Merge "Add Network Logging Feature"

10 files changed, 513 insertions, 28 deletions

diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicEndpoint.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicEndpoint.java
index a2ad4d3d..ef002f52 100644
--- a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicEndpoint.java
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicEndpoint.java
@@ -23,7 +23,8 @@ package org.onap.policy.common.endpoints.event.comm.bus;
 
 import java.util.List;
 import org.onap.policy.common.endpoints.event.comm.bus.internal.TopicBase;
-import org.onap.policy.common.utils.slf4j.LoggerFactoryWrapper;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -38,11 +39,6 @@ public abstract class NoopTopicEndpoint extends TopicBase {
     private static Logger logger = LoggerFactory.getLogger(NoopTopicEndpoint.class);
 
     /**
-     * Network logger.
-     */
-    private static final Logger netLogger = LoggerFactoryWrapper.getNetworkLogger();
-
-    /**
      * {@inheritDoc}.
      */
     public NoopTopicEndpoint(List<String> servers, String topic) {
@@ -52,10 +48,11 @@ public abstract class NoopTopicEndpoint extends TopicBase {
     /**
      *  I/O.
      *
+     * @param type "IN" or "OUT".
      * @param message message.
-     * @return true if sucessful.
+     * @return true if successful.
      */
-    protected boolean io(String message) {
+    protected boolean io(EventType type, String message) {
 
         if (message == null || message.isEmpty()) {
             throw new IllegalArgumentException("Message is empty");
@@ -70,8 +67,7 @@ public abstract class NoopTopicEndpoint extends TopicBase {
                 this.recentEvents.add(message);
             }
 
-            netLogger.info("[OUT|{}|{}]{}{}", this.getTopicCommInfrastructure(), this.topic, System.lineSeparator(),
-                    message);
+            NetLoggerUtil.log(type, this.getTopicCommInfrastructure(), this.topic, message);
 
             broadcast(message);
         } catch (Exception e) {
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSink.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSink.java
index f6ad433d..d3745940 100644
--- a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSink.java
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSink.java
@@ -7,9 +7,9 @@
  * 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.
@@ -22,6 +22,7 @@ package org.onap.policy.common.endpoints.event.comm.bus;
 
 import java.util.List;
 import org.onap.policy.common.endpoints.event.comm.TopicSink;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
 
 /**
  * No Operation Topic Sink.
@@ -45,7 +46,7 @@ public class NoopTopicSink extends NoopTopicEndpoint implements TopicSink {
      */
     @Override
     public boolean send(String message) {
-        return super.io(message);
+        return super.io(EventType.OUT, message);
     }
 
     /**
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSource.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSource.java
index c3215e04..95ed0fe6 100644
--- a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSource.java
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/NoopTopicSource.java
@@ -22,6 +22,7 @@ package org.onap.policy.common.endpoints.event.comm.bus;
 
 import java.util.List;
 import org.onap.policy.common.endpoints.event.comm.TopicSource;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
 
 /**
  * No Operation Topic Source.
@@ -45,7 +46,7 @@ public class NoopTopicSource extends NoopTopicEndpoint implements TopicSource {
      */
     @Override
     public boolean offer(String event) {
-        return super.io(event);
+        return super.io(EventType.IN, event);
     }
 
     /**
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/InlineBusTopicSink.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/InlineBusTopicSink.java
index d6ca824e..e94bdffa 100644
--- a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/InlineBusTopicSink.java
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/InlineBusTopicSink.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * policy-endpoints
  * ================================================================================
- * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2017-2019 AT&T Intellectual Property. All rights reserved.
  * Modifications Copyright (C) 2018-2019 Samsung Electronics Co., Ltd.
 * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -24,7 +24,8 @@ package org.onap.policy.common.endpoints.event.comm.bus.internal;
 import java.util.UUID;
 
 import org.onap.policy.common.endpoints.event.comm.bus.BusTopicSink;
-import org.onap.policy.common.utils.slf4j.LoggerFactoryWrapper;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -39,7 +40,6 @@ public abstract class InlineBusTopicSink extends BusTopicBase implements BusTopi
      * Loggers.
      */
     private static Logger logger = LoggerFactory.getLogger(InlineBusTopicSink.class);
-    private static final Logger netLogger = LoggerFactoryWrapper.getNetworkLogger();
 
     /**
      * The partition key to publish to.
@@ -140,8 +140,7 @@ public abstract class InlineBusTopicSink extends BusTopicBase implements BusTopi
                 this.recentEvents.add(message);
             }
 
