JERSEY-2291: Add test case to verify Immediate services are started immediately.

Author: jordmoz

core-common/src/test/java/org/glassfish/jersey/internal/inject/InjectionsTest.java

@@ -0,0 +1,67 @@
+package org.glassfish.jersey.internal.inject;
+
+import static org.junit.Assert.assertTrue;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import javax.inject.Inject;
+
+import org.glassfish.hk2.api.Immediate;
+import org.glassfish.hk2.api.ServiceLocator;
+import org.glassfish.hk2.utilities.binding.AbstractBinder;
+import org.junit.Test;
+
+/**
+ * Test for the {@link Injections} class.
+ *
+ * @author Jord Sonneveld ([email protected])
+ *
+ */
+public class InjectionsTest {
+
+  /**
+   * Verify that services marked with the HK2 Immediate annotation are indeed
+   * created "immediately" (or at least "soon").
+   *
+   * Because Immediate services are instantiated in a separate thread, we use a
+   * {@link CountDownLatch} to wait for the service to be created.
+   *
+   * After the {@link ServiceLocator} is created, we specifically do not call
+   * any more methods on it: the locator must instantiate the Immediate service
+   * without any further prompting to the locator.
+   *
+   * @throws InterruptedException
+   *           if awaiting on the latch is interrupted.
+   */
+  @Test
+  public void testHK2ImmediateAnnotation() throws InterruptedException {
+    final CountDownLatch latch = new CountDownLatch(1);
+
+    @SuppressWarnings("unused") // It is unused by design
+    ServiceLocator sl = Injections.createLocator(new AbstractBinder() {
+      @Override
+      protected void configure() {
+        bind(latch).to(CountDownLatch.class);
+        bind(ImmediateMe.class).to(ImmediateMe.class).in(Immediate.class);
+      }
+    });
+
+    // 10 seconds is a LONG time. It should be faster than that. However, 10
+    // seconds gives us a reasonable upper limit to wait in case the test fails.
+    assertTrue("Latch should be unlocked within 10 seconds.",
+        latch.await(10, TimeUnit.SECONDS));
+  }
+
+  /**
+   * Helper class for testing Immediate services.
+   *
+   */
+  public static final class ImmediateMe {
+    @Inject
+    public ImmediateMe(CountDownLatch latch) {
+      latch.countDown();
+    }
+  }
+
+}