Polishing (aligned with main)

spring-jdbc/src/main/java/org/springframework/jdbc/support/SQLExceptionSubclassTranslator.java

@@ -69,30 +69,30 @@ protected DataAccessException doTranslate(String task, @Nullable String sql, SQL
 			if (ex instanceof SQLTransientConnectionException) {
 				return new TransientDataAccessResourceException(buildMessage(task, sql, ex), ex);
 			}
-			else if (ex instanceof SQLTransactionRollbackException) {
+			if (ex instanceof SQLTransactionRollbackException) {
 				return new ConcurrencyFailureException(buildMessage(task, sql, ex), ex);
 			}
-			else if (ex instanceof SQLTimeoutException) {
+			if (ex instanceof SQLTimeoutException) {
 				return new QueryTimeoutException(buildMessage(task, sql, ex), ex);
 			}
 		}
 		else if (ex instanceof SQLNonTransientException) {
 			if (ex instanceof SQLNonTransientConnectionException) {
 				return new DataAccessResourceFailureException(buildMessage(task, sql, ex), ex);
 			}
-			else if (ex instanceof SQLDataException) {
+			if (ex instanceof SQLDataException) {
 				return new DataIntegrityViolationException(buildMessage(task, sql, ex), ex);
 			}
-			else if (ex instanceof SQLIntegrityConstraintViolationException) {
+			if (ex instanceof SQLIntegrityConstraintViolationException) {
 				return new DataIntegrityViolationException(buildMessage(task, sql, ex), ex);
 			}
-			else if (ex instanceof SQLInvalidAuthorizationSpecException) {
+			if (ex instanceof SQLInvalidAuthorizationSpecException) {
 				return new PermissionDeniedDataAccessException(buildMessage(task, sql, ex), ex);
 			}
-			else if (ex instanceof SQLSyntaxErrorException) {
+			if (ex instanceof SQLSyntaxErrorException) {
 				return new BadSqlGrammarException(task, (sql != null ? sql : ""), ex);
 			}
-			else if (ex instanceof SQLFeatureNotSupportedException) {
+			if (ex instanceof SQLFeatureNotSupportedException) {
 				return new InvalidDataAccessApiUsageException(buildMessage(task, sql, ex), ex);
 			}
 		}

spring-r2dbc/src/main/java/org/springframework/r2dbc/connection/ConnectionFactoryUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -221,7 +221,7 @@ public static DataAccessException convertR2dbcException(String task, @Nullable S
 				return new QueryTimeoutException(buildMessage(task, sql, ex), ex);
 			}
 		}
-		if (ex instanceof R2dbcNonTransientException) {
+		else if (ex instanceof R2dbcNonTransientException) {
 			if (ex instanceof R2dbcNonTransientResourceException) {
 				return new DataAccessResourceFailureException(buildMessage(task, sql, ex), ex);
 			}

spring-tx/src/main/java/org/springframework/dao/CannotAcquireLockException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -20,6 +20,9 @@
  * Exception thrown on failure to acquire a lock during an update,
  * for example during a "select for update" statement.
  *
+ * <p>Consider handling the general {@link PessimisticLockingFailureException}
+ * instead, semantically including a wider range of locking-related failures.
+ *
  * @author Rod Johnson
  */
 @SuppressWarnings("serial")

spring-tx/src/main/java/org/springframework/dao/CannotSerializeTransactionException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -20,6 +20,9 @@
  * Exception thrown on failure to complete a transaction in serialized mode
  * due to update conflicts.
  *
+ * <p>Consider handling the general {@link PessimisticLockingFailureException}
+ * instead, semantically including a wider range of locking-related failures.
+ *
  * @author Rod Johnson
  */
 @SuppressWarnings("serial")

spring-tx/src/main/java/org/springframework/dao/ConcurrencyFailureException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -19,17 +19,15 @@
 import org.springframework.lang.Nullable;
 
 /**
- * Exception thrown on concurrency failure.
+ * Exception thrown on various data access concurrency failures.
  *
- * <p>This exception should be subclassed to indicate the type of failure:
- * optimistic locking, failure to acquire lock, etc.
+ * <p>This exception provides subclasses for specific types of failure,
+ * in particular optimistic locking versus pessimistic locking.
  *
  * @author Thomas Risberg
  * @since 1.1
  * @see OptimisticLockingFailureException
  * @see PessimisticLockingFailureException
- * @see CannotAcquireLockException
- * @see DeadlockLoserDataAccessException
  */
 @SuppressWarnings("serial")
 public class ConcurrencyFailureException extends TransientDataAccessException {

spring-tx/src/main/java/org/springframework/dao/DataIntegrityViolationException.java

