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authorLuke Parker <lparker@amdocs.com>2018-05-22 17:35:18 +1000
committerLuke Parker <lparker@amdocs.com>2018-05-24 16:48:24 +1000
commit7a724b15b5a1266b8517d56008becd336db6a1c5 (patch)
tree8db4e6c052cda9fd166dff4270d8271c0bc2d042 /reference/logging-slf4j/src/main/java
parentbdbcf1dbddd8c4646acd4187bc836102f493a542 (diff)
Rename slf4j ref impl, add constants
Change-Id: Ib3f24c3aa4974ac8c87fa969613192e884674f00 Issue-ID: LOG-115 Signed-off-by: Luke Parker <lparker@amdocs.com>
Diffstat (limited to 'reference/logging-slf4j/src/main/java')
-rw-r--r--reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogAdapter.java611
-rw-r--r--reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogConstants.java253
-rw-r--r--reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/package-info.java32
3 files changed, 896 insertions, 0 deletions
diff --git a/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogAdapter.java b/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogAdapter.java
new file mode 100644
index 0000000..50693cb
--- /dev/null
+++ b/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogAdapter.java
@@ -0,0 +1,611 @@
+/**
+ * ============LICENSE_START=======================================================
+ * org.onap.logging
+ * ================================================================================
+ * Copyright © 2018 Amdocs
+ * 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.logging.ref.slf4j;
+
+import java.time.LocalDateTime;
+import java.util.UUID;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.slf4j.Logger;
+import org.slf4j.MDC;
+import org.slf4j.Marker;
+import org.slf4j.event.Level;
+
+/**
+ * Extensible adapter for cheaply meeting ONAP logging obligations using
+ * an SLF4J facade.
+ *
+ * <p>This can be used with any SLF4J-compatible logging provider, with
+ * appropriate provider configuration.</p>
+ *
+ * <p>The basics are that:
+ * <ul>
+ * <li>{@link #entering} sets all MDCs.</li>
+ * <li>{@link #exiting} unsets all MDCs *and* logs response information.</li>
+ * <li>{@link #invoke} logs and returns a UUID to passed during invocation,
+ * and optionally sets these for you on your downstream request by way of
+ * an adapter.</li>
+ * <li>Call {@link #getServiceDescriptor()} and its setters to set service-related MDCs.</li>
+ * <li>Call {@link #getResponseDescriptor()} and its setters to set response-related MDCs.</li>
+ * </ul>
+ * </p>
+ *
+ * <p>Minimal usage is:
+ * <ol>
+ * <li>#entering(RequestAdapter)</li>
+ * <li>#invoke, #invoke, ...</li>
+ * <li>#getResponse + setters (or #setResponse)</li>
+ * <li>#exiting</li>
+ * </ol>
+ * </p>
+ *
+ * <p> ... if you're happy for service information to be automatically derived as follows:
+ * <ul>
+ * <li><tt>ServiceName</tt> - from <tt>HttpServletRequest#getRequestURI()</tt></li>
+ * <li><tt>InstanceUUID</tt> - classloader-scope UUID.</li>
+ * </ul>
+ * </p>
+ *
+ * <p>... and if those defaults don't suit, then you can override using properties on
+ * {@link #getServiceDescriptor()}, or by injecting your own adapter using
+ * {@link #setServiceDescriptor(ServiceDescriptor)}, or by overriding
+ * a <tt>protected</tt> methods like{@link #setEnteringMDCs}.</p>
+ *
+ * <p>For everything else:
+ * <ul>
+ * <li>The underlying SLF4J {@link Logger} can be retrieved using {@link #unwrap}.
+ * Use this or create your own using the usual SLF4J factor.</li>
+ * <li>Set whatever MDCs you like.</li>
+ * <li>Log whatever else you like.</li>
+ * </ul>
+ * </p>
+ */
+public class ONAPLogAdapter {
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Constants.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /** String constant for messages <tt>ENTERING</tt>, <tt>EXITING</tt>, etc. */
+ private static final String EMPTY_MESSAGE = "";
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Fields.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /** Automatic UUID, overrideable per adapter or per invocation. */
+ private static UUID sInstanceUUID = UUID.randomUUID();
+
+ /** Logger delegate. */
+ private Logger mLogger;
+
+ /** Overrideable descriptor for the service doing the logging. */
+ private ServiceDescriptor mServiceDescriptor = new ServiceDescriptor();
+
+ /** Overrideable descriptor for the response returned by the service doing the logging. */
+ private ResponseDescriptor mResponseDescriptor = new ResponseDescriptor();
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Constructors.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Construct adapter.
