diff --git a/boot-service/src/main/java/com/xwbing/demo/Ademo.java b/boot-service/src/main/java/com/xwbing/demo/Ademo.java
index d1f4550..3ac6c98 100644
--- a/boot-service/src/main/java/com/xwbing/demo/Ademo.java
+++ b/boot-service/src/main/java/com/xwbing/demo/Ademo.java
@@ -1,5 +1,8 @@
 package com.xwbing.demo;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * 项目名称: boot-module-demo
  * 创建时间: 2018/1/23 14:45
@@ -8,14 +11,11 @@ package com.xwbing.demo;
  */
 public class Ademo {
     public static void main(String[] args) {
-      double a=10;
-      a=a+a*0.2;
-        System.out.println(a);
+        Map<String, String> aa = new HashMap<>();
+        aa.put(null,"aa");
+        String s = aa.get(null);
+        System.out.println(s);
 
     }
-    public static String aa(String aa){
-        aa="aa";
-        return aa;
-    }
 
 }
diff --git a/boot-service/src/main/java/com/xwbing/demo/ForEachMap.java b/boot-service/src/main/java/com/xwbing/demo/ForEachMap.java
index d835c3d..73200a2 100644
--- a/boot-service/src/main/java/com/xwbing/demo/ForEachMap.java
+++ b/boot-service/src/main/java/com/xwbing/demo/ForEachMap.java
@@ -21,6 +21,7 @@ import java.util.Set;
 public class ForEachMap {
     public static void main(String[] args) {
         Map<String, Integer> map = new HashMap<String, Integer>() {
+            private static final long serialVersionUID = 2832423252566685445L;
             {
                 put("语文", 99);
                 put("数学", 98);