Add more static imports to spotlessApply: Collections.empty* and singleton* (#16252)

Author: trask

conventions/src/main/kotlin/io/opentelemetry/instrumentation/gradle/StaticImportFormatter.kt

@@ -35,6 +35,11 @@ class StaticImportFormatter : FormatterFunc, Serializable {
         "java.nio.charset.StandardCharsets",
         "[A-Z][A-Z_0-9]*"
       ),
+      Triple(
+        "Collections",
+        "java.util.Collections",
+        "singleton[a-zA-Z0-9]*|empty[a-zA-Z0-9]*"
+      ),
       Triple(
         "ArgumentMatchers",
         "org.mockito.ArgumentMatchers",

declarative-config-bridge/src/main/java/io/opentelemetry/instrumentation/config/bridge/ConfigPropertiesBackedDeclarativeConfigProperties.java

@@ -5,14 +5,14 @@
 
 package io.opentelemetry.instrumentation.config.bridge;
 
+import static java.util.Collections.emptyList;
 import static java.util.Collections.emptySet;
 
 import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
 import io.opentelemetry.common.ComponentLoader;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import java.time.Duration;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -102,8 +102,7 @@ public final class ConfigPropertiesBackedDeclarativeConfigProperties
 
   public static DeclarativeConfigProperties createInstrumentationConfig(
       ConfigProperties configProperties) {
-    return new ConfigPropertiesBackedDeclarativeConfigProperties(
-        configProperties, Collections.emptyList());
+    return new ConfigPropertiesBackedDeclarativeConfigProperties(configProperties, emptyList());
   }
 
   private ConfigPropertiesBackedDeclarativeConfigProperties(

declarative-config-bridge/src/main/java/io/opentelemetry/instrumentation/config/bridge/DeclarativeConfigPropertiesBridge.java

@@ -6,6 +6,8 @@
 package io.opentelemetry.instrumentation.config.bridge;
 
 import static io.opentelemetry.api.incubator.config.DeclarativeConfigProperties.empty;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.emptyMap;
 import static java.util.Objects.requireNonNull;
 
 import io.opentelemetry.api.incubator.config.DeclarativeConfigProperties;
@@ -115,7 +117,7 @@ public List<String> getList(String propertyName) {
             propertyName,
             o -> (List<String>) o,
             (properties, lastPart) -> properties.getScalarList(lastPart, String.class));
-    return propertyValue == null ? Collections.emptyList() : propertyValue;
+    return propertyValue == null ? emptyList() : propertyValue;
   }
 
   @Override
@@ -126,7 +128,7 @@ public Map<String, String> getMap(String propertyName) {
             DeclarativeConfigProperties.class,
             DeclarativeConfigProperties::getStructured);
     if (propertyValue == null) {
-      return Collections.emptyMap();
+      return emptyMap();
     }
     Map<String, String> result = new HashMap<>();
     propertyValue

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/DbClientAttributesGetter.java

@@ -5,9 +5,10 @@
 
 package io.opentelemetry.instrumentation.api.incubator.semconv.db;
 
+import static java.util.Collections.emptyMap;
+
 import io.opentelemetry.instrumentation.api.semconv.network.NetworkAttributesGetter;
 import io.opentelemetry.instrumentation.api.semconv.network.ServerAttributesGetter;
-import java.util.Collections;
 import java.util.Map;
 import javax.annotation.Nullable;
 
@@ -79,6 +80,6 @@ default Long getDbOperationBatchSize(REQUEST request) {
 
   // TODO: make this required to implement
   default Map<String, String> getDbQueryParameters(REQUEST request) {
-    return Collections.emptyMap();
+    return emptyMap();
   }
 }

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/code/CodeAttributesExtractorTest.java

@@ -9,14 +9,14 @@
 import static io.opentelemetry.semconv.CodeAttributes.CODE_FUNCTION_NAME;
 import static io.opentelemetry.semconv.incubating.CodeIncubatingAttributes.CODE_FUNCTION;
 import static io.opentelemetry.semconv.incubating.CodeIncubatingAttributes.CODE_NAMESPACE;
+import static java.util.Collections.emptyMap;
 
