add nullaway

Author: zeitlinger

instrumentation/spring/spring-web/spring-web-3.1/library/build.gradle.kts

@@ -1,5 +1,6 @@
 plugins {
   id("otel.library-instrumentation")
+  id("otel.nullaway-conventions")
 }
 
 dependencies {

instrumentation/spring/spring-web/spring-web-3.1/library/src/main/java/io/opentelemetry/instrumentation/spring/web/v3_1/HeaderUtil.java

@@ -13,6 +13,7 @@
 import java.lang.invoke.MethodType;
 import java.util.List;
 import java.util.function.Supplier;
+import javax.annotation.Nullable;
 import org.springframework.http.HttpHeaders;
 
 class HeaderUtil {
@@ -29,12 +30,13 @@ class HeaderUtil {
   }
 
   // copied from java.util.Objects in Java 9+
-  private static <T> T requireNonNullElseGet(T obj, Supplier<? extends T> supplier) {
+  private static <T> T requireNonNullElseGet(@Nullable T obj, Supplier<? extends T> supplier) {
     return (obj != null)
         ? obj
         : requireNonNull(requireNonNull(supplier, "supplier").get(), "supplier.get()");
   }
 
+  @Nullable
   private static MethodHandle findGetHeadersMethod(MethodType methodType) {
     try {
       return MethodHandles.lookup().findVirtual(HttpHeaders.class, "get", methodType);

instrumentation/spring/spring-web/spring-web-3.1/library/src/main/java/io/opentelemetry/instrumentation/spring/web/v3_1/HttpRequestSetter.java

@@ -6,13 +6,17 @@
 package io.opentelemetry.instrumentation.spring.web.v3_1;
 
 import io.opentelemetry.context.propagation.TextMapSetter;
+import javax.annotation.Nullable;
 import org.springframework.http.HttpRequest;
 
 enum HttpRequestSetter implements TextMapSetter<HttpRequest> {
   INSTANCE;
 
   @Override
-  public void set(HttpRequest httpRequest, String key, String value) {
+  public void set(@Nullable HttpRequest httpRequest, String key, String value) {
+    if (httpRequest == null) {
+      return;
+    }
     httpRequest.getHeaders().set(key, value);
   }
 }

instrumentation/spring/spring-web/spring-web-3.1/library/src/main/java/io/opentelemetry/instrumentation/spring/web/v3_1/SpringWebHttpAttributesGetter.java

@@ -73,6 +73,7 @@ public List<String> getHttpRequestHeader(HttpRequest httpRequest, String name) {
   }
 
   @Override
+  @Nullable
   public Integer getHttpResponseStatusCode(
       HttpRequest httpRequest, ClientHttpResponse clientHttpResponse, @Nullable Throwable error) {
 

instrumentation/spring/spring-web/spring-web-3.1/library/src/main/java/io/opentelemetry/instrumentation/spring/web/v3_1/internal/WebTelemetryUtil.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.instrumentation.spring.web.v3_1.internal;
 
 import io.opentelemetry.instrumentation.api.incubator.builder.internal.DefaultHttpClientInstrumenterBuilder;
+import io.opentelemetry.instrumentation.api.internal.Initializer;
 import io.opentelemetry.instrumentation.spring.web.v3_1.SpringWebTelemetryBuilder;
 import java.util.function.Function;
 import org.springframework.http.HttpRequest;
@@ -31,6 +32,7 @@ private WebTelemetryUtil() {}
     return builderExtractor;
   }
 
+  @Initializer
   public static void setBuilderExtractor(
       Function<
               SpringWebTelemetryBuilder,