Fix overridden methods nullability

Issue: SPR-15869

spring-aop/src/main/java/org/springframework/aop/TargetSource.java

@@ -42,6 +42,7 @@ public interface TargetSource extends TargetClassAware {
 	 * @return the type of targets returned by this {@link TargetSource}
 	 */
 	@Override
+	@Nullable
 	Class<?> getTargetClass();
 
 	/**

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJAdviceParameterNameDiscoverer.java

@@ -222,6 +222,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 	 * @return the parameter names
 	 */
 	@Override
+	@Nullable
 	public String[] getParameterNames(Method method) {
 		this.argumentTypes = method.getParameterTypes();
 		this.numberOfRemainingUnboundArguments = this.argumentTypes.length;
@@ -310,6 +311,7 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 	 * {@link #setRaiseExceptions(boolean) raiseExceptions} has been set to {@code true}
 	 */
 	@Override
+	@Nullable
 	public String[] getParameterNames(Constructor<?> ctor) {
 		if (this.raiseExceptions) {
 			throw new UnsupportedOperationException("An advice method can never be a constructor");

spring-aop/src/main/java/org/springframework/aop/aspectj/SimpleAspectInstanceFactory.java

@@ -20,6 +20,7 @@ import java.lang.reflect.InvocationTargetException;
 
 import org.springframework.aop.framework.AopConfigException;
 import org.springframework.core.Ordered;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
 
@@ -76,6 +77,7 @@ public class SimpleAspectInstanceFactory implements AspectInstanceFactory {
 	}
 
 	@Override
+	@Nullable
 	public ClassLoader getAspectClassLoader() {
 		return this.aspectClass.getClassLoader();
 	}

spring-aop/src/main/java/org/springframework/aop/aspectj/SingletonAspectInstanceFactory.java

@@ -19,6 +19,7 @@ package org.springframework.aop.aspectj;
 import java.io.Serializable;
 
 import org.springframework.core.Ordered;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -53,6 +54,7 @@ public class SingletonAspectInstanceFactory implements AspectInstanceFactory, Se
 	}
 
 	@Override
+	@Nullable
 	public ClassLoader getAspectClassLoader() {
 		return this.aspectInstance.getClass().getClassLoader();
 	}

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/AbstractAspectJAdvisorFactory.java

@@ -261,6 +261,7 @@ public abstract class AbstractAspectJAdvisorFactory implements AspectJAdvisorFac
 	private static class AspectJAnnotationParameterNameDiscoverer implements ParameterNameDiscoverer {
 
 		@Override
+		@Nullable
 		public String[] getParameterNames(Method method) {
 			if (method.getParameterCount() == 0) {
 				return new String[0];
@@ -283,6 +284,7 @@ public abstract class AbstractAspectJAdvisorFactory implements AspectJAdvisorFac
 		}
 
 		@Override
+		@Nullable
 		public String[] getParameterNames(Constructor<?> ctor) {
 			throw new UnsupportedOperationException("Spring AOP cannot handle constructor advice");
 		}

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/BeanFactoryAspectInstanceFactory.java

@@ -91,6 +91,7 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 	}
 
 	@Override
+	@Nullable
 	public ClassLoader getAspectClassLoader() {
 		return (this.beanFactory instanceof ConfigurableBeanFactory ?
 				((ConfigurableBeanFactory) this.beanFactory).getBeanClassLoader() :
@@ -103,6 +104,7 @@ public class BeanFactoryAspectInstanceFactory implements MetadataAwareAspectInst
 	}
 
 	@Override
+	@Nullable
 	public Object getAspectCreationMutex() {
 		if (this.beanFactory.isSingleton(this.name)) {
 			// Rely on singleton semantics provided by the factory -> no local lock.

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/LazySingletonAspectInstanceFactoryDecorator.java

@@ -74,6 +74,7 @@ public class LazySingletonAspectInstanceFactoryDecorator implements MetadataAwar
 	}
 
 	@Override
+	@Nullable
 	public ClassLoader getAspectClassLoader() {
 		return this.maaif.getAspectClassLoader();
 	}
@@ -84,6 +85,7 @@ public class LazySingletonAspectInstanceFactoryDecorator implements MetadataAwar
 	}
 
 	@Override
+	@Nullable
 	public Object getAspectCreationMutex() {
 		return this.maaif.getAspectCreationMutex();
 	}

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/ReflectiveAspectJAdvisorFactory.java

@@ -184,6 +184,7 @@ public class ReflectiveAspectJAdvisorFactory extends AbstractAspectJAdvisorFacto
 
 
 	@Override
+	@Nullable
 	public Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aspectInstanceFactory,
 			int declarationOrderInAspect, String aspectName) {
 
@@ -218,6 +219,7 @@ public class ReflectiveAspectJAdvisorFactory extends AbstractAspectJAdvisorFacto
 
 
 	@Override
+	@Nullable
 	public Advice getAdvice(Method candidateAdviceMethod, AspectJExpressionPointcut expressionPointcut,
 			MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName) {
 

spring-aop/src/main/java/org/springframework/aop/config/AdvisorComponentDefinition.java

@@ -110,6 +110,7 @@ public class AdvisorComponentDefinition extends AbstractComponentDefinition {
 	}
 
 	@Override
+	@Nullable
 	public Object getSource() {
 		return this.advisorDefinition.getSource();
 	}

spring-aop/src/main/java/org/springframework/aop/config/AspectJAutoProxyBeanDefinitionParser.java

@@ -25,6 +25,7 @@ import org.springframework.beans.factory.config.TypedStringValue;
 import org.springframework.beans.factory.support.ManagedList;
 import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link BeanDefinitionParser} for the {@code aspectj-autoproxy} tag,
@@ -38,6 +39,7 @@ import org.springframework.beans.factory.xml.ParserContext;
 class AspectJAutoProxyBeanDefinitionParser implements BeanDefinitionParser {
 
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		AopNamespaceUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(parserContext, element);
 		extendBeanDefinition(element, parserContext);

spring-aop/src/main/java/org/springframework/aop/config/ConfigBeanDefinitionParser.java

@@ -97,6 +97,7 @@ class ConfigBeanDefinitionParser implements BeanDefinitionParser {
 
 
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		CompositeComponentDefinition compositeDef =
 				new CompositeComponentDefinition(element.getTagName(), parserContext.extractSource(element));

spring-aop/src/main/java/org/springframework/aop/config/MethodLocatingFactoryBean.java

@@ -84,6 +84,7 @@ public class MethodLocatingFactoryBean implements FactoryBean<Method>, BeanFacto
 
 
 	@Override
+	@Nullable
 	public Method getObject() throws Exception {
 		return this.method;
 	}

spring-aop/src/main/java/org/springframework/aop/config/PointcutComponentDefinition.java

