Add experimental JdkHttpSender

all/build.gradle.kts

@@ -8,10 +8,11 @@ otelJava.moduleName.set("io.opentelemetry.all")
 tasks {
   // We don't compile much here, just some API boundary tests. This project is mostly for
   // aggregating jacoco reports and it doesn't work if this isn't at least as high as the
-  // highest supported Java version in any of our projects. All of our projects target
-  // Java 8.
+  // highest supported Java version in any of our projects. All of our
+  // projects target Java 8 except :exporters:http-sender:jdk, which targets
+  // Java 11
   withType(JavaCompile::class) {
-    options.release.set(8)
+    options.release.set(11)
   }
 
   val testJavaVersion: String? by project

exporters/common/build.gradle.kts

@@ -34,3 +34,35 @@ dependencies {
   testImplementation("io.grpc:grpc-testing")
   testRuntimeOnly("io.grpc:grpc-netty-shaded")
 }
+
+val testJavaVersion: String? by project
+
+testing {
+  suites {
+    register<JvmTestSuite>("testHttpSenderProvider") {
+      dependencies {
+        implementation(project(":exporters:sender:jdk"))
+        implementation(project(":exporters:sender:okhttp"))
+      }
+      targets {
+        all {
+          testTask {
+            enabled = !testJavaVersion.equals("8")
+          }
+        }
+      }
+    }
+  }
+}
+
+tasks {
+  check {
+    dependsOn(testing.suites)
+  }
+}
+
+afterEvaluate {
+  tasks.named<JavaCompile>("compileTestHttpSenderProviderJava") {
+    options.release.set(11)
+  }
+}

exporters/common/src/main/java/io/opentelemetry/exporter/internal/http/HttpExporterBuilder.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.exporter.internal.http;
 
 import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.internal.ConfigUtil;
 import io.opentelemetry.api.metrics.MeterProvider;
 import io.opentelemetry.exporter.internal.ExporterBuilderUtil;
 import io.opentelemetry.exporter.internal.TlsConfigHelper;
@@ -129,29 +130,80 @@ public HttpExporter<T> build() {
     Map<String, String> headers = this.headers == null ? Collections.emptyMap() : this.headers;
     Supplier<Map<String, String>> headerSupplier = () -> headers;
 
-    HttpSender httpSender = null;
-    // TODO: once we publish multiple HttpSenderProviders, log warning when multiple are found
-    for (HttpSenderProvider httpSenderProvider :
+    HttpSenderProvider httpSenderProvider = resolveHttpSenderProvider();
+    HttpSender httpSender =
+        httpSenderProvider.createSender(
+            endpoint,
+            compressionEnabled,
+            exportAsJson ? "application/json" : "application/x-protobuf",
+            timeoutNanos,
+            headerSupplier,
+            authenticator,
+            retryPolicy,
+            tlsConfigHelper.getSslContext(),
+            tlsConfigHelper.getTrustManager());
+    LOGGER.log(Level.FINE, "Using HttpSender: " + httpSender.getClass().getName());
+
+    return new HttpExporter<>(exporterName, type, httpSender, meterProviderSupplier, exportAsJson);
+  }
+
+  /**
+   * Resolve the {@link HttpSenderProvider}.
+   *
+   * <p>If no {@link HttpSenderProvider} is available, throw {@link IllegalStateException}.
+   *
+   * <p>If only one {@link HttpSenderProvider} is available, use it.
+   *
+   * <p>If multiple are available and..
+   *
+   * <ul>
+   *   <li>{@code io.opentelemetry.exporter.internal.http.HttpSenderProvider} is empty, use the
+   *       first found.
+   *   <li>{@code io.opentelemetry.exporter.internal.http.HttpSenderProvider} is set, use the
+   *       matching provider. If none match, throw {@link IllegalStateException}.
+   * </ul>
+   */
+  private static HttpSenderProvider resolveHttpSenderProvider() {
+    Map<String, HttpSenderProvider> httpSenderProviders = new HashMap<>();
+    for (HttpSenderProvider spi :
         ServiceLoader.load(HttpSenderProvider.class, HttpExporterBuilder.class.getClassLoader())) {
-      httpSender =
-          httpSenderProvider.createSender(
-              endpoint,
-              compressionEnabled,
-              exportAsJson ? "application/json" : "application/x-protobuf",
-              timeoutNanos,
-              headerSupplier,
-              authenticator,
-              retryPolicy,
-              tlsConfigHelper.getSslContext(),
-              tlsConfigHelper.getTrustManager());
-      LOGGER.log(Level.FINE, "Using HttpSender: " + httpSender.getClass().getName());
-      break;
+      httpSenderProviders.put(spi.getClass().getName(), spi);
     }
-    if (httpSender == null) {
+
+    // No provider on classpath, throw
+    if (httpSenderProviders.isEmpty()) {
       throw new IllegalStateException(
-          "No HttpSenderProvider found on classpath. Please add dependency on opentelemetry-exporter-sender-okhttp");
+          "No HttpSenderProvider found on classpath. Please add dependency on "
+              + "opentelemetry-exporter-sender-okhttp or opentelemetry-exporter-sender-jdk");
     }
 