+ *
+ * @param logger non-null logger.
+ */
+ public ONAPLogAdapter(final Logger logger) {
+ this.mLogger = checkNotNull(logger);
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Public methods.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Get logger.
+ *
+ * @return unwrapped logger.
+ */
+ public Logger unwrap() {
+ return this.mLogger;
+ }
+
+ /**
+ * Report <tt>ENTERING</tt> marker.
+ *
+ * @param request non-null incoming request (wrapper).
+ * @return this.
+ */
+ public ONAPLogAdapter entering(final RequestAdapter request) {
+
+ checkNotNull(request);
+
+ // Default the service name.
+
+ this.setEnteringMDCs(request);
+ this.mLogger.info(ONAPLogConstants.Markers.ENTRY, EMPTY_MESSAGE);
+
+ return this;
+ }
+
+ /**
+ * Report <tt>ENTERING</tt> marker.
+ *
+ * @param request non-null incoming request.
+ * @return this.
+ */
+ public ONAPLogAdapter entering(final HttpServletRequest request) {
+ return this.entering(new HttpServletRequestAdapter(checkNotNull(request)));
+ }
+
+ /**
+ * Report <tt>EXITING</tt> marker.
+ *
+ * @return this.
+ */
+ public ONAPLogAdapter exiting() {
+ try {
+ this.mResponseDescriptor.setMDCs();
+ this.mLogger.info(ONAPLogConstants.Markers.EXIT, EMPTY_MESSAGE);
+ }
+ finally {
+ MDC.clear();
+ }
+ return this;
+ }
+
+ /**
+ * Report pending invocation with <tt>INVOKE</tt> marker.
+ *
+ * <p>If you call this variant, then YOU are assuming responsibility for
+ * setting the requisite ONAP headers.</p>
+ *
+ * @param sync whether synchronous.
+ * @return invocation ID to be passed with invocation.
+ */
+ public UUID invoke(final ONAPLogConstants.InvocationMode sync) {
+
+ final UUID invocationID = UUID.randomUUID();
+
+ // Derive SYNC/ASYNC marker.
+
+ final Marker marker = (sync == null) ? ONAPLogConstants.Markers.INVOKE : sync.getMarker();
+
+ // Log INVOKE*, with the invocationID as the message body.
+ // (We didn't really want this kind of behavior in the standard,
+ // but is it worse than new, single-message MDC?)
+
+ this.mLogger.info(marker, "{}", invocationID);
+ return invocationID;
+ }
+
+ /**
+ * Report pending invocation with <tt>INVOKE</tt> marker,
+ * setting standard ONAP logging headers automatically.
+ *
+ * @param builder request builder, for setting headers.
+ * @param sync whether synchronous, nullable.
+ * @return invocation ID to be passed with invocation.
+ */
+ public UUID invoke(final RequestBuilder builder,
+ final ONAPLogConstants.InvocationMode sync) {
+
+ // Sync can be defaulted. Builder cannot.
+
+ checkNotNull(builder);
+
+ // Log INVOKE, and retain invocation ID for header + return.
+
+ final UUID invocationID = this.invoke(sync);
+
+ // Set standard HTTP headers on (southbound request) builder.
+
+ builder.setHeader(ONAPLogConstants.Headers.REQUEST_ID,
+ defaultToEmpty(MDC.get(ONAPLogConstants.MDCs.REQUEST_ID)));
+ builder.setHeader(ONAPLogConstants.Headers.INVOCATION_ID,
+ defaultToEmpty(invocationID));
+ builder.setHeader(ONAPLogConstants.Headers.PARTNER_NAME,
+ defaultToEmpty(MDC.get(ONAPLogConstants.MDCs.PARTNER_NAME)));
+
+ return invocationID;
+ }
+
+ /**
+ * Report vanilla <tt>INVOKE</tt> marker.
+ *
+ * @param builder builder for downstream requests, if you want the
+ * standard ONAP headers to be added automatically.
+ * @return invocation ID to be passed with invocation.
+ */
+ public UUID invoke(final RequestBuilder builder) {
+ return this.invoke(builder, (ONAPLogConstants.InvocationMode)null);
+ }
+
+ /**
+ * Get descriptor, for overriding service details.
+ * @return non-null descriptor.
