[java] How to configure log4j.properties for SpringJUnit4ClassRunner?

Suddenly this keeps happening during a JUnit test. Everything was working, I wrote some new tests and this error occured. If I revert it, it won't go away. Why is that?

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.

If you don't want to bother with a file, you can do something like this in your code:

static
{
    Logger rootLogger = Logger.getRootLogger();
    rootLogger.setLevel(Level.INFO);
    rootLogger.addAppender(new ConsoleAppender(
               new PatternLayout("%-6r [%p] %c - %m%n")));
}

Add a log4j.properties(log4j.xml) file with at least one appender in root of your classpath.

The contents of the file(log4j.properties) can be as simple as

log4j.rootLogger=WARN,A1

# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d{ISO8601} [%t] %-5p %c %x - %m%n

This will enable log4j logging with default log level as WARN and use the java console to log the messages.

I was using Maven in eclipse and I did not want to have an additional copy of the properties file in the root folder. You can do the following in eclipse:

1. Open run dialog (click the little arrow next to the play button and go to run configurations)
2. Go to the "classpath" tab
3. Select the "User Entries" and click the "Advanced" button on the right side.
4. Now select the "Add External folder" radio button.
5. Select the resources folder

Because I don't like to have duplicate files (log4j.properties in test and main), and I have quite many test classes, they each runwith SpringJUnit4ClassRunner class, so I have to customize it. This is what I use:

import java.io.FileNotFoundException;

import org.junit.runners.model.InitializationError;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.util.Log4jConfigurer;

public class MySpringJUnit4ClassRunner extends SpringJUnit4ClassRunner {

    static {
        String log4jLocation = "classpath:log4j-oops.properties";
        try {
            Log4jConfigurer.initLogging(log4jLocation);
        } catch (FileNotFoundException ex) {
            System.err.println("Cannot Initialize log4j at location: " + log4jLocation);
        }
    }

    public MySpringJUnit4ClassRunner(Class<?> clazz) throws InitializationError {
        super(clazz);
    }
}

When you use it, replace SpringJUnit4ClassRunner with MySpringJUnit4ClassRunner

@RunWith(MySpringJUnit4ClassRunner.class) 
@ContextConfiguration("classpath:conf/applicationContext.xml") 
public class TestOrderController {
    private Logger LOG = LoggerFactory.getLogger(this.getClass());

    private MockMvc mockMvc;
...
}

I have the log4j.properties configured properly. That's not the problem. After a while I discovered that the problem was in Eclipse IDE which had an old build in "cache" and didn't create a new one (Maven dependecy problem). I had to build the project manually and now it works.

I know this is old, but I was having trouble too. For Spring 3 using Maven and Eclipse, I needed to put the log4j.xml in src/test/resources for the Unit test to log properly. Placing in in the root of the test did not work for me. Hopefully this helps others.