@@ -18,6 +18,7 @@ package org.springframework.aop.config;
 
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.parsing.AbstractComponentDefinition;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -62,6 +63,7 @@ public class PointcutComponentDefinition extends AbstractComponentDefinition {
 	}
 
 	@Override
+	@Nullable
 	public Object getSource() {
 		return this.pointcutDefinition.getSource();
 	}

spring-aop/src/main/java/org/springframework/aop/config/SimpleBeanFactoryAwareAspectInstanceFactory.java

@@ -69,6 +69,7 @@ public class SimpleBeanFactoryAwareAspectInstanceFactory implements AspectInstan
 	}
 
 	@Override
+	@Nullable
 	public ClassLoader getAspectClassLoader() {
 		if (this.beanFactory instanceof ConfigurableBeanFactory) {
 			return ((ConfigurableBeanFactory) this.beanFactory).getBeanClassLoader();

spring-aop/src/main/java/org/springframework/aop/framework/AbstractSingletonProxyFactoryBean.java

@@ -221,6 +221,7 @@ public abstract class AbstractSingletonProxyFactoryBean extends ProxyConfig
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getObjectType() {
 		if (this.proxy != null) {
 			return this.proxy.getClass();

spring-aop/src/main/java/org/springframework/aop/framework/ProxyFactoryBean.java

@@ -247,6 +247,7 @@ public class ProxyFactoryBean extends ProxyCreatorSupport
 	 * @return a fresh AOP proxy reflecting the current state of this factory
 	 */
 	@Override
+	@Nullable
 	public Object getObject() throws BeansException {
 		initializeAdvisorChain();
 		if (isSingleton()) {

spring-aop/src/main/java/org/springframework/aop/framework/ReflectiveMethodInvocation.java

@@ -262,6 +262,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 	}
 
 	@Override
+	@Nullable
 	public Object getUserAttribute(String key) {
 		return (this.userAttributes != null ? this.userAttributes.get(key) : null);
 	}

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AbstractAutoProxyCreator.java

@@ -218,6 +218,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 
 
 	@Override
+	@Nullable
 	public Class<?> predictBeanType(Class<?> beanClass, String beanName) {
 		if (this.proxyTypes.isEmpty()) {
 			return null;
@@ -227,6 +228,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 	}
 
 	@Override
+	@Nullable
 	public Constructor<?>[] determineCandidateConstructors(Class<?> beanClass, String beanName) throws BeansException {
 		return null;
 	}

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/target/AbstractBeanFactoryBasedTargetSourceCreator.java

@@ -89,6 +89,7 @@ public abstract class AbstractBeanFactoryBasedTargetSourceCreator
 	//---------------------------------------------------------------------
 
 	@Override
+	@Nullable
 	public final TargetSource getTargetSource(Class<?> beanClass, String beanName) {
 		AbstractBeanFactoryBasedTargetSource targetSource =
 				createBeanFactoryBasedTargetSource(beanClass, beanName);

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/target/LazyInitTargetSourceCreator.java

@@ -20,6 +20,7 @@ import org.springframework.aop.target.AbstractBeanFactoryBasedTargetSource;
 import org.springframework.aop.target.LazyInitTargetSource;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.lang.Nullable;
 
 /**
  * TargetSourceCreator that enforces a LazyInitTargetSource for each bean
@@ -59,6 +60,7 @@ public class LazyInitTargetSourceCreator extends AbstractBeanFactoryBasedTargetS
 	}
 
 	@Override
+	@Nullable
 	protected AbstractBeanFactoryBasedTargetSource createBeanFactoryBasedTargetSource(
 			Class<?> beanClass, String beanName) {
 

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/target/QuickTargetSourceCreator.java

@@ -20,6 +20,7 @@ import org.springframework.aop.target.AbstractBeanFactoryBasedTargetSource;
 import org.springframework.aop.target.CommonsPool2TargetSource;
 import org.springframework.aop.target.PrototypeTargetSource;
 import org.springframework.aop.target.ThreadLocalTargetSource;
+import org.springframework.lang.Nullable;
 
 /**
  * Convenient TargetSourceCreator using bean name prefixes to create one of three
@@ -41,6 +42,7 @@ public class QuickTargetSourceCreator extends AbstractBeanFactoryBasedTargetSour
 	public static final String PREFIX_PROTOTYPE = "!";
 
 	@Override
+	@Nullable
 	protected final AbstractBeanFactoryBasedTargetSource createBeanFactoryBasedTargetSource(
 			Class<?> beanClass, String beanName) {
 

spring-aop/src/main/java/org/springframework/aop/interceptor/AsyncExecutionInterceptor.java

@@ -138,6 +138,7 @@ public class AsyncExecutionInterceptor extends AsyncExecutionAspectSupport imple
 	 * @see #determineAsyncExecutor(Method)
 	 */
 	@Override
+	@Nullable
 	protected String getExecutorQualifier(Method method) {
 		return null;
 	}
@@ -151,6 +152,7 @@ public class AsyncExecutionInterceptor extends AsyncExecutionAspectSupport imple
 	 * @see #DEFAULT_TASK_EXECUTOR_BEAN_NAME
 	 */
 	@Override
+	@Nullable
 	protected Executor getDefaultExecutor(@Nullable BeanFactory beanFactory) {
 		Executor defaultExecutor = super.getDefaultExecutor(beanFactory);
 		return (defaultExecutor != null ? defaultExecutor : new SimpleAsyncTaskExecutor());

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

@@ -20,6 +20,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.aop.TargetSource;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link org.springframework.aop.TargetSource} implementation that will
@@ -65,6 +66,7 @@ public abstract class AbstractLazyCreationTargetSource implements TargetSource {
 	 * @see #isInitialized()
 	 */
 	@Override
+	@Nullable
 	public synchronized Class<?> getTargetClass() {
 		return (this.lazyTarget != null ? this.lazyTarget.getClass() : null);
 	}

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

@@ -22,6 +22,7 @@ import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanInitializationException;
 import org.springframework.beans.factory.DisposableBean;
+import org.springframework.lang.Nullable;
 
 /**
  * Abstract base class for pooling {@link org.springframework.aop.TargetSource}
@@ -100,6 +101,7 @@ public abstract class AbstractPoolingTargetSource extends AbstractPrototypeBased
 	 * APIs, so we're forgiving with our exception signature
 	 */
 	@Override
+	@Nullable
 	public abstract Object getTarget() throws Exception;
 
 	/**

spring-aop/src/main/java/org/springframework/aop/target/CommonsPool2TargetSource.java

@@ -23,6 +23,8 @@ import org.apache.commons.pool2.impl.DefaultPooledObject;
 import org.apache.commons.pool2.impl.GenericObjectPool;
 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
 
