There seem to be two approaches for invoking JUnit tests from the OS command shell:
java junit.textui.TestRunner <class-name>
and
java org.junit.runner.JUnitCore <class-name>
When do we use one versus the other?
Also, are there other ways to invoke Junit tests from the OS command shell?
JUnitCore is an entry point of JUnit - so if you want to run a test programmatically or of from some non-java script, I think, its the way to go for JUnit 4.
TestRunner is something a very old junit 3.x
Notice, that nowadays JUnit 5 is the latest available major release and it has yet another way to run the tests.
The question about different ways of running the tests from command line has been already answered Here so I can't add much to this.
However, I can comment on:
Also, are there other ways to invoke Junit tests from the OS command shell?
Nowadays in regular projects people do not run tests like this, instead they use one of build tools (Maven, Gradle for example) that among other things take care of tests.
So for example if you use maven, you can run mvn test and it will compile everything you need, including source code of tests, will take care about all test dependencies and will run all the tests with the help of build-in surefire plugin.
If you don't want to compile anything (assuming that all the code has been already compiled and all is set, you can use mvn surefire:test)
These build tools are also integrated with CI tools (like Jenkins, etc.) So this is considered to be a solved problem.
So unless you're doing something really different (like writing the IDE UI that should run test selected by user on demand or something) there is no really need to run tests with the options you've mentioned.
