Polishing.

A round of minor code style improvements.

Original Pull Request: #3695

Author: christophstrobl

spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java

@@ -281,14 +281,14 @@ public <A extends Attribute<S, U>, U> Path<S, U> dot(A attribute) {
 		 * @return
 		 */
 		public <P extends PluralAttribute<S, ?, U>, U> Path<S, U> dot(P attribute) {
-			return new Path<S, U>(add(attribute));
+			return new Path<>(add(attribute));
 		}
 
 		private List<Attribute<?, ?>> add(Attribute<?, ?> attribute) {
 
 			Assert.notNull(attribute, "Attribute must not be null");
 
-			List<Attribute<?, ?>> newAttributes = new ArrayList<Attribute<?, ?>>(attributes.size() + 1);
+			List<Attribute<?, ?>> newAttributes = new ArrayList<>(attributes.size() + 1);
 			newAttributes.addAll(attributes);
 			newAttributes.add(attribute);
 			return newAttributes;

spring-data-jpa/src/main/java/org/springframework/data/jpa/mapping/JpaPersistentPropertyImpl.java

@@ -57,13 +57,9 @@ class JpaPersistentPropertyImpl extends AnnotationBasedPersistentProperty<JpaPer
 
 	static {
 
-		Set<Class<? extends Annotation>> annotations = new HashSet<>();
-		annotations.add(OneToMany.class);
-		annotations.add(OneToOne.class);
-		annotations.add(ManyToMany.class);
-		annotations.add(ManyToOne.class);
+		Set<Class<? extends Annotation>> annotations;
 
-		ASSOCIATION_ANNOTATIONS = Collections.unmodifiableSet(annotations);
+        ASSOCIATION_ANNOTATIONS = Set.of(OneToMany.class, OneToOne.class, ManyToMany.class, ManyToOne.class);
 
 		annotations = new HashSet<>();
 		annotations.add(Id.class);
@@ -107,7 +103,7 @@ public JpaPersistentPropertyImpl(JpaMetamodel metamodel, Property property,
 		this.associationTargetType = detectAssociationTargetType();
 		this.updateable = detectUpdatability();
 
-		this.isIdProperty = Lazy.of(() -> ID_ANNOTATIONS.stream().anyMatch(it -> isAnnotationPresent(it)) //
+		this.isIdProperty = Lazy.of(() -> ID_ANNOTATIONS.stream().anyMatch(this::isAnnotationPresent) //
 				|| metamodel.isSingleIdAttribute(getOwner().getType(), getName(), getType()));
 		this.isEntity = Lazy.of(() -> metamodel.isMappedType(getActualType()));
 	}

spring-data-jpa/src/main/java/org/springframework/data/jpa/projection/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * JPA specific support projection support.
+ */
+@org.springframework.lang.NonNullApi
+package org.springframework.data.jpa.projection;

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/AbstractStringBasedJpaQuery.java

@@ -93,9 +93,7 @@ public AbstractStringBasedJpaQuery(JpaQueryMethod method, EntityManager em, Stri
 			return query.deriveCountQuery(method.getCountQueryProjection());
 		});
 
-		this.countParameterBinder = Lazy.of(() -> {
-			return this.createBinder(this.countQuery.get());
-		});
+		this.countParameterBinder = Lazy.of(() -> this.createBinder(this.countQuery.get()));
 
 		this.queryRewriter = queryRewriter;
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/JSqlParserQueryEnhancer.java

@@ -98,7 +98,8 @@ public JSqlParserQueryEnhancer(DeclaredQuery query) {
 	/**
 	 * Parses a query string with JSqlParser.
 	 *
-	 * @param query the query to parse
+	 * @param sql the query to parse
+	 * @param classOfT the query to parse
 	 * @return the parsed query
 	 */
 	static <T extends Statement> T parseStatement(String sql, Class<T> classOfT) {
@@ -502,7 +503,7 @@ private static boolean onlyASingleColumnProjection(List<SelectItem<?>> projectio
 	 * </ul>
 	 */
 	enum ParsedType {
-		DELETE, UPDATE, SELECT, INSERT, MERGE, OTHER;
+		DELETE, UPDATE, SELECT, INSERT, MERGE, OTHER
 	}
 
