Merge pull request Snailclimb#1169 from xiaod-dev/patch-1

fix multiple annotations NPE

Author: Snailclimb

docs/java/new-features/Java8新特性总结.md

@@ -872,6 +872,7 @@ System.out.println(string);     // Nov 03, 2014 - 07:13
 首先定义一个包装类Hints注解用来放置一组具体的Hint注解：
 
 ```java
+@Retention(RetentionPolicy.RUNTIME)
 @interface Hints {
     Hint[] value();
 }