Pulls up ConstantHttpEndpointSupplier (#251)

Signed-off-by: Adrian Cole <adrian@tetrate.io>

RATIONALE.md

@@ -34,7 +34,7 @@ internal detail.
 
 Someone who wants to employ client-side loadbalancer logic can do that inside the
 `HttpEndpointSupplier`, and return a chosen endpoint. This will work because the supplier is
-documented to not be cached, unless it implements `HttpEndpointSupplier.Constant`.
+documented to not be cached, unless it is a `ConstantHttpEndpointSupplier`.
 
 ### Why is `HttpEndpointSupplier` closeable?
 

benchmarks/src/main/java/zipkin2/reporter/internal/SenderBenchmarks.java

@@ -34,7 +34,6 @@
 import zipkin2.TestObjects;
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.InMemoryReporterMetrics;
-import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.SpanBytesEncoder;
 
 /**

brave/src/main/java/zipkin2/reporter/brave/ZipkinSpanHandler.java

@@ -20,8 +20,8 @@
 import brave.propagation.TraceContext;
 import java.io.Closeable;
 import zipkin2.Span;
-import zipkin2.reporter.SpanBytesEncoder;
 import zipkin2.reporter.Reporter;
+import zipkin2.reporter.SpanBytesEncoder;
 
 /**
  * This allows you to send spans recorded by Brave to a pre-configured {@linkplain Reporter Zipkin

core/src/main/java/zipkin2/reporter/ConstantHttpEndpointSupplier.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2016-2024 The OpenZipkin Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package zipkin2.reporter;
+
+/**
+ * HTTP {@link BytesMessageSender senders} check for this type, and will cache its first value.
+ *
+ * @since 3.3
+ */
+public final class ConstantHttpEndpointSupplier implements HttpEndpointSupplier {
+  /**
+   * HTTP {@link BytesMessageSender sender} builders check for this symbol, and return the input as
+   * a {@linkplain ConstantHttpEndpointSupplier} result rather than perform dynamic lookups.
+   *
+   * @since 3.3
+   */
+  public static final HttpEndpointSupplier.Factory FACTORY = new Factory() {
+    @Override public ConstantHttpEndpointSupplier create(String endpoint) {
+      return new ConstantHttpEndpointSupplier(endpoint);
+    }
+  };
+
+  public static ConstantHttpEndpointSupplier create(String endpoint) {
+    return new ConstantHttpEndpointSupplier(endpoint);
+  }
+
+  private final String endpoint;
+
+  ConstantHttpEndpointSupplier(String endpoint) {
+    if (endpoint == null) throw new NullPointerException("endpoint == null");
+    this.endpoint = endpoint;
+  }
+
+  @Override public String get() {
+    return endpoint;
+  }
+
+  @Override public void close() {
+  }
+
+  @Override public String toString() {
+    return endpoint;
+  }
+}

core/src/main/java/zipkin2/reporter/HttpEndpointSupplier.java

@@ -25,7 +25,8 @@
  * <p>{@link BytesMessageSender senders} should implement the following logic:
  * <ul>
  *   <li>During build, the sender should invoke the {@linkplain Factory}.</li>
- *   <li>If the result is {@link Constant}, build the sender to use a static value.</li>
+ *   <li>If the result is {@link ConstantHttpEndpointSupplier}, build the sender to use a static
+ *       value.</li>
  *   <li>Otherwise, call {@link HttpEndpointSupplier#get()} each time
  *       {@linkplain BytesMessageSender#send(List)} is invoked.</li>
  *   <li>Call {@link #close()} once during {@link BytesMessageSender#close()}.</li>
@@ -48,23 +49,11 @@
  * @since 3.3
  */
 public interface HttpEndpointSupplier extends Closeable {
-  /**
-   * HTTP {@link BytesMessageSender sender} builders check for this symbol, and return the input as
-   * a {@linkplain Constant} result rather than perform dynamic lookups.
-   *
-   * @since 3.3
-   */
-  Factory CONSTANT_FACTORY = new Factory() {
-    @Override public Constant create(String endpoint) {
-      return new Constant(endpoint);
-    }
-  };
-
   /**
    * Returns a possibly cached endpoint to an HTTP {@link BytesMessageSender sender}.
    *
    * <p>This will be called inside {@linkplain BytesMessageSender#send(List)}, unless this is an
-   * instance of {@linkplain Constant}.
+   * instance of {@linkplain ConstantHttpEndpointSupplier}.
    *
    * @since 3.3
    */
@@ -81,35 +70,15 @@ public interface HttpEndpointSupplier extends Closeable {
   interface Factory {
 
