Refine null-safety in more modules

This commit refines the null-safety in all remaining modules
except spring-test.

See spring-projectsgh-32475

spring-aop/src/main/java/org/springframework/aop/target/LazyInitTargetSource.java

@@ -65,6 +65,7 @@ public class LazyInitTargetSource extends AbstractBeanFactoryBasedTargetSource {
 
 
 	@Override
+	@Nullable
 	public synchronized Object getTarget() throws BeansException {
 		if (this.target == null) {
 			this.target = getBeanFactory().getBean(getTargetBeanName());

spring-context-support/src/main/java/org/springframework/cache/jcache/JCacheCacheManager.java

@@ -121,6 +121,7 @@ protected Collection<Cache> loadCaches() {
 	}
 
 	@Override
+	@Nullable
 	protected Cache getMissingCache(String name) {
 		CacheManager cacheManager = getCacheManager();
 		Assert.state(cacheManager != null, "No CacheManager set");

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/AnnotationJCacheOperationSource.java

@@ -46,6 +46,7 @@
 public abstract class AnnotationJCacheOperationSource extends AbstractFallbackJCacheOperationSource {
 
 	@Override
+	@Nullable
 	protected JCacheOperation<?> findCacheOperation(Method method, @Nullable Class<?> targetType) {
 		CacheResult cacheResult = method.getAnnotation(CacheResult.class);
 		CachePut cachePut = method.getAnnotation(CachePut.class);

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/CachePutInterceptor.java

@@ -23,6 +23,7 @@
 import org.springframework.cache.interceptor.CacheErrorHandler;
 import org.springframework.cache.interceptor.CacheOperationInvocationContext;
 import org.springframework.cache.interceptor.CacheOperationInvoker;
+import org.springframework.lang.Nullable;
 
 /**
  * Intercept methods annotated with {@link CachePut}.
@@ -39,6 +40,7 @@ public CachePutInterceptor(CacheErrorHandler errorHandler) {
 
 
 	@Override
+	@Nullable
 	protected Object invoke(
 			CacheOperationInvocationContext<CachePutOperation> context, CacheOperationInvoker invoker) {
 

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/CacheRemoveAllInterceptor.java

@@ -22,6 +22,7 @@
 import org.springframework.cache.interceptor.CacheErrorHandler;
 import org.springframework.cache.interceptor.CacheOperationInvocationContext;
 import org.springframework.cache.interceptor.CacheOperationInvoker;
+import org.springframework.lang.Nullable;
 
 /**
  * Intercept methods annotated with {@link CacheRemoveAll}.
@@ -38,6 +39,7 @@ protected CacheRemoveAllInterceptor(CacheErrorHandler errorHandler) {
 
 
 	@Override
+	@Nullable
 	protected Object invoke(
 			CacheOperationInvocationContext<CacheRemoveAllOperation> context, CacheOperationInvoker invoker) {
 

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/CacheRemoveEntryInterceptor.java

@@ -22,6 +22,7 @@
 import org.springframework.cache.interceptor.CacheErrorHandler;
 import org.springframework.cache.interceptor.CacheOperationInvocationContext;
 import org.springframework.cache.interceptor.CacheOperationInvoker;
+import org.springframework.lang.Nullable;
 
 /**
  * Intercept methods annotated with {@link CacheRemove}.
@@ -38,6 +39,7 @@ protected CacheRemoveEntryInterceptor(CacheErrorHandler errorHandler) {
 
 
 	@Override
+	@Nullable
 	protected Object invoke(
 			CacheOperationInvocationContext<CacheRemoveOperation> context, CacheOperationInvoker invoker) {
 

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/JCacheAspectSupport.java

@@ -180,6 +180,7 @@ public CacheOperationInvokerAdapter(CacheOperationInvoker delegate) {
 		}
 
 		@Override
+		@Nullable
 		public Object invoke() throws ThrowableWrapper {
 			return invokeOperation(this.delegate);
 		}

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/SimpleExceptionCacheResolver.java

@@ -24,6 +24,7 @@
 import org.springframework.cache.interceptor.BasicOperation;
 import org.springframework.cache.interceptor.CacheOperationInvocationContext;
 import org.springframework.cache.interceptor.CacheResolver;
+import org.springframework.lang.Nullable;
 
 /**
  * A simple {@link CacheResolver} that resolves the exception cache
@@ -41,6 +42,7 @@ public SimpleExceptionCacheResolver(CacheManager cacheManager) {
 	}
 
 	@Override
+	@Nullable
 	protected Collection<String> getCacheNames(CacheOperationInvocationContext<?> context) {
 		BasicOperation operation = context.getOperation();
 		if (!(operation instanceof CacheResultOperation cacheResultOperation)) {

spring-context-support/src/main/java/org/springframework/cache/transaction/TransactionAwareCacheDecorator.java

