Metrics 4.0 implementation

examples/metrics/exemplar/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright (c) 2021 Oracle and/or its affiliates.
+    Copyright (c) 2021, 2022 Oracle and/or its affiliates.
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
@@ -15,7 +15,8 @@
     See the License for the specific language governing permissions and
     limitations under the License.
 
---><project xmlns="http://maven.apache.org/POM/4.0.0"
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <parent>
@@ -62,6 +63,11 @@
             <artifactId>helidon-tracing-zipkin</artifactId>
             <scope>runtime</scope>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.config</groupId>
+            <artifactId>helidon-config-yaml</artifactId>
+            <scope>runtime</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>

examples/metrics/filtering/se/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright (c) 2021 Oracle and/or its affiliates.
+    Copyright (c) 2021, 2022 Oracle and/or its affiliates.
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
@@ -46,6 +46,11 @@
             <groupId>io.helidon.metrics</groupId>
             <artifactId>helidon-metrics</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.config</groupId>
+            <artifactId>helidon-config-yaml</artifactId>
+            <scope>runtime</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>

examples/metrics/kpi/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright (c) 2021 Oracle and/or its affiliates.
+    Copyright (c) 2021, 2022 Oracle and/or its affiliates.
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
@@ -46,6 +46,11 @@
             <groupId>io.helidon.metrics</groupId>
             <artifactId>helidon-metrics</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.config</groupId>
+            <artifactId>helidon-config-yaml</artifactId>
+            <scope>runtime</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>

metrics/api/src/main/java/io/helidon/metrics/api/AbstractMetric.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Oracle and/or its affiliates.
+ * Copyright (c) 2021, 2022 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,6 +29,12 @@ public abstract class AbstractMetric implements HelidonMetric {
     private final Metadata metadata;
     private volatile boolean isDeleted;
 
+    /**
+     * Common initialization logic in creating a new metric.
+     *
+     * @param registryType type of metric registry the metric is registered in
+     * @param metadata metric metadata describing the metric
+     */
     protected AbstractMetric(String registryType, Metadata metadata) {
         this.registryType = registryType;
         this.metadata = metadata;