Misc minor cleanups (#178)

* Use singleton map for consistency

* Use singletonMap static import for consistency

* Remove unnecessary attribute

instrumentation/akka-http-10.0/src/main/java/io/opentelemetry/auto/instrumentation/akkahttp/AkkaHttpClientInstrumentation.java

@@ -96,7 +96,7 @@ public final class AkkaHttpClientInstrumentation extends Instrumenter.Default {
 
     @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
     public static void methodExit(
-        @Advice.Argument(value = 0) final HttpRequest request,
+        @Advice.Argument(0) final HttpRequest request,
         @Advice.This final HttpExt thiz,
         @Advice.Return final Future<HttpResponse> responseFuture,
         @Advice.Enter final SpanWithScope spanWithScope,

instrumentation/akka-http-10.0/src/main/java/io/opentelemetry/auto/instrumentation/akkahttp/AkkaHttpServerInstrumentation.java

@@ -89,7 +89,7 @@ public final class AkkaHttpServerInstrumentation extends Instrumenter.Default {
     public static void wrapHandler(
         @Advice.Argument(value = 0, readOnly = false)
             Function1<HttpRequest, Future<HttpResponse>> handler,
-        @Advice.Argument(value = 7) final Materializer materializer) {
+        @Advice.Argument(7) final Materializer materializer) {
       handler = new AsyncWrapper(handler, materializer.executionContext());
     }
   }

instrumentation/apache-httpasyncclient-4.0/src/main/java/io/opentelemetry/auto/instrumentation/apachehttpasyncclient/ApacheHttpClientRedirectInstrumentation.java

@@ -46,7 +46,7 @@ public class ApacheHttpClientRedirectInstrumentation extends Instrumenter.Defaul
   public static class ClientRedirectAdvice {
     @Advice.OnMethodExit(suppress = Throwable.class)
     private static void onAfterExecute(
-        @Advice.Argument(value = 0) final HttpRequest original,
+        @Advice.Argument(0) final HttpRequest original,
         @Advice.Return(typing = Assigner.Typing.DYNAMIC) final HttpRequest redirect) {
       if (redirect == null) {
         return;

instrumentation/aws-java-sdk-2.2/src/main/java/io/opentelemetry/auto/instrumentation/aws/v2/AwsHttpClientInstrumentation.java

@@ -2,6 +2,7 @@ package io.opentelemetry.auto.instrumentation.aws.v2;
 
 import static io.opentelemetry.auto.instrumentation.aws.v2.TracingExecutionInterceptor.ScopeHolder.CURRENT;
 import static io.opentelemetry.auto.tooling.ByteBuddyElementMatchers.safeHasSuperType;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isInterface;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isPublic;
@@ -11,7 +12,6 @@ import static net.bytebuddy.matcher.ElementMatchers.not;
 import com.google.auto.service.AutoService;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.context.Scope;
-import java.util.Collections;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -38,7 +38,7 @@ public final class AwsHttpClientInstrumentation extends AbstractAwsClientInstrum
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
-    return Collections.singletonMap(
+    return singletonMap(
         isMethod().and(isPublic()).and(named("execute")),
         AwsHttpClientInstrumentation.class.getName() + "$AwsHttpClientAdvice");
   }

instrumentation/couchbase-2.6/src/main/java/io/opentelemetry/auto/instrumentation/couchbase/client/CouchbaseCoreInstrumentation.java

@@ -14,7 +14,6 @@ import io.opentelemetry.auto.bootstrap.InstrumentationContext;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.trace.Span;
 import io.opentelemetry.trace.Tracer;
-import java.util.Collections;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -35,8 +34,7 @@ public class CouchbaseCoreInstrumentation extends Instrumenter.Default {
 
   @Override
   public Map<String, String> contextStore() {
-    return Collections.singletonMap(
+    return singletonMap("com.couchbase.client.core.message.CouchbaseRequest", Span.class.getName());
-        "com.couchbase.client.core.message.CouchbaseRequest", Span.class.getName());
   }
 
   @Override

instrumentation/couchbase-2.6/src/main/java/io/opentelemetry/auto/instrumentation/couchbase/client/CouchbaseNetworkInstrumentation.java

