Apply "switch expressions" where applicable

spring-context/src/main/java/org/springframework/format/datetime/standard/DateTimeFormatterFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -139,14 +139,14 @@ public class DateTimeFormatterFactory {
 
 	@Nullable
 	private FormatStyle convertStyleCharacter(char c) {
-		switch (c) {
-			case 'S': return FormatStyle.SHORT;
-			case 'M': return FormatStyle.MEDIUM;
-			case 'L': return FormatStyle.LONG;
-			case 'F': return FormatStyle.FULL;
-			case '-': return null;
-			default: throw new IllegalArgumentException("Invalid style character '" + c + "'");
-		}
+		return switch (c) {
+			case 'S' -> FormatStyle.SHORT;
+			case 'M' -> FormatStyle.MEDIUM;
+			case 'L' -> FormatStyle.LONG;
+			case 'F' -> FormatStyle.FULL;
+			case '-' -> null;
+			default -> throw new IllegalArgumentException("Invalid style character '" + c + "'");
+		};
 	}
 
 	/**
@@ -183,28 +183,12 @@ public class DateTimeFormatterFactory {
 			dateTimeFormatter = DateTimeFormatterUtils.createStrictDateTimeFormatter(this.pattern);
 		}
 		else if (this.iso != null && this.iso != ISO.NONE) {
-			// TODO Use switch expression once spring-javaformat 0.0.30 has been released.
-			// See https://github.com/spring-io/spring-javaformat/issues/300
-			//
-			// dateTimeFormatter = switch (this.iso) {
-			// 	case DATE -> DateTimeFormatter.ISO_DATE;
-			// 	case TIME -> DateTimeFormatter.ISO_TIME;
-			// 	case DATE_TIME -> DateTimeFormatter.ISO_DATE_TIME;
-			// 	default -> throw new IllegalStateException("Unsupported ISO format: " + this.iso);
-			// };
-			switch (this.iso) {
-				case DATE:
-					dateTimeFormatter = DateTimeFormatter.ISO_DATE;
-					break;
-				case TIME:
-					dateTimeFormatter = DateTimeFormatter.ISO_TIME;
-					break;
-				case DATE_TIME:
-					dateTimeFormatter = DateTimeFormatter.ISO_DATE_TIME;
-					break;
-				default:
-					throw new IllegalStateException("Unsupported ISO format: " + this.iso);
-			}
+			dateTimeFormatter = switch (this.iso) {
+				case DATE -> DateTimeFormatter.ISO_DATE;
+				case TIME -> DateTimeFormatter.ISO_TIME;
+				case DATE_TIME -> DateTimeFormatter.ISO_DATE_TIME;
+				default -> throw new IllegalStateException("Unsupported ISO format: " + this.iso);
+			};
 		}
 		else if (this.dateStyle != null && this.timeStyle != null) {
 			dateTimeFormatter = DateTimeFormatter.ofLocalizedDateTime(this.dateStyle, this.timeStyle);

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseConfigurerFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -42,16 +42,12 @@ final class EmbeddedDatabaseConfigurerFactory {
 	public static EmbeddedDatabaseConfigurer getConfigurer(EmbeddedDatabaseType type) throws IllegalStateException {
 		Assert.notNull(type, "EmbeddedDatabaseType is required");
 		try {
-			switch (type) {
-				case HSQL:
-					return HsqlEmbeddedDatabaseConfigurer.getInstance();
-				case H2:
-					return H2EmbeddedDatabaseConfigurer.getInstance();
-				case DERBY:
-					return DerbyEmbeddedDatabaseConfigurer.getInstance();
-				default:
-					throw new UnsupportedOperationException("Embedded database type [" + type + "] is not supported");
-			}
+			return switch (type) {
+				case HSQL -> HsqlEmbeddedDatabaseConfigurer.getInstance();
+				case H2 -> H2EmbeddedDatabaseConfigurer.getInstance();
+				case DERBY -> DerbyEmbeddedDatabaseConfigurer.getInstance();
+				default -> throw new UnsupportedOperationException("Embedded database type [" + type + "] is not supported");
+			};
 		}
 		catch (ClassNotFoundException | NoClassDefFoundError ex) {
 			throw new IllegalStateException("Driver for test database type [" + type + "] is not available", ex);

spring-jdbc/src/main/java/org/springframework/jdbc/support/SQLErrorCodeSQLExceptionTranslator.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.
@@ -64,6 +64,7 @@ import org.springframework.util.function.SupplierUtils;
  * @author Rod Johnson
  * @author Thomas Risberg
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @see SQLErrorCodesFactory
  * @see SQLStateSQLExceptionTranslator
  */
@@ -359,39 +360,45 @@ public class SQLErrorCodeSQLExceptionTranslator extends AbstractFallbackSQLExcep
 
