Nullability refinements and related polishing (backported)

spring-context/src/main/java/org/springframework/validation/support/BindingAwareConcurrentModel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.validation.support;
 
 import java.util.Map;
 
+import org.springframework.lang.Nullable;
 import org.springframework.ui.ConcurrentModel;
 import org.springframework.validation.BindingResult;
 
@@ -36,17 +37,19 @@ import org.springframework.validation.BindingResult;
  * @author Rossen Stoyanchev
  * @since 5.0
  * @see BindingResult
+ * @see BindingAwareModelMap
  */
 @SuppressWarnings("serial")
 public class BindingAwareConcurrentModel extends ConcurrentModel {
 
 	@Override
-	public Object put(String key, Object value) {
+	@Nullable
+	public Object put(String key, @Nullable Object value) {
 		removeBindingResultIfNecessary(key, value);
 		return super.put(key, value);
 	}
 
-	private void removeBindingResultIfNecessary(String key, Object value) {
+	private void removeBindingResultIfNecessary(String key, @Nullable Object value) {
 		if (!key.startsWith(BindingResult.MODEL_KEY_PREFIX)) {
 			String resultKey = BindingResult.MODEL_KEY_PREFIX + key;
 			BindingResult result = (BindingResult) get(resultKey);

spring-context/src/main/java/org/springframework/validation/support/BindingAwareModelMap.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,6 +18,7 @@ package org.springframework.validation.support;
 
 import java.util.Map;
 
+import org.springframework.lang.Nullable;
 import org.springframework.ui.ExtendedModelMap;
 import org.springframework.validation.BindingResult;
 
@@ -39,7 +40,7 @@ import org.springframework.validation.BindingResult;
 public class BindingAwareModelMap extends ExtendedModelMap {
 
 	@Override
-	public Object put(String key, Object value) {
+	public Object put(String key, @Nullable Object value) {
 		removeBindingResultIfNecessary(key, value);
 		return super.put(key, value);
 	}
@@ -50,7 +51,7 @@ public class BindingAwareModelMap extends ExtendedModelMap {
 		super.putAll(map);
 	}
 
-	private void removeBindingResultIfNecessary(Object key, Object value) {
+	private void removeBindingResultIfNecessary(Object key, @Nullable Object value) {
 		if (key instanceof String) {
 			String attributeName = (String) key;
 			if (!attributeName.startsWith(BindingResult.MODEL_KEY_PREFIX)) {

spring-core/src/main/java/org/springframework/util/ClassUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -88,13 +88,13 @@ public abstract class ClassUtils {
 	 * Map with primitive wrapper type as key and corresponding primitive
 	 * type as value, for example: Integer.class -> int.class.
 	 */
-	private static final Map<Class<?>, Class<?>> primitiveWrapperTypeMap = new IdentityHashMap<>(8);
+	private static final Map<Class<?>, Class<?>> primitiveWrapperTypeMap = new IdentityHashMap<>(9);
 
 	/**
 	 * Map with primitive type as key and corresponding wrapper
 	 * type as value, for example: int.class -> Integer.class.
 	 */
-	private static final Map<Class<?>, Class<?>> primitiveTypeToWrapperMap = new IdentityHashMap<>(8);
+	private static final Map<Class<?>, Class<?>> primitiveTypeToWrapperMap = new IdentityHashMap<>(9);
 
 	/**
 	 * Map with primitive type name as key and corresponding primitive
@@ -1322,7 +1322,7 @@ public abstract class ClassUtils {
 	 * Note that, despite being synthetic, bridge methods ({@link Method#isBridge()}) are considered
 	 * as user-level methods since they are eventually pointing to a user-declared generic method.
 	 * @param method the method to check
-	 * @return {@code true} if the method can be considered as user-declared; [@code false} otherwise
+	 * @return {@code true} if the method can be considered as user-declared; {@code false} otherwise
 	 */
 	public static boolean isUserLevelMethod(Method method) {
 		Assert.notNull(method, "Method must not be null");

spring-core/src/main/java/org/springframework/util/StringUtils.java

@@ -565,7 +565,7 @@ public abstract class StringUtils {
 
 		char[] chars = str.toCharArray();
 		chars[0] = updatedChar;
-		return new String(chars, 0, chars.length);
+		return new String(chars);
 	}
 
 	/**

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/DefaultMessageHandlerMethodFactory.java

@@ -120,8 +120,7 @@ public class DefaultMessageHandlerMethodFactory
 	 * the ones configured by default. This is an advanced option. For most use cases
 	 * it should be sufficient to use {@link #setCustomArgumentResolvers(java.util.List)}.
 	 */
-	@SuppressWarnings("ConstantConditions")
+	public void setArgumentResolvers(@Nullable List<HandlerMethodArgumentResolver> argumentResolvers) {
-	public void setArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
 		if (argumentResolvers == null) {
 			this.argumentResolvers.clear();
 			return;

spring-messaging/src/main/java/org/springframework/messaging/rsocket/annotation/support/RSocketFrameTypeMessageCondition.java