+import org.springframework.lang.Nullable;
+
 /**
  * {@link org.springframework.aop.TargetSource} implementation that holds
  * objects in a configurable Apache Commons2 Pool.
@@ -78,6 +80,7 @@ public class CommonsPool2TargetSource extends AbstractPoolingTargetSource implem
 	/**
 	 * The Apache Commons {@code ObjectPool} used to pool target objects
 	 */
+	@Nullable
 	private ObjectPool pool;
 
 

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

@@ -92,6 +92,7 @@ public class EmptyTargetSource implements TargetSource, Serializable {
 	 * Always returns the specified target Class, or {@code null} if none.
 	 */
 	@Override
+	@Nullable
 	public Class<?> getTargetClass() {
 		return this.targetClass;
 	}
@@ -108,6 +109,7 @@ public class EmptyTargetSource implements TargetSource, Serializable {
 	 * Always returns {@code null}.
 	 */
 	@Override
+	@Nullable
 	public Object getTarget() {
 		return null;
 	}

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

@@ -17,6 +17,7 @@
 package org.springframework.aop.target;
 
 import org.springframework.beans.BeansException;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link org.springframework.aop.TargetSource} that lazily accesses a
@@ -59,10 +60,12 @@ import org.springframework.beans.BeansException;
 @SuppressWarnings("serial")
 public class LazyInitTargetSource extends AbstractBeanFactoryBasedTargetSource {
 
+	@Nullable
 	private Object target;
 
 
 	@Override
+	@Nullable
 	public synchronized Object getTarget() throws BeansException {
 		if (this.target == null) {
 			this.target = getBeanFactory().getBean(getTargetBeanName());

spring-aop/src/main/java/org/springframework/aop/target/dynamic/AbstractRefreshableTargetSource.java

@@ -20,6 +20,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.aop.TargetSource;
+import org.springframework.lang.Nullable;
 
 /**
  * Abstract {@link org.springframework.aop.TargetSource} implementation that
@@ -41,6 +42,7 @@ public abstract class AbstractRefreshableTargetSource implements TargetSource, R
 	/** Logger available to subclasses */
 	protected final Log logger = LogFactory.getLog(getClass());
 
+	@Nullable
 	protected Object targetObject;
 
 	private long refreshCheckDelay = -1;
@@ -80,6 +82,7 @@ public abstract class AbstractRefreshableTargetSource implements TargetSource, R
 	}
 
 	@Override
+	@Nullable
 	public final synchronized Object getTarget() {
 		if ((refreshCheckDelayElapsed() && requiresRefresh()) || this.targetObject == null) {
 			refresh();

spring-aop/src/main/java/org/springframework/aop/target/package.html

@@ -1,15 +0,0 @@
-<html>
-<body>
-
-This package contains implementations of the org.springframework.aop.TargetSource interface.
-<br>
-The simplest implementation is the SingletonTargetSource, used by default in the AOP framework
-to wrap a single target instance. This is normally appropriate.
-
-<br>
-Other provided implementations include pooling implementations, that provide a target
-from a pool for each request, ensuring a single threaded programming model; and a 
-"prototype" implementation, that uses a new target instance for each invocation.
-
-</body>
-</html>

spring-beans/src/main/java/org/springframework/beans/AbstractNestablePropertyAccessor.java

@@ -483,6 +483,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getPropertyType(String propertyName) throws BeansException {
 		try {
 			PropertyHandler ph = getPropertyHandler(propertyName);
@@ -510,6 +511,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	}
 
 	@Override
+	@Nullable
 	public TypeDescriptor getPropertyTypeDescriptor(String propertyName) throws BeansException {
 		try {
 			AbstractNestablePropertyAccessor nestedPa = getPropertyAccessorForPropertyPath(propertyName);
@@ -603,6 +605,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 	}
 
 	@Override
+	@Nullable
 	public Object getPropertyValue(String propertyName) throws BeansException {
 		AbstractNestablePropertyAccessor nestedPa = getPropertyAccessorForPropertyPath(propertyName);
 		PropertyTokenHolder tokens = getPropertyNameTokens(getFinalPath(nestedPa, propertyName));

spring-beans/src/main/java/org/springframework/beans/AbstractPropertyAccessor.java

@@ -127,6 +127,7 @@ public abstract class AbstractPropertyAccessor extends TypeConverterSupport impl
 
 	// Redefined with public visibility.
 	@Override
+	@Nullable
 	public Class<?> getPropertyType(String propertyPath) {
 		return null;
 	}
@@ -141,6 +142,7 @@ public abstract class AbstractPropertyAccessor extends TypeConverterSupport impl
 	 * accessor method failed
 	 */
 	@Override
+	@Nullable
 	public abstract Object getPropertyValue(String propertyName) throws BeansException;
 
 	/**

spring-beans/src/main/java/org/springframework/beans/BeanMetadataAttributeAccessor.java

@@ -74,12 +74,14 @@ public class BeanMetadataAttributeAccessor extends AttributeAccessorSupport impl
 	}
 
 	@Override
+	@Nullable
 	public Object getAttribute(String name) {
 		BeanMetadataAttribute attribute = (BeanMetadataAttribute) super.getAttribute(name);
 		return (attribute != null ? attribute.getValue() : null);
 	}
 
 	@Override
+	@Nullable
 	public Object removeAttribute(String name) {
 		BeanMetadataAttribute attribute = (BeanMetadataAttribute) super.removeAttribute(name);
 		return (attribute != null ? attribute.getValue() : null);

spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java

@@ -225,6 +225,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	}
 
 	@Override
+	@Nullable
 	protected BeanPropertyHandler getLocalPropertyHandler(String propertyName) {
 		PropertyDescriptor pd = getCachedIntrospectionResults().getPropertyDescriptor(propertyName);
 		if (pd != null) {
@@ -284,11 +285,13 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 		}
 
 		@Override
+		@Nullable
 		public TypeDescriptor nested(int level) {
 			return TypeDescriptor.nested(property(pd), level);
 		}
 
 		@Override
+		@Nullable
 		public Object getValue() throws Exception {
 			final Method readMethod = this.pd.getReadMethod();
 			if (System.getSecurityManager() != null) {

spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java

@@ -117,11 +117,13 @@ public class DirectFieldAccessor extends AbstractNestablePropertyAccessor {
 		}
 
 		@Override
+		@Nullable
 		public TypeDescriptor nested(int level) {
 			return TypeDescriptor.nested(this.field, level);
 		}
 
 		@Override
+		@Nullable
 		public Object getValue() throws Exception {
 			try {
 				ReflectionUtils.makeAccessible(this.field);

spring-beans/src/main/java/org/springframework/beans/ExtendedBeanInfoFactory.java

