Consistent use of ClassUtils.toClassArray (and related polishing)

spring-core/src/main/java/org/springframework/util/ClassUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -1064,11 +1064,12 @@ public abstract class ClassUtils {
 	}
 
 	/**
-	 * Copy the given Collection into a Class array.
-	 * The Collection must contain Class elements only.
-	 * @param collection the Collection to copy
-	 * @return the Class array ({@code null} if the passed-in
-	 * Collection was {@code null})
+	 * Copy the given {@code Collection} into a {@code Class} array.
+	 * <p>The {@code Collection} must contain {@code Class} elements only.
+	 * @param collection the {@code Collection} to copy
+	 * @return the {@code Class} array
+	 * @since 3.1
+	 * @see StringUtils#toStringArray
 	 */
 	public static Class<?>[] toClassArray(Collection<Class<?>> collection) {
 		if (collection == null) {
@@ -1109,8 +1110,7 @@ public abstract class ClassUtils {
 	 * @return all interfaces that the given object implements as an array
 	 */
 	public static Class<?>[] getAllInterfacesForClass(Class<?> clazz, ClassLoader classLoader) {
-		Set<Class<?>> ifcs = getAllInterfacesForClassAsSet(clazz, classLoader);
-		return ifcs.toArray(new Class<?>[ifcs.size()]);
+		return toClassArray(getAllInterfacesForClassAsSet(clazz, classLoader));
 	}
 
 	/**
@@ -1150,12 +1150,13 @@ public abstract class ClassUtils {
 			return Collections.<Class<?>>singleton(clazz);
 		}
 		Set<Class<?>> interfaces = new LinkedHashSet<Class<?>>();
-		while (clazz != null) {
-			Class<?>[] ifcs = clazz.getInterfaces();
+		Class<?> current = clazz;
+		while (current != null) {
+			Class<?>[] ifcs = current.getInterfaces();
 			for (Class<?> ifc : ifcs) {
 				interfaces.addAll(getAllInterfacesForClassAsSet(ifc, classLoader));
 			}
-			clazz = clazz.getSuperclass();
+			current = current.getSuperclass();
 		}
 		return interfaces;
 	}

spring-core/src/main/java/org/springframework/util/StringUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -824,13 +824,9 @@ public abstract class StringUtils {
 			return array1;
 		}
 
-		List<String> result = new ArrayList<String>();
+		Set<String> result = new LinkedHashSet<String>();
 		result.addAll(Arrays.asList(array1));
-		for (String str : array2) {
-			if (!result.contains(str)) {
-				result.add(str);
-			}
-		}
+		result.addAll(Arrays.asList(array2));
 		return toStringArray(result);
 	}
 
@@ -858,7 +854,6 @@ public abstract class StringUtils {
 		if (collection == null) {
 			return null;
 		}
-
 		return collection.toArray(new String[collection.size()]);
 	}
 
@@ -872,9 +867,7 @@ public abstract class StringUtils {
 		if (enumeration == null) {
 			return null;
 		}
-
-		List<String> list = Collections.list(enumeration);
-		return list.toArray(new String[list.size()]);
+		return toStringArray(Collections.list(enumeration));
 	}
 
 	/**
@@ -939,10 +932,9 @@ public abstract class StringUtils {
 
 	/**
 	 * Take an array of strings and split each element based on the given delimiter.
-	 * A {@code Properties} instance is then generated, with the left of the
-	 * delimiter providing the key, and the right of the delimiter providing the value.
-	 * <p>Will trim both the key and value before adding them to the
-	 * {@code Properties} instance.
+	 * A {@code Properties} instance is then generated, with the left of the delimiter
+	 * providing the key, and the right of the delimiter providing the value.
+	 * <p>Will trim both the key and value before adding them to the {@code Properties}.
 	 * @param array the array to process
 	 * @param delimiter to split each element using (typically the equals symbol)
 	 * @return a {@code Properties} instance representing the array contents,