Updated tests for BAEL-1262 (#2917)

* updating test code for BAEL-1262

* some small change

core-java-concurrency/src/test/java/com/baeldung/concurrent/runnable/RunnableVsThreadTest.java

@@ -8,7 +8,9 @@ import java.util.concurrent.Future;
 
 import org.apache.commons.lang3.RandomUtils;
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -18,22 +20,34 @@ public class RunnableVsThreadTest {
 	private static Logger log = 
 	  LoggerFactory.getLogger(RunnableVsThreadTest.class);
 
+	private static ExecutorService executorService;
+	
+	@BeforeClass
+	public static void setup() {
+		executorService = Executors.newCachedThreadPool(); 
+	}
+	
 	@Test
 	public void givenARunnable_whenRunIt_thenResult() throws Exception{
 		Thread thread = new Thread(new SimpleRunnable(
 		  "SimpleRunnable executed using Thread"));
 		thread.start();
 		thread.join();
-		
-		ExecutorService executorService = 
-		  Executors.newCachedThreadPool();
+	}
+	
+	@Test
+	public void givenARunnable_whenSubmitToES_thenResult() throws Exception{
 		
 		executorService.submit(new SimpleRunnable(
 		  "SimpleRunnable executed using ExecutorService")).get();
+	}
+	
+	@Test
+	public void givenARunnableLambda_whenSubmitToES_thenResult() 
+	  throws Exception{
 		
 		executorService.submit(()-> 
 		  log.info("Lambda runnable executed!!!")).get();
-		executorService.shutdown();
 	}
 	
 	@Test
@@ -42,26 +56,39 @@ public class RunnableVsThreadTest {
 		  "SimpleThread executed using Thread");
 		thread.start();
 		thread.join();
+	}
+	
+	@Test
+	public void givenAThread_whenSubmitToES_thenResult() throws Exception{
 		
-		ExecutorService executorService = 
-		  Executors.newCachedThreadPool();
 		executorService.submit(new SimpleThread(
 		  "SimpleThread executed using ExecutorService")).get();
 	}
 	
 	@Test
-	public void givenACallable_whenRunIt_thenResult() throws Exception {
-		ExecutorService executorService = 
-		  Executors.newCachedThreadPool();
+	public void givenACallable_whenSubmitToES_thenResult() throws Exception {
 		
-		Future<Integer> future = executorService.submit(new SimpleCallable());
+		Future<Integer> future = executorService.submit(
+		  new SimpleCallable());
 		log.info("Result from callable: {}", future.get());
+	}
+	
+	@Test
+	public void givenACallableAsLambda_whenSubmitToES_thenResult() 
+	  throws Exception {
 		
-		future = executorService.submit(() -> {
+		Future<Integer> future = executorService.submit(() -> {
 		  return RandomUtils.nextInt(0, 100);
-		}); 
+		});
+		
 		log.info("Result from callable: {}", future.get());
-
+	}
+	
+	@AfterClass
+	public static void tearDown() {
+		if ( executorService != null && !executorService.isShutdown()) {
+			executorService.shutdown();
+		}
 	}
 }
 
@@ -107,4 +134,5 @@ class SimpleCallable implements Callable<Integer> {
 		return RandomUtils.nextInt(0, 100);
 	}
 
-}
+}
+