@@ -83,6 +83,7 @@ public ValueWrapper get(Object key) {
 	}
 
 	@Override
+	@Nullable
 	public <T> T get(Object key, @Nullable Class<T> type) {
 		return this.targetCache.get(key, type);
 	}

spring-context-support/src/main/java/org/springframework/scheduling/quartz/MethodInvokingJobDetailFactoryBean.java

@@ -199,6 +199,7 @@ protected void postProcessJobDetail(JobDetail jobDetail) {
 	 * Overridden to support the {@link #setTargetBeanName "targetBeanName"} feature.
 	 */
 	@Override
+	@Nullable
 	public Class<?> getTargetClass() {
 		Class<?> targetClass = super.getTargetClass();
 		if (targetClass == null && this.targetBeanName != null) {
@@ -212,6 +213,7 @@ public Class<?> getTargetClass() {
 	 * Overridden to support the {@link #setTargetBeanName "targetBeanName"} feature.
 	 */
 	@Override
+	@Nullable
 	public Object getTargetObject() {
 		Object targetObject = super.getTargetObject();
 		if (targetObject == null && this.targetBeanName != null) {

spring-context-support/src/main/java/org/springframework/scheduling/quartz/SchedulerFactoryBeanRuntimeHints.java

@@ -22,6 +22,7 @@
 import org.springframework.aot.hint.TypeHint.Builder;
 import org.springframework.aot.hint.TypeReference;
 import org.springframework.aot.hint.annotation.ReflectiveRuntimeHintsRegistrar;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -40,7 +41,7 @@ class SchedulerFactoryBeanRuntimeHints implements RuntimeHintsRegistrar {
 
 
 	@Override
-	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
+	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
 		if (!ClassUtils.isPresent(SCHEDULER_FACTORY_CLASS_NAME, classLoader)) {
 			return;
 		}

spring-context/src/main/java/org/springframework/cache/Cache.java

@@ -315,7 +315,7 @@ class ValueRetrievalException extends RuntimeException {
 		@Nullable
 		private final Object key;
 
-		public ValueRetrievalException(@Nullable Object key, Callable<?> loader, Throwable ex) {
+		public ValueRetrievalException(@Nullable Object key, Callable<?> loader, @Nullable Throwable ex) {
 			super(String.format("Value for key '%s' could not be loaded using '%s'", key, loader), ex);
 			this.key = key;
 		}

spring-context/src/main/java/org/springframework/cache/concurrent/ConcurrentMapCache.java

@@ -223,6 +223,7 @@ protected Object toStoreValue(@Nullable Object userValue) {
 	}
 
 	@Override
+	@Nullable
 	protected Object fromStoreValue(@Nullable Object storeValue) {
 		if (storeValue != null && this.serialization != null) {
 			try {

spring-context/src/main/java/org/springframework/cache/interceptor/NamedCacheResolver.java

@@ -52,6 +52,7 @@ public void setCacheNames(Collection<String> cacheNames) {
 	}
 
 	@Override
+	@Nullable
 	protected Collection<String> getCacheNames(CacheOperationInvocationContext<?> context) {
 		return this.cacheNames;
 	}

spring-context/src/main/java/org/springframework/context/annotation/CommonAnnotationBeanPostProcessor.java

@@ -314,6 +314,7 @@ public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, C
 	}
 
 	@Override
+	@Nullable
 	public BeanRegistrationAotContribution processAheadOfTime(RegisteredBean registeredBean) {
 		BeanRegistrationAotContribution parentAotContribution = super.processAheadOfTime(registeredBean);
 		Class<?> beanClass = registeredBean.getBeanClass();
@@ -350,6 +351,7 @@ public void resetBeanDefinition(String beanName) {
 	}
 
 	@Override
+	@Nullable
 	public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) {
 		return null;
 	}

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassEnhancer.java

@@ -334,6 +334,7 @@ public Object intercept(Object enhancedConfigInstance, Method beanMethod, Object
 			return resolveBeanReference(beanMethod, beanMethodArgs, beanFactory, beanName);
 		}
 
+		@Nullable
 		private Object resolveBeanReference(Method beanMethod, Object[] beanMethodArgs,
 				ConfigurableBeanFactory beanFactory, String beanName) {
 

spring-context/src/main/java/org/springframework/context/event/ApplicationListenerMethodAdapter.java