 			// invoke constructor
 			Constructor<?> exceptionConstructor;
-			switch (constructorType) {
-				case MESSAGE_SQL_SQLEX_CONSTRUCTOR:
+			return switch (constructorType) {
+				case MESSAGE_SQL_SQLEX_CONSTRUCTOR -> {
 					Class<?>[] messageAndSqlAndSqlExArgsClass = new Class<?>[] {String.class, String.class, SQLException.class};
 					Object[] messageAndSqlAndSqlExArgs = new Object[] {task, sql, sqlEx};
 					exceptionConstructor = exceptionClass.getConstructor(messageAndSqlAndSqlExArgsClass);
-					return (DataAccessException) exceptionConstructor.newInstance(messageAndSqlAndSqlExArgs);
-				case MESSAGE_SQL_THROWABLE_CONSTRUCTOR:
+					yield (DataAccessException) exceptionConstructor.newInstance(messageAndSqlAndSqlExArgs);
+				}
+				case MESSAGE_SQL_THROWABLE_CONSTRUCTOR -> {
 					Class<?>[] messageAndSqlAndThrowableArgsClass = new Class<?>[] {String.class, String.class, Throwable.class};
 					Object[] messageAndSqlAndThrowableArgs = new Object[] {task, sql, sqlEx};
 					exceptionConstructor = exceptionClass.getConstructor(messageAndSqlAndThrowableArgsClass);
-					return (DataAccessException) exceptionConstructor.newInstance(messageAndSqlAndThrowableArgs);
-				case MESSAGE_SQLEX_CONSTRUCTOR:
+					yield (DataAccessException) exceptionConstructor.newInstance(messageAndSqlAndThrowableArgs);
+				}
+				case MESSAGE_SQLEX_CONSTRUCTOR -> {
 					Class<?>[] messageAndSqlExArgsClass = new Class<?>[] {String.class, SQLException.class};
 					Object[] messageAndSqlExArgs = new Object[] {task + ": " + sqlEx.getMessage(), sqlEx};
 					exceptionConstructor = exceptionClass.getConstructor(messageAndSqlExArgsClass);
-					return (DataAccessException) exceptionConstructor.newInstance(messageAndSqlExArgs);
-				case MESSAGE_THROWABLE_CONSTRUCTOR:
+					yield (DataAccessException) exceptionConstructor.newInstance(messageAndSqlExArgs);
+				}
+				case MESSAGE_THROWABLE_CONSTRUCTOR -> {
 					Class<?>[] messageAndThrowableArgsClass = new Class<?>[] {String.class, Throwable.class};
 					Object[] messageAndThrowableArgs = new Object[] {task + ": " + sqlEx.getMessage(), sqlEx};
 					exceptionConstructor = exceptionClass.getConstructor(messageAndThrowableArgsClass);
-					return (DataAccessException)exceptionConstructor.newInstance(messageAndThrowableArgs);
-				case MESSAGE_ONLY_CONSTRUCTOR:
+					yield (DataAccessException)exceptionConstructor.newInstance(messageAndThrowableArgs);
+				}
+				case MESSAGE_ONLY_CONSTRUCTOR -> {
 					Class<?>[] messageOnlyArgsClass = new Class<?>[] {String.class};
 					Object[] messageOnlyArgs = new Object[] {task + ": " + sqlEx.getMessage()};
 					exceptionConstructor = exceptionClass.getConstructor(messageOnlyArgsClass);
-					return (DataAccessException) exceptionConstructor.newInstance(messageOnlyArgs);
-				default:
+					yield (DataAccessException) exceptionConstructor.newInstance(messageOnlyArgs);
+				}
+				default -> {
 					if (logger.isWarnEnabled()) {
 						logger.warn("Unable to find appropriate constructor of custom exception class [" +
 								exceptionClass.getName() + "]");
 					}
-					return null;
+					yield null;
 				}
+			};
 		}
 		catch (Throwable ex) {
 			if (logger.isWarnEnabled()) {

spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -179,16 +179,11 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 	public Message toMessage(Object object, Session session) throws JMSException, MessageConversionException {
 		Message message;
 		try {
-			switch (this.targetType) {
-				case TEXT:
-					message = mapToTextMessage(object, session, this.objectMapper.writer());
-					break;
-				case BYTES:
-					message = mapToBytesMessage(object, session, this.objectMapper.writer());
-					break;
-				default:
-					message = mapToMessage(object, session, this.objectMapper.writer(), this.targetType);
-			}
+			message = switch (this.targetType) {
+				case TEXT -> mapToTextMessage(object, session, this.objectMapper.writer());
+				case BYTES -> mapToBytesMessage(object, session, this.objectMapper.writer());
+				default -> mapToMessage(object, session, this.objectMapper.writer(), this.targetType);
+			};
 		}
 		catch (IOException ex) {
 			throw new MessageConversionException("Could not map JSON object [" + object + "]", ex);
@@ -242,16 +237,11 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 
 		Message message;
 		try {
-			switch (this.targetType) {
-				case TEXT:
-					message = mapToTextMessage(object, session, objectWriter);
-					break;
-				case BYTES:
-					message = mapToBytesMessage(object, session, objectWriter);
-					break;
-				default:
-					message = mapToMessage(object, session, objectWriter, this.targetType);
-			}
+			message = switch (this.targetType) {
+				case TEXT -> mapToTextMessage(object, session, objectWriter);
+				case BYTES -> mapToBytesMessage(object, session, objectWriter);
+				default -> mapToMessage(object, session, objectWriter, this.targetType);
+			};
 		}
 		catch (IOException ex) {
 			throw new MessageConversionException("Could not map JSON object [" + object + "]", ex);