Add nullability annotations to module/spring-boot-reactor-netty

See gh-46587

module/spring-boot-reactor-netty/build.gradle

@@ -29,6 +29,8 @@ dependencies {
 	api("io.projectreactor.netty:reactor-netty-http")
 	api("org.springframework:spring-web")
 
+	compileOnly("com.google.code.findbugs:jsr305")
+
 	implementation(project(":module:spring-boot-netty"))
 
 	optional(project(":core:spring-boot-autoconfigure"))

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/CompressionCustomizer.java

@@ -22,6 +22,7 @@ import java.util.function.BiPredicate;
 
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
+import org.jspecify.annotations.Nullable;
 import reactor.netty.http.server.HttpServer;
 import reactor.netty.http.server.HttpServerRequest;
 import reactor.netty.http.server.HttpServerResponse;
@@ -82,7 +83,7 @@ final class CompressionCustomizer implements NettyServerCustomizer {
 		};
 	}
 
-	private CompressionPredicate getExcludedUserAgentsPredicate(String[] excludedUserAgents) {
+	private CompressionPredicate getExcludedUserAgentsPredicate(String @Nullable [] excludedUserAgents) {
 		if (ObjectUtils.isEmpty(excludedUserAgents)) {
 			return ALWAYS_COMPRESS;
 		}

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/GracefulShutdown.java

@@ -21,6 +21,7 @@ import java.util.function.Supplier;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 import reactor.netty.DisposableServer;
 
 import org.springframework.boot.web.server.GracefulShutdownCallback;
@@ -35,13 +36,13 @@ final class GracefulShutdown {
 
 	private static final Log logger = LogFactory.getLog(GracefulShutdown.class);
 
-	private final Supplier<DisposableServer> disposableServer;
+	private final Supplier<@Nullable DisposableServer> disposableServer;
 
-	private volatile Thread shutdownThread;
+	private volatile @Nullable Thread shutdownThread;
 
 	private volatile boolean shuttingDown;
 
-	GracefulShutdown(Supplier<DisposableServer> disposableServer) {
+	GracefulShutdown(Supplier<@Nullable DisposableServer> disposableServer) {
 		this.disposableServer = disposableServer;
 	}
 

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/NettyReactiveWebServerFactory.java

@@ -25,9 +25,11 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
+import org.jspecify.annotations.Nullable;
 import reactor.netty.http.HttpProtocol;
 import reactor.netty.http.server.HttpServer;
 
+import org.springframework.boot.ssl.SslBundles;
 import org.springframework.boot.web.server.Shutdown;
 import org.springframework.boot.web.server.Ssl;
 import org.springframework.boot.web.server.WebServer;
@@ -53,13 +55,11 @@ public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 
 	private final List<NettyRouteProvider> routeProviders = new ArrayList<>();
 
-	private Duration lifecycleTimeout;
+	private @Nullable Duration lifecycleTimeout;
 
 	private boolean useForwardHeaders;
 
-	private ReactorResourceFactory resourceFactory;
-
-	private Shutdown shutdown;
+	private @Nullable ReactorResourceFactory resourceFactory;
 
 	public NettyReactiveWebServerFactory() {
 	}
@@ -79,7 +79,7 @@ public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 	}
 
 	NettyWebServer createNettyWebServer(HttpServer httpServer, ReactorHttpHandlerAdapter handlerAdapter,
-			Duration lifecycleTimeout, Shutdown shutdown) {
+			@Nullable Duration lifecycleTimeout, Shutdown shutdown) {
 		return new NettyWebServer(httpServer, handlerAdapter, lifecycleTimeout, shutdown, this.resourceFactory);
 	}
 
@@ -127,7 +127,7 @@ public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 	 * server.
 	 * @param lifecycleTimeout the lifecycle timeout
 	 */
-	public void setLifecycleTimeout(Duration lifecycleTimeout) {
+	public void setLifecycleTimeout(@Nullable Duration lifecycleTimeout) {
 		this.lifecycleTimeout = lifecycleTimeout;
 	}
 