+ */
+ public ServiceDescriptor getServiceDescriptor() {
+ return checkNotNull(this.mServiceDescriptor);
+ }
+
+ /**
+ * Override {@link ServiceDescriptor}.
+ * @param d non-null override.
+ * @return this.
+ */
+ public ONAPLogAdapter setServiceDescriptor(final ServiceDescriptor d) {
+ this.mServiceDescriptor = checkNotNull(d);
+ return this;
+ }
+
+ /**
+ * Get descriptor, for setting response details.
+ * @return non-null descriptor.
+ */
+ public ResponseDescriptor getResponseDescriptor() {
+ return checkNotNull(this.mResponseDescriptor);
+ }
+
+ /**
+ * Override {@link ResponseDescriptor}.
+ * @param d non-null override.
+ * @return this.
+ */
+ public ONAPLogAdapter setResponseDescriptor(final ResponseDescriptor d) {
+ this.mResponseDescriptor = checkNotNull(d);
+ return this;
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Protected methods.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Set MDCs that persist for the duration of an invocation.
+ *
+ * <p>It would be better to roll this into {@link #entering}, like
+ * with {@link #exiting}. Then it would be easier to do, but it
+ * would mean more work. </p>
+ *
+ * @param request incoming HTTP request.
+ * @return this.
+ */
+ protected ONAPLogAdapter setEnteringMDCs(final RequestAdapter<?> request) {
+
+ // Extract MDC values from standard HTTP headers.
+
+ final String requestID = defaultToUUID(request.getHeader(ONAPLogConstants.Headers.REQUEST_ID));
+ final String invocationID = defaultToUUID(request.getHeader(ONAPLogConstants.Headers.INVOCATION_ID));
+ final String partnerName = defaultToEmpty(request.getHeader(ONAPLogConstants.Headers.PARTNER_NAME));
+
+ // Set standard MDCs. Override this entire method if you want to set
+ // others, OR set them BEFORE or AFTER the invocation of #entering,
+ // depending on where you need them to appear, OR extend the
+ // ServiceDescriptor to add them.
+
+ MDC.put(ONAPLogConstants.MDCs.INVOKE_TIMESTAMP, LocalDateTime.now().toString());
+ MDC.put(ONAPLogConstants.MDCs.REQUEST_ID, requestID);
+ MDC.put(ONAPLogConstants.MDCs.INVOCATION_ID, invocationID);
+ MDC.put(ONAPLogConstants.MDCs.PARTNER_NAME, partnerName);
+ MDC.put(ONAPLogConstants.MDCs.CLIENT_IP_ADDRESS, defaultToEmpty(request.getClientAddress()));
+ MDC.put(ONAPLogConstants.MDCs.SERVER_FQDN, defaultToEmpty(request.getServerAddress()));
+
+ // Delegate to the service adapter, for service-related DMCs.
+
+ this.mServiceDescriptor.setMDCs();
+
+ // Default the service name to the requestURI, in the event that
+ // no value has been provided.
+
+ if (MDC.get(ONAPLogConstants.MDCs.SERVICE_NAME) == null) {
+ MDC.put(ONAPLogConstants.MDCs.SERVICE_NAME, request.getRequestURI());
+ }
+
+ return this;
+ }
+
+ /**
+ * Dependency-free nullcheck.
+ *
+ * @param in to be checked.
+ * @param <T> argument (and return) type.
+ * @return input arg.
+ */
+ protected static <T> T checkNotNull(final T in) {
+ if (in == null) {
+ throw new NullPointerException();
+ }
+ return in;
+ }
+
+ /**
+ * Dependency-free string default.
+ *
+ * @param in to be filtered.
+ * @return input string or null.
+ */
+ protected static String defaultToEmpty(final Object in) {
+ if (in == null) {
+ return "";
+ }
+ return in.toString();
+ }
+
+ /**
+ * Dependency-free string default.
+ *
+ * @param in to be filtered.
+ * @return input string or null.
+ */
+ protected static String defaultToUUID(final String in) {
+ if (in == null) {
+ return UUID.randomUUID().toString();
+ }
+ return in;
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Inner classes.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Extensible descriptor for reporting service details.
+ *
+ * <p>In most cases extension isn't required. </p>
+ */
+ public static class ServiceDescriptor {
+
+ /** <tt>ServiceName</tt>. */
+ protected String mName;
+
+ /** <tt>InstanceUUID</tt>. */
+ protected String mUUID = sInstanceUUID.toString();
+
+ /**
+ * Set name.
