Move ResourceNameDecorator to ResourceNameRule

dd-trace-ot/src/main/java/datadog/opentracing/decorators/DDDecoratorsFactory.java

@@ -22,7 +22,6 @@ public class DDDecoratorsFactory {
             new ForceManualKeepDecorator(),
             new OperationDecorator(),
             new PeerServiceDecorator(),
-            new ResourceNameDecorator(),
             new ServiceNameDecorator(),
             new ServiceNameDecorator("service", false),
             new ServletContextDecorator())) {

dd-trace-ot/src/main/java/datadog/opentracing/decorators/ResourceNameDecorator.java

@@ -1,18 +0,0 @@
-package datadog.opentracing.decorators;
-
-import datadog.opentracing.DDSpanContext;
-import datadog.trace.api.DDTags;
-
-public class ResourceNameDecorator extends AbstractDecorator {
-
-  public ResourceNameDecorator() {
-    super();
-    this.setMatchingTag(DDTags.RESOURCE_NAME);
-  }
-
-  @Override
-  public boolean shouldSetTag(final DDSpanContext context, final String tag, final Object value) {
-    context.setResourceName(String.valueOf(value));
-    return false;
-  }
-}

dd-trace-ot/src/main/java/datadog/trace/common/processor/TraceProcessor.java

@@ -3,6 +3,7 @@ package datadog.trace.common.processor;
 import datadog.opentracing.DDSpan;
 import datadog.trace.api.Config;
 import datadog.trace.common.processor.rule.ErrorRule;
+import datadog.trace.common.processor.rule.ResourceNameRule;
 import datadog.trace.common.processor.rule.SpanTypeRule;
 import datadog.trace.common.processor.rule.Status404Rule;
 import datadog.trace.common.processor.rule.Status5XXRule;
@@ -18,6 +19,7 @@ public class TraceProcessor {
   final Rule[] DEFAULT_RULES =
       new Rule[] {
         // Rules are applied in order.
+        new ResourceNameRule(),
         new SpanTypeRule(),
         new Status5XXRule(),
         new ErrorRule(),

dd-trace-ot/src/main/java/datadog/trace/common/processor/rule/ResourceNameRule.java

@@ -0,0 +1,24 @@
+package datadog.trace.common.processor.rule;
+
+import datadog.opentracing.DDSpan;
+import datadog.trace.api.DDTags;
+import datadog.trace.common.processor.TraceProcessor;
+import java.util.Collection;
+import java.util.Map;
+
+/** Converts resource name tag to field */
+public class ResourceNameRule implements TraceProcessor.Rule {
+  @Override
+  public String[] aliases() {
+    return new String[] {"ResourceNameDecorator"};
+  }
+
+  @Override
+  public void processSpan(
+      final DDSpan span, final Map<String, Object> tags, final Collection<DDSpan> trace) {
+    if (tags.containsKey(DDTags.RESOURCE_NAME)) {
+      span.setResourceName(tags.get(DDTags.RESOURCE_NAME).toString());
+      span.setTag(DDTags.RESOURCE_NAME, (String) null); // Remove the tag
+    }
+  }
+}