How do I run JUnit tests from inside my java application?

Question

Is it possible to run JUnit tests from inside my java application?

Are there test frameworks I can use (such as JUnit.jar?), or am I force to find the test files, in

Answer 1

In JUnit 5 you can use Launcher API for this goals.

    final LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
            .selectors(
                    selectPackage("path_to_folder_with_tests")
            )
            .build();

    final Launcher launcher = LauncherFactory.create();

    final boolean pathContainsTests = launcher.discover(request).containsTests()
    if (!pathContainsTests) {
        System.out.println("This path is invalid or folder doesn't consist tests");
    }

    final SummaryGeneratingListener listener = new SummaryGeneratingListener();

    launcher.execute(request, listener);

    final TestExecutionSummary summary = listener.getSummary();

    final long containersFoundCount = summary.getContainersFoundCount();
    System.out.println("containers Found Count  " + containersFoundCount);

    final long containersSkippedCount = summary.getContainersSkippedCount();
    System.out.println("containers Skipped Count  " + containersSkippedCount);

    final long testsFoundCount = summary.getTestsFoundCount();
    System.out.println("tests Found Count  " + testsFoundCount);

    final long testsSkippedCount = summary.getTestsSkippedCount();
    System.out.println("tests Skipped Count  " + testsSkippedCount);