DATAJPA-1333 - Minor performance improvements.

Original pull request: #269.

src/main/java/org/springframework/data/jpa/convert/QueryByExamplePredicateBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -18,6 +18,7 @@ package org.springframework.data.jpa.convert;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Set;
 
@@ -91,7 +92,7 @@ public class QueryByExamplePredicateBuilder {
 			return predicates.iterator().next();
 		}
 
-		Predicate[] array = predicates.toArray(new Predicate[predicates.size()]);
+		Predicate[] array = predicates.toArray(new Predicate[0]);
 
 		return matcher.isAllMatching() ? cb.and(array) : cb.or(array);
 	}

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

@@ -187,7 +187,7 @@ public class JpaSort extends Sort {
 	public static <A extends Attribute<T, S>, T, S> Path<T, S> path(A attribute) {
 
 		Assert.notNull(attribute, "Attribute must not be null!");
-		return new Path<T, S>(Arrays.asList(attribute));
+		return new Path<T, S>(Collections.singletonList(attribute));
 	}
 
 	/**
@@ -200,7 +200,7 @@ public class JpaSort extends Sort {
 	public static <P extends PluralAttribute<T, ?, S>, T, S> Path<T, S> path(P attribute) {
 
 		Assert.notNull(attribute, "Attribute must not be null!");
-		return new Path<T, S>(Arrays.asList(attribute));
+		return new Path<T, S>(Collections.singletonList(attribute));
 	}
 
 	/**
@@ -240,7 +240,7 @@ public class JpaSort extends Sort {
 
 		Assert.notEmpty(properties, "Properties must not be empty!");
 
-		List<Order> orders = new ArrayList<Order>();
+		List<Order> orders = new ArrayList<Order>(properties.size());
 
 		for (String property : properties) {
 			orders.add(new JpaOrder(direction, property));
@@ -384,7 +384,7 @@ public class JpaSort extends Sort {
 			Assert.notEmpty(properties, "Properties must not be empty!");
 			Assert.noNullElements(properties, "Properties must not contain null values!");
 
-			List<Order> orders = new ArrayList<Order>();
+			List<Order> orders = new ArrayList<Order>(properties.length);
 
 			for (String property : properties) {
 				orders.add(new JpaOrder(getDirection(), property, getNullHandling(), isIgnoreCase(), this.unsafe));

src/main/java/org/springframework/data/jpa/repository/support/Querydsl.java

@@ -148,7 +148,7 @@ public class Querydsl {
 	private <T> JPQLQuery<T> addOrderByFrom(QSort qsort, JPQLQuery<T> query) {
 
 		List<OrderSpecifier<?>> orderSpecifiers = qsort.getOrderSpecifiers();
-		return query.orderBy(orderSpecifiers.toArray(new OrderSpecifier[orderSpecifiers.size()]));
+		return query.orderBy(orderSpecifiers.toArray(new OrderSpecifier[0]));
 	}
 
 	/**

src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -751,12 +751,12 @@ public class SimpleJpaRepository<T, ID extends Serializable>
 	 * @param query must not be {@literal null}.
 	 * @return
 	 */
-	private static Long executeCountQuery(TypedQuery<Long> query) {
+	private static long executeCountQuery(TypedQuery<Long> query) {
 
 		Assert.notNull(query, "TypedQuery must not be null!");
 
 		List<Long> totals = query.getResultList();
-		Long total = 0L;
+		long total = 0L;
 
 		for (Long element : totals) {
 			total += element == null ? 0 : element;

src/main/java/org/springframework/data/jpa/util/BeanDefinitionUtils.java

@@ -71,8 +71,8 @@ public class BeanDefinitionUtils {
 	 */
 	public static Iterable<String> getEntityManagerFactoryBeanNames(ListableBeanFactory beanFactory) {
 
-		Set<String> names = new HashSet<String>();
-		names.addAll(asList(beanNamesForTypeIncludingAncestors(beanFactory, EntityManagerFactory.class, true, false)));
+		String[] beanNames = beanNamesForTypeIncludingAncestors(beanFactory, EntityManagerFactory.class, true, false);
+		Set<String> names = new HashSet<String>(asList(beanNames));
 
 		for (String factoryBeanName : beanNamesForTypeIncludingAncestors(beanFactory,
 				AbstractEntityManagerFactoryBean.class, true, false)) {