Logging refactoring and global context

Implemented global context (instance ID, host address).
Refactored the logging context API for clarity and
separation of concerns. Added unit tests. Fixed Javadoc.

Change-Id: I6e29b7b3613aebf23112dc017490ad2828e0fb91
Issue-ID: SDC-772
Signed-off-by: vempo <vitaliy.emporopulo@amdocs.com>

11 files changed, 363 insertions, 198 deletions

diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/GlobalLoggingContext.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/GlobalLoggingContext.java
index 95dc52c85c..a708ed6715 100644
--- a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/GlobalLoggingContext.java
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/GlobalLoggingContext.java
@@ -16,13 +16,8 @@
 
 package org.openecomp.sdc.logging;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
-import java.nio.charset.StandardCharsets;
-import java.util.Properties;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.prefs.BackingStoreException;
@@ -38,45 +33,20 @@ import java.util.prefs.Preferences;
 @SuppressWarnings({"UseOfSystemOutOrSystemErr", "CallToPrintStackTrace", "squid:S106", "squid:S1148"})
 public class GlobalLoggingContext {
 
-    private static final String APPLICATION_ID_KEY = "ApplicationId";
-
-    private static final String CONFIGURATION_RESOURCE = "META-INF/logging/logger.properties";
-
-    @SuppressWarnings("squid:S1075")
-    private static final String ID_PREFERENCES_PATH = "/logging/instance/uuid";
-
-    private static final String APP_DISTINGUISHER_KEY = "app.distinguisher";
-
     // should be cashed to avoid low-level call, but with a timeout to account for IP or FQDN changes
-    private static final HostAddressCache HOST_ADDRESS = new HostAddressCache();
-
-    private static final String DISTINGUISHER;
+    private static final HostAddressCache HOST_ADDRESS_CACHE = new HostAddressCache();
 
-    private static final String APPLICATION_ID;
+    @SuppressWarnings("squid:S1075")
+    private static final String INSTANCE_UUID_PREFERENCES_PATH = "/logging/instance/uuid";
 
     private static final String INSTANCE_ID;
 
     static {
-        APPLICATION_ID = System.getProperty(APPLICATION_ID_KEY);
-        DISTINGUISHER = readDistinguisher();
         INSTANCE_ID = readInstanceId();
     }
 
-    private GlobalLoggingContext() { /* prevent instantiation */ }
-
-    public static String getApplicationId() {
-        return APPLICATION_ID;
-    }
-
-    /**
-     * A distinguisher to allow separation of logs created by applications running with the same configuration, but
-     * different class-loaders. For instance, when multiple web application are running in the same container and their
-     * logger configuration is passed at the JVM level.
-     *
-     * @return application distinguisher defined in a properties file
-     */
-    public static String getDistinguisher() {
-        return DISTINGUISHER;
+    private GlobalLoggingContext() {
+        // prevent instantiation
     }
 
     /**
@@ -96,25 +66,22 @@ public class GlobalLoggingContext {
      * @return local host address, may be null if could not be read for some reason
      */
     public static InetAddress getHostAddress() {
-        return HOST_ADDRESS.get();
+        return HOST_ADDRESS_CACHE.get();
     }
 
     private static String readInstanceId() {
 
-        String appId = System.getProperty(APPLICATION_ID_KEY);
-        String key = ID_PREFERENCES_PATH + (appId == null ? "" : "/" + appId);
-
         try {
 
-            // By default, this will be ~/.java/.userPrefs/prefs.xml
+            // On Linux, by default this will be ~/.java/.userPrefs/prefs.xml
             final Preferences preferences = Preferences.userRoot();
-            String existingId = preferences.get(key, null);
+            String existingId = preferences.get(INSTANCE_UUID_PREFERENCES_PATH, null);
             if (existingId != null) {
                 return existingId;
             }
 
             String newId = UUID.randomUUID().toString();
-            preferences.put(key, newId);
+            preferences.put(INSTANCE_UUID_PREFERENCES_PATH, newId);
             preferences.flush();
             return newId;
 
