Provide a new Tag for PEER_HOST_IPV4

opentracing-api/src/main/java/io/opentracing/tag/IntOrStringTag.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2016-2017 The OpenTracing Authors
+ *
+ * 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 io.opentracing.tag;
+
+import io.opentracing.BaseSpan;
+
+public class IntOrStringTag extends IntTag {
+    public IntOrStringTag(String key) {
+        super(key);
+    }
+
+    public void set(BaseSpan<?> span, String tagValue) {
+        span.setTag(super.key, tagValue);
+    }
+}

opentracing-api/src/main/java/io/opentracing/tag/Tags.java

@@ -63,7 +63,7 @@ private Tags() {
     /**
      * PEER_HOST_IPV4 records IPv4 host address of the peer.
      */
-    public static final IntTag PEER_HOST_IPV4 = new IntTag("peer.ipv4");
+    public static final IntOrStringTag PEER_HOST_IPV4 = new IntOrStringTag("peer.ipv4");
 
     /**
      * PEER_HOST_IPV6 records the IPv6 host address of the peer.