Add matching condition of spanKind

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/instrumenter/InstrumenterCustomizer.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.instrumentation.api.incubator.instrumenter;
 
+import io.opentelemetry.api.trace.SpanKind;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.ContextCustomizer;
 import io.opentelemetry.instrumentation.api.instrumenter.OperationMetrics;
@@ -30,6 +31,15 @@ public interface InstrumenterCustomizer {
    */
   String getInstrumentationName();
 
+  /**
+   * Returns the {@link SpanKind} that this customizer applies to. This allows distinguishing
+   * between different types of instrumenters (e.g., client, server) within the same
+   * instrumentation.
+   *
+   * @return the span kind this customizer targets
+   */
+  SpanKind getSpanKind();
+
   /**
    * Adds a single AttributesExtractor to the instrumenter. This extractor will be used to extract
    * attributes from requests and responses during span creation and enrichment.

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/instrumenter/internal/InstrumenterCustomizerImpl.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.instrumentation.api.incubator.instrumenter.internal;
 
+import io.opentelemetry.api.trace.SpanKind;
 import io.opentelemetry.instrumentation.api.incubator.instrumenter.InstrumenterCustomizer;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.ContextCustomizer;
@@ -30,6 +31,11 @@ public String getInstrumentationName() {
     return customizer.getInstrumentationName();
   }
 
+  @Override
+  public SpanKind getSpanKind() {
+    return customizer.getSpanKind();
+  }
+
   @Override
   public InstrumenterCustomizer addAttributesExtractor(AttributesExtractor<?, ?> extractor) {
     customizer.addAttributesExtractor(extractor);

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/InstrumenterBuilder.java

@@ -285,10 +285,10 @@ public Instrumenter<REQUEST, RESPONSE> buildInstrumenter(
   private Instrumenter<REQUEST, RESPONSE> buildInstrumenter(
       InstrumenterConstructor<REQUEST, RESPONSE> constructor,
       SpanKindExtractor<? super REQUEST> spanKindExtractor) {
+    this.spanKindExtractor = spanKindExtractor;
 
     applyCustomizers(this);
 
-    this.spanKindExtractor = spanKindExtractor;
     return constructor.create(this);
   }
 
@@ -393,6 +393,15 @@ public String getInstrumentationName() {
               return builder.instrumentationName;
             }
 
+            @Override
+            public SpanKind getSpanKind() {
+              try {
+                return builder.spanKindExtractor.extract(null);
+              } catch (RuntimeException e) {
+                return null;
+              }
+            }
+
             @Override
             public void addAttributesExtractor(AttributesExtractor<REQUEST, RESPONSE> extractor) {
               builder.addAttributesExtractor(extractor);

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/internal/InternalInstrumenterCustomizer.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.instrumentation.api.internal;
 
+import io.opentelemetry.api.trace.SpanKind;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.instrumenter.ContextCustomizer;
 import io.opentelemetry.instrumentation.api.instrumenter.OperationMetrics;
@@ -19,6 +20,8 @@ public interface InternalInstrumenterCustomizer<REQUEST, RESPONSE> {
 
   String getInstrumentationName();
 
+  SpanKind getSpanKind();
+
   void addAttributesExtractor(AttributesExtractor<REQUEST, RESPONSE> extractor);
 
   void addAttributesExtractors(

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/internal/InstrumentationCustomizerTest.java

@@ -22,6 +22,7 @@
 import io.opentelemetry.api.trace.SpanId;
 import io.opentelemetry.api.trace.SpanKind;
 import io.opentelemetry.context.Context;
+import io.opentelemetry.context.propagation.TextMapGetter;
 import io.opentelemetry.instrumentation.api.incubator.instrumenter.InstrumenterCustomizerProvider;
 import io.opentelemetry.instrumentation.api.incubator.instrumenter.internal.InternalInstrumenterCustomizerProviderImpl;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
@@ -110,6 +111,65 @@ void testGetInstrumentationName() {
     assertThat(customizerCalled).isTrue();
   }
 
+  @Test
+  void testGetSpanKind() {
+    AtomicBoolean clientCustomizerCalled = new AtomicBoolean();
+    AtomicBoolean serverCustomizerCalled = new AtomicBoolean();
+    AtomicBoolean exceptionCustomizerCalled = new AtomicBoolean();
+
+    setCustomizer(
+        customizer -> {
+          if (customizer.getSpanKind() == SpanKind.CLIENT) {
+            clientCustomizerCalled.set(true);
+            assertThat(customizer.getInstrumentationName()).isEqualTo("test");
+          } else if (customizer.getSpanKind() == SpanKind.SERVER) {
+            serverCustomizerCalled.set(true);
+            assertThat(customizer.getInstrumentationName()).isEqualTo("test");
+          } else if (customizer.getSpanKind() == null) {
+            // This case handles when spanKindExtractor throws an exception and returns null
+            exceptionCustomizerCalled.set(true);
+            assertThat(customizer.getInstrumentationName()).isEqualTo("test");
+          }
+        });
+
+    // Build client instrumenter
+    Instrumenter.<Map<String, String>, Map<String, String>>builder(
+            otelTesting.getOpenTelemetry(), "test", unused -> "client-span")
+        .buildClientInstrumenter((carrier, key, value) -> {
+        });
+
+    // Build server instrumenter
+    Instrumenter.<Map<String, String>, Map<String, String>>builder(
+            otelTesting.getOpenTelemetry(), "test", unused -> "server-span")
+        .buildServerInstrumenter(
+            new TextMapGetter<Map<String, String>>() {
+              @Override
+              public Iterable<String> keys(Map<String, String> carrier) {
+                return carrier.keySet();
+              }
+
+              @Override
+              public String get(Map<String, String> carrier, String key) {
+                return carrier.get(key);
+              }
+            });
+
+    // Build instrumenter with a span kind extractor that throws exception with null input
+    Instrumenter.<Map<String, String>, Map<String, String>>builder(
+            otelTesting.getOpenTelemetry(), "test", unused -> "test-span")
+        .buildInstrumenter(
+            request -> {
+              if (request == null) {
+                throw new NullPointerException("Request cannot be null");
+              }
+              return SpanKind.CLIENT;
+            });
+
+    assertThat(clientCustomizerCalled).isTrue();
+    assertThat(serverCustomizerCalled).isTrue();
+    assertThat(exceptionCustomizerCalled).isTrue();
+  }
+
   @Test
   void testAddAttributesExtractor() {
     AtomicBoolean customizerCalled = new AtomicBoolean();