-            netLogger.info("[OUT|{}|{}]{}{}", this.getTopicCommInfrastructure(), this.topic, System.lineSeparator(),
-                    message);
+            NetLoggerUtil.log(EventType.OUT, this.getTopicCommInfrastructure(), this.topic, message);
 
             publisher.send(this.partitionId, message);
             broadcast(message);
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/SingleThreadedBusTopicSource.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/SingleThreadedBusTopicSource.java
index 83f3760b..98e30e27 100644
--- a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/SingleThreadedBusTopicSource.java
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/event/comm/bus/internal/SingleThreadedBusTopicSource.java
@@ -2,7 +2,7 @@
  * ============LICENSE_START=======================================================
  * policy-endpoints
  * ================================================================================
- * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2017-2019 AT&T Intellectual Property. All rights reserved.
  * Modifications Copyright (C) 2018-2019 Samsung Electronics Co., Ltd.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -28,8 +28,9 @@ import org.onap.policy.common.endpoints.event.comm.FilterableTopicSource;
 import org.onap.policy.common.endpoints.event.comm.TopicListener;
 import org.onap.policy.common.endpoints.event.comm.bus.BusTopicSource;
 import org.onap.policy.common.endpoints.event.comm.bus.internal.BusConsumer.FilterableBusConsumer;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
 import org.onap.policy.common.utils.network.NetworkUtil;
-import org.onap.policy.common.utils.slf4j.LoggerFactoryWrapper;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -45,7 +46,6 @@ public abstract class SingleThreadedBusTopicSource extends BusTopicBase
      * that in a single file in a concise format.
      */
     private static Logger logger = LoggerFactory.getLogger(InlineBusTopicSink.class);
-    private static final Logger netLogger = LoggerFactoryWrapper.getNetworkLogger();
 
     /**
      * Bus consumer group.
@@ -228,8 +228,7 @@ public abstract class SingleThreadedBusTopicSource extends BusTopicBase
                         this.recentEvents.add(event);
                     }
 
-                    netLogger.info("[IN|{}|{}]{}{}", this.getTopicCommInfrastructure(), this.topic,
-                            System.lineSeparator(), event);
+                    NetLoggerUtil.log(EventType.IN, this.getTopicCommInfrastructure(), this.topic, event);
 
                     broadcast(event);
 
@@ -255,8 +254,7 @@ public abstract class SingleThreadedBusTopicSource extends BusTopicBase
             this.recentEvents.add(event);
         }
 
-        netLogger.info("[IN|{}|{}]{}{}", this.getTopicCommInfrastructure(), this.topic, System.lineSeparator(), event);
-
+        NetLoggerUtil.log(EventType.IN, this.getTopicCommInfrastructure(), this.topic, event);
 
