Log4j in JUnit test case

Question

I have a spring bean that has a log member and I use this logger to log some activities.
I also wrote a test case that uses SpringJUnit4ClassRunner . I configured Log4j with the properties file and in each test case I initialize the logger with these properties:

 @BeforeClass public static void init() { PropertyConfigurator.configure("src/com/config/log4j.properties"); } 

when i run the test it gives me a warning

 log4j:WARN No appenders could be found for logger (org.springframework.test.context.junit4.SpringJUnit4ClassRunner). log4j:WARN Please initialize the log4j system properly. log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info. 

However, the logger in my bean writes messages to the specified location in log4j.properties, that is, it works fine. Why does log4j give me such warnings?

Answer 1

I think the reason for this code is in SpringJUnit4ClassRunner

  public SpringJUnit4ClassRunner(Class<?> clazz) throws InitializationError { super(clazz); if (logger.isDebugEnabled()) { logger.debug("SpringJUnit4ClassRunner constructor called with [" + clazz + "]."); } this.testContextManager = createTestContextManager(clazz); } 

If you don’t want to see a warning about log4j, just follow as @DN suggested simply adding the log4j.properties file to your application class path. If you use the maven directory structure, add the log4j.properties file to (src / main / resources), which will clear the warning.

Answer 2

I wanted to save the log4j configuration from the default class in order to use different logging with unit tests and production. I worked around it, subclassing SpringJUnit4ClassRunner and using a static class initializer.

 // The new test runner public class JUnit4ClassRunner extends SpringJUnit4ClassRunner { static { try { Log4jConfigurer.initLogging( "classpath:test/log4jconfig.xml" ); } catch( FileNotFoundException ex ) { System.err.println( "Cannot Initialize log4j" ); } } public JUnit4ClassRunner( Class<?> clazz ) throws InitializationError { super( clazz ); } } 

Test change:

 @RunWith(JUnit4ClassRunner.class) @ContextConfiguration @TransactionConfiguration @Transactional public class LmpDaoImplTest extends AbstractTransactionalJUnit4SpringContextTests { ... 

Log4j is now configured before invoking the Spring test runner.

Answer 3

Because Runner runs runs before initializing Log4J.