thread-weaver with hibernate unit testing - multithreading

Question

I am trying to write a multithread unit test for my hibernate test.
I chose thread-weaver and got a little play with it.
I used the HSQL Database engine for my hibernate testing which is an in memory database.
It was working perfect until i wanted to write some multi thread unit tests.
Since i am new to thread weaver, i could make some newbie mistakes.
I knew the thread weaver is loading my class with its customized loader.
But in the #ThreadedBefore i try to set the sessionFactory for HSQL one. However, i got a bunch of error logs like
log4j:ERROR "org.apache.log4j.ConsoleAppender" was loaded by [sun.misc.Launcher$AppClassLoader#ece88d2].
log4j:ERROR Could not instantiate appender named "console".
log4j:ERROR A "org.apache.log4j.ConsoleAppender" object is not assignable to a "org.apache.log4j.Appender" variable.
log4j:ERROR The class "org.apache.log4j.Appender" was loaded by
log4j:ERROR [com.google.testing.instrumentation.InstrumentedClassLoader#2a57a184] whereas object of type
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.google.testing.threadtester.MethodCaller.invoke(MethodCaller.java:71)
at com.google.testing.threadtester.BaseThreadedTestRunner.runTests(BaseThreadedTestRunner.java:179)
at com.google.testing.threadtester.BaseThreadedTestRunner.runTests(BaseThreadedTestRunner.java:143)
at com.amazon.amazonclicksdali.test.simpleTest.run(simpleTest.java:39)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at com.intellij.junit4.JUnit4TestRunnerUtil$IgnoreIgnoredTestJUnit4ClassRunner.runChild(JUnit4TestRunnerUtil.java:306)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at com.google.testing.threadtester.MethodCaller.invoke(MethodCaller.java:68)
... 30 more
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.google.testing.threadtester.MethodCaller.invoke(MethodCaller.java:71)
at com.google.testing.threadtester.ThreadedTestWrapper.runTests(ThreadedTestWrapper.java:71)
... 35 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at com.google.testing.threadtester.MethodCaller.invoke(MethodCaller.java:68)
... 36 more
Caused by: java.lang.NullPointerException
at com.google.testing.instrumentation.InstrumentedClassLoader.loadClassData(InstrumentedClassLoader.java:152)
at com.google.testing.instrumentation.InstrumentedClassLoader.findClass(InstrumentedClassLoader.java:137)
at com.google.testing.instrumentation.InstrumentedClassLoader.loadClass(InstrumentedClassLoader.java:113)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:278)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:170)
at org.hibernate.cfg.Configuration.applyHibernateValidatorLegacyConstraintsOnDDL(Configuration.java:1663)
at org.hibernate.cfg.Configuration.applyConstraintsToDDL(Configuration.java:1653)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1445)
at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1375)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:717)
at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:188)
at com.amazon.amazonclicksdali.test.scheduler.repository.TestSessionHelper.getSessionFactory(TestSessionHelper.java:20)
at com.amazon.amazonclicksdali.test.simpleTest.setup(simpleTest.java:45)
... 41 more
A simple test is like this
public class simpleTest {
Script<RDBInternalReportRepository> main;
Script<RDBInternalReportRepository> second;
final RDBInternalReportRepository target = new RDBInternalReportRepository();
SessionFactory sessionFactory;
RDBInternalReport internalReport1;
#Test
public void run() {
new ThreadedTestRunner().runTests(getClass(), RDBInternalReportRepository.class);
}
#ThreadedBefore
public void setup() throws Exception {
TestSessionHelper testSessionHelper = new TestSessionHelper();
sessionFactory = testSessionHelper.getSessionFactory();
target.setSessionFactory(sessionFactory);
internalReport1 = new RDBInternalReport();
internalReport1.setReferenceId("aaa");
internalReport1.setReportName("testReportName");
internalReport1.setSubmittedDate(new DateTime(2015, 1, 1, 0, 0));
internalReport1.setMarketplaceId(1);
internalReport1.setHashKey("hashValues");
internalReport1.setDedupingString("uid");
internalReport1.setState(ReportState.SUBMITTED);
internalReport1.setErrorCount(0);
target.createOrUpdateInternalReport(internalReport1);
}
#ThreadedTest
public void testSession() throws Exception {
main = new Script<RDBInternalReportRepository>(target);
second = new Script<RDBInternalReportRepository>(target);
main.addTask(new ScriptedTask<RDBInternalReportRepository>() {
#Override
public void execute() throws Exception {
IInternalReport report1 = target.getInternalReport("aaa");
releaseTo(second);
}
});
second.addTask(new ScriptedTask<RDBInternalReportRepository>() {
#Override
public void execute() throws Exception {
releaseTo(main);
}
});
new Scripter<RDBInternalReportRepository>(main, second).execute();
}
}
It fails to even load the sessionFactory which is a simple HSQL database.

Answer 1

It looks as though the NullPointerException is caused by getSystemResourceAsStream() returning null. See line 136 here: https://github.com/google/thread-weaver/blob/5c316abcfdfa1832df981f90cfa5c5811003012e/main/com/google/testing/instrumentation/InstrumentedClassLoader.java
I found the following question which sounds like a pretty good explanation as to what's going on: getSystemResourceAsStream() returns null
It sounds as though a fix might be to add the following to 'InstrumentedCLassLoader.findClass()'
InputStream input = getSystemResourceAsStream(resourceName);
if (input == null) {
return Thread.currentThread().getContextClassLoader().findClass(className);
}
Can you try building threadweaver from source with this fix? Alternatively, I would need to run your entire test and verify.