diff --git a/s-day03/src/com/inmind/colletions04/Demo11.java b/s-day03/src/com/inmind/colletions04/Demo11.java
new file mode 100644
index 0000000..6470352
--- /dev/null
+++ b/s-day03/src/com/inmind/colletions04/Demo11.java
@@ -0,0 +1,32 @@
+package com.inmind.colletions04;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+
+/*
+Collections的常用方法
+static <T> boolean addAll(Collection<? super T> c, T... elements) 将所有指定的元素添加到指定的集合。
+
+static void shuffle(List<?> list) 使用默认的随机源随机排列指定的列表。
+ */
+public class Demo11 {
+    public static void main(String[] args) {
+        ArrayList<String> list = new ArrayList<>();
+        /*list.add("刘备");
+        list.add("关羽");
+        list.add("张飞");
+        list.add("张飞");*/
+        //static <T> boolean addAll(Collection<? super T> c, T... elements) 将所有指定的元素添加到指定的集合。
+        Collections.addAll(list, "刘备1", "刘备2", "刘备3", "刘备3");
+        System.out.println(list);
+        System.out.println("----------------------");
+        HashSet<String> sets = new HashSet<>();
+        Collections.addAll(sets,  "刘备5", "刘备6", "刘备6","刘备4");
+        System.out.println(sets);
+
+        //static void shuffle(List<?> list) 使用默认的随机源随机排列指定的列表。
+        Collections.shuffle(list);
+        System.out.println(list);
+    }
+}