         return broadcast(event);
     }
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/features/NetLoggerFeatureApi.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/features/NetLoggerFeatureApi.java
new file mode 100644
index 00000000..4e7d4444
--- /dev/null
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/features/NetLoggerFeatureApi.java
@@ -0,0 +1,62 @@
+/*
+ * ============LICENSE_START=======================================================
+ * policy-endpoints
+ * ================================================================================
+ * 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.features;
+
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
+import org.onap.policy.common.utils.services.OrderedService;
+import org.onap.policy.common.utils.services.OrderedServiceImpl;
+import org.slf4j.Logger;
+
+/**
+ * Logging Feature API. Provides interception points before and after logging a message.
+ */
+public interface NetLoggerFeatureApi extends OrderedService {
+
+    /**
+     * Feature providers implementing this interface.
+     */
+    OrderedServiceImpl<NetLoggerFeatureApi> providers =
+                    new OrderedServiceImpl<>(NetLoggerFeatureApi.class);
+
+    /**
+     * Intercepts a message before it is logged.
+     *
+     * @return true if this feature intercepts and takes ownership of the operation
+     *         preventing the invocation of lower priority features. False, otherwise.
+     */
+    default boolean beforeLog(Logger eventLogger, EventType type, CommInfrastructure protocol, String topic,
+                    String message) {
+        return false;
+    }
+
+    /**
+     * Intercepts a message after it is logged.
+     *
+     * @return true if this feature intercepts and takes ownership of the operation
+     *         preventing the invocation of lower priority features. False, otherwise.
+     */
+    default boolean afterLog(Logger eventLogger, EventType type, CommInfrastructure protocol, String topic,
+                    String message) {
+        return false;
+    }
+
+}
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/utils/NetLoggerUtil.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/utils/NetLoggerUtil.java
new file mode 100644
index 00000000..f82e6a8c
--- /dev/null
+++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/utils/NetLoggerUtil.java
@@ -0,0 +1,153 @@
+/*
+ * ============LICENSE_START=======================================================
+ * policy-endpoints
+ * ================================================================================
+ * 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.utils;
+
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.endpoints.features.NetLoggerFeatureApi;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A network logging utility class that allows drools applications code to access the
+ * network log (or other specified loggers) and logging features.
+ *
+ */
+public class NetLoggerUtil {
+
+    /**
+     * Loggers.
+     */
+    private static final Logger logger = LoggerFactory.getLogger(NetLoggerUtil.class);
+    private static final Logger netLogger = LoggerFactory.getLogger("network");
+
+    /**
+     * Constant for the system line separator.
+     */
+    public static final String SYSTEM_LS = System.lineSeparator();
+
+    /**
+     * Specifies if the message is coming in or going out.
+     */
+    public enum EventType {
+        IN, OUT
+    }
+
+    /**
+     * Get Network Logger.
+     *
+     * @return logger instance
+     */
+    public static Logger getNetworkLogger() {
+        return netLogger;
+    }
+
+    /**
+     * Logs a message to the network logger.
+     *
+     * @param type can either be IN or OUT
+     * @param protocol the protocol used to receive/send the message
+     * @param topic the topic the message came from or null if the type is REST
+     * @param message message to be logged
+     */
+    public static void log(EventType type, CommInfrastructure protocol, String topic, String message) {
+        log(netLogger, type, protocol, topic, message);
+    }
+
+    /**
+     * Logs a message to the specified logger (i.e. a controller logger).
+     *
+     * @param eventLogger the logger that will have the message appended
+     * @param type can either be IN or OUT
+     * @param protocol the protocol used to receive/send the message
+     * @param topic the topic the message came from or null if the type is REST
+     * @param message message to be logged
+     */
+    public static void log(Logger eventLogger, EventType type, CommInfrastructure protocol, String topic,
+                    String message) {
+        if (eventLogger == null) {
+            logger.debug("the logger is null, defaulting to network logger");
+            eventLogger = netLogger;
+        }
+
+        if (featureBeforeLog(eventLogger, type, protocol, topic, message)) {
+            return;
+        }
+
+        eventLogger.info("[{}|{}|{}]{}{}", type, protocol, topic, SYSTEM_LS, message);
+
+        featureAfterLog(eventLogger, type, protocol, topic, message);
+    }
+
+    /**
+     * Executes features that pre-process a message before it is logged.
+     *
+     * @param eventLogger the logger that will have the message appended
+     * @param type can either be IN or OUT
+     * @param protocol the protocol used to receive/send the message
+     * @param topic the topic the message came from or null if the type is REST
+     * @param message message to be logged
+     *
+     * @return true if this feature intercepts and takes ownership of the operation
+     *         preventing the invocation of lower priority features. False, otherwise