@@ -145,24 +145,15 @@ public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 	 * @param resourceFactory the server resources
 	 * @since 4.0.0
 	 */
-	public void setResourceFactory(ReactorResourceFactory resourceFactory) {
+	public void setResourceFactory(@Nullable ReactorResourceFactory resourceFactory) {
 		this.resourceFactory = resourceFactory;
 	}
 
-	@Override
-	public void setShutdown(Shutdown shutdown) {
-		this.shutdown = shutdown;
-	}
-
-	@Override
-	public Shutdown getShutdown() {
-		return this.shutdown;
-	}
-
 	private HttpServer createHttpServer() {
 		HttpServer server = HttpServer.create().bindAddress(this::getListenAddress);
-		if (Ssl.isEnabled(getSsl())) {
-			server = customizeSslConfiguration(server);
+		Ssl ssl = getSsl();
+		if (Ssl.isEnabled(ssl)) {
+			server = customizeSslConfiguration(server, ssl);
 		}
 		if (getCompression() != null && getCompression().getEnabled()) {
 			CompressionCustomizer compressionCustomizer = new CompressionCustomizer(getCompression());
@@ -172,19 +163,22 @@ public class NettyReactiveWebServerFactory extends AbstractReactiveWebServerFact
 		return applyCustomizers(server);
 	}
 
-	private HttpServer customizeSslConfiguration(HttpServer httpServer) {
-		SslServerCustomizer customizer = new SslServerCustomizer(getHttp2(), getSsl().getClientAuth(), getSslBundle(),
+	private HttpServer customizeSslConfiguration(HttpServer httpServer, Ssl ssl) {
+		SslServerCustomizer customizer = new SslServerCustomizer(getHttp2(), ssl.getClientAuth(), getSslBundle(),
 				getServerNameSslBundles());
-		addBundleUpdateHandler(null, getSsl().getBundle(), customizer);
-		getSsl().getServerNameBundles()
+		addBundleUpdateHandler(null, ssl.getBundle(), customizer);
+		ssl.getServerNameBundles()
 			.forEach((serverNameSslBundle) -> addBundleUpdateHandler(serverNameSslBundle.serverName(),
 					serverNameSslBundle.bundle(), customizer));
 		return customizer.apply(httpServer);
 	}
 
-	private void addBundleUpdateHandler(String serverName, String bundleName, SslServerCustomizer customizer) {
+	private void addBundleUpdateHandler(@Nullable String serverName, @Nullable String bundleName,
+			SslServerCustomizer customizer) {
 		if (StringUtils.hasText(bundleName)) {
-			getSslBundles().addBundleUpdateHandler(bundleName,
+			SslBundles sslBundles = getSslBundles();
+			Assert.state(sslBundles != null, "'sslBundles' must not be null");
+			sslBundles.addBundleUpdateHandler(bundleName,
 					(sslBundle) -> customizer.updateSslBundle(serverName, sslBundle));
 		}
 	}

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/NettyWebServer.java

@@ -28,6 +28,7 @@ import io.netty.channel.unix.Errors.NativeIoException;
 import io.netty.util.concurrent.DefaultEventExecutor;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 import org.reactivestreams.Publisher;
 import reactor.netty.ChannelBindException;
 import reactor.netty.DisposableServer;
@@ -72,15 +73,15 @@ public class NettyWebServer implements WebServer {
 
 	private final BiFunction<? super HttpServerRequest, ? super HttpServerResponse, ? extends Publisher<Void>> handler;
 
-	private final Duration lifecycleTimeout;
+	private final @Nullable Duration lifecycleTimeout;
 
-	private final GracefulShutdown gracefulShutdown;
+	private final @Nullable GracefulShutdown gracefulShutdown;
 
-	private final ReactorResourceFactory resourceFactory;
+	private final @Nullable ReactorResourceFactory resourceFactory;
 
 	private List<NettyRouteProvider> routeProviders = Collections.emptyList();
 
-	private volatile DisposableServer disposableServer;
+	private volatile @Nullable DisposableServer disposableServer;
 
