Add nullability annotations to module/spring-boot-opentelemetry

See gh-46587

Author: mhalbritter

module/spring-boot-opentelemetry/src/main/java/org/springframework/boot/opentelemetry/autoconfigure/OpenTelemetryResourceAttributes.java

@@ -24,6 +24,8 @@
 import java.util.function.BiConsumer;
 import java.util.function.Function;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.core.env.Environment;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -52,7 +54,7 @@ public class OpenTelemetryResourceAttributes {
 
 	private final Map<String, String> resourceAttributes;
 
-	private final Function<String, String> systemEnvironment;
+	private final Function<String, @Nullable String> systemEnvironment;
 
 	/**
 	 * Creates a new instance of {@link OpenTelemetryResourceAttributes}.
@@ -69,8 +71,8 @@ public OpenTelemetryResourceAttributes(Environment environment, Map<String, Stri
 	 * @param resourceAttributes user-provided resource attributes to be used
 	 * @param systemEnvironment a function to retrieve environment variables by name
 	 */
-	OpenTelemetryResourceAttributes(Environment environment, Map<String, String> resourceAttributes,
-			Function<String, String> systemEnvironment) {
+	OpenTelemetryResourceAttributes(Environment environment, @Nullable Map<String, String> resourceAttributes,
+			@Nullable Function<String, @Nullable String> systemEnvironment) {
 		Assert.notNull(environment, "'environment' must not be null");
 		this.environment = environment;
 		this.resourceAttributes = (resourceAttributes != null) ? resourceAttributes : Collections.emptyMap();
@@ -106,7 +108,7 @@ private String getApplicationName() {
 		return this.environment.getProperty("spring.application.name", DEFAULT_SERVICE_NAME);
 	}
 
-	private String getServiceNamespace() {
+	private @Nullable String getServiceNamespace() {
 		return this.environment.getProperty("spring.application.group");
 	}
 
@@ -137,7 +139,7 @@ private Map<String, String> getResourceAttributesFromEnv() {
 		return attributes;
 	}
 
-	private String getEnv(String name) {
+	private @Nullable String getEnv(String name) {
 		return this.systemEnvironment.apply(name);
 	}
 

module/spring-boot-opentelemetry/src/main/java/org/springframework/boot/opentelemetry/autoconfigure/logging/OpenTelemetryLoggingConnectionDetailsConfiguration.java

@@ -55,7 +55,9 @@ public String getUrl(Transport transport) {
 			Assert.state(transport == this.properties.getTransport(),
 					"Requested transport %s doesn't match configured transport %s".formatted(transport,
 							this.properties.getTransport()));
-			return this.properties.getEndpoint();
+			String endpoint = this.properties.getEndpoint();
+			Assert.state(endpoint != null, "'endpoint' must not be null");
+			return endpoint;
 		}
 
 	}

module/spring-boot-opentelemetry/src/main/java/org/springframework/boot/opentelemetry/autoconfigure/logging/OpenTelemetryLoggingExportProperties.java

@@ -20,6 +20,8 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
@@ -34,7 +36,7 @@ public class OpenTelemetryLoggingExportProperties {
 	/**
 	 * URL to the OTel collector's HTTP API.
 	 */
-	private String endpoint;
+	private @Nullable String endpoint;
 
 	/**
 	 * Call timeout for the OTel Collector to process an exported batch of data. This
@@ -64,11 +66,11 @@ public class OpenTelemetryLoggingExportProperties {
 	 */
 	private final Map<String, String> headers = new HashMap<>();
 
-	public String getEndpoint() {
+	public @Nullable String getEndpoint() {
 		return this.endpoint;
 	}
 
-	public void setEndpoint(String endpoint) {
+	public void setEndpoint(@Nullable String endpoint) {
 		this.endpoint = endpoint;
 	}
 

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

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for exporting logs with OpenTelemetry.
  */
+@NullMarked
 package org.springframework.boot.opentelemetry.autoconfigure.logging;
+
+import org.jspecify.annotations.NullMarked;

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

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for OpenTelemetry.
  */
+@NullMarked
 package org.springframework.boot.opentelemetry.autoconfigure;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-opentelemetry/src/main/java/org/springframework/boot/opentelemetry/docker/compose/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Support for Docker Compose OpenTelemetry logging service connections.
  */
+@NullMarked
 package org.springframework.boot.opentelemetry.docker.compose;
+
+import org.jspecify.annotations.NullMarked;

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

@@ -17,4 +17,7 @@
 /**
  * Support for Testcontainers OpenTelemetry logging service connections.
  */
+@NullMarked
 package org.springframework.boot.opentelemetry.testcontainers;
+
+import org.jspecify.annotations.NullMarked;