Address review comments

Author: steverao

instrumentation/apache-dubbo-2.7/library-autoconfigure/src/main/java/io/opentelemetry/instrumentation/apachedubbo/v2_7/DubboTelemetry.java

@@ -37,11 +37,11 @@ public static DubboTelemetryBuilder builder(OpenTelemetry openTelemetry) {
 
   /** Returns a new Dubbo client {@link Filter} that traces Dubbo RPC invocations. */
   public Filter newClientFilter() {
-    return TracingFilter.newClientFilter(clientInstrumenter);
+    return new TracingFilter(clientInstrumenter, true);
   }
 
   /** Returns a new Dubbo server {@link Filter} that traces Dubbo RPC invocations. */
   public Filter newServerFilter() {
-    return TracingFilter.newServerFilter(serverInstrumenter);
+    return new TracingFilter(serverInstrumenter, false);
   }
 }

instrumentation/apache-dubbo-2.7/library-autoconfigure/src/main/java/io/opentelemetry/instrumentation/apachedubbo/v2_7/TracingFilter.java

@@ -18,35 +18,13 @@
 
 final class TracingFilter implements Filter {
 
-  private final InstrumenterSupplier instrumenterSupplier;
+  private final Instrumenter<DubboRequest, Result> instrumenter;
 
-  private TracingFilter(InstrumenterSupplier instrumenterSupplier) {
-    this.instrumenterSupplier = instrumenterSupplier;
-  }
-
-  static TracingFilter newClientFilter(Instrumenter<DubboRequest, Result> clientInstrumenter) {
-    return newFilter(clientInstrumenter, true);
-  }
-
-  static TracingFilter newServerFilter(Instrumenter<DubboRequest, Result> serverInstrumenter) {
-    return newFilter(serverInstrumenter, false);
-  }
+  private final boolean isClientSide;
 
-  private static TracingFilter newFilter(
-      Instrumenter<DubboRequest, Result> instrumenter, boolean isClientSide) {
-    return new TracingFilter(
-        new InstrumenterSupplier() {
-
-          @Override
-          public Instrumenter<DubboRequest, Result> get(RpcContext rpcContext) {
-            return instrumenter;
-          }
-
-          @Override
-          public boolean isClientSide(RpcContext rpcContext) {
-            return isClientSide;
-          }
-        });
+  TracingFilter(Instrumenter<DubboRequest, Result> instrumenter, boolean isClientSide) {
+    this.instrumenter = instrumenter;
+    this.isClientSide = isClientSide;
   }
 
   @Override
@@ -61,7 +39,6 @@ public Result invoke(Invoker<?> invoker, Invocation invocation) {
       return invoker.invoke(invocation);
     }
 
-    Instrumenter<DubboRequest, Result> instrumenter = instrumenterSupplier.get(rpcContext);
     Context parentContext = Context.current();
     DubboRequest request = DubboRequest.create((RpcInvocation) invocation, rpcContext);
 
@@ -74,7 +51,7 @@ public Result invoke(Invoker<?> invoker, Invocation invocation) {
     boolean isSynchronous = true;
     try (Scope ignored = context.makeCurrent()) {
       result = invoker.invoke(invocation);
-      if (instrumenterSupplier.isClientSide(rpcContext)) {
+      if (isClientSide) {
         CompletableFuture<Object> future = rpcContext.getCompletableFuture();
         if (future != null) {
           isSynchronous = false;
@@ -91,10 +68,4 @@ public Result invoke(Invoker<?> invoker, Invocation invocation) {
     }
     return result;
   }
-
-  private interface InstrumenterSupplier {
-    Instrumenter<DubboRequest, Result> get(RpcContext rpcContext);
-
-    boolean isClientSide(RpcContext rpcContext);
-  }
 }