 	/**
 	 * Creates a new {@code NettyWebServer} instance.
@@ -92,8 +93,9 @@ public class NettyWebServer implements WebServer {
 	 * resources}, may be {@code null}
 	 * @since 4.0.0
 	 */
-	public NettyWebServer(HttpServer httpServer, ReactorHttpHandlerAdapter handlerAdapter, Duration lifecycleTimeout,
-			Shutdown shutdown, ReactorResourceFactory resourceFactory) {
+	public NettyWebServer(HttpServer httpServer, ReactorHttpHandlerAdapter handlerAdapter,
+			@Nullable Duration lifecycleTimeout, @Nullable Shutdown shutdown,
+			@Nullable ReactorResourceFactory resourceFactory) {
 		Assert.notNull(httpServer, "'httpServer' must not be null");
 		Assert.notNull(handlerAdapter, "'handlerAdapter' must not be null");
 		this.lifecycleTimeout = lifecycleTimeout;
@@ -138,6 +140,7 @@ public class NettyWebServer implements WebServer {
 	}
 
 	protected String getStartedLogMessage() {
+		Assert.state(this.disposableServer != null, "'disposableServer' must not be null");
 		return getStartedOnMessage(this.disposableServer);
 	}
 
@@ -171,7 +174,7 @@ public class NettyWebServer implements WebServer {
 		return server.bindNow();
 	}
 
-	private boolean isPermissionDenied(Throwable bindExceptionCause) {
+	private boolean isPermissionDenied(@Nullable Throwable bindExceptionCause) {
 		try {
 			if (bindExceptionCause instanceof NativeIoException nativeException) {
 				return nativeException.expectedErr() == ERROR_NO_EACCES;

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/SslServerCustomizer.java

@@ -22,6 +22,7 @@ import java.util.Map;
 import io.netty.handler.ssl.ClientAuth;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 import reactor.netty.http.Http11SslContextSpec;
 import reactor.netty.http.Http2SslContextSpec;
 import reactor.netty.http.server.HttpServer;
@@ -52,7 +53,7 @@ public class SslServerCustomizer implements NettyServerCustomizer {
 
 	private static final Log logger = LogFactory.getLog(SslServerCustomizer.class);
 
-	private final Http2 http2;
+	private final @Nullable Http2 http2;
 
 	private final ClientAuth clientAuth;
 
@@ -60,7 +61,7 @@ public class SslServerCustomizer implements NettyServerCustomizer {
 
 	private final Map<String, SslProvider> serverNameSslProviders;
 
-	public SslServerCustomizer(Http2 http2, Ssl.ClientAuth clientAuth, SslBundle sslBundle,
+	public SslServerCustomizer(@Nullable Http2 http2, Ssl.@Nullable ClientAuth clientAuth, SslBundle sslBundle,
 			Map<String, SslBundle> serverNameSslBundles) {
 		this.http2 = http2;
 		this.clientAuth = Ssl.ClientAuth.map(clientAuth, ClientAuth.NONE, ClientAuth.OPTIONAL, ClientAuth.REQUIRE);
@@ -82,7 +83,7 @@ public class SslServerCustomizer implements NettyServerCustomizer {
 		});
 	}
 
-	void updateSslBundle(String serverName, SslBundle sslBundle) {
+	void updateSslBundle(@Nullable String serverName, SslBundle sslBundle) {
 		logger.debug("SSL Bundle has been updated, reloading SSL configuration");
 		if (serverName == null) {
 			this.sslProvider = createSslProvider(sslBundle);

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/autoconfigure/NettyReactiveWebServerFactoryCustomizer.java

@@ -66,7 +66,7 @@ public class NettyReactiveWebServerFactoryCustomizer
 		map.from(this.nettyProperties::getIdleTimeout).to((idleTimeout) -> customizeIdleTimeout(factory, idleTimeout));
 		map.from(this.nettyProperties::getMaxKeepAliveRequests)
 			.to((maxKeepAliveRequests) -> customizeMaxKeepAliveRequests(factory, maxKeepAliveRequests));
-		if (this.serverProperties.getHttp2() != null && this.serverProperties.getHttp2().isEnabled()) {
+		if (this.serverProperties.getHttp2().isEnabled()) {
 			map.from(this.serverProperties.getMaxHttpRequestHeaderSize())
 				.to((size) -> customizeHttp2MaxHeaderSize(factory, size.toBytes()));
 		}

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/autoconfigure/NettyServerProperties.java