+ * @param name <tt>ServiceName</tt>.
+ * @return this.
+ */
+ public ServiceDescriptor setServiceName(final String name) {
+ this.mName = name;
+ return this;
+ }
+
+ /**
+ * Set name.
+ * @param uuid <tt>InstanceUUID</tt>.
+ * @return this.
+ */
+ public ServiceDescriptor setServiceUUID(final String uuid) {
+ this.mUUID = uuid;
+ return this;
+ }
+
+ /**
+ * Set MDCs. Once set they remain set until everything is cleared.
+ */
+ protected void setMDCs() {
+ MDC.put(ONAPLogConstants.MDCs.SERVICE_NAME, defaultToEmpty(this.mName));
+ MDC.put(ONAPLogConstants.MDCs.INSTANCE_UUID, defaultToEmpty(this.mUUID));
+ }
+ }
+
+ /**
+ * Response is different in that response MDCs are normally only
+ * reported once, for a single log message. (But there's no method
+ * for clearing them, because this is only expected to be called
+ * during <tt>#exiting</tt>.)
+ */
+ public static class ResponseDescriptor {
+
+ /** Response errorcode. */
+ protected String mCode;
+
+ /** Response description. */
+ protected String mDescription;
+
+ /** Response severity. */
+ protected Level mSeverity;
+
+ /** Response status, of {<tt>COMPLETED</tt>, <tt>ERROR</tt>}. */
+ protected ONAPLogConstants.ResponseStatus mStatus;
+
+ /**
+ * Setter.
+ *
+ * @param code response (error) code.
+ * @return this.
+ */
+ public ResponseDescriptor setResponseCode(final String code) {
+ this.mCode = code;
+ return this;
+ }
+
+ /**
+ * Setter.
+ *
+ * @param description response description.
+ * @return this.
+ */
+ public ResponseDescriptor setResponseDescription(final String description) {
+ this.mDescription = description;
+ return this;
+ }
+
+ /**
+ * Setter.
+ *
+ * @param severity response outcome severity.
+ * @return this.
+ */
+ public ResponseDescriptor setResponseSeverity(final Level severity) {
+ this.mSeverity = severity;
+ return this;
+ }
+
+ /**
+ * Setter.
+ *
+ * @param status response overall status.
+ * @return this.
+ */
+ public ResponseDescriptor setResponseStatus(final ONAPLogConstants.ResponseStatus status) {
+ this.mStatus = status;
+ return this;
+ }
+
+ /**
+ * Overrideable method to set MDCs based on property values.
+ */
+ protected void setMDCs() {
+ MDC.put(ONAPLogConstants.MDCs.RESPONSE_CODE, defaultToEmpty(this.mCode));
+ MDC.put(ONAPLogConstants.MDCs.RESPONSE_DESCRIPTION, defaultToEmpty(this.mDescription));
+ MDC.put(ONAPLogConstants.MDCs.RESPONSE_SEVERITY, defaultToEmpty(this.mSeverity));
+ MDC.put(ONAPLogConstants.MDCs.RESPONSE_STATUS_CODE, defaultToEmpty(this.mStatus));
+ }
+ }
+
+ /**
+ * Adapter for reading information from an incoming HTTP request.
+ *
+ * <p>Incoming is generally easy, because in most cases you'll be able to
+ * get your hands on the <tt>HttpServletRequest</tt>.</p>
+ *
+ * <p>Perhaps should be generalized to refer to constants instead of
+ * requiring the implementation of specific methods.</p>
+ *
+ * @param <T> type, for chaining.
+ */
+ public interface RequestAdapter<T extends RequestAdapter> {
+
+ /**
+ * Get header by name.
+ * @param name header name.
+ * @return header value, or null.
+ */
+ String getHeader(String name);
+
+ /**
+ * Get client address.
+ * @return address, if available.
+ */
+ String getClientAddress();
+
+ /**
+ * Get server address.
+ * @return address, if available.
+ */
+ String getServerAddress();
+
+ /**
+ * Get default service name, from service URI.
+ * @return service name default.
+ */
+ String getRequestURI();
+ }
+
+ /**
+ * Default {@link RequestBuilder} impl for {@link HttpServletRequest}, which
+ * will should available for most incoming REST requests.
+ */
+ public static class HttpServletRequestAdapter implements RequestAdapter<HttpServletRequestAdapter> {
+
+ /** Wrapped HTTP request. */
+ private final HttpServletRequest mRequest;
+
+ /**
+ * Construct adapter for HTTP request.