-    return new HttpExporter<>(exporterName, type, httpSender, meterProviderSupplier, exportAsJson);
+    // Exactly one provider on classpath, use it
+    if (httpSenderProviders.size() == 1) {
+      return httpSenderProviders.values().stream().findFirst().get();
+    }
+
+    // If we've reached here, there are multiple HttpSenderProviders
+    String configuredSender =
+        ConfigUtil.getString("io.opentelemetry.exporter.internal.http.HttpSenderProvider", "");
+
+    // Multiple providers but none configured, use first we find and log a warning
+    if (configuredSender.isEmpty()) {
+      LOGGER.log(
+          Level.WARNING,
+          "Multiple HttpSenderProvider found. Please include only one, "
+              + "or specify preference setting io.opentelemetry.exporter.internal.http.HttpSenderProvider "
+              + "to the FQCN of the preferred provider.");
+      return httpSenderProviders.values().stream().findFirst().get();
+    }
+
+    // Multiple providers with configuration match, use configuration match
+    if (httpSenderProviders.containsKey(configuredSender)) {
+      return httpSenderProviders.get(configuredSender);
+    }
+
+    // Multiple providers, configured does not match, throw
+    throw new IllegalStateException(
+        "No HttpSenderProvider matched configured io.opentelemetry.exporter.internal.http.HttpSenderProvider: "
+            + configuredSender);
   }
 }

exporters/common/src/test/java/io/opentelemetry/exporter/internal/http/HttpExporterTest.java

@@ -16,6 +16,7 @@ void build_NoHttpSenderProvider() {
     assertThatThrownBy(() -> new HttpExporterBuilder<>("name", "type", "http://localhost").build())
         .isInstanceOf(IllegalStateException.class)
         .hasMessage(
-            "No HttpSenderProvider found on classpath. Please add dependency on opentelemetry-exporter-sender-okhttp");
+            "No HttpSenderProvider found on classpath. Please add dependency on "
+                + "opentelemetry-exporter-sender-okhttp or opentelemetry-exporter-sender-jdk");
   }
 }

exporters/common/src/testHttpSenderProvider/java/io/opentelemetry/exporter/internal/http/HttpExporterTest.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.exporter.internal.http;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import io.github.netmikey.logunit.api.LogCapturer;
+import io.opentelemetry.exporter.sender.jdk.internal.JdkHttpSender;
+import io.opentelemetry.exporter.sender.okhttp.internal.OkHttpHttpSender;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junitpioneer.jupiter.SetSystemProperty;
+
+class HttpExporterTest {
+
+  @RegisterExtension
+  LogCapturer logCapturer =
+      LogCapturer.create().captureForLogger(HttpExporterBuilder.class.getName());
+
+  @Test
+  void build_multipleSendersNoConfiguration() {
+    Assertions.assertThatCode(
+            () -> new HttpExporterBuilder<>("exporter", "type", "http://localhost").build())
+        .doesNotThrowAnyException();
+
+    logCapturer.assertContains(
+        "Multiple HttpSenderProvider found. Please include only one, "
+            + "or specify preference setting io.opentelemetry.exporter.internal.http.HttpSenderProvider "
+            + "to the FQCN of the preferred provider.");
+  }
+
+  @Test
+  @SetSystemProperty(
+      key = "io.opentelemetry.exporter.internal.http.HttpSenderProvider",
+      value = "io.opentelemetry.exporter.sender.jdk.internal.JdkHttpSenderProvider")
+  void build_multipleSendersWithJdk() {
+    assertThat(new HttpExporterBuilder<>("exporter", "type", "http://localhost").build())
+        .extracting("httpSender")
+        .isInstanceOf(JdkHttpSender.class);
+
+    assertThat(logCapturer.getEvents()).isEmpty();
+  }
+
+  @Test
+  @SetSystemProperty(
+      key = "io.opentelemetry.exporter.internal.http.HttpSenderProvider",
+      value = "io.opentelemetry.exporter.sender.okhttp.internal.OkHttpHttpSenderProvider")
+  void build_multipleSendersWithOkHttp() {
+    assertThat(new HttpExporterBuilder<>("exporter", "type", "http://localhost").build())
+        .extracting("httpSender")
+        .isInstanceOf(OkHttpHttpSender.class);
+
+    assertThat(logCapturer.getEvents()).isEmpty();
+  }
+
+  @Test
+  @SetSystemProperty(
+      key = "io.opentelemetry.exporter.internal.http.HttpSenderProvider",
+      value = "foo")
+  void build_multipleSendersNoMatch() {
+    assertThatThrownBy(
+            () -> new HttpExporterBuilder<>("exporter", "type", "http://localhost").build())
+        .isInstanceOf(IllegalStateException.class)
+        .hasMessage(
+            "No HttpSenderProvider matched configured io.opentelemetry.exporter.internal.http.HttpSenderProvider: foo");
+
+    assertThat(logCapturer.getEvents()).isEmpty();
+  }
+}

