Polishing.

Remove unused imports.
Simplify if & switch statements.
Use Set.of, List.of for unmodifiable collections.
Remove redundant usage of semicolon.
Fix broken references in Javadoc.
Fix Typos.
Extend value caching for MongoPersistentProperties.

See: #4555
Original pull request: #4556

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/SessionAwareMethodInterceptor.java

@@ -135,12 +135,8 @@ protected Object decorate(Object target) {
 
 	private static boolean requiresSession(Method method) {
 
-		if (method.getParameterCount() == 0
-				|| !ClassUtils.isAssignable(ClientSession.class, method.getParameterTypes()[0])) {
-			return true;
-		}
-
-		return false;
+		return method.getParameterCount() == 0
+				|| !ClassUtils.isAssignable(ClientSession.class, method.getParameterTypes()[0]);
 	}
 
 	private static Object[] prependSessionToArguments(ClientSession session, MethodInvocation invocation) {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/SessionSynchronization.java

@@ -48,5 +48,5 @@ public enum SessionSynchronization {
 	 *
 	 * @since 3.2.5
 	 */
-	NEVER;
+	NEVER
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/aot/MongoAotPredicates.java

@@ -31,7 +31,7 @@
 public class MongoAotPredicates {
 
 	public static final Predicate<Class<?>> IS_SIMPLE_TYPE = (type) ->  MongoSimpleTypes.HOLDER.isSimpleType(type) || TypeUtils.type(type).isPartOf("org.bson");
-	public static final Predicate<ReactiveLibrary> IS_REACTIVE_LIBARARY_AVAILABLE = (lib) -> ReactiveWrappers.isAvailable(lib);
+	public static final Predicate<ReactiveLibrary> IS_REACTIVE_LIBARARY_AVAILABLE = ReactiveWrappers::isAvailable;
 	public static final Predicate<ClassLoader> IS_SYNC_CLIENT_PRESENT = (classLoader) -> ClassUtils.isPresent("com.mongodb.client.MongoClient", classLoader);
 
 	public static boolean isReactorPresent() {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MappingMongoConverterParser.java

@@ -18,8 +18,6 @@
 import static org.springframework.data.mongodb.config.BeanNames.*;
 
 import java.io.IOException;
-import java.util.Arrays;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -63,7 +61,6 @@
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.util.xml.DomUtils;
-
 import org.w3c.dom.Element;
 
 /**
@@ -97,7 +94,7 @@ public BeanDefinition parse(Element element, ParserContext parserContext) {
 		id = StringUtils.hasText(id) ? id : DEFAULT_CONVERTER_BEAN_NAME;
 
 		String autoIndexCreation = element.getAttribute("auto-index-creation");
-		boolean autoIndexCreationEnabled = StringUtils.hasText(autoIndexCreation) && Boolean.valueOf(autoIndexCreation);
+		boolean autoIndexCreationEnabled = StringUtils.hasText(autoIndexCreation) && Boolean.parseBoolean(autoIndexCreation);
 
 		parserContext.pushContainingComponent(new CompositeComponentDefinition("Mapping Mongo Converter", element));
 
@@ -371,7 +368,7 @@ public NegatingFilter(TypeFilter... filters) {
 
 			Assert.notNull(filters, "TypeFilters must not be null");
 
-			this.delegates = new HashSet<>(Arrays.asList(filters));
+			this.delegates = Set.of(filters);
 		}
 
 		public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoCredentialPropertyEditor.java

@@ -16,9 +16,9 @@
 package org.springframework.data.mongodb.config;
 
 import java.beans.PropertyEditorSupport;
-import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Method;
 import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -228,10 +228,6 @@ private static void verifyUserNamePresent(String[] source) {
 	}
 
 	private static String decodeParameter(String it) {
-		try {
-			return URLDecoder.decode(it, "UTF-8");
-		} catch (UnsupportedEncodingException e) {
-			throw new IllegalArgumentException("o_O UTF-8 not supported", e);
-		}
+		return URLDecoder.decode(it, StandardCharsets.UTF_8);
 	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoDbFactoryParser.java

@@ -18,8 +18,6 @@
 import static org.springframework.data.config.ParsingUtils.*;
 import static org.springframework.data.mongodb.config.MongoParsingUtils.*;
 
-import java.util.Collections;
-import java.util.HashSet;
 import java.util.Set;
 
 import org.springframework.beans.factory.BeanDefinitionStoreException;
@@ -51,16 +49,7 @@
  */
 public class MongoDbFactoryParser extends AbstractBeanDefinitionParser {
 
-	private static final Set<String> MONGO_URI_ALLOWED_ADDITIONAL_ATTRIBUTES;
-
-	static {
-
-		Set<String> mongoUriAllowedAdditionalAttributes = new HashSet<String>();
-		mongoUriAllowedAdditionalAttributes.add("id");
-		mongoUriAllowedAdditionalAttributes.add("write-concern");
-
-		MONGO_URI_ALLOWED_ADDITIONAL_ATTRIBUTES = Collections.unmodifiableSet(mongoUriAllowedAdditionalAttributes);
-	}
+	private static final Set<String> MONGO_URI_ALLOWED_ADDITIONAL_ATTRIBUTES = Set.of("id", "write-concern");
 
 	@Override
 	protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext)

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/AggregationUtil.java

@@ -43,9 +43,9 @@
  */
 class AggregationUtil {
 
-	QueryMapper queryMapper;
-	MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
-	Lazy<AggregationOperationContext> untypedMappingContext;
+	final QueryMapper queryMapper;
+	final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+	final Lazy<AggregationOperationContext> untypedMappingContext;
 
 	AggregationUtil(QueryMapper queryMapper,
 			MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext) {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/BulkOperations.java

@@ -60,7 +60,7 @@ enum BulkMode {
 
 		/** Perform bulk operations in parallel. Processing will continue on errors. */
 		UNORDERED
-	};
+	}
 
 	/**
 	 * Add a single insert to the bulk operation.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ChangeStreamOptions.java

@@ -132,7 +132,7 @@ public static ChangeStreamOptions empty() {
 
 	/**
 	 * Obtain a shiny new {@link ChangeStreamOptionsBuilder} and start defining options in this fancy fluent way. Just
-	 * don't forget to call {@link ChangeStreamOptionsBuilder#build() build()} when your're done.
+	 * don't forget to call {@link ChangeStreamOptionsBuilder#build() build()} when done.
 	 *
 	 * @return new instance of {@link ChangeStreamOptionsBuilder}.
 	 */

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/CursorPreparer.java

@@ -49,7 +49,7 @@ public interface CursorPreparer extends ReadPreferenceAware {
 	FindIterable<Document> prepare(FindIterable<Document> iterable);
 
 	/**
-	 * Apply query specific settings to {@link MongoCollection} and initate a find operation returning a
+	 * Apply query specific settings to {@link MongoCollection} and initiate a find operation returning a
 	 * {@link FindIterable} via the given {@link Function find} function.
 	 *
 	 * @param collection must not be {@literal null}.