Add nullability annotations to tests in module/spring-boot-jetty

See gh-47263

module/spring-boot-jetty/build.gradle

@@ -48,6 +48,8 @@ dependencies {
 	testImplementation(testFixtures(project(":core:spring-boot-autoconfigure")))
 	testImplementation("org.apache.httpcomponents.client5:httpclient5")
 
+	testCompileOnly("com.google.code.findbugs:jsr305")
+
 	testRuntimeOnly("ch.qos.logback:logback-classic")
 	testRuntimeOnly("io.projectreactor:reactor-test")
 	testRuntimeOnly("io.projectreactor.netty:reactor-netty-http")
@@ -61,3 +63,6 @@ test {
 	jvmArgs += "--add-opens=java.base/java.net=ALL-UNNAMED"
 }
 
+tasks.named("compileTestJava") {
+	options.nullability.checking = "tests"
+}

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/SslServerCustomizerTests.java

@@ -96,7 +96,8 @@ class SslServerCustomizerTests {
 	void configureSslWhenSslIsEnabledWithNoKeyStoreAndNotPkcs11ThrowsException() {
 		Ssl ssl = new Ssl();
 		assertThatIllegalStateException().isThrownBy(() -> {
-			SslServerCustomizer customizer = new SslServerCustomizer(null, null, null, WebServerSslBundle.get(ssl));
+			SslServerCustomizer customizer = new SslServerCustomizer(null, new InetSocketAddress(0), null,
+					WebServerSslBundle.get(ssl));
 			customizer.configureSsl(new SslContextFactory.Server(), ssl.getClientAuth());
 		}).withMessageContaining("SSL is enabled but no trust material is configured");
 	}
@@ -110,7 +111,8 @@ class SslServerCustomizerTests {
 		ssl.setKeyStore("classpath:test.jks");
 		ssl.setKeyPassword("password");
 		assertThatIllegalStateException().isThrownBy(() -> {
-			SslServerCustomizer customizer = new SslServerCustomizer(null, null, null, WebServerSslBundle.get(ssl));
+			SslServerCustomizer customizer = new SslServerCustomizer(null, new InetSocketAddress(0), null,
+					WebServerSslBundle.get(ssl));
 			customizer.configureSsl(new SslContextFactory.Server(), ssl.getClientAuth());
 		}).withMessageContaining("must be empty or null for PKCS11 hardware key stores");
 	}
@@ -122,7 +124,8 @@ class SslServerCustomizerTests {
 		ssl.setKeyStoreProvider(MockPkcs11SecurityProvider.NAME);
 		ssl.setKeyStorePassword("1234");
 		assertThatNoException().isThrownBy(() -> {
-			SslServerCustomizer customizer = new SslServerCustomizer(null, null, null, WebServerSslBundle.get(ssl));
+			SslServerCustomizer customizer = new SslServerCustomizer(null, new InetSocketAddress(0), null,
+					WebServerSslBundle.get(ssl));
 			customizer.configureSsl(new SslContextFactory.Server(), ssl.getClientAuth());
 		});
 	}

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/autoconfigure/JettyWebServerFactoryCustomizerTests.java

@@ -378,7 +378,9 @@ class JettyWebServerFactoryCustomizerTests {
 	}
 
 	private BlockingQueue<?> getQueue(ThreadPool threadPool) {
-		return ReflectionTestUtils.invokeMethod(threadPool, "getQueue");
+		BlockingQueue<?> queue = ReflectionTestUtils.invokeMethod(threadPool, "getQueue");
+		assertThat(queue).isNotNull();
+		return queue;
 	}
 
 	private void bind(String... inlinedProperties) {

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/autoconfigure/metrics/JettyMetricsAutoConfigurationTests.java

@@ -217,7 +217,7 @@ class JettyMetricsAutoConfigurationTests {
 	}
 
 	private ApplicationStartedEvent createApplicationStartedEvent(ConfigurableApplicationContext context) {
-		return new ApplicationStartedEvent(new SpringApplication(), null, context, null);
+		return new ApplicationStartedEvent(new SpringApplication(), new String[0], context, null);
 	}
 
 	@Configuration(proxyBeanMethods = false)