@@ -15,7 +15,6 @@ import io.opentelemetry.auto.bootstrap.InstrumentationContext;
 import io.opentelemetry.auto.instrumentation.api.Tags;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.trace.Span;
-import java.util.Collections;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -36,8 +35,7 @@ public class CouchbaseNetworkInstrumentation extends Instrumenter.Default {
 
   @Override
   public Map<String, String> contextStore() {
-    return Collections.singletonMap(
+    return singletonMap("com.couchbase.client.core.message.CouchbaseRequest", Span.class.getName());
-        "com.couchbase.client.core.message.CouchbaseRequest", Span.class.getName());
   }
 
   @Override

instrumentation/google-http-client-1.19/src/main/java/io/opentelemetry/auto/instrumentation/googlehttpclient/GoogleHttpClientInstrumentation.java

@@ -4,6 +4,7 @@ import static io.opentelemetry.auto.instrumentation.googlehttpclient.GoogleHttpC
 import static io.opentelemetry.auto.instrumentation.googlehttpclient.GoogleHttpClientDecorator.TRACER;
 import static io.opentelemetry.auto.instrumentation.googlehttpclient.HeadersInjectAdapter.SETTER;
 import static io.opentelemetry.trace.Span.Kind.CLIENT;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isPublic;
 import static net.bytebuddy.matcher.ElementMatchers.named;
@@ -20,7 +21,6 @@ import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.trace.Span;
 import io.opentelemetry.trace.Status;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
@@ -42,8 +42,7 @@ public class GoogleHttpClientInstrumentation extends Instrumenter.Default {
 
   @Override
   public Map<String, String> contextStore() {
-    return Collections.singletonMap(
+    return singletonMap("com.google.api.client.http.HttpRequest", RequestState.class.getName());
-        "com.google.api.client.http.HttpRequest", RequestState.class.getName());
   }
 
   @Override

instrumentation/hibernate/core-4.3/src/main/java/io/opentelemetry/auto/instrumentation/hibernate/core/v4_3/SessionInstrumentation.java

@@ -1,6 +1,7 @@
 package io.opentelemetry.auto.instrumentation.hibernate.core.v4_3;
 
 import static io.opentelemetry.auto.tooling.ByteBuddyElementMatchers.safeHasSuperType;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isInterface;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.named;
@@ -57,13 +58,9 @@ public class SessionInstrumentation extends Instrumenter.Default {
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
-    final Map<ElementMatcher<? super MethodDescription>, String> transformers = new HashMap<>();
+    return singletonMap(
-
-    transformers.put(
         isMethod().and(returns(safeHasSuperType(named("org.hibernate.procedure.ProcedureCall")))),
         SessionInstrumentation.class.getName() + "$GetProcedureCallAdvice");
-
-    return transformers;
   }
 
   public static class GetProcedureCallAdvice {

instrumentation/java-concurrent/src/main/java/io/opentelemetry/auto/instrumentation/java/concurrent/AkkaExecutorInstrumentation.java

@@ -1,6 +1,7 @@
 package io.opentelemetry.auto.instrumentation.java.concurrent;
 
 import static io.opentelemetry.auto.instrumentation.java.concurrent.AdviceUtils.TRACER;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.nameMatches;
 import static net.bytebuddy.matcher.ElementMatchers.named;
 import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
@@ -12,7 +13,6 @@ import io.opentelemetry.auto.bootstrap.InstrumentationContext;
 import io.opentelemetry.auto.bootstrap.instrumentation.java.concurrent.State;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.trace.Span;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.Executor;
@@ -38,8 +38,7 @@ public final class AkkaExecutorInstrumentation extends AbstractExecutorInstrumen
 
   @Override
   public Map<String, String> contextStore() {
-    return Collections.singletonMap(
+    return singletonMap(AkkaForkJoinTaskInstrumentation.TASK_CLASS_NAME, State.class.getName());
-        AkkaForkJoinTaskInstrumentation.TASK_CLASS_NAME, State.class.getName());
   }
 
   @Override

instrumentation/java-concurrent/src/main/java/io/opentelemetry/auto/instrumentation/java/concurrent/JavaForkJoinTaskInstrumentation.java

