Refine null-safety in more modules

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

See gh-32475

Author: sdeleuze

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) {