 	/**

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryLookupStrategy.java

@@ -143,7 +143,8 @@ private static class DeclaredQueryLookupStrategy extends AbstractQueryLookupStra
 		 *
 		 * @param em must not be {@literal null}.
 		 * @param queryMethodFactory must not be {@literal null}.
-		 * @param evaluationContextProvider must not be {@literal null}.
+		 * @param delegate must not be {@literal null}.
+		 * @param queryRewriterProvider must not be {@literal null}.
 		 */
 		public DeclaredQueryLookupStrategy(EntityManager em, JpaQueryMethodFactory queryMethodFactory,
 				ValueExpressionDelegate delegate, QueryRewriterProvider queryRewriterProvider) {

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/JpqlQueryBuilder.java

@@ -848,9 +848,7 @@ public String getAlias(Origin source) {
 		 */
 		public String getAlias(Origin source) {
 
-			return aliases.computeIfAbsent(source, it -> JpqlQueryBuilder.getAlias(source.getName(), s -> {
-				return !aliases.containsValue(s);
-			}, () -> "join_" + (counter++)));
+			return aliases.computeIfAbsent(source, it -> JpqlQueryBuilder.getAlias(source.getName(), s -> !aliases.containsValue(s), () -> "join_" + (counter++)));
 		}
 
 		/**

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/KeysetScrollDelegate.java

@@ -138,7 +138,7 @@ public Sort createSort(Sort sort, JpaEntityInformation<?, ?> entity) {
 	}
 
 	/**
-	 * Reverse scrolling variant applying {@link Direction#Backward}. In reverse scrolling, we need to flip directions for
+	 * Reverse scrolling variant applying {@link Direction#BACKWARD}. In reverse scrolling, we need to flip directions for
 	 * the actual query so that we do not get everything from the top position and apply the limit but rather flip the
 	 * sort direction, apply the limit and then reverse the result to restore the actual sort order.
 	 */

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/ParameterBinding.java

@@ -653,7 +653,7 @@ static MethodInvocationArgument ofParameter(@Nullable String name, @Nullable Int
 		/**
 		 * Creates a {@link MethodInvocationArgument} object for {@code position}.
 		 *
-		 * @param position the parameter position (1-based) from the method invocation.
+		 * @param parameter the parameter from the method invocation.
 		 * @return {@link MethodInvocationArgument} object for {@code position}.
 		 */
 		static MethodInvocationArgument ofParameter(Parameter parameter) {

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/ParameterMetadataProvider.java

@@ -273,17 +273,12 @@ public Object prepare(@Nullable Object value) {
 
 			if (String.class.equals(parameterType) && !noWildcards) {
 
-				switch (type) {
-					case STARTING_WITH:
-						return String.format("%s%%", escape.escape(value.toString()));
-					case ENDING_WITH:
-						return String.format("%%%s", escape.escape(value.toString()));
-					case CONTAINING:
-					case NOT_CONTAINING:
-						return String.format("%%%s%%", escape.escape(value.toString()));
-					default:
-						return value;
-				}
+                return switch (type) {
+                    case STARTING_WITH -> String.format("%s%%", escape.escape(value.toString()));
+                    case ENDING_WITH -> String.format("%%%s", escape.escape(value.toString()));
+                    case CONTAINING, NOT_CONTAINING -> String.format("%%%s%%", escape.escape(value.toString()));
+                    default -> value;
+                };
 			}
 
 			return Collection.class.isAssignableFrom(parameterType) //

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/QueryParameterSetterFactory.java

@@ -93,7 +93,6 @@ static QueryParameterSetterFactory forSynthetic() {
 	 *
 	 * @param parser must not be {@literal null}.
 	 * @param evaluationContextProvider must not be {@literal null}.
-	 * @param parameters must not be {@literal null}.
 	 * @return a {@link QueryParameterSetterFactory} that can handle
 	 *         {@link org.springframework.expression.spel.standard.SpelExpression}s.
 	 */
@@ -170,7 +169,6 @@ private static class ExpressionBasedQueryParameterSetterFactory extends QueryPar
 		/**
 		 * @param parser must not be {@literal null}.
 		 * @param evaluationContextProvider must not be {@literal null}.
-		 * @param parameters must not be {@literal null}.
 		 */
 		ExpressionBasedQueryParameterSetterFactory(ValueExpressionParser parser,
 				ValueEvaluationContextProvider evaluationContextProvider) {

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/QueryTokenStream.java

@@ -46,20 +46,23 @@ static QueryTokenStream empty() {
 
 	/**
 	 * Creates a QueryTokenStream from a {@link QueryToken}.
+	 * @since 4.0
 	 */
 	static QueryTokenStream from(QueryToken token) {
 		return QueryRenderer.from(Collections.singletonList(token));
 	}
 