@@ -1,6 +1,7 @@
 package io.opentelemetry.auto.instrumentation.java.concurrent;
 
 import static io.opentelemetry.auto.tooling.ByteBuddyElementMatchers.safeHasSuperType;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isAbstract;
 import static net.bytebuddy.matcher.ElementMatchers.isInterface;
 import static net.bytebuddy.matcher.ElementMatchers.named;
@@ -62,11 +63,9 @@ public final class JavaForkJoinTaskInstrumentation extends Instrumenter.Default
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
-    final Map<ElementMatcher<? super MethodDescription>, String> transformers = new HashMap<>();
+    return singletonMap(
-    transformers.put(
         named("exec").and(takesArguments(0)).and(not(isAbstract())),
         JavaForkJoinTaskInstrumentation.class.getName() + "$ForkJoinTaskAdvice");
-    return transformers;
   }
 
   public static class ForkJoinTaskAdvice {

instrumentation/java-concurrent/src/main/java/io/opentelemetry/auto/instrumentation/java/concurrent/ScalaExecutorInstrumentation.java

@@ -1,6 +1,7 @@
 package io.opentelemetry.auto.instrumentation.java.concurrent;
 
 import static io.opentelemetry.auto.instrumentation.java.concurrent.AdviceUtils.TRACER;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.nameMatches;
 import static net.bytebuddy.matcher.ElementMatchers.named;
 import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
@@ -11,7 +12,6 @@ import io.opentelemetry.auto.bootstrap.InstrumentationContext;
 import io.opentelemetry.auto.bootstrap.instrumentation.java.concurrent.State;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.trace.Span;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.Executor;
@@ -38,8 +38,7 @@ public final class ScalaExecutorInstrumentation extends AbstractExecutorInstrume
 
   @Override
   public Map<String, String> contextStore() {
-    return Collections.singletonMap(
+    return singletonMap(ScalaForkJoinTaskInstrumentation.TASK_CLASS_NAME, State.class.getName());
-        ScalaForkJoinTaskInstrumentation.TASK_CLASS_NAME, State.class.getName());
   }
 
   @Override

instrumentation/java-concurrent/src/main/java/io/opentelemetry/auto/instrumentation/java/concurrent/ScalaForkJoinTaskInstrumentation.java

@@ -1,6 +1,7 @@
 package io.opentelemetry.auto.instrumentation.java.concurrent;
 
 import static io.opentelemetry.auto.tooling.ByteBuddyElementMatchers.safeHasSuperType;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isAbstract;
 import static net.bytebuddy.matcher.ElementMatchers.isInterface;
 import static net.bytebuddy.matcher.ElementMatchers.named;
@@ -64,11 +65,9 @@ public final class ScalaForkJoinTaskInstrumentation extends Instrumenter.Default
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
-    final Map<ElementMatcher<? super MethodDescription>, String> transformers = new HashMap<>();
+    return singletonMap(
-    transformers.put(
         named("exec").and(takesArguments(0)).and(not(isAbstract())),
         ScalaForkJoinTaskInstrumentation.class.getName() + "$ForkJoinTaskAdvice");
-    return transformers;
   }
 
   public static class ForkJoinTaskAdvice {

instrumentation/jax-rs-annotations-2.0/src/main/java/io/opentelemetry/auto/instrumentation/jaxrs2/JaxRsAsyncResponseInstrumentation.java

@@ -2,6 +2,7 @@ package io.opentelemetry.auto.instrumentation.jaxrs2;
 
 import static io.opentelemetry.auto.instrumentation.jaxrs2.JaxRsAnnotationsDecorator.DECORATE;
 import static io.opentelemetry.auto.tooling.ByteBuddyElementMatchers.safeHasSuperType;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isPublic;
 import static net.bytebuddy.matcher.ElementMatchers.named;
 import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
@@ -11,7 +12,6 @@ import io.opentelemetry.auto.bootstrap.ContextStore;
 import io.opentelemetry.auto.bootstrap.InstrumentationContext;
 import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.trace.Span;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import javax.ws.rs.container.AsyncResponse;
@@ -29,7 +29,7 @@ public final class JaxRsAsyncResponseInstrumentation extends Instrumenter.Defaul
 
