diff --git a/panda-beans/src/main/java/org/panda/beans/util/BeanUtil.java b/panda-beans/src/main/java/org/panda/beans/util/BeanUtil.java
index 04888d5..cefd4dd 100644
--- a/panda-beans/src/main/java/org/panda/beans/util/BeanUtil.java
+++ b/panda-beans/src/main/java/org/panda/beans/util/BeanUtil.java
@@ -1,6 +1,7 @@
 package org.panda.beans.util;
 
 
+import com.sun.tools.javac.util.Assert;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -27,8 +28,8 @@ public class BeanUtil {
      */
     public static List<Field> getAllField(Class clazz){
         Field[] fields = getField(clazz);
-        List<Field> fieldList = new ArrayList<>();
         Field[] superFields = getSuperField(clazz);
+        List<Field> fieldList = new ArrayList<>(fields.length+superFields.length);
         if (superFields!=null&&superFields.length>0){
             for (Field field:superFields) {
                 fieldList.add(field);
@@ -217,6 +218,7 @@ public class BeanUtil {
      */
     public static  <T> T instantiateClass(Class<T> clazz){
         T t = null;
+        Assert.checkNonNull(clazz);
         try {
             t = clazz.newInstance();
         } catch (InstantiationException e) {
@@ -237,6 +239,7 @@ public class BeanUtil {
      */
     public static  <T> T instantiateClass(Class<T> clazz,Object... params){
         T t = null;
+        Assert.checkNonNull(clazz);
         Class[] classes = new Class[params.length];
         for (int i=0;i<params.length;i++){
             classes[i] = params[i].getClass();