BAEL-1264 - class and tests for killing a thread (#3069)

core-java-concurrency/src/main/java/com/baeldung/concurrent/stopping/ControlSubThread.java

@@ -0,0 +1,52 @@
+package com.baeldung.concurrent.stopping;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public class ControlSubThread implements Runnable {
+
+    private Thread worker;
+    private int interval = 100;
+    private AtomicBoolean running = new AtomicBoolean(false);
+    private AtomicBoolean stopped = new AtomicBoolean(true);
+
+
+    public ControlSubThread(int sleepInterval) {
+        interval = sleepInterval;
+    }
+
+    public void start() {
+        worker = new Thread(this);
+        worker.start();
+    }
+
+    public void stop() {
+        running.set(false);
+    }
+
+    public void interrupt() {
+        running.set(false);
+        worker.interrupt();
+    }
+
+    boolean isRunning() {
+        return running.get();
+    }
+
+    boolean isStopped() {
+        return stopped.get();
+    }
+
+    public void run() {
+        running.set(true);
+        stopped.set(false);
+        while (running.get()) {
+            try {
+                Thread.sleep(interval);
+            } catch (InterruptedException e) {
+                // no-op, just loop again
+            }
+            // do something
+        }
+        stopped.set(true);
+    }
+}

core-java-concurrency/src/test/java/com/baeldung/concurrent/stopping/StopThreadTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.concurrent.stopping;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class StopThreadTest {
+
+    @Test
+    public void whenStoppedThreadIsStopped() throws InterruptedException {
+
+        int interval = 100;
+
+        ControlSubThread controlSubThread = new ControlSubThread(interval);
+        controlSubThread.start();
+
+        // Give things a chance to get set up
+        Thread.sleep(interval);
+        assertTrue(controlSubThread.isRunning());
+        assertFalse(controlSubThread.isStopped());
+
+        // Stop it and make sure the flags have been reversed
+        controlSubThread.stop();
+        Thread.sleep(interval);
+        assertTrue(controlSubThread.isStopped());
+    }
+
+
+    @Test
+    public void whenInterruptedThreadIsStopped() throws InterruptedException {
+
+        int interval = 5000;
+
+        ControlSubThread controlSubThread = new ControlSubThread(interval);
+        controlSubThread.start();
+
+        // Give things a chance to get set up
+        Thread.sleep(100);
+        assertTrue(controlSubThread.isRunning());
+        assertFalse(controlSubThread.isStopped());
+
+        // Stop it and make sure the flags have been reversed
+        controlSubThread.interrupt();
+
+        // Wait less than the time we would normally sleep, and make sure we exited.
+        Thread.sleep(interval/10);
+        assertTrue(controlSubThread.isStopped());
+    }
+}