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/autoconfigure/reactive/JettyReactiveWebServerAutoConfigurationTests.java

@@ -76,6 +76,7 @@ class JettyReactiveWebServerAutoConfigurationTests extends AbstractReactiveWebSe
 		this.serverRunner.run((context) -> {
 			WebServer webServer = ((ReactiveWebServerApplicationContext) context.getSourceApplicationContext())
 				.getWebServer();
+			assertThat(webServer).isNotNull();
 			ServletContextHandler servletContextHandler = (ServletContextHandler) ((StatisticsHandler) ((JettyWebServer) webServer)
 				.getServer()
 				.getHandler()).getHandler();

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/autoconfigure/servlet/JettyServletWebServerAutoConfigurationTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.jetty.autoconfigure.servlet;
 import java.util.Map;
 
 import jakarta.servlet.Filter;
+import jakarta.servlet.ServletContext;
 import org.eclipse.jetty.ee11.websocket.servlet.WebSocketUpgradeFilter;
 import org.eclipse.jetty.server.Server;
 import org.junit.jupiter.api.Test;
@@ -75,9 +76,11 @@ class JettyServletWebServerAutoConfigurationTests extends AbstractServletWebServ
 
 	@Test
 	void jettyWebSocketUpgradeFilterIsAddedToServletContex() {
-		this.serverRunner.run((context) -> assertThat(
-				context.getServletContext().getFilterRegistration(WebSocketUpgradeFilter.class.getName()))
-			.isNotNull());
+		this.serverRunner.run((context) -> {
+			ServletContext servletContext = context.getServletContext();
+			assertThat(servletContext).isNotNull();
+			assertThat(servletContext.getFilterRegistration(WebSocketUpgradeFilter.class.getName())).isNotNull();
+		});
 	}
 
 	@Test

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/reactive/JettyReactiveWebServerFactoryTests.java

@@ -72,6 +72,7 @@ class JettyReactiveWebServerFactoryTests extends AbstractReactiveWebServerFactor
 	}
 
 	@Test
+	@SuppressWarnings("NullAway") // Test null check
 	void setNullServerCustomizersShouldThrowException() {
 		JettyReactiveWebServerFactory factory = getFactory();
 		assertThatIllegalArgumentException().isThrownBy(() -> factory.setServerCustomizers(null))
@@ -79,6 +80,7 @@ class JettyReactiveWebServerFactoryTests extends AbstractReactiveWebServerFactor
 	}
 
 	@Test
+	@SuppressWarnings("NullAway") // Test null check
 	void addNullServerCustomizersShouldThrowException() {
 		JettyReactiveWebServerFactory factory = getFactory();
 		assertThatIllegalArgumentException()

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/servlet/JettyServletWebServerFactoryTests.java

@@ -58,6 +58,7 @@ import org.eclipse.jetty.util.ClassMatcher;
 import org.eclipse.jetty.util.ssl.SslContextFactory;
 import org.eclipse.jetty.util.thread.QueuedThreadPool;
 import org.eclipse.jetty.util.thread.ThreadPool;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.mockito.InOrder;
@@ -123,7 +124,7 @@ class JettyServletWebServerFactoryTests extends AbstractServletWebServerFactoryT
 	}
 
 	@Override
-	protected JspServlet getJspServlet() throws Exception {
+	protected @Nullable JspServlet getJspServlet() throws Exception {
 		WebAppContext context = findWebAppContext((JettyWebServer) this.webServer);
 		ServletHolder holder = context.getServletHandler().getServlet("jsp");
 		if (holder == null) {
@@ -141,7 +142,7 @@ class JettyServletWebServerFactoryTests extends AbstractServletWebServerFactoryT
 	}
 
