetchObject(DatastorePersistenceHandler.java:517) at org.datanucleus.state.JDOStateManagerImpl.validate(JDOStateManagerImpl.java:4263) at org.datanucleus.ObjectManagerImpl.findObject(ObjectManagerImpl.java:2444) at org.datanucleus.jdo.JDOPersistenceManager.getObjectById(JDOPersistenceManager.java:1671) at org.datanucleus.jdo.JDOPersistenceManager.getObjectById(JDOPersistenceManager.java:1767) at org.datanucleus.store.appengine.jdo.DatastoreJDOPersistenceManager.getObjectById(DatastoreJDOPersistenceManager.java:73) at it.icaroproject.main.persistence.dao.GaedatastoreUserAccountDAO.addCategories(GaedatastoreUserAccountDAO.java:174) at it.icaroproject.main.business.CategoryBusiness.createEntities(CategoryBusiness.java:83) at it.icaroproject.main.business.CategoryBusiness.createEntity(CategoryBusiness.java:76) at it.icaroproject.test.business.UserAccountLifeCycle.run(UserAccountLifeCycle.java:52) at java.lang.Thread.run(Thread.java:680)

If I run this code works:

for(int i=0;i<10;i++) {
    UserAccountLifeCycle lifeCycle = new UserAccountLifeCycle(i,testUser.getKey());
    lifeCycle.run();
}

(I know it doesn't run the method as a thread, but it is intended as the proof that JUnit test is configured correctly with GAE local testing)

Upvotes: 2

Views: 1010

Answers (2)

Nick Johnson
Nick Johnson

Reputation: 101149

Although the App Engine Java runtime supports threads, the dev_appserver doesn't. Results from testing concurrency on the local dev environment are thus not going to be representative of the production environment.

Upvotes: 2

dragonx
dragonx

Reputation: 15143

You might try the solution suggested here inside your new thread:

Acceptance testing preloading of data into GAE dev server datastore

Upvotes: 0

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