@@ -125,35 +92,6 @@ public class GlobalLoggingContext {
         }
     }
 
-    private static String readDistinguisher() {
-
-        try {
-            Properties properties = loadConfiguration();
-            return properties.getProperty(APP_DISTINGUISHER_KEY, "");
-        } catch (IOException e) {
-            e.printStackTrace(); // can't write to a log
-            return "";
-        }
-    }
-
-    private static Properties loadConfiguration() throws IOException {
-
-        Properties properties = new Properties();
-
-        try (InputStream is = Thread.currentThread().getContextClassLoader()
-            .getResourceAsStream(CONFIGURATION_RESOURCE)) {
-
-            if (is == null) {
-                return properties;
-            }
-
-            try (InputStreamReader reader = new InputStreamReader(is, StandardCharsets.UTF_8)) {
-                properties.load(reader);
-                return properties;
-            }
-        }
-    }
-
     private static class HostAddressCache {
 
         private static final long REFRESH_TIME = 60000L;
@@ -161,7 +99,7 @@ public class GlobalLoggingContext {
         private final AtomicLong lastUpdated = new AtomicLong(0L);
         private InetAddress hostAddress;
 
-        public InetAddress get() {
+        InetAddress get() {
 
             long current = System.currentTimeMillis();
             if (current - lastUpdated.get() > REFRESH_TIME) {
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/BaseMDCCopyingWrapper.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/BaseMDCCopyingWrapper.java
deleted file mode 100644
index d667ff769c..0000000000
--- a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/BaseMDCCopyingWrapper.java
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * Copyright © 2016-2017 European Support Limited
- *
- * 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.
- */
-
-package org.openecomp.sdc.logging.slf4j;
-
-import java.util.EnumMap;
-import java.util.Map;
-import org.openecomp.sdc.logging.slf4j.SLF4JLoggingServiceProvider.ContextField;
-import org.slf4j.MDC;
-
-/**
- * Because we don't know which information should be carried over from MDC, and which shouldn't, copy just the keys that
- * the logging service uses.
- *
- * @author evitaliy
- * @since 08 Jan 2018
- */
-abstract class BaseMDCCopyingWrapper {
-
-    private final Map<ContextField, String> context;
-
-    BaseMDCCopyingWrapper() {
-        this.context = fromMdc();
-    }
-
-    final Map<ContextField, String> replace() {
-        Map<ContextField, String> old = fromMdc();
-        toMdc(this.context);
-        return old;
-    }
-
-    final void revert(Map<ContextField, String> old) {
-        toMdc(old);
-    }
-
-    private Map<ContextField, String> fromMdc() {
-
-        Map<ContextField, String> copy = new EnumMap<>(ContextField.class);
-        for (ContextField k : ContextField.values()) {
-            String v = MDC.get(k.asKey());
-            if (v != null) {
-                copy.put(k, v);
-            }
-        }
-
-        return copy;
-    }
-
-    private static void toMdc(Map<ContextField, String> context) {
-
-        for (ContextField k : ContextField.values()) {
-            String v = context.get(k);
-            if (v != null) {
-                MDC.put(k.asKey(), v);
-            } else {
-                MDC.remove(k.asKey());
-            }
-        }
-    }
-}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/Context.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/Context.java
new file mode 100644
index 0000000000..25784fefcd
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/Context.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright © 2016-2017 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdc.logging.slf4j;
+
+import java.util.Map;
+
+/**
+ * Does not store a state other than initial context values. Objects of this class may be reused by multiple threads,
+ * therefore they must be stateless to prevent inadvertent exchange of context values between threads.
+ *
+ * @author evitaliy
+ * @since 08 Jan 2018
+ */
+final class Context {
+
+    private final Map<ContextField, String> originalCtx;
+
+    Context() {
+        this.originalCtx = MDCDelegate.copy();
+    }
+
+    /**