@@ -131,7 +131,6 @@ public class RSocketFrameTypeMessageCondition extends AbstractMessageCondition<R
 	 * @param message the current message
 	 * @return the frame type or {@code null} if not found
 	 */
-	@SuppressWarnings("ConstantConditions")
 	@Nullable
 	public static FrameType getFrameType(Message<?> message) {
 		return (FrameType) message.getHeaders().get(RSocketFrameTypeMessageCondition.FRAME_TYPE_HEADER);

spring-web/src/main/java/org/springframework/web/bind/annotation/CookieValue.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,7 @@ import java.lang.annotation.Target;
 import org.springframework.core.annotation.AliasFor;
 
 /**
- * Annotation which indicates that a method parameter should be bound to an HTTP cookie.
+ * Annotation to indicate that a method parameter is bound to an HTTP cookie.
  *
  * <p>The method parameter may be declared as type {@link javax.servlet.http.Cookie}
  * or as cookie value type (String, int, etc.).

spring-web/src/main/java/org/springframework/web/cors/CorsConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -59,8 +59,7 @@ public class CorsConfiguration {
 	private static final List<String> DEFAULT_PERMIT_METHODS = Collections.unmodifiableList(
 			Arrays.asList(HttpMethod.GET.name(), HttpMethod.HEAD.name(), HttpMethod.POST.name()));
 
-	private static final List<String> DEFAULT_PERMIT_ALL = Collections.unmodifiableList(
+	private static final List<String> DEFAULT_PERMIT_ALL = Collections.singletonList(ALL);
-			Collections.singletonList(ALL));
 
 
 	@Nullable

spring-webmvc/src/main/java/org/springframework/web/servlet/function/support/RouterFunctionMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -59,7 +59,6 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 	private boolean detectHandlerFunctionsInAncestorContexts = false;
 
 
-
 	/**
 	 * Create an empty {@code RouterFunctionMapping}.
 	 * <p>If this constructor is used, this mapping will detect all
@@ -77,6 +76,7 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 		this.routerFunction = routerFunction;
 	}
 
+
 	/**
 	 * Set the router function to map to.
 	 * <p>If this property is used, no application context detection will occur.
@@ -97,6 +97,10 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 		return this.routerFunction;
 	}
 
+	/**
+	 * Set the message body converters to use.
+	 * <p>These converters are used to convert from and to HTTP requests and responses.
+	 */
 	public void setMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
 		this.messageConverters = messageConverters;
 	}
@@ -113,6 +117,7 @@ public class RouterFunctionMapping extends AbstractHandlerMapping implements Ini
 		this.detectHandlerFunctionsInAncestorContexts = detectHandlerFunctionsInAncestorContexts;
 	}
 
+
 	@Override
 	public void afterPropertiesSet() throws Exception {
 		if (this.routerFunction == null) {

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -359,6 +359,7 @@ public abstract class AbstractHandlerMethodMapping<T> extends AbstractHandlerMap
 	 * Look up a handler method for the given request.
 	 */
 	@Override
+	@Nullable
 	protected HandlerMethod getHandlerInternal(HttpServletRequest request) throws Exception {
 		String lookupPath = getUrlPathHelper().getLookupPathForRequest(request);
 		request.setAttribute(LOOKUP_PATH, lookupPath);

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/RequestMappingInfoHandlerMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,7 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.InvalidMediaTypeException;
 import org.springframework.http.MediaType;
+import org.springframework.lang.Nullable;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
@@ -104,6 +105,7 @@ public abstract class RequestMappingInfoHandlerMapping extends AbstractHandlerMe
 	}
 
 	@Override
+	@Nullable
 	protected HandlerMethod getHandlerInternal(HttpServletRequest request) throws Exception {
 		request.removeAttribute(PRODUCIBLE_MEDIA_TYPES_ATTRIBUTE);
 		try {

src/docs/asciidoc/core/core-beans.adoc

@@ -847,12 +847,12 @@ This approach shows that the factory bean itself can be managed and configured t
 dependency injection (DI). See <<beans-factory-properties-detailed,Dependencies and
 Configuration in Detail>>.
 
-NOTE: In Spring documentation, "`factory bean`" refers to a bean that is configured in
+NOTE: In Spring documentation, "factory bean" refers to a bean that is configured in the
-the Spring container and that creates objects through an
+Spring container and that creates objects through an
 <<beans-factory-class-instance-factory-method,instance>> or
 <<beans-factory-class-static-factory-method,static>> factory method. By contrast,
 `FactoryBean` (notice the capitalization) refers to a Spring-specific
-<<beans-factory-extension-factorybean, `FactoryBean` >> implementation class.
+<<beans-factory-extension-factorybean, `FactoryBean`>> implementation class.
 
 
 [[beans-factory-type-determination]]
@@ -8279,7 +8279,7 @@ it resembles the following:
 	fun userService(): Service {
 		return SimpleUserService().apply {
 			// a reference to the proxied userPreferences bean
-			setUserPreferences(userPreferences()
+			setUserPreferences(userPreferences())
 		}
 	}
 ----