TestNG test failure even if expected exception is specified - unit-testing

Question

Im writing tests with TestNG framework. Everything works fine, except one test, when Im checking Service failure and Im expecting Exception class.
Here is my code:
#Test(expectedExceptions = BookNotFoundException.class)
public void findBookFailureTest() throws BookNotFoundException{
when(booksRepository.findOne(new Long(1))).thenReturn(book);
booksService.findBook(new Long(67));
}
And here is test resut:
Results :
Failed tests:
findBookFailureTest(pl.library.services.BooksServiceImplTest): (..)
Tests run: 7, Failures: 1, Errors: 0, Skipped: 0
Why that test fails even if I specified that I expect that Exception?
Stack Trace:
-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running TestSuite
Configuring TestNG with: org.apache.maven.surefire.testng.conf.TestNG652Configurator#5d22bbb7
Tests run: 7, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.734 sec <<< FAILURE!
findBookFailureTest(pl.library.services.BooksServiceImplTest) Time elapsed: 0 sec <<< FAILURE!
org.testng.TestException:
Method BooksServiceImplTest.findBookFailureTest()[pri:0, instance:pl.library.services.BooksServiceImplTest#3b81a1bc] should have thrown an exception of class pl.exceptions.BookNotFoundException
at org.testng.internal.Invoker.handleInvocationResults(Invoker.java:1512)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:754)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
at org.testng.TestRunner.privateRun(TestRunner.java:767)
at org.testng.TestRunner.run(TestRunner.java:617)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:348)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:343)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:305)
at org.testng.SuiteRunner.run(SuiteRunner.java:254)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
at org.testng.TestNG.run(TestNG.java:1057)
at org.apache.maven.surefire.testng.TestNGExecutor.run(TestNGExecutor.java:77)
at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.executeMulti(TestNGDirectoryTestSuite.java:159)
at org.apache.maven.surefire.testng.TestNGDirectoryTestSuite.execute(TestNGDirectoryTestSuite.java:99)
at org.apache.maven.surefire.testng.TestNGProvider.invoke(TestNGProvider.java:106)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)

Answer 1

Ok problem solved. I have to tell my Mock object, that in some case, it must throw Exception.
here is my BooksService method code:
public Book findBook(Long id) throws BookNotFoundException {
try {
return booksRepository.findOne(id);
} catch (Exception e) {
throw new BookNotFoundException();
}
}
and here is working test:
#Test(expectedExceptions = BookNotFoundException.class)
public void findBookFailureTest() throws BookNotFoundException{
Long id = new Long(65);
when(booksRepository.findOne(id)).thenThrow(Exception.class);
booksService.findBook(id);
}
Thanks for answers. It helps me a lot. :)