 	@Override
-	protected Charset getCharset(Locale locale) {
+	protected @Nullable Charset getCharset(Locale locale) {
 		WebAppContext context = findWebAppContext((JettyWebServer) this.webServer);
 		String charsetName = context.getLocaleEncoding(locale);
 		return (charsetName != null) ? Charset.forName(charsetName) : null;
@@ -314,7 +315,11 @@ class JettyServletWebServerFactoryTests extends AbstractServletWebServerFactoryT
 		catch (NoSuchMethodError ex) {
 			Method getSslContextFactory = ReflectionUtils.findMethod(connectionFactory.getClass(),
 					"getSslContextFactory");
-			return (SslContextFactory) ReflectionUtils.invokeMethod(getSslContextFactory, connectionFactory);
+			assertThat(getSslContextFactory).isNotNull();
+			SslContextFactory sslContextFactory = (SslContextFactory) ReflectionUtils.invokeMethod(getSslContextFactory,
+					connectionFactory);
+			assertThat(sslContextFactory).isNotNull();
+			return sslContextFactory;
 		}
 	}
 
@@ -528,6 +533,7 @@ class JettyServletWebServerFactoryTests extends AbstractServletWebServerFactoryT
 				// Jetty 10
 				Method addEventListener = ReflectionUtils.findMethod(context.getClass(), "addEventListener",
 						EventListener.class);
+				assertThat(addEventListener).isNotNull();
 				ReflectionUtils.invokeMethod(addEventListener, context, eventListener);
 			}
 		});

module/spring-boot-jetty/src/test/java/org/springframework/boot/jetty/servlet/LoaderHidingResourceTests.java

@@ -70,10 +70,14 @@ class LoaderHidingResourceTests {
 		URI warUri = createExampleWar(temp);
 		Resource resource = new PathResourceFactory().newResource(warUri);
 		LoaderHidingResource loaderHidingResource = new LoaderHidingResource(resource, resource);
-		assertThat(loaderHidingResource.resolve("/assets/image.jpg").exists()).isTrue();
-		assertThat(loaderHidingResource.resolve("/assets/image.jpg")).isInstanceOf(LoaderHidingResource.class);
-		assertThat(loaderHidingResource.resolve("/assets/non-existent.jpg").exists()).isFalse();
-		assertThat(loaderHidingResource.resolve("/assets/non-existent.jpg")).isInstanceOf(LoaderHidingResource.class);
+		Resource image = loaderHidingResource.resolve("/assets/image.jpg");
+		assertThat(image).isNotNull();
+		assertThat(image.exists()).isTrue();
+		assertThat(image).isInstanceOf(LoaderHidingResource.class);
+		Resource doesntExist = loaderHidingResource.resolve("/assets/non-existent.jpg");
+		assertThat(doesntExist).isNotNull();
+		assertThat(doesntExist.exists()).isFalse();
+		assertThat(doesntExist).isInstanceOf(LoaderHidingResource.class);
 		assertThat(loaderHidingResource.resolve("/org/springframework/boot/Loader.class")).isNull();
 	}
 

module/spring-boot-web-server/src/testFixtures/java/org/springframework/boot/web/server/servlet/AbstractServletWebServerFactoryTests.java

@@ -106,6 +106,7 @@ import org.awaitility.Awaitility;
 import org.eclipse.jetty.client.ContentResponse;
 import org.eclipse.jetty.http2.client.HTTP2Client;
 import org.eclipse.jetty.http2.client.transport.HttpClientTransportOverHTTP2;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Assumptions;
 import org.junit.jupiter.api.Test;
@@ -1507,7 +1508,7 @@ public abstract class AbstractServletWebServerFactoryTests {
 
 	protected abstract Map<String, String> getActualMimeMappings();
 
-	protected abstract Charset getCharset(Locale locale);
+	protected abstract @Nullable Charset getCharset(Locale locale);
 
 	protected void addTestTxtFile(ConfigurableServletWebServerFactory factory) throws IOException {
 		FileCopyUtils.copy("test", new FileWriter(new File(this.tempDir, "test.txt")));
@@ -1588,7 +1589,7 @@ public abstract class AbstractServletWebServerFactoryTests {
 
 	protected abstract ConfigurableServletWebServerFactory getFactory();
 
-	protected abstract org.apache.jasper.servlet.JspServlet getJspServlet() throws Exception;
+	protected abstract org.apache.jasper.servlet.@Nullable JspServlet getJspServlet() throws Exception;
 
 	protected ServletContextInitializer exampleServletRegistration() {
 		return new ServletRegistrationBean<>(new ExampleServlet(), "/hello");