KeyRotatorImpl looks a *lot* like DatabaseCleanerImpl.

test/net/sf/briar/db/KeyRotatorImplTest.java

@@ -0,0 +1,53 @@
+package net.sf.briar.db;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import net.sf.briar.BriarTestCase;
+import net.sf.briar.api.db.DbException;
+import net.sf.briar.db.KeyRotator.Callback;
+
+import org.junit.Test;
+
+public class KeyRotatorImplTest extends BriarTestCase {
+
+	@Test
+	public void testCleanerRunsPeriodically() throws Exception {
+		final CountDownLatch latch = new CountDownLatch(5);
+		Callback callback = new Callback() {
+
+			public void rotateKeys() throws DbException {
+				latch.countDown();
+			}
+		};
+		KeyRotatorImpl cleaner = new KeyRotatorImpl();
+		// Start the rotator
+		cleaner.startRotating(callback, 10L);
+		// The keys should be rotated five times (allow 5 secs for system load)
+		assertTrue(latch.await(5, TimeUnit.SECONDS));
+		// Stop the rotator
+		cleaner.stopRotating();
+	}
+
+	@Test
+	public void testStoppingCleanerWakesItUp() throws Exception {
+		final CountDownLatch latch = new CountDownLatch(1);
+		Callback callback = new Callback() {
+
+			public void rotateKeys() throws DbException {
+				latch.countDown();
+			}
+		};
+		KeyRotatorImpl cleaner = new KeyRotatorImpl();
+		long start = System.currentTimeMillis();
+		// Start the rotator
+		cleaner.startRotating(callback, 10L * 1000L);
+		// The keys should be rotated once at startup
+		assertTrue(latch.await(5, TimeUnit.SECONDS));
+		// Stop the rotator (it should be waiting between rotations)
+		cleaner.stopRotating();
+		long end = System.currentTimeMillis();
+		// Check that much less than 10 seconds expired
+		assertTrue(end - start < 10L * 1000L);
+	}
+}