 	/**
 	 * Creates an token QueryRenderer from an AST {@link TerminalNode}.
+	 * @since 4.0
 	 */
 	static QueryTokenStream ofToken(TerminalNode node) {
 		return from(QueryTokens.token(node));
 	}
 
 	/**
 	 * Creates an token QueryRenderer from an AST {@link Token}.
+	 * @since 4.0
 	 */
 	static QueryTokenStream ofToken(Token node) {
 		return from(QueryTokens.token(node));
@@ -148,6 +151,7 @@ default QueryToken getFirst() {
 
 	/**
 	 * @return the required first query token or throw {@link java.util.NoSuchElementException} if empty.
+	 * @since 4.0
 	 */
 	default QueryToken getRequiredFirst() {
 
@@ -170,6 +174,7 @@ default QueryToken getLast() {
 
 	/**
 	 * @return the required last query token or throw {@link java.util.NoSuchElementException} if empty.
+	 * @since 4.0
 	 */
 	default QueryToken getRequiredLast() {
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/SimpleJpaQuery.java

@@ -84,23 +84,13 @@ private void validateQuery(String query, String errorMessage, Object... argument
 			return;
 		}
 
-		EntityManager validatingEm = null;
-
-		try {
-			validatingEm = getEntityManager().getEntityManagerFactory().createEntityManager();
-			validatingEm.createQuery(query);
-
-		} catch (RuntimeException e) {
-
-			// Needed as there's ambiguities in how an invalid query string shall be expressed by the persistence provider
-			// https://java.net/projects/jpa-spec/lists/jsr338-experts/archive/2012-07/message/17
-			throw new IllegalArgumentException(String.format(errorMessage, arguments), e);
-
-		} finally {
-
-			if (validatingEm != null) {
-				validatingEm.close();
-			}
-		}
+        try (EntityManager validatingEm = getEntityManager().getEntityManagerFactory().createEntityManager()) {
+            validatingEm.createQuery(query);
+        } catch (RuntimeException e) {
+
+            // Needed as there's ambiguities in how an invalid query string shall be expressed by the persistence provider
+            // https://java.net/projects/jpa-spec/lists/jsr338-experts/archive/2012-07/message/17
+            throw new IllegalArgumentException(String.format(errorMessage, arguments), e);
+        }
 	}
 }

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/StringQuery.java

@@ -304,25 +304,17 @@ String parseParameterBindingsOfQueryIntoBindingsAndReturnCleanedQuery(String que
 						: ParameterOrigin.ofExpression(expression);
 
 				BindingIdentifier targetBinding = queryParameter;
-				Function<BindingIdentifier, ParameterBinding> bindingFactory;
-				switch (ParameterBindingType.of(typeSource)) {
+				Function<BindingIdentifier, ParameterBinding> bindingFactory = switch (ParameterBindingType.of(typeSource)) {
+                    case LIKE -> {
 
-					case LIKE:
+                        Type likeType = LikeParameterBinding.getLikeTypeFrom(matcher.group(2));
+                        yield (identifier) -> new LikeParameterBinding(identifier, origin, likeType);
+                    }
+                    case IN -> (identifier) -> new InParameterBinding(identifier, origin); // fall-through we don't need a special parameter queryParameter for the given parameter.
+                    default -> (identifier) -> new ParameterBinding(identifier, origin);
+                };
 
-						Type likeType = LikeParameterBinding.getLikeTypeFrom(matcher.group(2));
-						bindingFactory = (identifier) -> new LikeParameterBinding(identifier, origin, likeType);
-						break;
-
-					case IN:
-						bindingFactory = (identifier) -> new InParameterBinding(identifier, origin);
-						break;
-
-					case AS_IS: // fall-through we don't need a special parameter queryParameter for the given parameter.
-					default:
-						bindingFactory = (identifier) -> new ParameterBinding(identifier, origin);
-				}
-
-				if (origin.isExpression()) {
+                if (origin.isExpression()) {
 					parameterBindings.register(bindingFactory.apply(queryParameter));
 				} else {
 					targetBinding = parameterBindings.register(queryParameter, origin, bindingFactory);

spring-data-jpa/src/main/java/org/springframework/data/jpa/support/ClasspathScanningPersistenceUnitPostProcessor.java

@@ -193,7 +193,7 @@ private Set<String> scanForMappingFileLocations() {
 	 * @param uri
 	 * @return
 	 */
-	private static String getResourcePath(URI uri) throws IOException {
+	private static String getResourcePath(URI uri) {
 
 		if (uri.isOpaque()) {
 			// e.g. jar:file:/foo/lib/somelib.jar!/com/acme/orm.xml