@@ -19,8 +19,13 @@
 /**
  * Exception thrown when an attempt to insert or update data
  * results in violation of an integrity constraint. Note that this
- * is not purely a relational concept; unique primary keys are
- * required by most database types.
+ * is not purely a relational concept; integrity constraints such
+ * as unique primary keys are required by most database types.
+ *
+ * <p>Serves as a superclass for more specific exceptions, e.g.
+ * {@link DuplicateKeyException}. However, it is generally
+ * recommended to handle {@code DataIntegrityViolationException}
+ * itself instead of relying on specific exception subclasses.
  *
  * @author Rod Johnson
  */

spring-tx/src/main/java/org/springframework/dao/DeadlockLoserDataAccessException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -20,6 +20,9 @@
  * Generic exception thrown when the current process was
  * a deadlock loser, and its transaction rolled back.
  *
+ * <p>Consider handling the general {@link PessimisticLockingFailureException}
+ * instead, semantically including a wider range of locking-related failures.
+ *
  * @author Rod Johnson
  */
 @SuppressWarnings("serial")

spring-tx/src/main/java/org/springframework/dao/DuplicateKeyException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -22,6 +22,9 @@
  * Note that this is not necessarily a purely relational concept;
  * unique primary keys are required by most database types.
  *
+ * <p>Consider handling the general {@link DataIntegrityViolationException}
+ * instead, semantically including a wider range of constraint violations.
+ *
  * @author Thomas Risberg
  */
 @SuppressWarnings("serial")

spring-tx/src/main/java/org/springframework/dao/PessimisticLockingFailureException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -21,13 +21,13 @@
  * Thrown by Spring's SQLException translation mechanism
  * if a corresponding database error is encountered.
  *
- * <p>Serves as superclass for more specific exceptions, like
- * CannotAcquireLockException and DeadlockLoserDataAccessException.
+ * <p>Serves as a superclass for more specific exceptions, e.g.
+ * {@link CannotAcquireLockException}. However, it is generally
+ * recommended to handle {@code PessimisticLockingFailureException}
+ * itself instead of relying on specific exception subclasses.
  *
  * @author Thomas Risberg
  * @since 1.2
- * @see CannotAcquireLockException
- * @see DeadlockLoserDataAccessException
  * @see OptimisticLockingFailureException
  */
 @SuppressWarnings("serial")

spring-web/src/main/java/org/springframework/http/codec/ClientCodecConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -92,11 +92,11 @@ interface ClientDefaultCodecs extends DefaultCodecs {
 
 		/**
 		 * Configure the {@code Decoder} to use for Server-Sent Events.
-		 * <p>By default if this is not set, and Jackson is available, the
-		 * {@link #jackson2JsonDecoder} override is used instead. Use this property
-		 * if you want to further customize the SSE decoder.
-		 * <p>Note that {@link #maxInMemorySize(int)}, if configured, will be
-		 * applied to the given decoder.
+		 * <p>By default if this is not set, and Jackson is available,
+		 * the {@link #jackson2JsonDecoder} override is used instead.
+		 * Use this method to customize the SSE decoder.
+		 * <p>Note that {@link #maxInMemorySize(int)}, if configured,
+		 * will be applied to the given decoder.
 		 * @param decoder the decoder to use
 		 */
 		void serverSentEventDecoder(Decoder<?> decoder);

spring-web/src/main/java/org/springframework/http/codec/ServerCodecConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -78,7 +78,7 @@ static ServerCodecConfigurer create() {
 
 
 	/**
-	 * {@link CodecConfigurer.DefaultCodecs} extension with extra client-side options.
+	 * {@link CodecConfigurer.DefaultCodecs} extension with extra server-side options.
 	 */
 	interface ServerDefaultCodecs extends DefaultCodecs {
 
@@ -101,9 +101,9 @@ interface ServerDefaultCodecs extends DefaultCodecs {
 
 		/**
 		 * Configure the {@code Encoder} to use for Server-Sent Events.
-		 * <p>By default if this is not set, and Jackson is available, the
-		 * {@link #jackson2JsonEncoder} override is used instead. Use this method
-		 * to customize the SSE encoder.
+		 * <p>By default if this is not set, and Jackson is available,
+		 * the {@link #jackson2JsonEncoder} override is used instead.
+		 * Use this method to customize the SSE encoder.
 		 */
 		void serverSentEventEncoder(Encoder<?> encoder);
 	}