Polishing

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

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -313,9 +313,9 @@ public abstract class CacheAspectSupport extends AbstractCacheInvoker
 	 * @param expectedType type for the bean
 	 * @return the bean matching that name
 	 * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException if such bean does not exist
-	 * @see CacheOperation#keyGenerator
-	 * @see CacheOperation#cacheManager
-	 * @see CacheOperation#cacheResolver
+	 * @see CacheOperation#getKeyGenerator()
+	 * @see CacheOperation#getCacheManager()
+	 * @see CacheOperation#getCacheResolver()
 	 */
 	protected <T> T getBean(String beanName, Class<T> expectedType) {
 		if (this.beanFactory == null) {
@@ -353,8 +353,8 @@ public abstract class CacheAspectSupport extends AbstractCacheInvoker
 
 	/**
 	 * Execute the underlying operation (typically in case of cache miss) and return
-	 * the result of the invocation. If an exception occurs it will be wrapped in
-	 * a {@link CacheOperationInvoker.ThrowableWrapper}: the exception can be handled
+	 * the result of the invocation. If an exception occurs it will be wrapped in a
+	 * {@link CacheOperationInvoker.ThrowableWrapper}: the exception can be handled
 	 * or modified but it <em>must</em> be wrapped in a
 	 * {@link CacheOperationInvoker.ThrowableWrapper} as well.
 	 * @param invoker the invoker handling the operation being cached

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

 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -27,13 +27,14 @@ import org.springframework.lang.Nullable;
  * source level, or elsewhere.
  *
  * @author Costin Leau
+ * @author Juergen Hoeller
  * @since 3.1
  */
 public interface CacheOperationSource {
 
 	/**
-	 * Return the collection of cache operations for this method, or {@code null}
-	 * if the method contains no <em>cacheable</em> annotations.
+	 * Return the collection of cache operations for this method,
+	 * or {@code null} if the method contains no <em>cacheable</em> annotations.
 	 * @param method the method to introspect
 	 * @param targetClass the target class (may be {@code null}, in which case
 	 * the declaring class of the method must be used)

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

 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -29,6 +29,7 @@ import org.springframework.util.Assert;
  * over a given array of {@code CacheOperationSource} instances.
  *
  * @author Costin Leau
+ * @author Juergen Hoeller
  * @since 3.1
  */
 @SuppressWarnings("serial")
@@ -42,7 +43,7 @@ public class CompositeCacheOperationSource implements CacheOperationSource, Seri
 	 * @param cacheOperationSources the CacheOperationSource instances to combine
 	 */
 	public CompositeCacheOperationSource(CacheOperationSource... cacheOperationSources) {
-		Assert.notEmpty(cacheOperationSources, "cacheOperationSources array must not be empty");
+		Assert.notEmpty(cacheOperationSources, "CacheOperationSource array must not be empty");
 		this.cacheOperationSources = cacheOperationSources;
 	}
 
@@ -54,21 +55,21 @@ public class CompositeCacheOperationSource implements CacheOperationSource, Seri
 		return this.cacheOperationSources;
 	}
 
+
 	@Override
 	@Nullable
 	public Collection<CacheOperation> getCacheOperations(Method method, @Nullable Class<?> targetClass) {
 		Collection<CacheOperation> ops = null;
-
 		for (CacheOperationSource source : this.cacheOperationSources) {
 			Collection<CacheOperation> cacheOperations = source.getCacheOperations(method, targetClass);
 			if (cacheOperations != null) {
 				if (ops == null) {
 					ops = new ArrayList<>();
 				}
-
 				ops.addAll(cacheOperations);
 			}
 		}
 		return ops;
 	}
+
 }

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

 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -36,7 +36,7 @@ import org.springframework.util.StringUtils;
 /**
  * {@link org.springframework.scripting.ScriptFactory} implementation based
  * on the JSR-223 script engine abstraction (as included in Java 6+).
- * Supports JavaScript, Groovy, JRuby and other JSR-223 compliant engines.
+ * Supports JavaScript, Groovy, JRuby, and other JSR-223 compliant engines.
  *
  * <p>Typically used in combination with a
  * {@link org.springframework.scripting.support.ScriptFactoryPostProcessor};
@@ -151,6 +151,7 @@ public class StandardScriptFactory implements ScriptFactory, BeanClassLoaderAwar
 				if (script instanceof Class ? !requestedIfc.isAssignableFrom((Class<?>) script) :
 						!requestedIfc.isInstance(script)) {
 					adaptationRequired = true;
+					break;
 				}
 			}
 			if (adaptationRequired) {

spring-core/src/main/java/org/springframework/lang/NonNull.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -26,8 +26,9 @@ import javax.annotation.meta.TypeQualifierNickname;
 