@@ -350,7 +350,7 @@ protected void handleAsyncError(Throwable t) {
 	 * Invoke the event listener method with the given argument values.
 	 */
 	@Nullable
-	protected Object doInvoke(Object... args) {
+	protected Object doInvoke(@Nullable Object... args) {
 		Object bean = getTargetBean();
 		// Detect package-protected NullBean instance through equals(null) check
 		if (bean.equals(null)) {
@@ -416,8 +416,8 @@ protected String getCondition() {
 	 * the given error message.
 	 * @param message error message to append the HandlerMethod details to
 	 */
-	protected String getDetailedErrorMessage(Object bean, String message) {
-		StringBuilder sb = new StringBuilder(message).append('\n');
+	protected String getDetailedErrorMessage(Object bean, @Nullable String message) {
+		StringBuilder sb = (StringUtils.hasLength(message) ? new StringBuilder(message).append('\n') : new StringBuilder());
 		sb.append("HandlerMethod details: \n");
 		sb.append("Bean [").append(bean.getClass().getName()).append("]\n");
 		sb.append("Method [").append(this.method.toGenericString()).append("]\n");
@@ -431,7 +431,7 @@ protected String getDetailedErrorMessage(Object bean, String message) {
 	 * beans, and others). Event listener beans that require proxying should prefer
 	 * class-based proxy mechanisms.
 	 */
-	private void assertTargetBean(Method method, Object targetBean, Object[] args) {
+	private void assertTargetBean(Method method, Object targetBean, @Nullable Object[] args) {
 		Class<?> methodDeclaringClass = method.getDeclaringClass();
 		Class<?> targetBeanClass = targetBean.getClass();
 		if (!methodDeclaringClass.isAssignableFrom(targetBeanClass)) {
@@ -443,7 +443,7 @@ private void assertTargetBean(Method method, Object targetBean, Object[] args) {
 		}
 	}
 
-	private String getInvocationErrorMessage(Object bean, String message, Object[] resolvedArgs) {
+	private String getInvocationErrorMessage(Object bean, @Nullable String message, @Nullable Object[] resolvedArgs) {
 		StringBuilder sb = new StringBuilder(getDetailedErrorMessage(bean, message));
 		sb.append("Resolved arguments: \n");
 		for (int i = 0; i < resolvedArgs.length; i++) {

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -1463,6 +1463,7 @@ protected BeanFactory getInternalParentBeanFactory() {
 	//---------------------------------------------------------------------
 
 	@Override
+	@Nullable
 	public String getMessage(String code, @Nullable Object[] args, @Nullable String defaultMessage, Locale locale) {
 		return getMessageSource().getMessage(code, args, defaultMessage, locale);
 	}

spring-context/src/main/java/org/springframework/context/support/AbstractMessageSource.java

@@ -137,6 +137,7 @@ protected boolean isUseCodeAsDefaultMessage() {
 
 
 	@Override
+	@Nullable
 	public final String getMessage(String code, @Nullable Object[] args, @Nullable String defaultMessage, Locale locale) {
 		String msg = getMessageInternal(code, args, locale);
 		if (msg != null) {

spring-context/src/main/java/org/springframework/context/support/ContextTypeMatchClassLoader.java

@@ -123,6 +123,7 @@ protected boolean isEligibleForOverriding(String className) {
 		}
 
 		@Override
+		@Nullable
 		protected Class<?> loadClassForOverriding(String name) throws ClassNotFoundException {
 			byte[] bytes = bytesCache.get(name);
 			if (bytes == null) {

spring-context/src/main/java/org/springframework/context/support/ReloadableResourceBundleMessageSource.java

@@ -191,6 +191,7 @@ public void setResourceLoader(@Nullable ResourceLoader resourceLoader) {
 	 * returning the value found in the bundle as-is (without MessageFormat parsing).
 	 */
 	@Override
+	@Nullable
 	protected String resolveCodeWithoutArguments(String code, Locale locale) {
 		if (getCacheMillis() < 0) {
 			PropertiesHolder propHolder = getMergedProperties(locale);

spring-context/src/main/java/org/springframework/context/support/ResourceBundleMessageSource.java

@@ -145,6 +145,7 @@ public void setBeanClassLoader(ClassLoader classLoader) {
 	 * returning the value found in the bundle as-is (without MessageFormat parsing).
 	 */
 	@Override
+	@Nullable
 	protected String resolveCodeWithoutArguments(String code, Locale locale) {
 		Set<String> basenames = getBasenameSet();
 		for (String basename : basenames) {

spring-context/src/main/java/org/springframework/format/support/FormattingConversionServiceRuntimeHints.java