     /**
-     * Returns a possibly {@linkplain Constant} endpoint supplier, given a static endpoint from
-     * configuration.
+     * Returns a possibly {@linkplain ConstantHttpEndpointSupplier} endpoint supplier, given a
+     * static endpoint from configuration.
      *
-     * <p>Note: Some factories may perform I/O to lazy-create a {@linkplain Constant} endpoint.
+     * <p>Note: Some factories may perform I/O to lazy-create a
+     * {@linkplain ConstantHttpEndpointSupplier} endpoint.
      *
      * @param endpoint a static HTTP endpoint from configuration. For example,
      *                 http://localhost:9411/api/v2/spans
      */
     HttpEndpointSupplier create(String endpoint);
   }
-
-  /**
-   * HTTP {@link BytesMessageSender senders} check for this type, and will cache its first value.
-   *
-   * @since 3.3
-   */
-  final class Constant implements HttpEndpointSupplier {
-    private final String endpoint;
-
-    public Constant(String endpoint) {
-      if (endpoint == null) throw new NullPointerException("endpoint == null");
-      this.endpoint = endpoint;
-    }
-
-    @Override public String get() {
-      return endpoint;
-    }
-
-    @Override public void close() {
-    }
-  }
 }

core/src/main/java/zipkin2/reporter/internal/AsyncReporter.java

@@ -15,7 +15,6 @@
 
 import java.io.Closeable;
 import java.io.Flushable;
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.concurrent.CountDownLatch;
@@ -33,7 +32,6 @@
 import zipkin2.reporter.Component;
 import zipkin2.reporter.Reporter;
 import zipkin2.reporter.ReporterMetrics;
-import zipkin2.reporter.Sender;
 
 import static java.lang.String.format;
 import static java.util.logging.Level.FINE;

core/src/test/java/zipkin2/reporter/AwaitableCallbackTest.java

@@ -14,7 +14,6 @@
 package zipkin2.reporter;
 
 import java.io.IOException;
-import java.util.concurrent.atomic.AtomicBoolean;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;

okhttp3/src/main/java/zipkin2/reporter/okhttp3/OkHttpSender.java

@@ -37,6 +37,7 @@
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.CheckResult;
 import zipkin2.reporter.ClosedSenderException;
+import zipkin2.reporter.ConstantHttpEndpointSupplier;
 import zipkin2.reporter.Encoding;
 import zipkin2.reporter.HttpEndpointSupplier;
 import zipkin2.reporter.Sender;
@@ -98,7 +99,7 @@ public static Builder newBuilder() {
 
   public static final class Builder {
     final OkHttpClient.Builder clientBuilder;
-    HttpEndpointSupplier.Factory endpointSupplierFactory = HttpEndpointSupplier.CONSTANT_FACTORY;
+    HttpEndpointSupplier.Factory endpointSupplierFactory = ConstantHttpEndpointSupplier.FACTORY;
     String endpoint;
     Encoding encoding = Encoding.JSON;
     boolean compressionEnabled = true;
@@ -207,7 +208,7 @@ public OkHttpSender build() {
       if (endpointSupplier == null) {
         throw new NullPointerException("endpointSupplierFactory.create() returned null");
       }
-      if (endpointSupplier instanceof HttpEndpointSupplier.Constant) {
+      if (endpointSupplier instanceof ConstantHttpEndpointSupplier) {
         endpoint = endpointSupplier.get(); // eagerly resolve the endpoint
         return new OkHttpSender(this, new ConstantHttpUrlSupplier(endpoint));
       }

okhttp3/src/test/java/zipkin2/reporter/okhttp3/OkHttpSenderTest.java

@@ -24,8 +24,8 @@
 import zipkin2.reporter.AsyncReporter;
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.ClosedSenderException;
+import zipkin2.reporter.ConstantHttpEndpointSupplier;
 import zipkin2.reporter.HttpEndpointSupplier;
-import zipkin2.reporter.HttpEndpointSupplier.Constant;
 
 import static java.util.stream.Collectors.toList;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -42,14 +42,14 @@ class OkHttpSenderTest {
 