   @Override
   public Map<String, String> contextStore() {
-    return Collections.singletonMap("javax.ws.rs.container.AsyncResponse", Span.class.getName());
+    return singletonMap("javax.ws.rs.container.AsyncResponse", Span.class.getName());
   }
 
   @Override

instrumentation/jax-rs-client-1.1/src/main/java/io/opentelemetry/auto/instrumentation/jaxrs/v1/JaxRsClientV1Instrumentation.java

@@ -62,8 +62,7 @@ public final class JaxRsClientV1Instrumentation extends Instrumenter.Default {
 
     @Advice.OnMethodEnter
     public static SpanWithScope onEnter(
-        @Advice.Argument(value = 0) final ClientRequest request,
+        @Advice.Argument(0) final ClientRequest request, @Advice.This final ClientHandler thisObj) {
-        @Advice.This final ClientHandler thisObj) {
 
       // WARNING: this might be a chain...so we only have to trace the first in the chain.
       final boolean isRootClientHandler = null == request.getProperties().get(SPAN_ATTRIBUTE);

instrumentation/rmi/src/main/java/io/opentelemetry/auto/instrumentation/rmi/context/client/RmiClientContextInstrumentation.java

@@ -84,8 +84,7 @@ public class RmiClientContextInstrumentation extends Instrumenter.Default {
   public static class StreamRemoteCallConstructorAdvice {
     @Advice.OnMethodEnter(suppress = Throwable.class)
     public static void onEnter(
-        @Advice.Argument(value = 0) final Connection c,
+        @Advice.Argument(0) final Connection c, @Advice.Argument(1) final ObjID id) {
-        @Advice.Argument(value = 1) final ObjID id) {
       if (!c.isReusable()) {
         return;
       }

instrumentation/spring-data-1.8/src/main/java/io/opentelemetry/auto/instrumentation/springdata/SpringRepositoryInstrumentation.java

@@ -4,6 +4,7 @@ package io.opentelemetry.auto.instrumentation.springdata;
 
 import static io.opentelemetry.auto.instrumentation.springdata.SpringDataDecorator.DECORATOR;
 import static io.opentelemetry.auto.instrumentation.springdata.SpringDataDecorator.TRACER;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.isConstructor;
 import static net.bytebuddy.matcher.ElementMatchers.isInterface;
 import static net.bytebuddy.matcher.ElementMatchers.named;
@@ -14,7 +15,6 @@ import io.opentelemetry.auto.tooling.Instrumenter;
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.trace.Span;
 import java.lang.reflect.Method;
-import java.util.Collections;
 import java.util.Map;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.method.MethodDescription;
@@ -54,7 +54,7 @@ public final class SpringRepositoryInstrumentation extends Instrumenter.Default
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
-    return Collections.singletonMap(
+    return singletonMap(
         isConstructor(),
         SpringRepositoryInstrumentation.class.getName() + "$RepositoryFactorySupportAdvice");
   }

instrumentation/trace-annotation/src/main/java/io/opentelemetry/auto/instrumentation/trace_annotation/TraceAnnotationsInstrumentation.java

@@ -2,6 +2,7 @@ package io.opentelemetry.auto.instrumentation.trace_annotation;
 
 import static io.opentelemetry.auto.instrumentation.trace_annotation.TraceConfigInstrumentation.PACKAGE_CLASS_NAME_REGEX;
 import static io.opentelemetry.auto.tooling.ByteBuddyElementMatchers.safeHasSuperType;
+import static java.util.Collections.singletonMap;
 import static net.bytebuddy.matcher.ElementMatchers.declaresMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isAnnotatedWith;
 import static net.bytebuddy.matcher.ElementMatchers.named;
@@ -97,7 +98,6 @@ public final class TraceAnnotationsInstrumentation extends Instrumenter.Default
 
   @Override
   public Map<? extends ElementMatcher<? super MethodDescription>, String> transformers() {
-    return Collections.singletonMap(
+    return singletonMap(isAnnotatedWith(methodTraceMatcher), packageName + ".TraceAdvice");
-        isAnnotatedWith(methodTraceMatcher), packageName + ".TraceAdvice");
   }
 }