Don't use singleton for propagator getters/setters (#3054)

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/instrumenter/InstrumenterTest.java

@@ -86,8 +86,7 @@ class InstrumenterTest {
     }
   }
 
-  enum MapGetter implements TextMapGetter<Map<String, String>> {
+  class MapGetter implements TextMapGetter<Map<String, String>> {
-    INSTANCE;
 
     @Override
     public Iterable<String> keys(Map<String, String> carrier) {
@@ -109,7 +108,7 @@ class InstrumenterTest {
         Instrumenter.<Map<String, String>, Map<String, String>>newBuilder(
                 otelTesting.getOpenTelemetry(), "test", unused -> "span")
             .addAttributesExtractors(new AttributesExtractor1(), new AttributesExtractor2())
-            .newServerInstrumenter(MapGetter.INSTANCE);
+            .newServerInstrumenter(new MapGetter());
 
     Context context = instrumenter.start(Context.root(), REQUEST);
     SpanContext spanContext = Span.fromContext(context).getSpanContext();
@@ -151,7 +150,7 @@ class InstrumenterTest {
         Instrumenter.<Map<String, String>, Map<String, String>>newBuilder(
                 otelTesting.getOpenTelemetry(), "test", unused -> "span")
             .addAttributesExtractors(new AttributesExtractor1(), new AttributesExtractor2())
-            .newServerInstrumenter(MapGetter.INSTANCE);
+            .newServerInstrumenter(new MapGetter());
 
     Context context = instrumenter.start(Context.root(), REQUEST);
     SpanContext spanContext = Span.fromContext(context).getSpanContext();
@@ -175,7 +174,7 @@ class InstrumenterTest {
         Instrumenter.<Map<String, String>, Map<String, String>>newBuilder(
                 otelTesting.getOpenTelemetry(), "test", unused -> "span")
             .addAttributesExtractors(new AttributesExtractor1(), new AttributesExtractor2())
-            .newServerInstrumenter(MapGetter.INSTANCE);
+            .newServerInstrumenter(new MapGetter());
 
     Map<String, String> request = new HashMap<>(REQUEST);
     W3CTraceContextPropagator.getInstance()

instrumentation/apache-httpclient/apache-httpclient-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v2_0/ApacheHttpClientInstrumenters.java

@@ -34,7 +34,7 @@ public final class ApacheHttpClientInstrumenters {
             .setSpanStatusExtractor(spanStatusExtractor)
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(new ApacheHttpClientNetAttributesExtractor())
-            .newClientInstrumenter(HttpHeaderSetter.INSTANCE);
+            .newClientInstrumenter(new HttpHeaderSetter());
   }
 
   public static Instrumenter<HttpMethod, Void> instrumenter() {

instrumentation/apache-httpclient/apache-httpclient-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v2_0/HttpHeaderSetter.java

@@ -9,8 +9,7 @@ import io.opentelemetry.context.propagation.TextMapSetter;
 import org.apache.commons.httpclient.Header;
 import org.apache.commons.httpclient.HttpMethod;
 
-enum HttpHeaderSetter implements TextMapSetter<HttpMethod> {
+final class HttpHeaderSetter implements TextMapSetter<HttpMethod> {
-  INSTANCE;
 
   @Override
   public void set(HttpMethod carrier, String key, String value) {

instrumentation/apache-httpclient/apache-httpclient-4.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v4_0/ApacheHttpClientInstrumenters.java

@@ -35,7 +35,7 @@ public final class ApacheHttpClientInstrumenters {
             .setSpanStatusExtractor(spanStatusExtractor)
             .addAttributesExtractor(httpAttributesExtractor)
             .addAttributesExtractor(new ApacheHttpClientNetAttributesExtractor())
-            .newClientInstrumenter(HttpHeaderSetter.INSTANCE);
+            .newClientInstrumenter(new HttpHeaderSetter());
   }
 
   public static Instrumenter<HttpUriRequest, HttpResponse> instrumenter() {

instrumentation/apache-httpclient/apache-httpclient-4.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/apachehttpclient/v4_0/HttpHeaderSetter.java

@@ -8,8 +8,7 @@ package io.opentelemetry.javaagent.instrumentation.apachehttpclient.v4_0;
 import io.opentelemetry.context.propagation.TextMapSetter;
 import org.apache.http.client.methods.HttpUriRequest;
 
-enum HttpHeaderSetter implements TextMapSetter<HttpUriRequest> {
+final class HttpHeaderSetter implements TextMapSetter<HttpUriRequest> {
-  INSTANCE;
 
   @Override
   public void set(HttpUriRequest carrier, String key, String value) {

instrumentation/armeria-1.3/library/src/main/java/io/opentelemetry/instrumentation/armeria/v1_3/ArmeriaTracingBuilder.java

@@ -86,7 +86,7 @@ public final class ArmeriaTracingBuilder {
     serverInstrumenterBuilder.addRequestMetrics(HttpServerMetrics.get());
 
     return new ArmeriaTracing(
-        clientInstrumenterBuilder.newClientInstrumenter(ClientRequestContextSetter.INSTANCE),
+        clientInstrumenterBuilder.newClientInstrumenter(new ClientRequestContextSetter()),
-        serverInstrumenterBuilder.newServerInstrumenter(RequestContextGetter.INSTANCE));
+        serverInstrumenterBuilder.newServerInstrumenter(new RequestContextGetter()));
   }
 }

instrumentation/armeria-1.3/library/src/main/java/io/opentelemetry/instrumentation/armeria/v1_3/ClientRequestContextSetter.java

@@ -9,8 +9,7 @@ import com.linecorp.armeria.client.ClientRequestContext;
 import io.opentelemetry.context.propagation.TextMapSetter;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-enum ClientRequestContextSetter implements TextMapSetter<ClientRequestContext> {
+final class ClientRequestContextSetter implements TextMapSetter<ClientRequestContext> {
-  INSTANCE;
 
   @Override
   public void set(@Nullable ClientRequestContext carrier, String key, String value) {

instrumentation/armeria-1.3/library/src/main/java/io/opentelemetry/instrumentation/armeria/v1_3/RequestContextGetter.java

@@ -12,8 +12,7 @@ import java.util.Collections;
 import java.util.stream.Collectors;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
-enum RequestContextGetter implements TextMapGetter<ServiceRequestContext> {
+final class RequestContextGetter implements TextMapGetter<ServiceRequestContext> {
-  INSTANCE;
 
   @Override
   public Iterable<String> keys(@Nullable ServiceRequestContext carrier) {

instrumentation/jms-1.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/jms/JmsInstrumenters.java

@@ -30,7 +30,7 @@ public final class JmsInstrumenters {
         Instrumenter.<MessageWithDestination, Void>newBuilder(
                 otel, INSTRUMENTATION_NAME, spanNameExtractor)
             .addAttributesExtractor(attributesExtractor)
-            .newProducerInstrumenter(MessagePropertySetter.INSTANCE);
+            .newProducerInstrumenter(new MessagePropertySetter());
     // MessageConsumer does not do context propagation
     CONSUMER_INSTRUMENTER =
         Instrumenter.<MessageWithDestination, Void>newBuilder(

instrumentation/jms-1.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/jms/MessagePropertySetter.java

@@ -10,8 +10,7 @@ import javax.jms.JMSException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-enum MessagePropertySetter implements TextMapSetter<MessageWithDestination> {
+final class MessagePropertySetter implements TextMapSetter<MessageWithDestination> {
-  INSTANCE;
 
   private static final Logger log = LoggerFactory.getLogger(MessagePropertySetter.class);