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.internal.SemconvStability;
 import io.opentelemetry.instrumentation.testing.junit.code.SemconvCodeStabilityUtil;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
@@ -84,7 +84,7 @@ void shouldExtractNoAttributesIfNoneAreAvailable() {
 
     // when
     AttributesBuilder attributes = Attributes.builder();
-    underTest.onStart(attributes, Context.root(), Collections.emptyMap());
+    underTest.onStart(attributes, Context.root(), emptyMap());
 
     // then
     assertThat(attributes.build().isEmpty()).isTrue();

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/DbClientAttributesExtractorTest.java

@@ -19,13 +19,13 @@
 import static io.opentelemetry.semconv.incubating.DbIncubatingAttributes.DB_STATEMENT;
 import static io.opentelemetry.semconv.incubating.DbIncubatingAttributes.DB_SYSTEM;
 import static io.opentelemetry.semconv.incubating.DbIncubatingAttributes.DB_USER;
+import static java.util.Collections.emptyMap;
 import static org.assertj.core.api.Assertions.entry;
 
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import javax.annotation.Nullable;
@@ -144,7 +144,7 @@ void shouldExtractNoAttributesIfNoneAreAvailable() {
 
     // when
     AttributesBuilder attributes = Attributes.builder();
-    underTest.onStart(attributes, Context.root(), Collections.emptyMap());
+    underTest.onStart(attributes, Context.root(), emptyMap());
 
     // then
     assertThat(attributes.build().isEmpty()).isTrue();

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/SqlClientAttributesExtractorTest.java

@@ -22,8 +22,10 @@
 import static io.opentelemetry.semconv.incubating.DbIncubatingAttributes.DB_STATEMENT;
 import static io.opentelemetry.semconv.incubating.DbIncubatingAttributes.DB_SYSTEM;
 import static io.opentelemetry.semconv.incubating.DbIncubatingAttributes.DB_USER;
+import static java.util.Collections.emptyMap;
 import static java.util.Collections.emptySet;
 import static java.util.Collections.singleton;
+import static java.util.Collections.singletonMap;
 import static org.assertj.core.api.Assertions.entry;
 
 import io.opentelemetry.api.common.Attributes;
@@ -32,7 +34,6 @@
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
@@ -81,7 +82,7 @@ public Long getDbOperationBatchSize(Map<String, Object> map) {
     public Map<String, String> getDbQueryParameters(Map<String, Object> map) {
       Map<String, String> parameters =
           (Map<String, String>) read(map, "db.query.parameter", Map.class);
-      return parameters != null ? parameters : Collections.emptyMap();
+      return parameters != null ? parameters : emptyMap();
     }
 
     protected String read(Map<String, Object> map, String key) {
@@ -243,7 +244,7 @@ void shouldExtractNoAttributesIfNoneAreAvailable() {
 
     // when
     AttributesBuilder attributes = Attributes.builder();
-    underTest.onStart(attributes, Context.root(), Collections.emptyMap());
+    underTest.onStart(attributes, Context.root(), emptyMap());
 
     // then
     assertThat(attributes.build().isEmpty()).isTrue();
@@ -443,7 +444,7 @@ void shouldNotExtractQueryParametersForBatch() {
     request.put("db.namespace", "potatoes");
     request.put("db.query.texts", singleton("INSERT INTO potato VALUES(?)"));
     request.put(DB_OPERATION_BATCH_SIZE.getKey(), 2L);
-    request.put("db.query.parameter", Collections.singletonMap("0", "1"));
+    request.put("db.query.parameter", singletonMap("0", "1"));
 
     Context context = Context.root();
 

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/http/HttpExperimentalAttributesExtractorTest.java

