launcher to run junit5 tests

SpringExtensionTestsLauncher.java

package org.springframework.test.context.junit5;

import org.junit.gen5.console.ColoredPrintingTestListener;
import org.junit.gen5.engine.TestPlanSpecification;
import org.junit.gen5.launcher.Launcher;
import org.junit.gen5.launcher.listeners.SummaryCreatingTestListener;
import org.junit.gen5.launcher.listeners.TestExecutionSummary;

import java.io.PrintWriter;

/**
 * @author Tadaya Tsuyukubo
 */
public class SpringExtensionTestsLauncher {

    public static void main(String[] args) {
        Launcher launcher = new Launcher();

        TestPlanSpecification testPlanSpecification = TestPlanSpecification.build(
                TestPlanSpecification.forPackage("org.springframework.test.context.junit5")
        );

        TestExecutionSummary summary = new TestExecutionSummary();
        launcher.registerTestPlanExecutionListeners(new SummaryCreatingTestListener(summary));
        launcher.registerTestPlanExecutionListeners(new ColoredPrintingTestListener(System.out, false));

        launcher.execute(testPlanSpecification);

        try (PrintWriter writer = new PrintWriter(System.out)) {
            summary.printFailuresOn(writer);
            summary.printOn(writer);
        }
    }
}