exporters/otlp/all/build.gradle.kts

@@ -39,6 +39,8 @@ dependencies {
   jmhRuntimeOnly("io.grpc:grpc-netty")
 }
 
+val testJavaVersion: String? by project
+
 testing {
   suites {
     register<JvmTestSuite>("testGrpcNetty") {
@@ -65,6 +67,22 @@ testing {
         implementation("io.grpc:grpc-stub")
       }
     }
+    register<JvmTestSuite>("testJdkHttpSender") {
+      dependencies {
+        implementation(project(":exporters:sender:jdk"))
+        implementation(project(":exporters:otlp:testing-internal"))
+
+        implementation("io.grpc:grpc-stub")
+      }
+      targets {
+        all {
+          testTask {
+            systemProperty("io.opentelemetry.exporter.internal.http.HttpSenderProvider", "io.opentelemetry.exporter.sender.jdk.internal.JdkHttpSenderProvider")
+            enabled = !testJavaVersion.equals("8")
+          }
+        }
+      }
+    }
     register<JvmTestSuite>("testSpanPipeline") {
       dependencies {
         implementation("io.opentelemetry.proto:opentelemetry-proto")
@@ -86,3 +104,9 @@ tasks {
     )
   }
 }
+
+afterEvaluate {
+  tasks.named<JavaCompile>("compileTestJdkHttpSenderJava") {
+    options.release.set(11)
+  }
+}

exporters/otlp/all/src/test/java/io/opentelemetry/exporter/otlp/http/logs/OtlpHttpLogRecordExporterTest.java → exporters/otlp/all/src/test/java/io/opentelemetry/exporter/otlp/http/logs/OtlpHttpLogRecordExporterOkHttpSenderTest.java

@@ -21,10 +21,10 @@
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.X509TrustManager;
 
-class OtlpHttpLogRecordExporterTest
+class OtlpHttpLogRecordExporterOkHttpSenderTest
     extends AbstractHttpTelemetryExporterTest<LogRecordData, ResourceLogs> {
 
-  protected OtlpHttpLogRecordExporterTest() {
+  protected OtlpHttpLogRecordExporterOkHttpSenderTest() {
     super("log", "/v1/logs", ResourceLogs.getDefaultInstance());
   }
 

exporters/otlp/all/src/test/java/io/opentelemetry/exporter/otlp/http/metrics/OtlpHttpMetricExporterTest.java → exporters/otlp/all/src/test/java/io/opentelemetry/exporter/otlp/http/metrics/OtlpHttpMetricExporterOkHttpSenderTest.java

@@ -31,10 +31,10 @@
 import javax.net.ssl.X509TrustManager;
 import org.junit.jupiter.api.Test;
 
-class OtlpHttpMetricExporterTest
+class OtlpHttpMetricExporterOkHttpSenderTest
     extends AbstractHttpTelemetryExporterTest<MetricData, ResourceMetrics> {
 
-  protected OtlpHttpMetricExporterTest() {
+  protected OtlpHttpMetricExporterOkHttpSenderTest() {
     super("metric", "/v1/metrics", ResourceMetrics.getDefaultInstance());
   }
 

exporters/otlp/all/src/test/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporterTest.java → exporters/otlp/all/src/test/java/io/opentelemetry/exporter/otlp/http/trace/OtlpHttpSpanExporterOkHttpSenderTest.java

@@ -21,9 +21,10 @@
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.X509TrustManager;
 
-class OtlpHttpSpanExporterTest extends AbstractHttpTelemetryExporterTest<SpanData, ResourceSpans> {
+class OtlpHttpSpanExporterOkHttpSenderTest
+    extends AbstractHttpTelemetryExporterTest<SpanData, ResourceSpans> {
 
-  protected OtlpHttpSpanExporterTest() {
+  protected OtlpHttpSpanExporterOkHttpSenderTest() {
     super("span", "/v1/traces", ResourceSpans.getDefaultInstance());
   }