+     */
+    private static boolean featureBeforeLog(Logger eventLogger, EventType type, CommInfrastructure protocol,
+                    String topic, String message) {
+        for (NetLoggerFeatureApi feature : NetLoggerFeatureApi.providers.getList()) {
+            try {
+                if (feature.beforeLog(eventLogger, type, protocol, topic, message)) {
+                    return true;
+                }
+            } catch (Exception e) {
+                logger.error("feature {} before-log failure because of {}", feature.getClass().getName(),
+                                e.getMessage(), e);
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Executes features that post-process a message after it is logged.
+     *
+     * @param eventLogger the logger that will have the message appended
+     * @param type can either be IN or OUT
+     * @param protocol the protocol used to receive/send the message
+     * @param topic the topic the message came from or null if the type is rest
+     * @param message message to be logged
+     *
+     * @return true if this feature intercepts and takes ownership of the operation
+     *         preventing the invocation of lower priority features. False, otherwise
+     */
+    private static boolean featureAfterLog(Logger eventLogger, EventType type, CommInfrastructure protocol,
+                    String topic, String message) {
+        for (NetLoggerFeatureApi feature : NetLoggerFeatureApi.providers.getList()) {
+            try {
+                if (feature.afterLog(eventLogger, type, protocol, topic, message)) {
+                    return true;
+                }
+            } catch (Exception e) {
+                logger.error("feature {} after-log failure because of {}", feature.getClass().getName(), e.getMessage(),
+                                e);
+            }
+        }
+        return false;
+    }
+
+}
diff --git a/policy-endpoints/src/test/java/org/onap/policy/common/endpoints/utils/NetLoggerUtilTest.java b/policy-endpoints/src/test/java/org/onap/policy/common/endpoints/utils/NetLoggerUtilTest.java
new file mode 100644
index 00000000..6e84c137
--- /dev/null
+++ b/policy-endpoints/src/test/java/org/onap/policy/common/endpoints/utils/NetLoggerUtilTest.java
@@ -0,0 +1,268 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * policy-endpoints
+ * ================================================================================
+ * 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.utils;
+
+import static org.junit.Assert.assertEquals;
+
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.AppenderBase;
+import java.util.ArrayList;
+import java.util.List;
+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.endpoints.features.NetLoggerFeatureApi;
+import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
+import org.slf4j.Logger;
+
+/**
+ * Test class for network log utilities such as logging and feature invocation.
+ */
+public class NetLoggerUtilTest {
+
+    private static final String MESSAGE = "hello world!";
+    /**
+     * Test feature used for junits.
+     */
+    private static NetLoggerFeature netLoggerFeature;
+
+    /**
+     * Obtains the test implementation of NetLoggerFeatureApi.
+     */
+    @BeforeClass
+    public static void setUp() {
+        netLoggerFeature = (NetLoggerFeature) NetLoggerFeatureApi.providers.getList().get(0);
+    }
+
+    /**
+     * Clears events list and resets return/exceptions flags before invoking every unit test.
+     */
+    @Before
+    public void reset() {
+        TestAppender.clear();
+        netLoggerFeature.setReturnValue(false, false);
+        netLoggerFeature.setExceptions(false, false);
+    }
+
+    /**
+     * Tests obtaining the network logger instance.
+     */
+    @Test
+    public void getNetworkLoggerTest() {
+        assertEquals("network", NetLoggerUtil.getNetworkLogger().getName());
+    }
+
+    /**
+     * Tests logging a message to the network logger and invoking features before/after logging.
+     */
+    @Test
+    public void logTest() {
+        NetLoggerUtil.log(EventType.IN, CommInfrastructure.NOOP, "test-topic", MESSAGE);
+        assertEquals(3, TestAppender.events.size());
+    }
+
+    /**
+     * Tests that the network logger is used to log messages if a logger is not passed in.
+     */
+    @Test
+    public void logDefaultTest() {
+        NetLoggerUtil.log(null, EventType.IN, CommInfrastructure.NOOP, "test-topic", MESSAGE);
+        assertEquals(3, TestAppender.events.size());
+        assertEquals("network", TestAppender.events.get(0).getLoggerName());
+    }
+
+    /**
+     * Tests a NetLoggerFeature that replaces base implementation before logging.
+     */
+    @Test
+    public void beforeLogReturnTrueTest() {
+        netLoggerFeature.setReturnValue(true, false);
+        NetLoggerUtil.log(null, EventType.IN, CommInfrastructure.NOOP, "test-topic", MESSAGE);
+        assertEquals(1, TestAppender.events.size());
+    }
+
+    /**
+     * Tests a NetLoggerFeature that post processes a logged message.
+     */
+    @Test
+    public void afterLogReturnTrueTest() {
+        netLoggerFeature.setReturnValue(false, true);
+        NetLoggerUtil.log(null, EventType.IN, CommInfrastructure.NOOP, "test-topic", MESSAGE);
+        assertEquals(3, TestAppender.events.size());
+    }
+
+    /**
+     * Tests throwing an exception in the before hook.
+     */
+    @Test
+    public void beforeLogExceptionTest() {
+        netLoggerFeature.setExceptions(true, false);
+        NetLoggerUtil.log(null, EventType.IN, CommInfrastructure.NOOP, "test-topic", MESSAGE);
+        assertEquals(2, TestAppender.events.size());
+    }
+
+    /**
