From ed3a61538ebd776023168405befada19fe6e35ac Mon Sep 17 00:00:00 2001
From: Matt Bishop <matthew.bishop@elasticpath.com>
Date: Mon, 30 May 2016 10:47:28 -0700
Subject: [PATCH] SHIRO-566 Use Collections wrappers to save memory and cpu.

---
 .../org/apache/shiro/util/CollectionUtils.java    | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/lang/src/main/java/org/apache/shiro/util/CollectionUtils.java b/lang/src/main/java/org/apache/shiro/util/CollectionUtils.java
index 4b9c8e4788..67e990139d 100644
--- a/lang/src/main/java/org/apache/shiro/util/CollectionUtils.java
+++ b/lang/src/main/java/org/apache/shiro/util/CollectionUtils.java
@@ -18,7 +18,7 @@
  */
 package org.apache.shiro.util;
 
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashSet;
@@ -39,6 +39,11 @@ public static <E> Set<E> asSet(E... elements) {
         if (elements == null || elements.length == 0) {
             return Collections.emptySet();
         }
+
+        if (elements.length == 1) {
+            return Collections.singleton(elements[0]);
+        }
+
         LinkedHashSet<E> set = new LinkedHashSet<E>(elements.length * 4 / 3 + 1);
         Collections.addAll(set, elements);
         return set;
@@ -97,11 +102,9 @@ public static <E> List<E> asList(E... elements) {
         if (elements == null || elements.length == 0) {
             return Collections.emptyList();
         }
-        // Avoid integer overflow when a large array is passed in
-        int capacity = computeListCapacity(elements.length);
-        ArrayList<E> list = new ArrayList<E>(capacity);
-        Collections.addAll(list, elements);
-        return list;
+
+        // Integer overflow does not occur when a large array is passed in because the list array already exists
+        return Arrays.asList(elements);
     }
 
     /*public static <E> Deque<E> asDeque(E... elements) {