@@ -22,6 +22,7 @@ import java.beans.Introspector;
 import java.lang.reflect.Method;
 
 import org.springframework.core.Ordered;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link BeanInfoFactory} implementation that evaluates whether bean classes have
@@ -42,6 +43,7 @@ public class ExtendedBeanInfoFactory implements BeanInfoFactory, Ordered {
 	 * Return an {@link ExtendedBeanInfo} for the given bean class, if applicable.
 	 */
 	@Override
+	@Nullable
 	public BeanInfo getBeanInfo(Class<?> beanClass) throws IntrospectionException {
 		return (supports(beanClass) ? new ExtendedBeanInfo(Introspector.getBeanInfo(beanClass)) : null);
 	}

spring-beans/src/main/java/org/springframework/beans/MutablePropertyValues.java

@@ -250,6 +250,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 	}
 
 	@Override
+	@Nullable
 	public PropertyValue getPropertyValue(String propertyName) {
 		for (PropertyValue pv : this.propertyValueList) {
 			if (pv.getName().equals(propertyName)) {

spring-beans/src/main/java/org/springframework/beans/TypeConverterSupport.java

@@ -39,11 +39,13 @@ public abstract class TypeConverterSupport extends PropertyEditorRegistrySupport
 
 
 	@Override
+	@Nullable
 	public <T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType) throws TypeMismatchException {
 		return doConvert(value, requiredType, null, null);
 	}
 
 	@Override
+	@Nullable
 	public <T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType, @Nullable MethodParameter methodParam)
 			throws TypeMismatchException {
 
@@ -51,6 +53,7 @@ public abstract class TypeConverterSupport extends PropertyEditorRegistrySupport
 	}
 
 	@Override
+	@Nullable
 	public <T> T convertIfNecessary(@Nullable Object value, @Nullable Class<T> requiredType, @Nullable Field field)
 			throws TypeMismatchException {
 

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AnnotationBeanWiringInfoResolver.java

@@ -18,6 +18,7 @@ package org.springframework.beans.factory.annotation;
 
 import org.springframework.beans.factory.wiring.BeanWiringInfo;
 import org.springframework.beans.factory.wiring.BeanWiringInfoResolver;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -37,6 +38,7 @@ import org.springframework.util.ClassUtils;
 public class AnnotationBeanWiringInfoResolver implements BeanWiringInfoResolver {
 
 	@Override
+	@Nullable
 	public BeanWiringInfo resolveWiringInfo(Object beanInstance) {
 		Assert.notNull(beanInstance, "Bean instance must not be null");
 		Configurable annotation = beanInstance.getClass().getAnnotation(Configurable.class);

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.java

@@ -234,6 +234,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	}
 
 	@Override
+	@Nullable
 	public Constructor<?>[] determineCandidateConstructors(Class<?> beanClass, final String beanName)
 			throws BeanCreationException {
 

spring-beans/src/main/java/org/springframework/beans/factory/annotation/QualifierAnnotationAutowireCandidateResolver.java

@@ -330,6 +330,7 @@ public class QualifierAnnotationAutowireCandidateResolver extends GenericTypeAwa
 	 * @see Value
 	 */
 	@Override
+	@Nullable
 	public Object getSuggestedValue(DependencyDescriptor descriptor) {
 		Object value = findValue(descriptor.getAnnotations());
 		if (value == null) {

spring-beans/src/main/java/org/springframework/beans/factory/config/AbstractFactoryBean.java

@@ -206,6 +206,7 @@ public abstract class AbstractFactoryBean<T>
 	 * @see org.springframework.beans.factory.FactoryBean#getObjectType()
 	 */
 	@Override
+	@Nullable
 	public abstract Class<?> getObjectType();
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/config/BeanDefinitionHolder.java

@@ -113,6 +113,7 @@ public class BeanDefinitionHolder implements BeanMetadataElement {
 	 * @see BeanDefinition#getSource()
 	 */
 	@Override
+	@Nullable
 	public Object getSource() {
 		return this.beanDefinition.getSource();
 	}

spring-beans/src/main/java/org/springframework/beans/factory/config/EmbeddedValueResolver.java

@@ -49,6 +49,7 @@ public class EmbeddedValueResolver implements StringValueResolver {
 
 
 	@Override
+	@Nullable
 	public String resolveStringValue(String strVal) {
 		String value = this.exprContext.getBeanFactory().resolveEmbeddedValue(strVal);
 		if (this.exprResolver != null && value != null) {

spring-beans/src/main/java/org/springframework/beans/factory/config/FieldRetrievingFactoryBean.java

@@ -208,6 +208,7 @@ public class FieldRetrievingFactoryBean
 
 
 	@Override
+	@Nullable
 	public Object getObject() throws IllegalAccessException {
 		if (this.fieldObject == null) {
 			throw new FactoryBeanNotInitializedException();

spring-beans/src/main/java/org/springframework/beans/factory/config/InstantiationAwareBeanPostProcessorAdapter.java

@@ -21,6 +21,7 @@ import java.lang.reflect.Constructor;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.PropertyValues;
+import org.springframework.lang.Nullable;
 
 /**
  * Adapter that implements all methods on {@link SmartInstantiationAwareBeanPostProcessor}
@@ -40,11 +41,13 @@ import org.springframework.beans.PropertyValues;
 public abstract class InstantiationAwareBeanPostProcessorAdapter implements SmartInstantiationAwareBeanPostProcessor {
 
 	@Override
+	@Nullable
 	public Class<?> predictBeanType(Class<?> beanClass, String beanName) {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public Constructor<?>[] determineCandidateConstructors(Class<?> beanClass, String beanName) throws BeansException {
 		return null;
 	}
@@ -55,6 +58,7 @@ public abstract class InstantiationAwareBeanPostProcessorAdapter implements Smar
 	}
 
 	@Override
+	@Nullable
 	public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException {
 		return null;
 	}

spring-beans/src/main/java/org/springframework/beans/factory/config/MethodInvokingFactoryBean.java

@@ -116,6 +116,7 @@ public class MethodInvokingFactoryBean extends MethodInvokingBean implements Fac
 	 * specified method on the fly.
 	 */
 	@Override
+	@Nullable
 	public Object getObject() throws Exception {
 		if (this.singleton) {
 			if (!this.initialized) {

spring-beans/src/main/java/org/springframework/beans/factory/config/PropertiesFactoryBean.java

@@ -75,6 +75,7 @@ public class PropertiesFactoryBean extends PropertiesLoaderSupport
 	}
 
 	@Override
+	@Nullable
 	public final Properties getObject() throws IOException {
 		if (this.singleton) {
 			return this.singletonInstance;

spring-beans/src/main/java/org/springframework/beans/factory/config/PropertyPathFactoryBean.java