+ * @param request to be wrapped;
+ */
+ public HttpServletRequestAdapter(final HttpServletRequest request) {
+ this.mRequest = checkNotNull(request);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public String getHeader(final String name) {
+ return this.mRequest.getHeader(name);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public String getClientAddress() {
+ return this.mRequest.getRemoteAddr();
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public String getServerAddress() {
+ return this.mRequest.getServerName();
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public String getRequestURI() {
+ return this.mRequest.getRequestURI();
+ }
+ }
+
+ /**
+ * Header builder, which (unlike {@link RequestAdapter} will tend to
+ * vary a lot from caller to caller, since they each get to choose their
+ * own REST (or HTTP, or whatever) client APIs.
+ *
+ * <p>No default implementation, because there's no HTTP client that's
+ * sufficiently ubiquitous to warrant incurring a mandatory dependency.</p>
+ *
+ * @param <T> type, for chaining.
+ */
+ public interface RequestBuilder<T extends RequestBuilder> {
+
+ /**
+ * Set HTTP header.
+ * @param name header name.
+ * @param value header value.
+ * @return this.
+ */
+ T setHeader(String name, String value);
+ }
+}
diff --git a/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogConstants.java b/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogConstants.java
new file mode 100644
index 0000000..744f99f
--- /dev/null
+++ b/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/ONAPLogConstants.java
@@ -0,0 +1,253 @@
+/**
+ * ============LICENSE_START=======================================================
+ * org.onap.logging
+ * ================================================================================
+ * Copyright © 2018 Amdocs
+ * 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.logging.ref.slf4j;
+
+import org.slf4j.Marker;
+import org.slf4j.MarkerFactory;
+
+/**
+ * Constants for standard ONAP headers, MDCs, etc.
+ *
+ * <p>See <tt>package-info.java</tt>.</p>
+ */
+public final class ONAPLogConstants {
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Constructors.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Hide and forbid construction.
+ */
+ private ONAPLogConstants() {
+ throw new UnsupportedOperationException();
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Inner classes.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Marker constants.
+ */
+ public static final class Markers {
+
+ /** Marker reporting invocation. */
+ public static final Marker INVOKE = MarkerFactory.getMarker("INVOKE");
+
+ /** Marker reporting synchronous invocation. */
+ public static final Marker INVOKE_SYNCHRONOUS = build("INVOKE", "SYNCHRONOUS");
+
+ /** Marker reporting asynchronous invocation. */
+ public static final Marker INVOKE_ASYNCHRONOUS = build("INVOKE", "ASYNCHRONOUS");
+
+ /** Marker reporting entry into a component. */
+ public static final Marker ENTRY = MarkerFactory.getMarker("ENTRY");
+
+ /** Marker reporting exit from a component. */
+ public static final Marker EXIT = MarkerFactory.getMarker("EXIT");
+
+ /**
+ * Build nested, detached marker.
+ * @param m1 top token.
+ * @param m2 sub-token.
+ * @return detached Marker.
+ */
+ private static Marker build(final String m1, final String m2) {
+ final Marker marker = MarkerFactory.getDetachedMarker(m1);
+ marker.add(MarkerFactory.getDetachedMarker(m2));
+ return marker;
+ }
+
+ /**
+ * Hide and forbid construction.
+ */
+ private Markers() {
+ throw new UnsupportedOperationException();
+ }
+ }
+
+ /**
+ * MDC name constants.
+ */
+ public static final class MDCs {
+
+ // Tracing. ////////////////////////////////////////////////////////////
+
+ /** MDC correlating messages for an invocation. */
+ public static final String INVOCATION_ID = "InvocationID";
+
+ /** MDC correlating messages for a logical transaction. */
+ public static final String REQUEST_ID = "RequestID";
+
+ /** MDC recording calling service. */
+ public static final String PARTNER_NAME = "PartnerName";
+
+ /** MDC recording current service. */
+ public static final String SERVICE_NAME = "ServiceName";
+
+ /** MDC recording target service. */
+ public static final String TARGET_SERVICE_NAME = "TargetServiceName";
+
+ /** MDC recording current service instance. */
+ public static final String INSTANCE_UUID = "InstanceUUID";
+
+ // Network. ////////////////////////////////////////////////////////////
+
+ /** MDC recording caller address. */
+ public static final String CLIENT_IP_ADDRESS = "ClientIPAddress";
+
+ /** MDC recording server address. */
+ public static final String SERVER_FQDN = "ServerFQDN";
+
+ /**
+ * MDC recording timestamp at the start of the current request,
+ * with the same scope as {@link #REQUEST_ID}.