+     * Pushes the initial context onto current thread, and returns the existing context. The result cannot be stored as
+     * local state (see the class comments), and must be kept in a local variable to work properly.
+     *
+     * @return previous context values
+     */
+    final Map<ContextField, String> replace() {
+        Map<ContextField, String> old = MDCDelegate.copy();
+        MDCDelegate.replace(this.originalCtx);
+        return old;
+    }
+
+    /**
+     * Pushes an old context onto current thread.
+     *
+     * @param old copy of the old context returned by {@link #replace()}
+     */
+    final void revert(Map<ContextField, String> old) {
+        MDCDelegate.replace(old);
+    }
+}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/ContextField.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/ContextField.java
new file mode 100644
index 0000000000..6aa689bf21
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/ContextField.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdc.logging.slf4j;
+
+/**
+ * MDC fields to work with - populate, clear, copy.
+ *
+ * @author evitaliy
+ * @since 23 Mar 2018
+ */
+enum ContextField {
+
+    REQUEST_ID("RequestId"),
+    SERVICE_NAME("ServiceName"),
+    PARTNER_NAME("PartnerName"),
+    INSTANCE_ID("InstanceId"),
+    SERVER("Server"),
+    SERVER_IP_ADDRESS("ServerIpAddress");
+
+    private final String key;
+
+    ContextField(String key) {
+        this.key = key;
+    }
+
+    public String asKey() {
+        return key;
+    }
+}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/ContextProvider.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/ContextProvider.java
new file mode 100644
index 0000000000..f9a7144b22
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/ContextProvider.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdc.logging.slf4j;
+
+import java.util.Map;
+
+/**
+ * Abstracts a source of MDC values.
+ *
+ * @author evitaliy
+ * @since 23 Mar 2018
+ */
+interface ContextProvider {
+    Map<ContextField, String> values();
+}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/GlobalContextProvider.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/GlobalContextProvider.java
new file mode 100644
index 0000000000..a415e22c63
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/GlobalContextProvider.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdc.logging.slf4j;
+
+import java.net.InetAddress;
+import java.util.EnumMap;
+import java.util.Map;
+import org.openecomp.sdc.logging.GlobalLoggingContext;
+
+/**
+ * Maps global logging context to corresponding MDC fields.
+ *
+ * @author evitaliy
+ * @since 23 Mar 2018
+ */
+class GlobalContextProvider implements ContextProvider {
+
+    @Override
+    public Map<ContextField, String> values() {
+
+        Map<ContextField, String> values = new EnumMap<>(ContextField.class);
+        values.put(ContextField.INSTANCE_ID, GlobalLoggingContext.getInstanceId());
+
+        InetAddress hostAddress = GlobalLoggingContext.getHostAddress();
+        if (hostAddress != null) {
+            values.put(ContextField.SERVER, hostAddress.getHostName());
+            values.put(ContextField.SERVER_IP_ADDRESS, hostAddress.getHostAddress());
+        }
+
+        return values;
+    }
+}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCCallableWrapper.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCCallableWrapper.java
index 07d0f935f7..84aa256d95 100644
--- a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCCallableWrapper.java
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCCallableWrapper.java
@@ -18,30 +18,32 @@ package org.openecomp.sdc.logging.slf4j;
 
 import java.util.Map;
 import java.util.concurrent.Callable;
-import org.openecomp.sdc.logging.slf4j.SLF4JLoggingServiceProvider.ContextField;
 
 /**
- * @author EVITALIY
+ * Carries MDC values over to a Callable from the instantiating thread to the moment the callable will run.
+ *
+ * @author evitaliy
  * @since 08 Jan 18
  */
-class MDCCallableWrapper<V> extends BaseMDCCopyingWrapper implements Callable<V> {
+class MDCCallableWrapper<V> implements Callable<V> {
+
+    private final Context context = new Context();
 
     private final Callable<V> task;
 
     MDCCallableWrapper(Callable<V> task) {
-        super();
         this.task = task;
     }
 