@@ -201,6 +201,7 @@ public class PropertyPathFactoryBean implements FactoryBean<Object>, BeanNameAwa
 
 
 	@Override
+	@Nullable
 	public Object getObject() throws BeansException {
 		BeanWrapper target = this.targetBeanWrapper;
 		if (target != null) {

spring-beans/src/main/java/org/springframework/beans/factory/config/PropertyPlaceholderConfigurer.java

@@ -239,6 +239,7 @@ public class PropertyPlaceholderConfigurer extends PlaceholderConfigurerSupport
 		}
 
 		@Override
+		@Nullable
 		public String resolveStringValue(String strVal) throws BeansException {
 			String resolved = this.helper.replacePlaceholders(strVal, this.resolver);
 			if (trimValues) {
@@ -258,6 +259,7 @@ public class PropertyPlaceholderConfigurer extends PlaceholderConfigurerSupport
 		}
 
 		@Override
+		@Nullable
 		public String resolvePlaceholder(String placeholderName) {
 			return PropertyPlaceholderConfigurer.this.resolvePlaceholder(placeholderName, props, systemPropertiesMode);
 		}

spring-beans/src/main/java/org/springframework/beans/factory/config/ServiceLocatorFactoryBean.java

@@ -329,6 +329,7 @@ public class ServiceLocatorFactoryBean implements FactoryBean<Object>, BeanFacto
 
 
 	@Override
+	@Nullable
 	public Object getObject() {
 		return this.proxy;
 	}

spring-beans/src/main/java/org/springframework/beans/factory/config/YamlMapFactoryBean.java

@@ -97,6 +97,7 @@ public class YamlMapFactoryBean extends YamlProcessor implements FactoryBean<Map
 	}
 
 	@Override
+	@Nullable
 	public Map<String, Object> getObject() {
 		return (this.map != null ? this.map : createMap());
 	}

spring-beans/src/main/java/org/springframework/beans/factory/config/YamlPropertiesFactoryBean.java

@@ -108,6 +108,7 @@ public class YamlPropertiesFactoryBean extends YamlProcessor implements FactoryB
 	}
 
 	@Override
+	@Nullable
 	public Properties getObject() {
 		return (this.properties != null ? this.properties : createProperties());
 	}

spring-beans/src/main/java/org/springframework/beans/factory/serviceloader/ServiceFactoryBean.java

@@ -20,6 +20,7 @@ import java.util.Iterator;
 import java.util.ServiceLoader;
 
 import org.springframework.beans.factory.BeanClassLoaderAware;
+import org.springframework.lang.Nullable;
 
 /**
  * {@link org.springframework.beans.factory.FactoryBean} that exposes the
@@ -43,6 +44,7 @@ public class ServiceFactoryBean extends AbstractServiceLoaderBasedFactoryBean im
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getObjectType() {
 		return getServiceType();
 	}

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -340,6 +340,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	}
 
 	@Override
+	@Nullable
 	public Object resolveDependency(DependencyDescriptor descriptor, @Nullable String requestingBeanName) throws BeansException {
 		return resolveDependency(descriptor, requestingBeanName, null, null);
 	}
@@ -409,11 +410,13 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	}
 
 	@Override
+	@Nullable
 	public Object initializeBean(Object existingBean, String beanName) {
 		return initializeBean(beanName, existingBean, null);
 	}
 
 	@Override
+	@Nullable
 	public Object applyBeanPostProcessorsBeforeInitialization(Object existingBean, String beanName)
 			throws BeansException {
 
@@ -428,6 +431,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	}
 
 	@Override
+	@Nullable
 	public Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String beanName)
 			throws BeansException {
 
@@ -457,6 +461,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 * @see #doCreateBean
 	 */
 	@Override
+	@Nullable
 	protected Object createBean(String beanName, RootBeanDefinition mbd, @Nullable Object[] args)
 			throws BeanCreationException {
 
@@ -634,6 +639,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	}
 
 	@Override
+	@Nullable
 	protected Class<?> predictBeanType(String beanName, RootBeanDefinition mbd, Class<?>... typesToMatch) {
 		Class<?> targetType = determineTargetType(beanName, mbd, typesToMatch);
 
@@ -800,6 +806,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 * it will be fully created to check the type of its exposed object.
 	 */
 	@Override
+	@Nullable
 	protected Class<?> getTypeForFactoryBean(String beanName, RootBeanDefinition mbd) {
 		String factoryBeanName = mbd.getFactoryBeanName();
 		String factoryMethodName = mbd.getFactoryMethodName();
@@ -1177,6 +1184,7 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 * @see #obtainFromSupplier
 	 */
 	@Override
+	@Nullable
 	protected Object getObjectForBeanInstance(
 			@Nullable Object beanInstance, String name, String beanName, @Nullable RootBeanDefinition mbd) {
 

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanDefinition.java

@@ -358,6 +358,7 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 	 * Return the current bean class name of this bean definition.
 	 */
 	@Override
+	@Nullable
 	public String getBeanClassName() {
 		Object beanClassObject = this.beanClass;
 		if (beanClassObject instanceof Class) {
@@ -971,6 +972,7 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 	 * came from (for the purpose of showing context in case of errors).
 	 */
 	@Override
+	@Nullable
 	public String getResourceDescription() {
 		return (this.resource != null ? this.resource.getDescription() : null);
 	}
@@ -989,6 +991,7 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 	 * originator chain to find the original BeanDefinition as defined by the user.
 	 */
 	@Override
+	@Nullable
 	public BeanDefinition getOriginatingBeanDefinition() {
 		return (this.resource instanceof BeanDefinitionResource ?
 				((BeanDefinitionResource) this.resource).getBeanDefinition() : null);

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java

@@ -599,6 +599,7 @@ public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport imp
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getType(String name) throws NoSuchBeanDefinitionException {
 		String beanName = transformedBeanName(name);
 
@@ -840,6 +841,7 @@ public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport imp
 	}
 
 	@Override
+	@Nullable
 	public String resolveEmbeddedValue(@Nullable String value) {
 		if (value == null) {
 			return null;
@@ -926,6 +928,7 @@ public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport imp
 	}
 
 	@Override
+	@Nullable
 	public Scope getRegisteredScope(String scopeName) {
 		Assert.notNull(scopeName, "Scope identifier must not be null");
 		return this.scopes.get(scopeName);

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -570,6 +570,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	 * if not found on the exposed bean reference (e.g. in case of a proxy).
 	 */
 	@Override
+	@Nullable
 	public <A extends Annotation> A findAnnotationOnBean(String beanName, Class<A> annotationType)
 			throws NoSuchBeanDefinitionException{
 