@@ -18,6 +18,8 @@ package org.springframework.boot.reactor.netty.autoconfigure;
 
 import java.time.Duration;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.util.unit.DataSize;
 
@@ -55,7 +57,7 @@ public class NettyServerProperties {
 	/**
 	 * Connection timeout of the Netty channel.
 	 */
-	private Duration connectionTimeout;
+	private @Nullable Duration connectionTimeout;
 
 	/**
 	 * Maximum content length of an H2C upgrade request.
@@ -76,7 +78,7 @@ public class NettyServerProperties {
 	 * Maximum number of requests that can be made per connection. By default, a
 	 * connection serves unlimited number of requests.
 	 */
-	private Integer maxKeepAliveRequests;
+	private @Nullable Integer maxKeepAliveRequests;
 
 	/**
 	 * Whether to validate headers when decoding requests.
@@ -86,13 +88,13 @@ public class NettyServerProperties {
 	/**
 	 * Idle timeout of the Netty channel. When not specified, an infinite timeout is used.
 	 */
-	private Duration idleTimeout;
+	private @Nullable Duration idleTimeout;
 
-	public Duration getConnectionTimeout() {
+	public @Nullable Duration getConnectionTimeout() {
 		return this.connectionTimeout;
 	}
 
-	public void setConnectionTimeout(Duration connectionTimeout) {
+	public void setConnectionTimeout(@Nullable Duration connectionTimeout) {
 		this.connectionTimeout = connectionTimeout;
 	}
 
@@ -120,11 +122,11 @@ public class NettyServerProperties {
 		this.maxInitialLineLength = maxInitialLineLength;
 	}
 
-	public Integer getMaxKeepAliveRequests() {
+	public @Nullable Integer getMaxKeepAliveRequests() {
 		return this.maxKeepAliveRequests;
 	}
 
-	public void setMaxKeepAliveRequests(Integer maxKeepAliveRequests) {
+	public void setMaxKeepAliveRequests(@Nullable Integer maxKeepAliveRequests) {
 		this.maxKeepAliveRequests = maxKeepAliveRequests;
 	}
 
@@ -136,11 +138,11 @@ public class NettyServerProperties {
 		this.validateHeaders = validateHeaders;
 	}
 
-	public Duration getIdleTimeout() {
+	public @Nullable Duration getIdleTimeout() {
 		return this.idleTimeout;
 	}
 
-	public void setIdleTimeout(Duration idleTimeout) {
+	public void setIdleTimeout(@Nullable Duration idleTimeout) {
 		this.idleTimeout = idleTimeout;
 	}
 

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/autoconfigure/ReactorNettyProperties.java

@@ -18,6 +18,8 @@ package org.springframework.boot.reactor.netty.autoconfigure;
 
 import java.time.Duration;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
@@ -32,13 +34,13 @@ public class ReactorNettyProperties {
 	/**
 	 * Amount of time to wait before shutting down resources.
 	 */
-	private Duration shutdownQuietPeriod;
+	private @Nullable Duration shutdownQuietPeriod;
 
-	public Duration getShutdownQuietPeriod() {
+	public @Nullable Duration getShutdownQuietPeriod() {
 		return this.shutdownQuietPeriod;
 	}
 
-	public void setShutdownQuietPeriod(Duration shutdownQuietPeriod) {
+	public void setShutdownQuietPeriod(@Nullable Duration shutdownQuietPeriod) {
 		this.shutdownQuietPeriod = shutdownQuietPeriod;
 	}
 

module/spring-boot-reactor-netty/src/main/java/org/springframework/boot/reactor/netty/autoconfigure/actuate/web/server/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for Reactor Netty actuator web concerns.
  */
+@NullMarked
 package org.springframework.boot.reactor.netty.autoconfigure.actuate.web.server;
+
+import org.jspecify.annotations.NullMarked;

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

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for Reactor Netty.
  */
+@NullMarked
 package org.springframework.boot.reactor.netty.autoconfigure;
+
+import org.jspecify.annotations.NullMarked;

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

@@ -16,6 +16,8 @@
 
 /**
  * Reactive web server implementation backed by Netty.
- *
  */
+@NullMarked
 package org.springframework.boot.reactor.netty;
+
+import org.jspecify.annotations.NullMarked;