diff --git a/src/main/java/com/lq/cms/web/LoginController.java b/src/main/java/com/lq/cms/web/LoginController.java
index 3c90b64..97591d4 100644
--- a/src/main/java/com/lq/cms/web/LoginController.java
+++ b/src/main/java/com/lq/cms/web/LoginController.java
@@ -30,6 +30,7 @@ import java.awt.image.BufferedImage;
 import java.io.IOException;
 import java.util.Map;
 import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
 
 /**管理后台登陆页
  * Created by qi on 2017/7/16.
@@ -121,7 +122,7 @@ public class LoginController extends BaseController{
     public void getAuthCode(HttpServletRequest request, HttpServletResponse response,HttpSession session)throws IOException{
         int width=63;
         int height=37;
-        Random random=new Random();
+        ThreadLocalRandom threadLocalRandom=ThreadLocalRandom.current();
         //设置response头部信息
         //禁止缓存
         response.setHeader("Pragma","No-cache");
@@ -138,18 +139,18 @@ public class LoginController extends BaseController{
         //绘制干扰线
         for (int i=0;i<40;i++){
             g.setColor(getRandColor(130,200));
-            int x=random.nextInt(width);
-            int y=random.nextInt(height);
-            int x1=random.nextInt(12);
-            int y1=random.nextInt(12);
+            int x=threadLocalRandom.nextInt(width);
+            int y=threadLocalRandom.nextInt(height);
+            int x1=threadLocalRandom.nextInt(12);
+            int y1=threadLocalRandom.nextInt(12);
             g.drawLine(x,y,x+x1,y+y1);
         }
         //绘制字符
         String strCode="";
         for (int i=0;i<4;i++){
-            String rand=String.valueOf(random.nextInt(10));
+            String rand=String.valueOf(threadLocalRandom.nextInt(10));
             strCode=strCode+rand;
-            g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
+            g.setColor(new Color(20+threadLocalRandom.nextInt(110),20+threadLocalRandom.nextInt(110),20+threadLocalRandom.nextInt(110)));
             g.drawString(rand,13*i+6,28);
         }
         //将字符保存的session中用于前端的验证
diff --git a/src/main/java/com/lq/code/util/StringUtil.java b/src/main/java/com/lq/code/util/StringUtil.java
index e502971..8cea1e9 100644
--- a/src/main/java/com/lq/code/util/StringUtil.java
+++ b/src/main/java/com/lq/code/util/StringUtil.java
@@ -2,6 +2,7 @@ package com.lq.code.util;
 
 
 import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
 
 /**
  * Created by qi on 2017/8/13.
@@ -55,8 +56,9 @@ public class StringUtil {
      * @return
      */
     public static char  randomChar(int startInt,int range){
-        Random random=new Random();
-        int randomNum=random.nextInt(range-1);
+      //  Random random=new Random();
+        ThreadLocalRandom threadLocalRandom = ThreadLocalRandom.current();
+        int randomNum=threadLocalRandom.nextInt(range-1);
         int randomInt=randomNum+startInt;
         return (char)randomInt ;
     }
@@ -94,8 +96,10 @@ public class StringUtil {
 
     public String randomString(int length,String needRule){
 
-        Random random=new Random();
-        random.nextInt(100);
+//        Random random=new Random();
+        //jdk 1.7 以后用来取代Random,性能会有提升
+        ThreadLocalRandom threadLocalRandom = ThreadLocalRandom.current();
+        threadLocalRandom.nextInt(100);
         char a1='a';
         int i=a1;
 
diff --git a/src/main/resources/spring/spring-shiro.xml b/src/main/resources/spring/spring-shiro.xml
index 3f7e66c..275f374 100644
--- a/src/main/resources/spring/spring-shiro.xml
+++ b/src/main/resources/spring/spring-shiro.xml
@@ -120,9 +120,10 @@
 
     <!--自定义授权和认证的Realm-->
     <bean id="myRealm" class="com.lq.code.interceptor.shiro.ShiroRealm">
-        <!-- 启动认证缓存-->
-        <property name="authenticationCachingEnabled" value="true"/>
-        <property name="authenticationCacheName" value="authenticationCache"/>
+        <!-- 启动认证缓存 默认false-->
+        <property name="authenticationCachingEnabled" value="false"/>
+        <!-- 启动授权缓存 -->
+        <property name="authorizationCachingEnabled" value="false"/>
 
     </bean>