Logs in Junit test methods printed after all tests are executed [duplicate] - junit

Question

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Maven parallel test output
(1 answer)
Closed 5 years ago.
I am using Java util logging (JUL) in a Junit test class with JUL working in default config (i.e. printing to console).
Logs statements from methods annotated with #BeforeClass and #AfterClass are getting printed when they are executed but logs in '#Test' methods are printed only after all test execution is finished.
Not sure what exactly is wrong because the same were working earlier.
Logger instantiation:
private static Logger logger = Logger.getLogger(MainIntegrationTest.class.getName());
Logger use:
logger.info("start test");
The test cases are run using maven. I noticed that this started happening only after I started running the test classes in parallel using this surefire configuration:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.20</version>
<configuration>
<parallel>classes</parallel>
<useUnlimitedThreads>true</useUnlimitedThreads>
</configuration>
</plugin>
The logs are printed at test execution time if I run the test classes in serial fashion.

Answer 1

The test cases are run using maven. I noticed that this started happening only after I started running the test classes in parallel using this surefire configuration
The output would become scrambled if all tests were writing to console concurrently. For concurrent execution the results have to be buffered for the whole run and then written to the console as one chunk. The only safe time to write to the console is when the test is complete.
Even if the buffering was performed line by line this could lead to interleaved messages in the console which could be hard to read or even misdirect you as you don't know the source of the line.