Add various listener classes

Added various listener classes to support dispatch by message type
and request id.  The listeners are intended to form a pipeline:

	TopicSource =>
	MessageTypeDispatcher =>
	RequestIdDispatcher =>
	TypedMessageListener

Removed "PAP" from license.
Changed "handler" to "listener" in most places.
Simplified a test case.
Verified that no error message logged on success cases.
Removed println from test.
Updated some comments.

Change-Id: Ife265d14a6c5c8531601d9ce1343b88c1f8986a8
Issue-ID: POLICY-1444
Signed-off-by: Jim Hahn <jrh3@att.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/policy-endpoints/src/test/java/org/onap/policy/common/endpoints/listeners/JsonListenerTest.java b/policy-endpoints/src/test/java/org/onap/policy/common/endpoints/listeners/JsonListenerTest.java
new file mode 100644
index 00000000..39fc9d8f
--- /dev/null
+++ b/policy-endpoints/src/test/java/org/onap/policy/common/endpoints/listeners/JsonListenerTest.java
@@ -0,0 +1,120 @@
+/*
+ * ============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.endpoints.listeners;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.utils.coder.StandardCoderObject;
+import org.onap.policy.common.utils.test.log.logback.ExtractAppender;
+import org.slf4j.LoggerFactory;
+
+public class JsonListenerTest {
+
+    /**
+     * Used to attach an appender to the class' logger.
+     */
+    private static final Logger logger = (Logger) LoggerFactory.getLogger(JsonListener.class);
+    private static final ExtractAppender appender = new ExtractAppender();
+
+    /**
+     * Original logging level for the logger.
+     */
+    private static Level saveLevel;
+
+    private static final CommInfrastructure INFRA = CommInfrastructure.NOOP;
+    private static final String TOPIC = "my-topic";
+    private static final String JSON = "{'abc':'def'}".replace('\'', '"');
+
+    private JsonListener primary;
+
+    /**
+     * Initializes statics.
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        saveLevel = logger.getLevel();
+        logger.setLevel(Level.INFO);
+
+        appender.setContext(logger.getLoggerContext());
+        appender.start();
+    }
+
+    @AfterClass
+    public static void tearDownAfterClass() {
+        logger.setLevel(saveLevel);
+        appender.stop();
+    }
+
+    /**
+     * Initializes mocks and a listener.
+     */
+    @Before
+    public void setUp() {
+        appender.clearExtractions();
+
+        primary = new JsonListener() {
+            @Override
+            public void onTopicEvent(CommInfrastructure infra, String topic, StandardCoderObject sco) {}
+        };
+    }
+
+    @After
+    public void tearDown() {
+        logger.detachAppender(appender);
+    }
+
+    @Test
+    public void testOnTopicEvent() {
+        logger.addAppender(appender);
+
+        primary = spy(primary);
+
+        // success
+        primary.onTopicEvent(INFRA, TOPIC, JSON);
+        verify(primary).onTopicEvent(eq(INFRA), eq(TOPIC), any(StandardCoderObject.class));
+
+        // repeat
+        primary.onTopicEvent(INFRA, TOPIC, JSON);
+        verify(primary, times(2)).onTopicEvent(eq(INFRA), eq(TOPIC), any(StandardCoderObject.class));
+
+        assertFalse(appender.getExtracted().toString().contains("unable to decode"));
+
+        // invalid json - decode fails
+        appender.clearExtractions();
+        primary.onTopicEvent(INFRA, TOPIC, "[");
+        assertTrue(appender.getExtracted().toString().contains("unable to decode"));
+        verify(primary, times(2)).onTopicEvent(any(), any(), any(StandardCoderObject.class));
+    }
+}