Update samplers module to follow style guide

Co-authored-by: trask <[email protected]>

Author: Copilot

samplers/build.gradle.kts

@@ -7,12 +7,16 @@ description = "Sampler which makes its decision based on semantic attributes val
 otelJava.moduleName.set("io.opentelemetry.contrib.sampler")
 
 dependencies {
+  annotationProcessor("com.google.auto.service:auto-service")
+
   api("io.opentelemetry:opentelemetry-sdk")
 
+  compileOnly("com.google.auto.service:auto-service")
   compileOnly("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
   compileOnly("io.opentelemetry:opentelemetry-api-incubator")
   compileOnly("io.opentelemetry:opentelemetry-sdk-extension-incubator")
 
+  testImplementation("com.google.auto.service:auto-service")
   testImplementation("io.opentelemetry.semconv:opentelemetry-semconv-incubating")
   testImplementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
   testImplementation("io.opentelemetry:opentelemetry-sdk-extension-incubator")

samplers/src/main/java/io/opentelemetry/contrib/sampler/LinksParentAlwaysOnSamplerProvider.java

@@ -5,11 +5,13 @@
 
 package io.opentelemetry.contrib.sampler;
 
+import com.google.auto.service.AutoService;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSamplerProvider;
 import io.opentelemetry.sdk.trace.samplers.Sampler;
 
-public class LinksParentAlwaysOnSamplerProvider implements ConfigurableSamplerProvider {
+@AutoService(ConfigurableSamplerProvider.class)
+public final class LinksParentAlwaysOnSamplerProvider implements ConfigurableSamplerProvider {
   @Override
   public Sampler createSampler(ConfigProperties config) {
     return LinksBasedSampler.create(Sampler.parentBased(Sampler.alwaysOn()));

samplers/src/main/java/io/opentelemetry/contrib/sampler/internal/RuleBasedRoutingSamplerComponentProvider.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.contrib.sampler.internal;
 
+import com.google.auto.service.AutoService;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.incubator.config.DeclarativeConfigException;
 import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
@@ -22,7 +23,9 @@
  * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
  * at any time.
  */
-public class RuleBasedRoutingSamplerComponentProvider implements ComponentProvider<Sampler> {
+@AutoService(ComponentProvider.class)
+@SuppressWarnings("rawtypes")
+public final class RuleBasedRoutingSamplerComponentProvider implements ComponentProvider<Sampler> {
 
   private static final String ACTION_RECORD_AND_SAMPLE = "RECORD_AND_SAMPLE";
   private static final String ACTION_DROP = "DROP";

samplers/src/main/resources/META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.internal.ComponentProvider

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.contrib.sampler;
 
+import static java.util.Collections.emptyList;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import io.opentelemetry.api.common.Attributes;
@@ -20,7 +21,6 @@
 import io.opentelemetry.sdk.trace.samplers.Sampler;
 import io.opentelemetry.sdk.trace.samplers.SamplingDecision;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -57,7 +57,7 @@ void testEmptyAlwaysTrueRoot() {
                     SPAN_NAME,
                     SPAN_KIND,
                     Attributes.empty(),
-                    Collections.emptyList())
+                    emptyList())
                 .getDecision())
         .isEqualTo(SamplingDecision.RECORD_AND_SAMPLE);
   }
@@ -72,7 +72,7 @@ void testEmptyAlwaysFalseRoot() {
                     SPAN_NAME,
                     SPAN_KIND,
                     Attributes.empty(),
-                    Collections.emptyList())
+                    emptyList())
                 .getDecision())
         .isEqualTo(SamplingDecision.DROP);
   }