     // Change the supplier, but not the endpoint.
     sender = sender.toBuilder()
-      .endpointSupplierFactory(e -> new Constant("http://localhost:29092"))
+      .endpointSupplierFactory(e -> ConstantHttpEndpointSupplier.create("http://localhost:29092"))
       .build();
     assertThat(sender)
       .hasToString("OkHttpSender{http://localhost:29092/}");
 
     // Change the supplier, and see the prior endpoint.
     sender = sender.toBuilder()
-      .endpointSupplierFactory(HttpEndpointSupplier.CONSTANT_FACTORY)
+      .endpointSupplierFactory(ConstantHttpEndpointSupplier.FACTORY)
       .build();
     assertThat(sender)
       .hasToString("OkHttpSender{http://localhost:19092/}");
@@ -86,7 +86,7 @@ class OkHttpSenderTest {
   @Test void endpointSupplierFactory_constant() {
     sender.close();
     sender = sender.toBuilder()
-      .endpointSupplierFactory(e -> new Constant("http://localhost:29092"))
+      .endpointSupplierFactory(e -> ConstantHttpEndpointSupplier.create("http://localhost:29092"))
       .build();
 
     // The connection supplier has a constant URL
@@ -97,7 +97,7 @@ class OkHttpSenderTest {
 
   @Test void endpointSupplierFactory_constantBad() {
     OkHttpSender.Builder builder = sender.toBuilder()
-      .endpointSupplierFactory(e -> new Constant("htp://localhost:9411/api/v1/spans"));
+      .endpointSupplierFactory(e -> ConstantHttpEndpointSupplier.create("htp://localhost:9411/api/v1/spans"));
 
     assertThatThrownBy(builder::build)
       .isInstanceOf(IllegalArgumentException.class)

spring-beans/src/main/java/zipkin2/reporter/beans/BaseAsyncFactoryBean.java

@@ -16,7 +16,6 @@
 import org.springframework.beans.factory.config.AbstractFactoryBean;
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.ReporterMetrics;
-import zipkin2.reporter.Sender;
 
 abstract class BaseAsyncFactoryBean extends AbstractFactoryBean {
   BytesMessageSender sender;

spring-beans/src/test/java/zipkin2/reporter/beans/AsyncReporterFactoryBeanTest.java

@@ -20,7 +20,6 @@
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.Encoding;
 import zipkin2.reporter.ReporterMetrics;
-import zipkin2.reporter.Sender;
 import zipkin2.reporter.SpanBytesEncoder;
 
 import static org.assertj.core.api.Assertions.assertThat;

spring-beans/src/test/java/zipkin2/reporter/beans/AsyncZipkinSpanHandlerFactoryBeanTest.java

@@ -20,9 +20,7 @@
 import org.junit.jupiter.api.Test;
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.ReporterMetrics;
-import zipkin2.reporter.Sender;
 import zipkin2.reporter.brave.AsyncZipkinSpanHandler;
-import zipkin2.reporter.brave.ZipkinSpanHandler;
 
 import static org.assertj.core.api.Assertions.assertThat;
 

spring-beans/src/test/java/zipkin2/reporter/beans/ZipkinSpanHandlerFactoryBeanTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 The OpenZipkin Authors
+ * Copyright 2016-2024 The OpenZipkin Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -18,9 +18,7 @@
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import zipkin2.reporter.Reporter;
-import zipkin2.reporter.Sender;
 import zipkin2.reporter.brave.ZipkinSpanHandler;
-import zipkin2.reporter.urlconnection.URLConnectionSender;
 
 import static org.assertj.core.api.Assertions.assertThat;
 

urlconnection/src/main/java/zipkin2/reporter/urlconnection/URLConnectionSender.java

