Merge pull request #1857 from cyunrei/fix_typo

修正 java 8 新特性中 Comparator 接口示例代码变量名的错误

docs/java/new-features/java8-common-new-features.md

@@ -142,8 +142,8 @@ public int compare(Integer o1, Integer o2) {
 //Lambda
 Collections.sort(strings, (Integer o1, Integer o2) -> o1 - o2);
 //分解开
-Comparator<Integer> comperator = (Integer o1, Integer o2) -> o1 - o2;
-Collections.sort(strings, comperator);
+Comparator<Integer> comparator = (Integer o1, Integer o2) -> o1 - o2;
+Collections.sort(strings, comparator);
 ```
 
 **3.`Listener` 接口**