@@ -19,6 +19,7 @@
 import org.springframework.aot.hint.RuntimeHints;
 import org.springframework.aot.hint.RuntimeHintsRegistrar;
 import org.springframework.aot.hint.TypeReference;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link RuntimeHintsRegistrar} to register hints for {@link DefaultFormattingConversionService}.
@@ -29,7 +30,7 @@
 class FormattingConversionServiceRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
-	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
+	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
 		hints.reflection().registerType(TypeReference.of("javax.money.MonetaryAmount"));
 	}
 }

spring-context/src/main/java/org/springframework/jmx/access/InvalidInvocationException.java

@@ -18,6 +18,8 @@
 
 import javax.management.JMRuntimeException;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Thrown when trying to invoke an operation on a proxy that is not exposed
  * by the proxied MBean resource's management interface.
@@ -35,7 +37,7 @@ public class InvalidInvocationException extends JMRuntimeException {
 	 * error message.
 	 * @param msg the detail message
 	 */
-	public InvalidInvocationException(String msg) {
+	public InvalidInvocationException(@Nullable String msg) {
 		super(msg);
 	}
 

spring-context/src/main/java/org/springframework/jmx/access/MBeanProxyFactoryBean.java

@@ -108,6 +108,7 @@ public Object getObject() {
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getObjectType() {
 		return this.proxyInterface;
 	}

spring-context/src/main/java/org/springframework/jndi/JndiObjectFactoryBean.java

@@ -273,6 +273,7 @@ public Object getObject() {
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getObjectType() {
 		if (this.proxyInterfaces != null) {
 			if (this.proxyInterfaces.length == 1) {

spring-context/src/main/java/org/springframework/scheduling/annotation/AsyncConfigurerSupport.java

@@ -34,6 +34,7 @@
 public class AsyncConfigurerSupport implements AsyncConfigurer {
 
 	@Override
+	@Nullable
 	public Executor getAsyncExecutor() {
 		return null;
 	}

spring-context/src/main/java/org/springframework/scheduling/concurrent/ConcurrentTaskScheduler.java

@@ -334,16 +334,19 @@ public LastExecutionAdapter(@Nullable LastExecution le) {
 				}
 
 				@Override
+				@Nullable
 				public Instant lastScheduledExecution() {
 					return (this.le != null ? toInstant(this.le.getScheduledStart()) : null);
 				}
 
 				@Override
+				@Nullable
 				public Instant lastActualExecution() {
 					return (this.le != null ? toInstant(this.le.getRunStart()) : null);
 				}
 
 				@Override
+				@Nullable
 				public Instant lastCompletion() {
 					return (this.le != null ? toInstant(this.le.getRunEnd()) : null);
 				}

spring-context/src/main/java/org/springframework/scheduling/config/TaskSchedulerRouter.java

@@ -106,6 +106,7 @@ public void setBeanFactory(@Nullable BeanFactory beanFactory) {
 
 
 	@Override
+	@Nullable
 	public ScheduledFuture<?> schedule(Runnable task, Trigger trigger) {
 		return determineTargetScheduler(task).schedule(task, trigger);
 	}

spring-context/src/main/java/org/springframework/scheduling/support/CronTrigger.java

@@ -112,6 +112,7 @@ public String getExpression() {
 	 * previous execution; therefore, overlapping executions won't occur.
 	 */
 	@Override
+	@Nullable
 	public Instant nextExecution(TriggerContext triggerContext) {
 		Instant timestamp = determineLatestTimestamp(triggerContext);
 		ZoneId zone = (this.zoneId != null ? this.zoneId : triggerContext.getClock().getZone());

spring-context/src/main/java/org/springframework/scheduling/support/QuartzCronField.java

@@ -338,6 +338,7 @@ private static Temporal rollbackToMidnight(Temporal current, Temporal result) {
 
 
 	@Override
+	@Nullable
 	public <T extends Temporal & Comparable<? super T>> T nextOrSame(T temporal) {
 		T result = adjust(temporal);
 		if (result != null) {

spring-context/src/main/java/org/springframework/scripting/config/ScriptingDefaultsParser.java

@@ -22,6 +22,7 @@
 import org.springframework.beans.factory.config.TypedStringValue;
 import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 
 /**
@@ -38,6 +39,7 @@ class ScriptingDefaultsParser implements BeanDefinitionParser {
 
 
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		BeanDefinition bd =
 				LangNamespaceUtils.registerScriptFactoryPostProcessorIfNecessary(parserContext.getRegistry());

spring-context/src/main/java/org/springframework/scripting/support/ScriptFactoryPostProcessor.java

@@ -305,6 +305,7 @@ public PropertyValues postProcessProperties(PropertyValues pvs, Object bean, Str
 	}
 
 	@Override
+	@Nullable
 	public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) {
 		// We only apply special treatment to ScriptFactory implementations here.
 		if (!ScriptFactory.class.isAssignableFrom(beanClass)) {