 /**
  * A common Spring annotation to declare that annotated elements cannot be {@code null}.
- * Leverages JSR 305 meta-annotations to indicate nullability in Java to common tools with
- * JSR 305 support and used by Kotlin to infer nullability of Spring API.
+ *
+ * <p>Leverages JSR-305 meta-annotations to indicate nullability in Java to common
+ * tools with JSR-305 support and used by Kotlin to infer nullability of Spring API.
  *
  * <p>Should be used at parameter, return value, and field level. Method overrides should
  * repeat parent {@code @NonNull} annotations unless they behave differently.

spring-core/src/main/java/org/springframework/lang/NonNullFields.java

 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -36,7 +36,7 @@ import javax.annotation.meta.TypeQualifierDefault;
  *
  * @author Sebastien Deleuze
  * @since 5.0
- * @see NonNullFields
+ * @see NonNullApi
  * @see Nullable
  * @see NonNull
  */

spring-core/src/main/java/org/springframework/lang/Nullable.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -27,8 +27,10 @@ import javax.annotation.meta.When;
 
 /**
  * A common Spring annotation to declare that annotated elements can be {@code null} under
- * some circumstance. Leverages JSR 305 meta-annotations to indicate nullability in Java
- * to common tools with JSR 305 support and used by Kotlin to infer nullability of Spring API.
+ * some circumstance.
+ *
+ * <p>Leverages JSR-305 meta-annotations to indicate nullability in Java to common
+ * tools with JSR-305 support and used by Kotlin to infer nullability of Spring API.
  *
  * <p>Should be used at parameter, return value, and field level. Methods override should
  * repeat parent {@code @Nullable} annotations unless they behave differently.

spring-tx/src/main/java/org/springframework/transaction/interceptor/CompositeTransactionAttributeSource.java

 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -39,7 +39,7 @@ public class CompositeTransactionAttributeSource implements TransactionAttribute
 	 * Create a new CompositeTransactionAttributeSource for the given sources.
 	 * @param transactionAttributeSources the TransactionAttributeSource instances to combine
 	 */
-	public CompositeTransactionAttributeSource(TransactionAttributeSource[] transactionAttributeSources) {
+	public CompositeTransactionAttributeSource(TransactionAttributeSource... transactionAttributeSources) {
 		Assert.notNull(transactionAttributeSources, "TransactionAttributeSource array must not be null");
 		this.transactionAttributeSources = transactionAttributeSources;
 	}
@@ -56,10 +56,10 @@ public class CompositeTransactionAttributeSource implements TransactionAttribute
 	@Override
 	@Nullable
 	public TransactionAttribute getTransactionAttribute(Method method, @Nullable Class<?> targetClass) {
-		for (TransactionAttributeSource tas : this.transactionAttributeSources) {
-			TransactionAttribute ta = tas.getTransactionAttribute(method, targetClass);
-			if (ta != null) {
-				return ta;
+		for (TransactionAttributeSource source : this.transactionAttributeSources) {
+			TransactionAttribute attr = source.getTransactionAttribute(method, targetClass);
+			if (attr != null) {
+				return attr;
 			}
 		}
 		return null;

spring-tx/src/main/java/org/springframework/transaction/interceptor/TransactionAttributeSource.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -27,6 +27,7 @@ import org.springframework.lang.Nullable;
  * metadata attributes at source level (such as Java 5 annotations), or anywhere else.
  *
  * @author Rod Johnson
+ * @author Juergen Hoeller
  * @since 15.04.2003
  * @see TransactionInterceptor#setTransactionAttributeSource
  * @see TransactionProxyFactoryBean#setTransactionAttributeSource
@@ -40,8 +41,7 @@ public interface TransactionAttributeSource {
 	 * @param method the method to introspect
 	 * @param targetClass the target class (may be {@code null},
 	 * in which case the declaring class of the method must be used)
-	 * @return the TransactionAttribute the matching transaction attribute,
-	 * or {@code null} if none found
+	 * @return the matching transaction attribute, or {@code null} if none found
 	 */
 	@Nullable
 	TransactionAttribute getTransactionAttribute(Method method, @Nullable Class<?> targetClass);

spring-web/src/main/java/org/springframework/http/server/ServerHttpRequest.java

 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -21,6 +21,7 @@ import java.security.Principal;
 
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpRequest;
+import org.springframework.lang.Nullable;
 
 /**
  * Represents a server-side HTTP request.
@@ -33,9 +34,10 @@ public interface ServerHttpRequest extends HttpRequest, HttpInputMessage {
 
 	/**
 	 * Return a {@link java.security.Principal} instance containing the name of the
-	 * authenticated user. If the user has not been authenticated, the method returns
-	 * <code>null</code>.
+	 * authenticated user.
+	 * <p>If the user has not been authenticated, the method returns <code>null</code>.
 	 */
+	@Nullable
 	Principal getPrincipal();
 
 	/**