@@ -9,7 +9,9 @@
 import static io.opentelemetry.semconv.incubating.HttpIncubatingAttributes.HTTP_REQUEST_BODY_SIZE;
 import static io.opentelemetry.semconv.incubating.HttpIncubatingAttributes.HTTP_RESPONSE_BODY_SIZE;
 import static io.opentelemetry.semconv.incubating.UrlIncubatingAttributes.URL_TEMPLATE;
+import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
+import static java.util.Collections.singletonMap;
 import static org.mockito.Mockito.when;
 
 import io.opentelemetry.api.common.AttributeKey;
@@ -19,7 +21,6 @@
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import io.opentelemetry.instrumentation.api.semconv.http.HttpCommonAttributesGetter;
 import io.opentelemetry.instrumentation.api.semconv.http.HttpServerAttributesGetter;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
@@ -39,15 +40,12 @@ void shouldExtractRequestAndResponseSizes_client() {
     runTest(
         clientGetter,
         HttpExperimentalAttributesExtractor.create(clientGetter),
-        Collections.singletonMap(URL_TEMPLATE, "template"));
+        singletonMap(URL_TEMPLATE, "template"));
   }
 
   @Test
   void shouldExtractRequestAndResponseSizes_server() {
-    runTest(
-        serverGetter,
-        HttpExperimentalAttributesExtractor.create(serverGetter),
-        Collections.emptyMap());
+    runTest(serverGetter, HttpExperimentalAttributesExtractor.create(serverGetter), emptyMap());
   }
 
   void runTest(

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/messaging/MessagingAttributesExtractorTest.java

@@ -17,6 +17,7 @@
 import static io.opentelemetry.semconv.incubating.MessagingIncubatingAttributes.MESSAGING_MESSAGE_ID;
 import static io.opentelemetry.semconv.incubating.MessagingIncubatingAttributes.MESSAGING_OPERATION;
 import static io.opentelemetry.semconv.incubating.MessagingIncubatingAttributes.MESSAGING_SYSTEM;
+import static java.util.Collections.emptyMap;
 import static org.assertj.core.api.Assertions.entry;
 
 import io.opentelemetry.api.common.AttributeKey;
@@ -25,7 +26,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.instrumentation.api.instrumenter.AttributesExtractor;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -122,10 +122,10 @@ void shouldExtractNoAttributesIfNoneAreAvailable() {
 
     // when
     AttributesBuilder startAttributes = Attributes.builder();
-    underTest.onStart(startAttributes, context, Collections.emptyMap());
+    underTest.onStart(startAttributes, context, emptyMap());
 
     AttributesBuilder endAttributes = Attributes.builder();
-    underTest.onEnd(endAttributes, context, Collections.emptyMap(), null, null);
+    underTest.onEnd(endAttributes, context, emptyMap(), null, null);
 
     // then
     assertThat(startAttributes.build().isEmpty()).isTrue();

instrumentation-api/src/jmh/java/io/opentelemetry/instrumentation/api/instrumenter/InstrumenterBenchmark.java

@@ -5,6 +5,8 @@
 
 package io.opentelemetry.instrumentation.api.instrumenter;
 
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
 import static java.util.concurrent.TimeUnit.MICROSECONDS;
 
 import io.opentelemetry.api.OpenTelemetry;
@@ -13,7 +15,6 @@
 import io.opentelemetry.instrumentation.api.semconv.http.HttpClientAttributesGetter;
 import io.opentelemetry.instrumentation.api.semconv.http.HttpSpanNameExtractor;
 import java.net.InetSocketAddress;
-import java.util.Collections;
 import java.util.List;
 import javax.annotation.Nullable;
 import org.openjdk.jmh.annotations.Benchmark;
@@ -76,9 +77,9 @@ public String getHttpRequestMethod(Object unused) {
     @Override
     public List<String> getHttpRequestHeader(Object unused, String name) {
       if (name.equalsIgnoreCase("user-agent")) {
-        return Collections.singletonList("OpenTelemetryBot");
+        return singletonList("OpenTelemetryBot");
       }
-      return Collections.emptyList();
+      return emptyList();
     }
 
     @Override
@@ -89,7 +90,7 @@ public Integer getHttpResponseStatusCode(
 
     @Override
     public List<String> getHttpResponseHeader(Object unused, Void unused2, String name) {
-      return Collections.emptyList();
+      return emptyList();
     }
 
     @Override