     @Override
     public V call() throws Exception {
 
-        Map<ContextField, String> oldContext = replace();
+        Map<ContextField, String> oldContext = context.replace();
 
         try {
             return task.call();
         } finally {
-            revert(oldContext);
+            context.revert(oldContext);
         }
     }
 }
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCDelegate.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCDelegate.java
new file mode 100644
index 0000000000..8d719a2da8
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCDelegate.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdc.logging.slf4j;
+
+import java.util.EnumMap;
+import java.util.Map;
+import org.slf4j.MDC;
+
+/**
+ * Because we don't know which information should be carried over from MDC, and which shouldn't, copy just the keys that
+ * the logging service uses.
+ *
+ * @author evitaliy
+ * @since 23 Mar 2018
+ */
+class MDCDelegate {
+
+    private MDCDelegate() {
+        // static methods only, prevent instantiation
+    }
+
+    /**
+     * Get a copy of logging MDC fields.
+     */
+    static Map<ContextField, String> copy() {
+
+        Map<ContextField, String> copy = new EnumMap<>(ContextField.class);
+        for (ContextField k : ContextField.values()) {
+            String v = MDC.get(k.asKey());
+            if (v != null) {
+                copy.put(k, v);
+            }
+        }
+
+        return copy;
+    }
+
+    /**
+     * Entirely replaces the logging MDC context with the content of the argument. Logging keys that are not present in
+     * the input map will be cleared from MDC.
+     */
+    static void replace(Map<ContextField, String> values) {
+
+        for (ContextField key : ContextField.values()) {
+            updateKey(key, values.get(key));
+        }
+    }
+
+    /**
+     * Push data by multiple data providers on MDC.
+     */
+    static void put(ContextProvider... dataProviders) {
+
+        clear();
+
+        for (ContextProvider provider : dataProviders) {
+            push(provider.values());
+        }
+    }
+
+    /**
+     * Updates the logging MDC context with the content of the argument. Logging keys that are not present in the input
+     * map will remain "as is", keys with null values will be cleared from MDC.
+     */
+    private static void push(Map<ContextField, String> values) {
+
+        for (Map.Entry<ContextField, String> entry : values.entrySet()) {
+            updateKey(entry.getKey(), entry.getValue());
+        }
+    }
+
+    private static void updateKey(ContextField key, String value) {
+
+        if (value != null) {
+            MDC.put(key.asKey(), value);
+        } else {
+            MDC.remove(key.asKey());
+        }
+    }
+
+    static void clear() {
+
+        for (ContextField field : ContextField.values()) {
+            MDC.remove(field.asKey());
+        }
+    }
+}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCRunnableWrapper.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCRunnableWrapper.java
index e1b8f1e5c5..9d93246181 100644
--- a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCRunnableWrapper.java
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/MDCRunnableWrapper.java
@@ -17,30 +17,32 @@
 package org.openecomp.sdc.logging.slf4j;
 
 import java.util.Map;
-import org.openecomp.sdc.logging.slf4j.SLF4JLoggingServiceProvider.ContextField;
 
 /**
- * @author EVITALIY
+ * Carries MDC values over to a Runnable from the instantiating thread to the moment the callable will run.
+ *
+ * @author evitaliy
  * @since 08 Jan 18
  */
-class MDCRunnableWrapper extends BaseMDCCopyingWrapper implements Runnable {
+class MDCRunnableWrapper implements Runnable {
+
+    private final Context context = new Context();
 
     private final Runnable task;
 
     MDCRunnableWrapper(Runnable task) {
-        super();
         this.task = task;
     }
 
     @Override
     public void run() {
 
-        Map<ContextField, String> oldContext = replace();
+        Map<ContextField, String> oldContext = context.replace();
 