+     * Tests throwing an exception in the after hook.
+     */
+    @Test
+    public void afterLogExceptionTest() {
+        netLoggerFeature.setExceptions(false, true);
+        NetLoggerUtil.log(null, EventType.IN, CommInfrastructure.NOOP, "test-topic", MESSAGE);
+        assertEquals(2, TestAppender.events.size());
+    }
+
+    /**
+     * A custom list appender to track messages being logged to the network logger.
+     * NOTE: Check src/test/resources/logback-test.xml for network logger configurations.
+     */
+    public static class TestAppender extends AppenderBase<ILoggingEvent> {
+
+        /**
+         * List of logged events.
+         */
+        public static List<ILoggingEvent> events = new ArrayList<>();
+
+        /**
+         * Called after every unit test to clear list of events.
+         */
+        public static void clear() {
+            events.clear();
+        }
+
+        /**
+         * Appends each event to the event list.
+         */
+        @Override
+        protected void append(ILoggingEvent event) {
+            events.add(event);
+        }
+
+    }
+
+    /**
+     * Test implementation of NetLoggerFeatureApi to be used by junits.
+     */
+    public static class NetLoggerFeature implements NetLoggerFeatureApi {
+
+        /**
+         * Used for setting the return values of before/after hooks.
+         */
+        private boolean beforeReturn = false;
+        private boolean afterReturn = false;
+
+        /**
+         * Used for throwing an exception in the before/after hooks.
+         */
+        private boolean beforeException = false;
+        private boolean afterException = false;
+
+
+        /**
+         * Gets sequence number.
+         */
+        @Override
+        public int getSequenceNumber() {
+            return 0;
+        }
+
+        /**
+         * Get beforeLog return value.
+         */
+        public boolean getBeforeReturn() {
+            return this.beforeReturn;
+        }
+
+        /**
+         * Get afterLog return value.
+         */
+        public boolean getAfterReturn() {
+            return this.afterReturn;
+        }
+
+        /**
+         * Sets the return value for the before/after hooks.
+         *
+         * @param beforeVal beforeLog() return value
+         * @param afterVal afterLog() return value
+         */
+        public void setReturnValue(boolean beforeVal, boolean afterVal) {
+            this.beforeReturn = beforeVal;
+            this.afterReturn = afterVal;
+        }
+
+        /**
+         * Gets beforeException boolean.
+         */
+        public boolean getBeforeException() {
+            return this.beforeException;
+        }
+
+        /**
+         * Gets afterException boolean.
+         */
+        public boolean getAfterException() {
+            return this.afterException;
+        }
+
+        /**
+         * Sets before/after flags to determine if the feature should throw an exception.
+         */
+        public void setExceptions(boolean beforeException, boolean afterException) {
+            this.beforeException = beforeException;
+            this.afterException = afterException;
+        }
+
+        /**
+         * Simple beforeLog message.
+         */
+        @Override
+        public boolean beforeLog(Logger eventLogger, EventType type, CommInfrastructure protocol, String topic,
+                        String message) {
+
+            if (beforeException) {
+                throw new RuntimeException("beforeLog exception");
+            }
+
+            eventLogger.info("before feature test");
+
+            return this.beforeReturn;
+        }
+
+        /**
+         * Simple afterLog message.
+         */
+        @Override
+        public boolean afterLog(Logger eventLogger, EventType type, CommInfrastructure protocol, String topic,
+                        String message) {
+
+            if (afterException) {
+                throw new RuntimeException("afterLog exception");
+            }
+
+            eventLogger.info("after feature test");
+
+            return this.afterReturn;
+        }
+
+    }
+
+}
diff --git a/policy-endpoints/src/test/resources/META-INF/services/org.onap.policy.common.endpoints.features.NetLoggerFeatureApi b/policy-endpoints/src/test/resources/META-INF/services/org.onap.policy.common.endpoints.features.NetLoggerFeatureApi
new file mode 100644
index 00000000..c861ad18
--- /dev/null
+++ b/policy-endpoints/src/test/resources/META-INF/services/org.onap.policy.common.endpoints.features.NetLoggerFeatureApi
@@ -0,0 +1 @@
+org.onap.policy.common.endpoints.utils.NetLoggerUtilTest$NetLoggerFeature
diff --git a/policy-endpoints/src/test/resources/logback-test.xml b/policy-endpoints/src/test/resources/logback-test.xml
index b3feef90..4edcc9db 100644
--- a/policy-endpoints/src/test/resources/logback-test.xml
+++ b/policy-endpoints/src/test/resources/logback-test.xml
@@ -2,7 +2,7 @@
   ============LICENSE_START=======================================================
   ONAP
   ================================================================================
-  Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+  Copyright (C) 2018-2019 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.
@@ -27,8 +27,14 @@
         </encoder>
     </appender>
     
+    <appender name="testAppender" class="org.onap.policy.common.endpoints.utils.NetLoggerUtilTest$TestAppender"/>
+    
     <logger name="org.onap.policy.drools.http.server.test" level="INFO"/>
-
+    
+    <logger name="network" level="INFO">
+        <appender-ref ref="testAppender" />
+    </logger>
+    
     <root level="WARN">
         <appender-ref ref="STDOUT"/>
     </root>