@@ -1037,6 +1038,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	}
 
 	@Override
+	@Nullable
 	public Object resolveDependency(DependencyDescriptor descriptor, @Nullable String requestingBeanName,
 			@Nullable Set<String> autowiredBeanNames, @Nullable TypeConverter typeConverter) throws BeansException {
 
@@ -1613,6 +1615,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 
 		@Override
+		@Nullable
 		public Object getObject() throws BeansException {
 			if (this.optional) {
 				return createOptionalDependency(this.descriptor, this.beanName);
@@ -1623,6 +1626,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 
 		@Override
+		@Nullable
 		public Object getObject(final Object... args) throws BeansException {
 			if (this.optional) {
 				return createOptionalDependency(this.descriptor, this.beanName, args);
@@ -1639,6 +1643,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 
 		@Override
+		@Nullable
 		public Object getIfAvailable() throws BeansException {
 			if (this.optional) {
 				return createOptionalDependency(this.descriptor, this.beanName);
@@ -1655,6 +1660,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 
 		@Override
+		@Nullable
 		public Object getIfUnique() throws BeansException {
 			DependencyDescriptor descriptorToUse = new DependencyDescriptor(descriptor) {
 				@Override
@@ -1662,6 +1668,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 					return false;
 				}
 				@Override
+				@Nullable
 				public Object resolveNotUnique(Class<?> type, Map<String, Object> matchingBeans) {
 					return null;
 				}
@@ -1720,6 +1727,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 
 		@Override
+		@Nullable
 		public Object getOrderSource(Object obj) {
 			RootBeanDefinition beanDefinition = getRootBeanDefinition(this.instancesToBeanNames.get(obj));
 			if (beanDefinition == null) {

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultSingletonBeanRegistry.java

@@ -171,6 +171,7 @@ public class DefaultSingletonBeanRegistry extends SimpleAliasRegistry implements
 	}
 
 	@Override
+	@Nullable
 	public Object getSingleton(String beanName) {
 		return getSingleton(beanName, true);
 	}

spring-beans/src/main/java/org/springframework/beans/factory/support/SimpleAutowireCandidateResolver.java

@@ -41,11 +41,13 @@ public class SimpleAutowireCandidateResolver implements AutowireCandidateResolve
 	}
 
 	@Override
+	@Nullable
 	public Object getSuggestedValue(DependencyDescriptor descriptor) {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, @Nullable String beanName) {
 		return null;
 	}

spring-beans/src/main/java/org/springframework/beans/factory/support/StaticListableBeanFactory.java

@@ -355,6 +355,7 @@ public class StaticListableBeanFactory implements ListableBeanFactory {
 	}
 
 	@Override
+	@Nullable
 	public <A extends Annotation> A findAnnotationOnBean(String beanName, Class<A> annotationType)
 			throws NoSuchBeanDefinitionException{
 

spring-beans/src/main/java/org/springframework/beans/factory/xml/AbstractBeanDefinitionParser.java

@@ -58,6 +58,7 @@ public abstract class AbstractBeanDefinitionParser implements BeanDefinitionPars
 
 
 	@Override
+	@Nullable
 	public final BeanDefinition parse(Element element, ParserContext parserContext) {
 		AbstractBeanDefinition definition = parseInternal(element, parserContext);
 		if (definition != null && !parserContext.isNested()) {

spring-beans/src/main/java/org/springframework/beans/factory/xml/DefaultNamespaceHandlerResolver.java

@@ -113,6 +113,7 @@ public class DefaultNamespaceHandlerResolver implements NamespaceHandlerResolver
 	 * @return the located {@link NamespaceHandler}, or {@code null} if none found
 	 */
 	@Override
+	@Nullable
 	public NamespaceHandler resolve(String namespaceUri) {
 		Map<String, Object> handlerMappings = getHandlerMappings();
 		Object handlerOrClassName = handlerMappings.get(namespaceUri);

spring-beans/src/main/java/org/springframework/beans/factory/xml/NamespaceHandlerSupport.java

@@ -68,6 +68,7 @@ public abstract class NamespaceHandlerSupport implements NamespaceHandler {
 	 * registered for that {@link Element}.
 	 */
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		BeanDefinitionParser parser = findParserForElement(element, parserContext);
 		return (parser != null ? parser.parse(element, parserContext) : null);
@@ -93,6 +94,7 @@ public abstract class NamespaceHandlerSupport implements NamespaceHandler {
 	 * is registered to handle that {@link Node}.
 	 */
 	@Override
+	@Nullable
 	public BeanDefinitionHolder decorate(
 			Node node, BeanDefinitionHolder definition, ParserContext parserContext) {
 

spring-beans/src/main/java/org/springframework/beans/factory/xml/ResourceEntityResolver.java

@@ -71,6 +71,7 @@ public class ResourceEntityResolver extends DelegatingEntityResolver {
 
 
 	@Override
+	@Nullable
 	public InputSource resolveEntity(String publicId, @Nullable String systemId) throws SAXException, IOException {
 		InputSource source = super.resolveEntity(publicId, systemId);
 		if (source == null && systemId != null) {

spring-beans/src/main/java/org/springframework/beans/factory/xml/SimpleConstructorNamespaceHandler.java

@@ -28,6 +28,7 @@ import org.springframework.beans.factory.config.ConstructorArgumentValues;
 import org.springframework.beans.factory.config.ConstructorArgumentValues.ValueHolder;
 import org.springframework.beans.factory.config.RuntimeBeanReference;
 import org.springframework.core.Conventions;
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 
 /**
@@ -68,6 +69,7 @@ public class SimpleConstructorNamespaceHandler implements NamespaceHandler {
 	}
 
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		parserContext.getReaderContext().error(
 				"Class [" + getClass().getName() + "] does not support custom elements.", element);

spring-beans/src/main/java/org/springframework/beans/factory/xml/SimplePropertyNamespaceHandler.java

@@ -25,6 +25,7 @@ import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.config.RuntimeBeanReference;
 import org.springframework.core.Conventions;
+import org.springframework.lang.Nullable;
 
 /**
  * Simple {@code NamespaceHandler} implementation that maps custom attributes
@@ -57,6 +58,7 @@ public class SimplePropertyNamespaceHandler implements NamespaceHandler {
 	}
 
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		parserContext.getReaderContext().error(
 				"Class [" + getClass().getName() + "] does not support custom elements.", element);

spring-context-support/src/main/java/org/springframework/cache/caffeine/CaffeineCache.java

@@ -83,6 +83,7 @@ public class CaffeineCache extends AbstractValueAdaptingCache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper get(Object key) {
 		if (this.cache instanceof LoadingCache) {
 			Object value = ((LoadingCache<Object, Object>) this.cache).get(key);

spring-context-support/src/main/java/org/springframework/cache/caffeine/CaffeineCacheManager.java

