Add wrapper for ServiceManager

This makes it easier for a class to implement a Startable interface,
using a ServiceManager internally, while preventing other classes from
adding services to the manager (as would be the case if the class were
simply subclassed from the ServiceManager).

Changed the field name to be more descriptive.

Fixed a typo in a comment.

Change-Id: I1bed6291114d21c20d2324cbda81518bf9183139
Issue-ID: POLICY-1542
Signed-off-by: Jim Hahn <jrh3@att.com>

2 files changed, 214 insertions, 0 deletions

diff --git a/utils/src/main/java/org/onap/policy/common/utils/services/ServiceManagerContainer.java b/utils/src/main/java/org/onap/policy/common/utils/services/ServiceManagerContainer.java
new file mode 100644
index 00000000..6afc1ab0
--- /dev/null
+++ b/utils/src/main/java/org/onap/policy/common/utils/services/ServiceManagerContainer.java
@@ -0,0 +1,99 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.services;
+
+import org.onap.policy.common.capabilities.Startable;
+import org.onap.policy.common.utils.services.ServiceManager.RunnableWithEx;
+
+/**
+ * Container, of a service manager, that implements a {@link Startable} interface by
+ * delegating to the contained service manager. This allows subclasses to add actions to
+ * the service manager, while preventing other classes from doing so.
+ */
+public class ServiceManagerContainer implements Startable {
+
+    /**
+     * The contained manager.
+     */
+    private final ServiceManager serviceManager;
+
+    /**
+     * Constructs the object, with a default name.
+     */
+    public ServiceManagerContainer() {
+        serviceManager = new ServiceManager();
+    }
+
+    /**
+     * Constructs the object.
+     *
+     * @param name the manager's name, used for logging purposes
+     */
+    public ServiceManagerContainer(String name) {
+        serviceManager = new ServiceManager(name);
+    }
+
+    public String getName() {
+        return serviceManager.getName();
+    }
+
+    /**
+     * Adds a pair of service actions to the manager.
+     *
+     * @param stepName name to be logged when the service is started/stopped
+     * @param starter function to start the service
+     * @param stopper function to stop the service
+     */
+    protected void addAction(String stepName, RunnableWithEx starter, RunnableWithEx stopper) {
+        serviceManager.addAction(stepName, starter, stopper);
+    }
+
+    /**
+     * Adds a service to the manager. The manager will invoke the service's
+     * {@link Startable#start()} and {@link Startable#stop()} methods.
+     *
+     * @param stepName name to be logged when the service is started/stopped
+     * @param service object to be started/stopped
+     */
+    protected void addService(String stepName, Startable service) {
+        serviceManager.addService(stepName, service);
+    }
+
+    @Override
+    public boolean isAlive() {
+        return serviceManager.isAlive();
+    }
+
+    @Override
+    public boolean start() {
+        return serviceManager.start();
+    }
+
+    @Override
+    public boolean stop() {
+        return serviceManager.stop();
+    }
+
+    @Override
+    public void shutdown() {
+        serviceManager.shutdown();
+    }
+}
diff --git a/utils/src/test/java/org/onap/policy/common/utils/services/ServiceManagerContainerTest.java b/utils/src/test/java/org/onap/policy/common/utils/services/ServiceManagerContainerTest.java
new file mode 100644
index 00000000..e57901ac
--- /dev/null
+++ b/utils/src/test/java/org/onap/policy/common/utils/services/ServiceManagerContainerTest.java
@@ -0,0 +1,115 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.utils.services;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onap.policy.common.capabilities.Startable;
+import org.onap.policy.common.utils.services.ServiceManager.RunnableWithEx;
+
+public class ServiceManagerContainerTest {
+    private static final String MY_NAME = "my-name";
+    private static final String MY_ACTION = "my-action";
+    private static final String MY_OBJECT = "my-object";
+    private RunnableWithEx starter;
+    private RunnableWithEx stopper;
+    private Startable startObj;
+    private MyCont cont;
+
+    /**
+     * Set up.
+     */
+    @Before
+    public void setUp() {
+        starter = mock(RunnableWithEx.class);
+        stopper = mock(RunnableWithEx.class);
+        startObj = mock(Startable.class);
+
+        cont = new MyCont(MY_NAME);
+    }
+
+    @Test
+    public void testServiceManagerContainer() throws Exception {
+        // use no-arg constructor
+        cont = new MyCont();
+        assertEquals("service manager", cont.getName());
+
+        cont.start();
+        verify(starter).run();
+    }
+
+    @Test
+    public void test() throws Exception {
+        assertEquals(MY_NAME, cont.getName());
+
+        assertFalse(cont.isAlive());
+
+        cont.start();
+        assertTrue(cont.isAlive());
+        verify(starter).run();
+        verify(startObj).start();
+        verify(stopper, never()).run();
+        verify(startObj, never()).stop();
+        verify(startObj, never()).shutdown();
+
+        cont.stop();
+        assertFalse(cont.isAlive());
+        verify(starter).run();
+        verify(startObj).start();
+        verify(stopper).run();
+        verify(startObj).stop();
+        verify(startObj, never()).shutdown();
+    }
+
+    @Test
+    public void testShutdown() throws Exception {
+        cont.start();
+        cont.shutdown();
+        assertFalse(cont.isAlive());
+        verify(stopper).run();
+        verify(startObj).stop();
+        verify(startObj, never()).shutdown();
+    }
+
+    private class MyCont extends ServiceManagerContainer {
+
+        public MyCont() {
+            addServices();
+        }
+
+        public MyCont(String name) {
+            super(name);
+            addServices();
+        }
+
+        private void addServices() {
+            addAction(MY_ACTION, starter, stopper);
+            addService(MY_OBJECT, startObj);
+        }
+    }
+}