@@ -28,6 +28,7 @@
 import zipkin2.reporter.Callback;
 import zipkin2.reporter.CheckResult;
 import zipkin2.reporter.ClosedSenderException;
+import zipkin2.reporter.ConstantHttpEndpointSupplier;
 import zipkin2.reporter.Encoding;
 import zipkin2.reporter.HttpEndpointSupplier;
 import zipkin2.reporter.Sender;
@@ -52,7 +53,7 @@ public static Builder newBuilder() {
   }
 
   public static final class Builder {
-    HttpEndpointSupplier.Factory endpointSupplierFactory = HttpEndpointSupplier.CONSTANT_FACTORY;
+    HttpEndpointSupplier.Factory endpointSupplierFactory = ConstantHttpEndpointSupplier.FACTORY;
     String endpoint;
     Encoding encoding = Encoding.JSON;
     int messageMaxBytes = 500000;
@@ -141,7 +142,7 @@ public URLConnectionSender build() {
       if (endpointSupplier == null) {
         throw new NullPointerException("endpointSupplierFactory.create() returned null");
       }
-      if (endpointSupplier instanceof HttpEndpointSupplier.Constant) {
+      if (endpointSupplier instanceof ConstantHttpEndpointSupplier) {
         endpoint = endpointSupplier.get(); // eagerly resolve the endpoint
         return new URLConnectionSender(this, new ConstantHttpURLConnectionSupplier(endpoint));
       }

urlconnection/src/test/java/zipkin2/reporter/urlconnection/URLConnectionSenderTest.java

@@ -17,7 +17,6 @@
 import java.net.ConnectException;
 import java.net.MalformedURLException;
 import java.net.URI;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
@@ -26,8 +25,8 @@
 import zipkin2.reporter.AsyncReporter;
 import zipkin2.reporter.BytesMessageSender;
 import zipkin2.reporter.ClosedSenderException;
+import zipkin2.reporter.ConstantHttpEndpointSupplier;
 import zipkin2.reporter.HttpEndpointSupplier;
-import zipkin2.reporter.HttpEndpointSupplier.Constant;
 
 import static java.util.stream.Collectors.toList;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -44,14 +43,14 @@ class URLConnectionSenderTest {
 
     // Change the supplier, but not the endpoint
     sender = sender.toBuilder()
-      .endpointSupplierFactory(e -> new Constant("http://localhost:29092"))
+      .endpointSupplierFactory(e -> ConstantHttpEndpointSupplier.create("http://localhost:29092"))
       .build();
     assertThat(sender)
       .hasToString("URLConnectionSender{http://localhost:29092}");
 
     // Change the supplier, and see the prior endpoint.
     sender = sender.toBuilder()
-      .endpointSupplierFactory(HttpEndpointSupplier.CONSTANT_FACTORY)
+      .endpointSupplierFactory(ConstantHttpEndpointSupplier.FACTORY)
       .build();
     assertThat(sender)
       .hasToString("URLConnectionSender{http://localhost:19092}");
@@ -86,7 +85,7 @@ class URLConnectionSenderTest {
   @Test void endpointSupplierFactory_constant() throws MalformedURLException {
     sender.close();
     sender = sender.toBuilder()
-      .endpointSupplierFactory(e -> new Constant("http://localhost:29092"))
+      .endpointSupplierFactory(e -> ConstantHttpEndpointSupplier.create("http://localhost:29092"))
       .build();
 
     // The connection supplier has a constant URL
@@ -97,7 +96,7 @@ class URLConnectionSenderTest {
 
   @Test void endpointSupplierFactory_constantBad() {
     URLConnectionSender.Builder builder = sender.toBuilder()
-      .endpointSupplierFactory(e -> new Constant("htp://localhost:9411/api/v1/spans"));
+      .endpointSupplierFactory(e -> ConstantHttpEndpointSupplier.create("htp://localhost:9411/api/v1/spans"));
 
     assertThatThrownBy(builder::build)
       .isInstanceOf(IllegalArgumentException.class)