CheckExitCalled exception

Exception:

org.junit.contrib.java.lang.system.internal.CheckExitCalled: Tried to exit with status 0.

at org.junit.contrib.java.lang.system.internal.NoExitSecurityManager.checkExit(NoExitSecurityManager.java:24)

at java.base/java.lang.Runtime.exit(Runtime.java:111)

at java.base/java.lang.System.exit(System.java:1785)

at example.InputStats.countInput(InputStats.java:23)

at example.InputStatsTest.testCountInput2(InputStatsTest.java:60)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:567)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)

at org.junit.contrib.java.lang.system.ExpectedSystemExit$1.evaluate(ExpectedSystemExit.java:130)

at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)

at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)

at org.junit.contrib.java.lang.system.internal.LogPrintStream$1$1.evaluate(LogPrintStream.java:30)

at org.junit.contrib.java.lang.system.internal.PrintStreamHandler$3.evaluate(PrintStreamHandler.java:48)

at org.junit.contrib.java.lang.system.internal.LogPrintStream$1.evaluate(LogPrintStream.java:26)

at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:298)

at org.junit.internal.runners.statements.FailOnTimeout$CallableStatement.call(FailOnTimeout.java:292)

at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)

at java.base/java.lang.Thread.run(Thread.java:830)

This exception is thrown when multiple Unit tests are using System Rules and are run in parallel [source]. However, there is also another situation, which causes this exception, which is the location of the exit statement:

	public class InputStats {
	public void countInput() {
	try {
	System.exit(0);
	}catch(Exception e) {
	e.printStackTrace();
	}
	}
	}

view raw InputStats hosted with ❤ by GitHub

	import org.junit.Before;
	import org.junit.Rule;
	import org.junit.Test;
	import org.junit.contrib.java.lang.system.ExpectedSystemExit;
	public class InputStatsTest {
	InputStats stats;
	@Rule
	public final ExpectedSystemExit exit = ExpectedSystemExit.none();
	@Before
	public void setUp() throws Exception {
	stats = new InputStats();
	}
	@Test
	public void testCountInput2() {
	exit.expectSystemExit();
	stats.countInput();
	}
	}

view raw InputStatsTest hosted with ❤ by GitHub

The solution is to move the exit statement away from the try-catch block.