@@ -176,6 +176,7 @@ public class CaffeineCacheManager implements CacheManager {
 	}
 
 	@Override
+	@Nullable
 	public Cache getCache(String name) {
 		Cache cache = this.cacheMap.get(name);
 		if (cache == null && this.dynamic) {

spring-context-support/src/main/java/org/springframework/cache/ehcache/EhCacheCache.java

@@ -64,6 +64,7 @@ public class EhCacheCache implements Cache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper get(Object key) {
 		Element element = lookup(key);
 		return toValueWrapper(element);
@@ -125,6 +126,7 @@ public class EhCacheCache implements Cache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper putIfAbsent(Object key, @Nullable Object value) {
 		Element existingElement = this.cache.putIfAbsent(new Element(key, value));
 		return toValueWrapper(existingElement);

spring-context-support/src/main/java/org/springframework/cache/ehcache/EhCacheFactoryBean.java

@@ -287,6 +287,7 @@ public class EhCacheFactoryBean extends CacheConfiguration implements FactoryBea
 
 
 	@Override
+	@Nullable
 	public Ehcache getObject() {
 		return this.cache;
 	}

spring-context-support/src/main/java/org/springframework/cache/ehcache/EhCacheManagerFactoryBean.java

@@ -169,6 +169,7 @@ public class EhCacheManagerFactoryBean implements FactoryBean<CacheManager>, Ini
 
 
 	@Override
+	@Nullable
 	public CacheManager getObject() {
 		return this.cacheManager;
 	}

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

@@ -76,6 +76,7 @@ public class JCacheCache extends AbstractValueAdaptingCache {
 	}
 
 	@Override
+	@Nullable
 	public <T> T get(Object key, Callable<T> valueLoader) {
 		try {
 			return this.cache.invoke(key, new ValueLoaderEntryProcessor<T>(), valueLoader);
@@ -91,6 +92,7 @@ public class JCacheCache extends AbstractValueAdaptingCache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper putIfAbsent(Object key, @Nullable Object value) {
 		boolean set = this.cache.putIfAbsent(key, toStoreValue(value));
 		return (set ? null : get(key));

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

@@ -85,6 +85,7 @@ public class JCacheManagerFactoryBean
 
 
 	@Override
+	@Nullable
 	public CacheManager getObject() {
 		return this.cacheManager;
 	}

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

@@ -72,6 +72,7 @@ public class TransactionAwareCacheDecorator implements Cache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper get(Object key) {
 		return this.targetCache.get(key);
 	}
@@ -82,6 +83,7 @@ public class TransactionAwareCacheDecorator implements Cache {
 	}
 
 	@Override
+	@Nullable
 	public <T> T get(Object key, Callable<T> valueLoader) {
 		return this.targetCache.get(key, valueLoader);
 	}
@@ -102,6 +104,7 @@ public class TransactionAwareCacheDecorator implements Cache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper putIfAbsent(Object key, @Nullable Object value) {
 		return this.targetCache.putIfAbsent(key, value);
 	}

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

@@ -76,6 +76,7 @@ public class TransactionAwareCacheManagerProxy implements CacheManager, Initiali
 
 
 	@Override
+	@Nullable
 	public Cache getCache(String name) {
 		Assert.state(this.targetCacheManager != null, "No target CacheManager set");
 		Cache targetCache = this.targetCacheManager.getCache(name);

spring-context-support/src/main/java/org/springframework/mail/MailSendException.java

@@ -123,6 +123,7 @@ public class MailSendException extends MailException {
 
 
 	@Override
+	@Nullable
 	public String getMessage() {
 		if (ObjectUtils.isEmpty(this.messageExceptions)) {
 			return super.getMessage();

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

@@ -110,6 +110,7 @@ public class TimerManagerFactoryBean extends TimerManagerAccessor
 	//---------------------------------------------------------------------
 
 	@Override
+	@Nullable
 	public TimerManager getObject() {
 		return getTimerManager();
 	}

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

@@ -56,6 +56,7 @@ public class TimerManagerTaskScheduler extends TimerManagerAccessor implements T
 
 
 	@Override
+	@Nullable
 	public ScheduledFuture<?> schedule(Runnable task, Trigger trigger) {
 		return new ReschedulingTimerListener(errorHandlingTask(task, true), trigger).schedule();
 	}

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

@@ -266,6 +266,7 @@ public class CronTriggerFactoryBean implements FactoryBean<CronTrigger>, BeanNam
 
 
 	@Override
+	@Nullable
 	public CronTrigger getObject() {
 		return this.cronTrigger;
 	}

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

@@ -218,6 +218,7 @@ public class JobDetailFactoryBean
 
 
 	@Override
+	@Nullable
 	public JobDetail getObject() {
 		return this.jobDetail;
 	}

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

@@ -223,6 +223,7 @@ public class MethodInvokingJobDetailFactoryBean extends ArgumentConvertingMethod
 
 
 	@Override
+	@Nullable
 	public JobDetail getObject() {
 		return this.jobDetail;
 	}

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

@@ -708,6 +708,7 @@ public class SchedulerFactoryBean extends SchedulerAccessor implements FactoryBe
 	}
 
 	@Override
+	@Nullable
 	public Scheduler getObject() {
 		return this.scheduler;
 	}

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

@@ -251,6 +251,7 @@ public class SimpleTriggerFactoryBean implements FactoryBean<SimpleTrigger>, Bea
 
 
 	@Override
+	@Nullable
 	public SimpleTrigger getObject() {
 		return this.simpleTrigger;
 	}

spring-context-support/src/main/java/org/springframework/ui/freemarker/FreeMarkerConfigurationFactoryBean.java

@@ -65,6 +65,7 @@ public class FreeMarkerConfigurationFactoryBean extends FreeMarkerConfigurationF
 
 
 	@Override
+	@Nullable
 	public Configuration getObject() {
 		return this.configuration;
 	}

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

@@ -157,7 +157,8 @@ public interface Cache {
 		/**
 		 * Return the actual value in the cache.
 		 */
-		@Nullable Object get();
+		@Nullable
+		Object get();
 	}
 
 

spring-context/src/main/java/org/springframework/cache/annotation/AnnotationCacheOperationSource.java

@@ -106,11 +106,13 @@ public class AnnotationCacheOperationSource extends AbstractFallbackCacheOperati
 
 
 	@Override
+	@Nullable
 	protected Collection<CacheOperation> findCacheOperations(final Class<?> clazz) {
 		return determineCacheOperations(parser -> parser.parseCacheAnnotations(clazz));
 	}
 
 	@Override
+	@Nullable
 	protected Collection<CacheOperation> findCacheOperations(final Method method) {
 		return determineCacheOperations(parser -> parser.parseCacheAnnotations(method));
 	}

spring-context/src/main/java/org/springframework/cache/annotation/CachingConfigurerSupport.java