+ *
+ * <p>Open issues:
+ * <ul>
+ * <ul>Easily confused with {@link #INVOKE_TIMESTAMP}.</ul>
+ * <ul>No mechanism for propagation between components, e.g. via HTTP headers.</ul>
+ * <ul>Whatever mechanism we define, it's going to be costly.</ul>
+ * </ul>
+ * </p>
+ * */
+ public static final String ENTRY_TIMESTAMP = "EntryTimestamp";
+
+ /** MDC recording timestamp at the start of the current invocation. */
+ public static final String INVOKE_TIMESTAMP = "InvokeTimestamp";
+
+ // Outcomes. ///////////////////////////////////////////////////////////
+
+ /** MDC reporting outcome code. */
+ public static final String RESPONSE_CODE = "ResponseCode";
+
+ /** MDC reporting outcome description. */
+ public static final String RESPONSE_DESCRIPTION = "ResponseDescription";
+
+ /** MDC reporting outcome error level. */
+ public static final String RESPONSE_SEVERITY = "Severity";
+
+ /** MDC reporting outcome error level. */
+ public static final String RESPONSE_STATUS_CODE = "StatusCode";
+
+ // Unsorted. ///////////////////////////////////////////////////////////
+
+ /**
+ * Hide and forbid construction.
+ */
+ private MDCs() {
+ throw new UnsupportedOperationException();
+ }
+ }
+
+ /**
+ * Header name constants.
+ */
+ public static final class Headers {
+
+ /** HTTP <tt>X-ONAP-RequestID</tt> header. */
+ public static final String REQUEST_ID = "X-ONAP-RequestID";
+
+ /** HTTP <tt>X-ONAP-InvocationID</tt> header. */
+ public static final String INVOCATION_ID = "X-ONAP-InvocationID";
+
+ /** HTTP <tt>X-ONAP-PartnerName</tt> header. */
+ public static final String PARTNER_NAME = "X-ONAP-PartnerName";
+
+ /**
+ * Hide and forbid construction.
+ */
+ private Headers() {
+ throw new UnsupportedOperationException();
+ }
+ }
+
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+ //
+ // Enums.
+ //
+ ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+ /**
+ * Response success or not, for setting <tt>StatusCode</tt>.
+ */
+ public enum ResponseStatus {
+
+ /** Success. */
+ COMPLETED,
+
+ /** Not. */
+ ERROR,
+ }
+
+ /**
+ * Synchronous or asynchronous execution, for setting invocation marker.
+ */
+ public enum InvocationMode {
+
+ /** Synchronous, blocking. */
+ SYNCHRONOUS("SYNCHRONOUS", Markers.INVOKE_SYNCHRONOUS),
+
+ /** Asynchronous, non-blocking. */
+ ASYNCHRONOUS("ASYNCHRONOUS", Markers.INVOKE_ASYNCHRONOUS);
+
+ /** Enum value. */
+ private String mString;
+
+ /** Corresponding marker. */
+ private Marker mMarker;
+
+ /**
+ * Construct enum.
+ *
+ * @param s enum value.
+ * @param m corresponding Marker.
+ */
+ InvocationMode(final String s, final Marker m) {
+ this.mString = s;
+ this.mMarker = m;
+ }
+
+ /**
+ * Get Marker for enum.
+ *
+ * @return Marker.
+ */
+ public Marker getMarker() {
+ return this.mMarker;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public String toString() {
+ return this.mString;
+ }
+ }
+
+}
diff --git a/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/package-info.java b/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/package-info.java
new file mode 100644
index 0000000..d9a6247
--- /dev/null
+++ b/reference/logging-slf4j/src/main/java/org/onap/logging/ref/slf4j/package-info.java
@@ -0,0 +1,32 @@
+/**
+ * ============LICENSE_START=======================================================
+ * org.onap.logging
+ * ================================================================================
+ * Copyright © 2018 Amdocs
+ * 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.logging.ref.slf4j;
+
+/**
+ * <p>Code in here has potential application outside this reference
+ * example, and accordingly:
+ * <ul>
+ * <li>Packaged in <tt>common</tt>.</li>
+ * <li>Has minimal dependencies.</li>
+ * </ul>
+ * </p>
+ */ \ No newline at end of file