Add nullability annotations to module/spring-boot-webclient

See gh-46587

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/autoconfigure/AbstractWebClientProperties.java

@@ -20,6 +20,8 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
 import org.springframework.boot.http.client.autoconfigure.ApiversionProperties;
 import org.springframework.boot.http.client.autoconfigure.reactive.AbstractClientHttpConnectorProperties;
@@ -40,7 +42,7 @@ public abstract class AbstractWebClientProperties extends AbstractClientHttpConn
 	 * Base url to set in the underlying HTTP client group. By default, set to
 	 * {@code null}.
 	 */
-	private String baseUrl;
+	private @Nullable String baseUrl;
 
 	/**
 	 * Default request headers for interface client group. By default, set to empty
@@ -54,11 +56,11 @@ public abstract class AbstractWebClientProperties extends AbstractClientHttpConn
 	@NestedConfigurationProperty
 	private final ApiversionProperties apiversion = new ApiversionProperties();
 
-	public String getBaseUrl() {
+	public @Nullable String getBaseUrl() {
 		return this.baseUrl;
 	}
 
-	public void setBaseUrl(String baseUrl) {
+	public void setBaseUrl(@Nullable String baseUrl) {
 		this.baseUrl = baseUrl;
 	}
 

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/autoconfigure/PropertiesWebClientCustomizer.java

@@ -21,6 +21,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.boot.http.client.autoconfigure.ApiversionProperties;
 import org.springframework.boot.http.client.autoconfigure.PropertiesApiVersionInserter;
@@ -29,6 +31,7 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.web.client.ApiVersionFormatter;
 import org.springframework.web.client.ApiVersionInserter;
 import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.WebClient.Builder;
 
 /**
  * {@link WebClientCustomizer} to apply {@link AbstractWebClientProperties}.
@@ -38,18 +41,19 @@ import org.springframework.web.reactive.function.client.WebClient;
  */
 public class PropertiesWebClientCustomizer implements WebClientCustomizer {
 
-	private final AbstractWebClientProperties[] orderedProperties;
+	private final @Nullable AbstractWebClientProperties[] orderedProperties;
 
-	private ApiVersionInserter apiVersionInserter;
+	private final @Nullable ApiVersionInserter apiVersionInserter;
 
-	public PropertiesWebClientCustomizer(ApiVersionInserter apiVersionInserter, ApiVersionFormatter apiVersionFormatter,
-			AbstractWebClientProperties... orderedProperties) {
+	public PropertiesWebClientCustomizer(@Nullable ApiVersionInserter apiVersionInserter,
+			@Nullable ApiVersionFormatter apiVersionFormatter,
+			@Nullable AbstractWebClientProperties... orderedProperties) {
 		this.orderedProperties = orderedProperties;
 		this.apiVersionInserter = PropertiesApiVersionInserter.get(apiVersionInserter, apiVersionFormatter,
 				Arrays.stream(orderedProperties).map(this::getApiVersion));
 	}
 
-	private ApiversionProperties getApiVersion(AbstractWebClientProperties properties) {
+	private @Nullable ApiversionProperties getApiVersion(@Nullable AbstractWebClientProperties properties) {
 		return (properties != null) ? properties.getApiversion() : null;
 	}
 
@@ -62,13 +66,16 @@ public class PropertiesWebClientCustomizer implements WebClientCustomizer {
 			if (properties != null) {
 				map.from(properties::getBaseUrl).whenHasText().to(builder::baseUrl);
 				map.from(properties::getDefaultHeader).as(this::putAllHeaders).to(builder::defaultHeaders);
-				map.from(properties.getApiversion())
-					.as(ApiversionProperties::getDefaultVersion)
-					.to(builder::defaultApiVersion);
+				setDefaultApiVersion(builder, map, properties);
 			}
 		}
 	}
 
+	@SuppressWarnings("NullAway") // Lambda isn't detected with the correct nullability
+	private void setDefaultApiVersion(Builder builder, PropertyMapper map, AbstractWebClientProperties properties) {
+		map.from(properties.getApiversion()).as(ApiversionProperties::getDefaultVersion).to(builder::defaultApiVersion);
+	}
+
 	private Consumer<HttpHeaders> putAllHeaders(Map<String, List<String>> defaultHeaders) {
 		return (httpHeaders) -> httpHeaders.putAll(defaultHeaders);
 	}

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/autoconfigure/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for Spring Framework's functional web client.
  */
+@NullMarked
 package org.springframework.boot.webclient.autoconfigure;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/autoconfigure/service/ReactiveHttpServiceClientAutoConfiguration.java

@@ -53,6 +53,7 @@ import org.springframework.web.service.registry.ImportHttpServices;
 @EnableConfigurationProperties(ReactiveHttpClientServiceProperties.class)
 public final class ReactiveHttpServiceClientAutoConfiguration implements BeanClassLoaderAware {
 
+	@SuppressWarnings("NullAway.Init")
 	private ClassLoader beanClassLoader;
 
 	ReactiveHttpServiceClientAutoConfiguration() {

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/autoconfigure/service/WebClientPropertiesHttpServiceGroupConfigurer.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.webclient.autoconfigure.service;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.http.client.autoconfigure.reactive.ClientHttpConnectors;
 import org.springframework.boot.http.client.autoconfigure.reactive.HttpReactiveClientProperties;
@@ -54,9 +56,9 @@ class WebClientPropertiesHttpServiceGroupConfigurer implements WebClientHttpServ
 
 	private final ObjectProvider<ClientHttpConnectorSettings> clientConnectorSettings;
 
-	private final ApiVersionInserter apiVersionInserter;
+	private final @Nullable ApiVersionInserter apiVersionInserter;
 
-	private final ApiVersionFormatter apiVersionFormatter;
+	private final @Nullable ApiVersionFormatter apiVersionFormatter;
 
 	WebClientPropertiesHttpServiceGroupConfigurer(ClassLoader classLoader, ObjectProvider<SslBundles> sslBundles,
 			HttpReactiveClientProperties clientProperties, ReactiveHttpClientServiceProperties serviceProperties,
@@ -91,12 +93,13 @@ class WebClientPropertiesHttpServiceGroupConfigurer implements WebClientHttpServ
 	}
 
 	private PropertiesWebClientCustomizer getPropertiesWebClientCustomizer(
-			ReactiveHttpClientServiceProperties.Group groupProperties) {
+			ReactiveHttpClientServiceProperties.@Nullable Group groupProperties) {
 		return new PropertiesWebClientCustomizer(this.apiVersionInserter, this.apiVersionFormatter, groupProperties,
 				this.serviceProperties);
 	}
 
-	private ClientHttpConnector getClientConnector(ReactiveHttpClientServiceProperties.Group groupProperties) {
+	private ClientHttpConnector getClientConnector(
+			ReactiveHttpClientServiceProperties.@Nullable Group groupProperties) {
 		ClientHttpConnectors connectors = new ClientHttpConnectors(this.sslBundles, groupProperties,
 				this.serviceProperties, this.clientProperties);
 		ClientHttpConnectorBuilder<?> builder = this.clientConnectorBuilder

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/autoconfigure/service/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-Configuration for Spring's Reactive HTTP Service Interface Clients.
  */
+@NullMarked
 package org.springframework.boot.webclient.autoconfigure.service;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/observation/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Observation integration for WebClient.
  */
+@NullMarked
 package org.springframework.boot.webclient.observation;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-webclient/src/main/java/org/springframework/boot/webclient/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Spring WebFlux WebClient support abstractions.
  */
+@NullMarked
 package org.springframework.boot.webclient;
+
+import org.jspecify.annotations.NullMarked;