         try {
             task.run();
         } finally {
-            revert(oldContext);
+            context.revert(oldContext);
         }
     }
 }
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/RequestContextProvider.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/RequestContextProvider.java
new file mode 100644
index 0000000000..d79771c1c5
--- /dev/null
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/RequestContextProvider.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright © 2016-2018 European Support Limited
+ *
+ * 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.
+ */
+
+package org.openecomp.sdc.logging.slf4j;
+
+import java.util.EnumMap;
+import java.util.Map;
+import org.openecomp.sdc.logging.api.ContextData;
+
+/**
+ * Maps request data sent to the context service to corresponding MDC fields.
+ *
+ * @author evitaliy
+ * @since 23 Mar 2018
+ */
+class RequestContextProvider implements ContextProvider {
+
+    private final ContextData data;
+
+    RequestContextProvider(ContextData contextData) {
+        this.data = contextData;
+    }
+
+    @Override
+    public Map<ContextField, String> values() {
+
+        Map<ContextField, String> values = new EnumMap<>(ContextField.class);
+
+        putIfNotNull(values, ContextField.REQUEST_ID, data.getRequestId());
+        putIfNotNull(values, ContextField.SERVICE_NAME, data.getServiceName());
+        putIfNotNull(values, ContextField.PARTNER_NAME, data.getPartnerName());
+
+        return values;
+    }
+
+    private void putIfNotNull(Map<ContextField, String> values, ContextField field, String value) {
+
+        if (value != null) {
+            values.put(field, value);
+        }
+    }
+}
diff --git a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/SLF4JLoggingServiceProvider.java b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/SLF4JLoggingServiceProvider.java
index 6f69aae1b6..1a5d6facc2 100644
--- a/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/SLF4JLoggingServiceProvider.java
+++ b/openecomp-be/lib/openecomp-sdc-logging-lib/openecomp-sdc-logging-core/src/main/java/org/openecomp/sdc/logging/slf4j/SLF4JLoggingServiceProvider.java
@@ -16,39 +16,20 @@
 
 package org.openecomp.sdc.logging.slf4j;
 
-import static org.openecomp.sdc.logging.slf4j.SLF4JLoggingServiceProvider.ContextField.PARTNER_NAME;
-import static org.openecomp.sdc.logging.slf4j.SLF4JLoggingServiceProvider.ContextField.REQUEST_ID;
-import static org.openecomp.sdc.logging.slf4j.SLF4JLoggingServiceProvider.ContextField.SERVICE_NAME;
-
 import java.util.Objects;
 import java.util.concurrent.Callable;
+import org.openecomp.sdc.logging.api.ContextData;
 import org.openecomp.sdc.logging.api.Logger;
 import org.openecomp.sdc.logging.spi.LoggingServiceProvider;
-import org.slf4j.MDC;
 
 /**
+ * Uses SLF4J as backend for logging service.
+ *
  * @author evitaliy
  * @since 13 Sep 2016
  */
 public class SLF4JLoggingServiceProvider implements LoggingServiceProvider {
 
-    enum ContextField {
-
-        REQUEST_ID("RequestId"),
-        SERVICE_NAME("ServiceName"),
-        PARTNER_NAME("PartnerName");
-
-        private final String key;
-
-        ContextField(String key) {
-            this.key = key;
-        }
-
-        String asKey() {
-            return key;
-        }
-    }
-
     @Override
     public Logger getLogger(String className) {
         Objects.requireNonNull(className, "Name cannot be null");
@@ -62,29 +43,14 @@ public class SLF4JLoggingServiceProvider implements LoggingServiceProvider {
     }
 
     @Override
-    public void putRequestId(String requestId) {
-        put(REQUEST_ID.key, requestId);
-    }
-
-    @Override
-    public void putServiceName(String serviceName) {
-        put(SERVICE_NAME.key, serviceName);
-    }
-
-    @Override
-    public void putPartnerName(String partnerName) {
-        put(PARTNER_NAME.key, partnerName);
+    public void put(ContextData contextData) {
+        Objects.requireNonNull(contextData, "Context data cannot be null");
+        MDCDelegate.put(new RequestContextProvider(contextData), new GlobalContextProvider());
     }
 
     @Override
     public void clear() {
-        for (ContextField s : ContextField.values()) {
-            MDC.remove(s.key);
-        }
-    }
-
-    private void put(String key, String value) {
-        MDC.put(key, Objects.requireNonNull(value, key));
+        MDCDelegate.clear();
     }
 
     @Override