@@ -20,6 +20,7 @@ import org.springframework.cache.CacheManager;
 import org.springframework.cache.interceptor.CacheErrorHandler;
 import org.springframework.cache.interceptor.CacheResolver;
 import org.springframework.cache.interceptor.KeyGenerator;
+import org.springframework.lang.Nullable;
 
 /**
  * An implementation of {@link CachingConfigurer} with empty methods allowing
@@ -32,21 +33,25 @@ import org.springframework.cache.interceptor.KeyGenerator;
 public class CachingConfigurerSupport implements CachingConfigurer {
 
 	@Override
+	@Nullable
 	public CacheManager cacheManager() {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public KeyGenerator keyGenerator() {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public CacheResolver cacheResolver() {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public CacheErrorHandler errorHandler() {
 		return null;
 	}

spring-context/src/main/java/org/springframework/cache/annotation/SpringCacheAnnotationParser.java

@@ -48,12 +48,14 @@ import org.springframework.util.StringUtils;
 public class SpringCacheAnnotationParser implements CacheAnnotationParser, Serializable {
 
 	@Override
+	@Nullable
 	public Collection<CacheOperation> parseCacheAnnotations(Class<?> type) {
 		DefaultCacheConfig defaultConfig = getDefaultCacheConfig(type);
 		return parseCacheAnnotations(defaultConfig, type);
 	}
 
 	@Override
+	@Nullable
 	public Collection<CacheOperation> parseCacheAnnotations(Method method) {
 		DefaultCacheConfig defaultConfig = getDefaultCacheConfig(method.getDeclaringClass());
 		return parseCacheAnnotations(defaultConfig, method);

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

@@ -92,6 +92,7 @@ public class ConcurrentMapCacheFactoryBean
 
 
 	@Override
+	@Nullable
 	public ConcurrentMapCache getObject() {
 		return this.cache;
 	}

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

@@ -162,6 +162,7 @@ public class ConcurrentMapCacheManager implements CacheManager, BeanClassLoaderA
 	}
 
 	@Override
+	@Nullable
 	public Cache getCache(String name) {
 		Cache cache = this.cacheMap.get(name);
 		if (cache == null && this.dynamic) {

spring-context/src/main/java/org/springframework/cache/config/AnnotationDrivenCacheBeanDefinitionParser.java

@@ -75,6 +75,7 @@ class AnnotationDrivenCacheBeanDefinitionParser implements BeanDefinitionParser
 	 * register an AutoProxyCreator} with the container as necessary.
 	 */
 	@Override
+	@Nullable
 	public BeanDefinition parse(Element element, ParserContext parserContext) {
 		String mode = element.getAttribute("mode");
 		if ("aspectj".equals(mode)) {

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

@@ -83,6 +83,7 @@ public abstract class AbstractFallbackCacheOperationSource implements CacheOpera
 	 * is not cacheable
 	 */
 	@Override
+	@Nullable
 	public Collection<CacheOperation> getCacheOperations(Method method, @Nullable Class<?> targetClass) {
 		if (method.getDeclaringClass() == Object.class) {
 			return null;

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

@@ -36,6 +36,7 @@ public class BeanFactoryCacheOperationSourceAdvisor extends AbstractBeanFactoryP
 
 	private final CacheOperationSourcePointcut pointcut = new CacheOperationSourcePointcut() {
 		@Override
+		@Nullable
 		protected CacheOperationSource getCacheOperationSource() {
 			return cacheOperationSource;
 		}

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

@@ -22,6 +22,7 @@ import java.util.Set;
 
 import org.springframework.context.expression.MethodBasedEvaluationContext;
 import org.springframework.core.ParameterNameDiscoverer;
+import org.springframework.lang.Nullable;
 
 /**
  * Cache specific evaluation context that adds a method parameters as SpEL
@@ -69,6 +70,7 @@ class CacheEvaluationContext extends MethodBasedEvaluationContext {
 	 * Load the param information only when needed.
 	 */
 	@Override
+	@Nullable
 	public Object lookupVariable(String name) {
 		if (this.unavailableVariables.contains(name)) {
 			throw new VariableNotAvailableException(name);

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

@@ -55,6 +55,7 @@ public class CompositeCacheOperationSource implements CacheOperationSource, Seri
 	}
 
 	@Override
+	@Nullable
 	public Collection<CacheOperation> getCacheOperations(Method method, @Nullable Class<?> targetClass) {
 		Collection<CacheOperation> ops = null;
 

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

@@ -75,6 +75,7 @@ public class NameMatchCacheOperationSource implements CacheOperationSource, Seri
 	}
 
 	@Override
+	@Nullable
 	public Collection<CacheOperation> getCacheOperations(Method method, @Nullable Class<?> targetClass) {
 		// look for direct name match
 		String methodName = method.getName();

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

@@ -85,6 +85,7 @@ public abstract class AbstractCacheManager implements CacheManager, Initializing
 	// Lazy cache initialization on access
 
 	@Override
+	@Nullable
 	public Cache getCache(String name) {
 		Cache cache = this.cacheMap.get(name);
 		if (cache != null) {

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

@@ -27,6 +27,7 @@ import java.util.Set;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.cache.Cache;
 import org.springframework.cache.CacheManager;
+import org.springframework.lang.Nullable;
 
 /**
  * Composite {@link CacheManager} implementation that iterates over
@@ -98,6 +99,7 @@ public class CompositeCacheManager implements CacheManager, InitializingBean {
 
 
 	@Override
+	@Nullable
 	public Cache getCache(String name) {
 		for (CacheManager cacheManager : this.cacheManagers) {
 			Cache cache = cacheManager.getCache(name);

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

@@ -58,16 +58,19 @@ public class NoOpCache implements Cache {
 	}
 
 	@Override
+	@Nullable
 	public ValueWrapper get(Object key) {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public <T> T get(Object key, @Nullable Class<T> type) {
 		return null;
 	}
 
 	@Override
+	@Nullable
 	public <T> T get(Object key, Callable<T> valueLoader) {
 		try {
 			return valueLoader.call();

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

@@ -25,6 +25,7 @@ import java.util.concurrent.ConcurrentMap;
 
 import org.springframework.cache.Cache;
 import org.springframework.cache.CacheManager;
+import org.springframework.lang.Nullable;
 
 /**
  * A basic, no operation {@link CacheManager} implementation suitable
@@ -50,6 +51,7 @@ public class NoOpCacheManager implements CacheManager {
 	 * Additionally, the request cache will be remembered by the manager for consistency.
 	 */
 	@Override
+	@Nullable
 	public Cache getCache(String name) {
 		Cache cache = this.caches.get(name);
 		if (cache == null) {