Use TreeMap

amarziali · amarziali · commit ea116a8c71dd · 2026-01-08T16:26:52.000+01:00
diff --git a/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java/datadog/trace/instrumentation/httpclient/HttpHeadersInstrumentation.java b/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java/datadog/trace/instrumentation/httpclient/HttpHeadersInstrumentation.java
@@ -48,9 +48,7 @@ public ElementMatcher<TypeDescription> hierarchyMatcher() {
   @Override
   public String[] helperClassNames() {
     return new String[] {
-      packageName + ".CaseInsensitiveKey",
-      packageName + ".HttpHeadersInjectAdapter",
-      packageName + ".JavaNetClientDecorator",
+      packageName + ".HttpHeadersInjectAdapter", packageName + ".JavaNetClientDecorator",
     };
   }
 
diff --git a/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java11/datadog/trace/instrumentation/httpclient/CaseInsensitiveKey.java b/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java11/datadog/trace/instrumentation/httpclient/CaseInsensitiveKey.java
diff --git a/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java11/datadog/trace/instrumentation/httpclient/HeadersAdvice.java b/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java11/datadog/trace/instrumentation/httpclient/HeadersAdvice.java
@@ -4,29 +4,22 @@
 import static datadog.trace.instrumentation.httpclient.HttpHeadersInjectAdapter.KEEP;
 import static datadog.trace.instrumentation.httpclient.HttpHeadersInjectAdapter.SETTER;
 import static datadog.trace.instrumentation.httpclient.JavaNetClientDecorator.DECORATE;
+import static java.lang.String.CASE_INSENSITIVE_ORDER;
 
 import java.net.http.HttpHeaders;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.TreeMap;
 import net.bytebuddy.asm.Advice;
 
 public class HeadersAdvice {
   @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
   public static void methodExit(@Advice.Return(readOnly = false) HttpHeaders headers) {
-    final Map<CaseInsensitiveKey, List<String>> headerMap = new LinkedHashMap<>();
-    // Note: we don't want to modify the case of the current headers
-    // However adding duplicate keys will throw an IllegalArgumentException so we need to dedupe
+    // Note: adding duplicate keys will throw an IllegalArgumentException so we need to dedupe
     // case insensitively
-    for (final Map.Entry<String, List<String>> entry : headers.map().entrySet()) {
-      headerMap.put(new CaseInsensitiveKey(entry.getKey()), entry.getValue());
-    }
+    final Map<String, List<String>> headerMap = new TreeMap<>(CASE_INSENSITIVE_ORDER);
+    headerMap.putAll(headers.map());
     DECORATE.injectContext(getCurrentContext(), headerMap, SETTER);
-    // convert back
-    final Map<String, List<String>> finalMap = new LinkedHashMap<>();
-    for (final Map.Entry<CaseInsensitiveKey, List<String>> entry : headerMap.entrySet()) {
-      finalMap.put(entry.getKey().getValue(), entry.getValue());
-    }
-    headers = HttpHeaders.of(finalMap, KEEP);
+    headers = HttpHeaders.of(headerMap, KEEP);
   }
 }
diff --git a/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java11/datadog/trace/instrumentation/httpclient/HttpHeadersInjectAdapter.java b/dd-java-agent/instrumentation/java/java-net/java-net-11.0/src/main/java11/datadog/trace/instrumentation/httpclient/HttpHeadersInjectAdapter.java
@@ -6,18 +6,17 @@
 import java.util.Map;
 import java.util.function.BiPredicate;
 
-public class HttpHeadersInjectAdapter
-    implements CarrierSetter<Map<CaseInsensitiveKey, List<String>>> {
+public class HttpHeadersInjectAdapter implements CarrierSetter<Map<String, List<String>>> {
 
   public static final HttpHeadersInjectAdapter SETTER = new HttpHeadersInjectAdapter();
   public static final BiPredicate<String, String> KEEP = HttpHeadersInjectAdapter::keep;
 
-  public static boolean keep(String key, String value) {
-    return true;
+  @Override
+  public void set(final Map<String, List<String>> carrier, final String key, final String value) {
+    carrier.put(key, Collections.singletonList(value));
   }
 
-  @Override
-  public void set(Map<CaseInsensitiveKey, List<String>> carrier, String key, String value) {
-    carrier.put(new CaseInsensitiveKey(key), Collections.singletonList(value));
+  public static boolean keep(String key, String value) {
+    return true;
   }
 }
