Question

我想用多线程测试我的JDO - DAO，以验证持久层是否知道同步。

这是我在JUnit测试中的一段代码

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

..其中UserAccountLifeCycle是一个扩展另一个业务层类的类，而使用以下代码实现“Runnable”：

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

如果我参加测试，我会得到：

线程“Thread-6”中的异常java.lang.NullPointerException：无API 环境已注册此线程。在 com.google.appengine.api.datastore.DatastoreApiHelper.getCurrentAppId（DatastoreApiHelper.java:86）在 com.google.appengine.api.datastore.DatastoreAttributes。（DatastoreAttributes.java:28）在 com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.getDatastoreAttributes（AsyncDatastoreServiceImpl.java:952）在 com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.getDatastoreType（AsyncDatastoreServiceImpl.java:944）在 com.google.appengine.api.datastore.AsyncDatastoreServiceImpl.get（AsyncDatastoreServiceImpl.java:267）在 com.google.appengine.api.datastore.DatastoreServiceImpl $ 1.runInternal（DatastoreServiceImpl.java:78）在 com.google.appengine.api.datastore.DatastoreServiceImpl $ 1.runInternal（DatastoreServiceImpl.java:75）在 com.google.appengine.api.datastore.TransactionRunner.runInTransaction（TransactionRunner.java:31）在 com.google.appengine.api.datastore.DatastoreServiceImpl.get（DatastoreServiceImpl.java:75）在 com.google.appengine.api.datastore.DatastoreServiceImpl.get（DatastoreServiceImpl.java:62）在 org.datanucleus.store.appengine.RuntimeExceptionWrappingDatastoreService.get（RuntimeExceptionWrappingDatastoreService.java:56）在 org.datanucleus.store.appengine.DatastorePersistenceHandler.get（DatastorePersistenceHandler.java:100）在 org.datanucleus.store.appengine.DatastorePersistenceHandler.get（DatastorePersistenceHandler.java:112）在 org.datanucleus.store.appengine.DatastorePersistenceHandler.fetchObject（DatastorePersistenceHandler.java:517）在 org.datanucleus.state.JDOStateManagerImpl.validate（JDOStateManagerImpl.java:4263）在 org.datanucleus.ObjectManagerImpl.findObject（ObjectManagerImpl.java:2444）在 org.datanucleus.jdo.JDOPersistenceManager.getObjectById（JDOPersistenceManager.java:1671）在 org.datanucleus.jdo.JDOPersistenceManager.getObjectById（JDOPersistenceManager.java:1767）在 org.datanucleus.store.appengine.jdo.DatastoreJDOPersistenceManager.getObjectById（DatastoreJDOPersistenceManager.java:73）在 it.icaroproject.main.persistence.dao.GaedatastoreUserAccountDAO.addCategories（GaedatastoreUserAccountDAO.java:174）在 it.icaroproject.main.business.CategoryBusiness.createEntities（CategoryBusiness.java:83）在 it.icaroproject.main.business.CategoryBusiness.createEntity（CategoryBusiness.java:76）在 it.icaroproject.test.business.UserAccountLifeCycle.run（UserAccountLifeCycle.java:52）在java.lang.Thread.run（Thread.java:680）

如果我运行此代码有效：

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

（我知道它不会将该方法作为线程运行，但它的目的是证明JUnit测试已正确配置GAE local testing）

Answer 1

虽然App Engine Java运行时支持线程，但dev_appserver不支持。因此，在本地开发环境中测试并发性的结果不能代表生产环境。

Answer 2

您可以尝试在新线程中建议的解决方案：

Acceptance testing preloading of data into GAE dev server datastore

使用线程测试GAE数据存储区

2 个答案: