Add nullability annotations to module/spring-boot-health

mhalbritter · mhalbritter · commit 40d0560378a6 · 2025-08-01T09:16:11.000+02:00
See gh-46587
diff --git a/module/spring-boot-health/build.gradle b/module/spring-boot-health/build.gradle
@@ -26,6 +26,8 @@ description = "Spring Boot Health"
 dependencies {
 	api(project(":core:spring-boot"))
 
+	compileOnly("com.google.code.findbugs:jsr305")
+
 	optional(project(":core:spring-boot-autoconfigure"))
 	optional("io.projectreactor:reactor-core")
 	optional("com.fasterxml.jackson.core:jackson-annotations")
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/autoconfigure/contributor/package-info.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/autoconfigure/contributor/package-info.java
@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for health contributors.
  */
+@NullMarked
 package org.springframework.boot.health.autoconfigure.contributor;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/autoconfigure/registry/package-info.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/autoconfigure/registry/package-info.java
@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for health registries.
  */
+@NullMarked
 package org.springframework.boot.health.autoconfigure.registry;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/AbstractHealthIndicator.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/AbstractHealthIndicator.java
@@ -20,6 +20,7 @@
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
@@ -37,13 +38,13 @@
  */
 public abstract class AbstractHealthIndicator implements HealthIndicator {
 
-	private static final String NO_MESSAGE = null;
+	private static final @Nullable String NO_MESSAGE = null;
 
 	private static final String DEFAULT_MESSAGE = "Health check failed";
 
 	private final Log logger = LogFactory.getLog(getClass());
 
-	private final Function<Exception, String> healthCheckFailedMessage;
+	private final Function<Exception, @Nullable String> healthCheckFailedMessage;
 
 	/**
 	 * Create a new {@link AbstractHealthIndicator} instance with a default
@@ -58,7 +59,7 @@ protected AbstractHealthIndicator() {
 	 * log when the health check fails.
 	 * @param healthCheckFailedMessage the message to log on health check failure
 	 */
-	protected AbstractHealthIndicator(String healthCheckFailedMessage) {
+	protected AbstractHealthIndicator(@Nullable String healthCheckFailedMessage) {
 		this.healthCheckFailedMessage = (ex) -> healthCheckFailedMessage;
 	}
 
@@ -67,7 +68,7 @@ protected AbstractHealthIndicator(String healthCheckFailedMessage) {
 	 * log when the health check fails.
 	 * @param healthCheckFailedMessage the message to log on health check failure
 	 */
-	protected AbstractHealthIndicator(Function<Exception, String> healthCheckFailedMessage) {
+	protected AbstractHealthIndicator(Function<Exception, @Nullable String> healthCheckFailedMessage) {
 		Assert.notNull(healthCheckFailedMessage, "'healthCheckFailedMessage' must not be null");
 		this.healthCheckFailedMessage = healthCheckFailedMessage;
 	}
@@ -85,7 +86,7 @@ public final Health health() {
 		return builder.build();
 	}
 
-	private void logExceptionIfPresent(Throwable throwable) {
+	private void logExceptionIfPresent(@Nullable Throwable throwable) {
 		if (throwable != null && this.logger.isWarnEnabled()) {
 			String message = (throwable instanceof Exception ex) ? this.healthCheckFailedMessage.apply(ex) : null;
 			this.logger.warn(StringUtils.hasText(message) ? message : DEFAULT_MESSAGE, throwable);
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/AbstractReactiveHealthIndicator.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/AbstractReactiveHealthIndicator.java
@@ -20,6 +20,7 @@
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 import reactor.core.publisher.Mono;
 
 import org.springframework.util.Assert;
@@ -36,13 +37,13 @@
  */
 public abstract class AbstractReactiveHealthIndicator implements ReactiveHealthIndicator {
 
-	private static final String NO_MESSAGE = null;
+	private static final @Nullable String NO_MESSAGE = null;
 
 	private static final String DEFAULT_MESSAGE = "Health check failed";
 
 	private final Log logger = LogFactory.getLog(getClass());
 
-	private final Function<Throwable, String> healthCheckFailedMessage;
+	private final Function<Throwable, @Nullable String> healthCheckFailedMessage;
 
 	/**
 	 * Create a new {@link AbstractReactiveHealthIndicator} instance with a default
@@ -57,7 +58,7 @@ protected AbstractReactiveHealthIndicator() {
 	 * message to log when the health check fails.
 	 * @param healthCheckFailedMessage the message to log on health check failure
 	 */
-	protected AbstractReactiveHealthIndicator(String healthCheckFailedMessage) {
+	protected AbstractReactiveHealthIndicator(@Nullable String healthCheckFailedMessage) {
 		this.healthCheckFailedMessage = (ex) -> healthCheckFailedMessage;
 	}
 
@@ -66,7 +67,7 @@ protected AbstractReactiveHealthIndicator(String healthCheckFailedMessage) {
 	 * message to log when the health check fails.
 	 * @param healthCheckFailedMessage the message to log on health check failure
 	 */
-	protected AbstractReactiveHealthIndicator(Function<Throwable, String> healthCheckFailedMessage) {
+	protected AbstractReactiveHealthIndicator(Function<Throwable, @Nullable String> healthCheckFailedMessage) {
 		Assert.notNull(healthCheckFailedMessage, "'healthCheckFailedMessage' must not be null");
 		this.healthCheckFailedMessage = healthCheckFailedMessage;
 	}
@@ -83,7 +84,7 @@ public final Mono<Health> health() {
 		}
 	}
 
-	private void logExceptionIfPresent(Throwable ex) {
+	private void logExceptionIfPresent(@Nullable Throwable ex) {
 		if (ex != null && this.logger.isWarnEnabled()) {
 			String message = (ex instanceof Exception) ? this.healthCheckFailedMessage.apply(ex) : null;
 			this.logger.warn(StringUtils.hasText(message) ? message : DEFAULT_MESSAGE, ex);
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/CompositeHealthContributors.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/CompositeHealthContributors.java
@@ -22,6 +22,8 @@
 import java.util.Set;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * {@link HealthContributors} composed of other {@link HealthContributors}.
  *
@@ -37,7 +39,7 @@ class CompositeHealthContributors implements HealthContributors {
 	}
 
 	@Override
-	public HealthContributor getContributor(String name) {
+	public @Nullable HealthContributor getContributor(String name) {
 		return this.contributors.stream()
 			.map((contributors) -> contributors.getContributor(name))
 			.filter(Objects::nonNull)
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/CompositeReactiveHealthContributors.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/CompositeReactiveHealthContributors.java
@@ -22,6 +22,8 @@
 import java.util.Set;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * {@link ReactiveHealthContributors} composed of other
  * {@link ReactiveHealthContributors}.
@@ -38,7 +40,7 @@ class CompositeReactiveHealthContributors implements ReactiveHealthContributors
 	}
 
 	@Override
-	public ReactiveHealthContributor getContributor(String name) {
+	public @Nullable ReactiveHealthContributor getContributor(String name) {
 		return this.contributors.stream()
 			.map((reactiveContributors) -> reactiveContributors.getContributor(name))
 			.filter(Objects::nonNull)
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/Health.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/Health.java
@@ -23,6 +23,7 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.annotation.JsonUnwrapped;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.util.Assert;
 
@@ -183,7 +184,7 @@ public static class Builder {
 
 		private final Map<String, Object> details;
 
-		private Throwable exception;
+		private @Nullable Throwable exception;
 
 		/**
 		 * Create new Builder instance.
@@ -325,7 +326,7 @@ public Health build() {
 		 * Return the {@link Exception}.
 		 * @return the exception or {@code null} if the builder has no exception
 		 */
-		Throwable getException() {
+		@Nullable Throwable getException() {
 			return this.exception;
 		}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/HealthContributors.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/HealthContributors.java
@@ -19,6 +19,8 @@
 import java.util.Iterator;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 
 /**
@@ -34,7 +36,7 @@ public interface HealthContributors extends Iterable<HealthContributors.Entry> {
 	 * @param name the name of the contributor
 	 * @return a contributor instance or {@code null}
 	 */
-	HealthContributor getContributor(String name);
+	@Nullable HealthContributor getContributor(String name);
 
 	@Override
 	default Iterator<Entry> iterator() {
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/HealthContributorsAdapter.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/HealthContributorsAdapter.java
@@ -18,6 +18,8 @@
 
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Adapts {@link HealthContributors} to {@link ReactiveHealthContributors}.
  *
@@ -33,7 +35,7 @@ class HealthContributorsAdapter implements ReactiveHealthContributors {
 	}
 
 	@Override
-	public ReactiveHealthContributor getContributor(String name) {
+	public @Nullable ReactiveHealthContributor getContributor(String name) {
 		return ReactiveHealthContributor.adapt(this.delegate.getContributor(name));
 	}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/HealthIndicator.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/HealthIndicator.java
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.health.contributor;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Directly contributes {@link Health} information for specific component or subsystem.
  *
@@ -31,15 +33,18 @@ public non-sealed interface HealthIndicator extends HealthContributor {
 	 * @param includeDetails if details should be included or removed
 	 * @return the health
 	 */
-	default Health health(boolean includeDetails) {
+	default @Nullable Health health(boolean includeDetails) {
 		Health health = health();
+		if (health == null) {
+			return null;
+		}
 		return includeDetails ? health : health.withoutDetails();
 	}
 
 	/**
 	 * Return an indication of health.
 	 * @return the health
 	 */
-	Health health();
+	@Nullable Health health();
 
 }
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/MapCompositeHealthContributor.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/MapCompositeHealthContributor.java
@@ -22,6 +22,8 @@
 import java.util.function.Function;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 
 /**
@@ -49,7 +51,7 @@ class MapCompositeHealthContributor<V> implements CompositeHealthContributor {
 	}
 
 	@Override
-	public HealthContributor getContributor(String name) {
+	public @Nullable HealthContributor getContributor(String name) {
 		return this.contributors.get(name);
 	}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/MapCompositeReactiveHealthContributor.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/MapCompositeReactiveHealthContributor.java
@@ -22,6 +22,8 @@
 import java.util.function.Function;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 
 /**
@@ -51,7 +53,7 @@ class MapCompositeReactiveHealthContributor<V> implements CompositeReactiveHealt
 	}
 
 	@Override
-	public ReactiveHealthContributor getContributor(String name) {
+	public @Nullable ReactiveHealthContributor getContributor(String name) {
 		return this.contributors.get(name);
 	}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthContributor.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthContributor.java
@@ -16,8 +16,11 @@
 
 package org.springframework.boot.health.contributor;
 
+import org.jspecify.annotations.Nullable;
 import reactor.core.scheduler.Schedulers;
 
+import org.springframework.lang.Contract;
+
 /**
  * Contributes health information, either directly ({@link ReactiveHealthIndicator}) or
  * via other contributors ({@link CompositeReactiveHealthContributor}).
@@ -42,7 +45,8 @@ public sealed interface ReactiveHealthContributor permits ReactiveHealthIndicato
 	 * @param contributor the contributor to adapt or {@code null}
 	 * @return the adapted contributor
 	 */
-	static ReactiveHealthContributor adapt(HealthContributor contributor) {
+	@Contract("!null -> !null")
+	static @Nullable ReactiveHealthContributor adapt(@Nullable HealthContributor contributor) {
 		if (contributor == null) {
 			return null;
 		}
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthContributors.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthContributors.java
@@ -19,8 +19,10 @@
 import java.util.Iterator;
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
 import reactor.core.scheduler.Schedulers;
 
+import org.springframework.lang.Contract;
 import org.springframework.util.Assert;
 
 /**
@@ -36,7 +38,7 @@ public interface ReactiveHealthContributors extends Iterable<ReactiveHealthContr
 	 * @param name the name of the contributor
 	 * @return a contributor instance or {@code null}
 	 */
-	ReactiveHealthContributor getContributor(String name);
+	@Nullable ReactiveHealthContributor getContributor(String name);
 
 	@Override
 	default Iterator<Entry> iterator() {
@@ -75,7 +77,8 @@ static ReactiveHealthContributors of(ReactiveHealthContributors... contributors)
 	 * @return the adapted contributor
 	 * @see ReactiveHealthContributor#adapt(HealthContributor)
 	 */
-	static ReactiveHealthContributors adapt(HealthContributors contributors) {
+	@Contract("!null -> !null")
+	static @Nullable ReactiveHealthContributors adapt(@Nullable HealthContributors contributors) {
 		return (contributors != null) ? new HealthContributorsAdapter(contributors) : null;
 	}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthContributorsAdapter.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthContributorsAdapter.java
@@ -18,6 +18,10 @@
 
 import java.util.stream.Stream;
 
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.lang.Contract;
+
 /**
  * Adapts {@link ReactiveHealthContributors} to {@link HealthContributors}.
  *
@@ -33,7 +37,7 @@ class ReactiveHealthContributorsAdapter implements HealthContributors {
 	}
 
 	@Override
-	public HealthContributor getContributor(String name) {
+	public @Nullable HealthContributor getContributor(String name) {
 		return adapt(this.delegate.getContributor(name));
 	}
 
@@ -42,7 +46,8 @@ public Stream<Entry> stream() {
 		return this.delegate.stream().map((entry) -> new Entry(entry.name(), adapt(entry.contributor())));
 	}
 
-	private HealthContributor adapt(ReactiveHealthContributor contributor) {
+	@Contract("!null -> !null")
+	private @Nullable HealthContributor adapt(@Nullable ReactiveHealthContributor contributor) {
 		return (contributor != null) ? contributor.asHealthContributor() : null;
 	}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthIndicatorAdapter.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/ReactiveHealthIndicatorAdapter.java
@@ -16,6 +16,8 @@
 
 package org.springframework.boot.health.contributor;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Adapts a {@link ReactiveHealthIndicator} to a {@link HealthIndicator}.
  *
@@ -31,12 +33,12 @@ class ReactiveHealthIndicatorAdapter implements HealthIndicator {
 	}
 
 	@Override
-	public Health health(boolean includeDetails) {
+	public @Nullable Health health(boolean includeDetails) {
 		return this.delegate.health(includeDetails).block();
 	}
 
 	@Override
-	public Health health() {
+	public @Nullable Health health() {
 		return this.delegate.health().block();
 	}
 
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/package-info.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/contributor/package-info.java
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/AbstractRegistry.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/AbstractRegistry.java
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/DefaultHealthContributorRegistry.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/DefaultHealthContributorRegistry.java
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/DefaultReactiveHealthContributorRegistry.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/DefaultReactiveHealthContributorRegistry.java
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/HealthContributorRegistry.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/HealthContributorRegistry.java
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/ReactiveHealthContributorRegistry.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/ReactiveHealthContributorRegistry.java
diff --git a/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/package-info.java b/module/spring-boot-health/src/main/java/org/springframework/boot/health/registry/package-info.java

Original file line number	Diff line number	Diff line change
`@@ -18,6 +18,8 @@`
`18`	`18`
`19`	`19`	`import java.util.stream.Stream;`
`20`	`20`
	`21`	`+import org.jspecify.annotations.Nullable;`
	`22`	`+`
`21`	`23`	`/**`
`22`	`24`	`* Adapts {@link HealthContributors} to {@link ReactiveHealthContributors}.`
`23`	`25`	`*`
`@@ -33,7 +35,7 @@ class HealthContributorsAdapter implements ReactiveHealthContributors {`
`33`	`35`	`}`
`34`	`36`
`35`	`37`	`@Override`
`36`		`- public ReactiveHealthContributor getContributor(String name) {`
	`38`	`+ public @Nullable ReactiveHealthContributor getContributor(String name) {`
`37`	`39`	`return ReactiveHealthContributor.adapt(this.delegate.getContributor(name));`
`38`	`40`	`}`
`39`	`41`