java tests cleanup work

core-java/src/test/java/org/baeldung/java/JavaIoIntegrationTest.java

@@ -14,7 +14,7 @@ import org.slf4j.LoggerFactory;
 import com.google.common.base.Charsets;
 import com.google.common.io.Files;
 
-public class CoreJavaIoIntegrationTest {
+public class JavaIoIntegrationTest {
     protected final Logger logger = LoggerFactory.getLogger(getClass());
 
     // tests - iterate lines in a file

core-java/src/test/java/org/baeldung/java/JavaRandomUnitTest.java

@@ -7,7 +7,7 @@ import org.apache.commons.lang3.RandomStringUtils;
 import org.apache.commons.math3.random.RandomDataGenerator;
 import org.junit.Test;
 
-public class CoreJavaRandomUnitTest {
+public class JavaRandomUnitTest {
 
     // tests - random long
 

core-java/src/test/java/org/baeldung/java/JavaTimerUnitTest.java

@@ -0,0 +1,30 @@
+package org.baeldung.java;
+
+import java.util.Date;
+import java.util.Timer;
+import java.util.TimerTask;
+
+import org.junit.Test;
+
+public class JavaTimerUnitTest {
+
+    // tests
+
+    @Test
+    public void givenUsingTimer_whenSchedulingTaskOnce_thenCorrect() throws InterruptedException {
+        final TimerTask timerTask = new TimerTask() {
+            @Override
+            public void run() {
+                System.out.println("Task performed on " + new Date() + "\n" + "Thread's name: " + Thread.currentThread().getName());
+            }
+        };
+
+        final Timer timer = new Timer("Timer");
+        final long delay = 1000L;
+        timer.schedule(timerTask, delay);
+
+        Thread.sleep(delay * 2);
+        timer.cancel();
+    }
+
+}