diff --git a/quickstart.md b/quickstart.md
index f75107a1..ca1432e7 100644
--- a/quickstart.md
+++ b/quickstart.md
@@ -1,5 +1,7 @@
 # easyexcel核心功能
 ## 目录
+### 前言
+读写的对象都用到了[Lombok](https://www.projectlombok.org/),他会自动生成`get`,`set` ，如果不需要自己创建对象并生成`get`,`set` 。
 ### 读
 DEMO代码地址：[https://github.com/alibaba/easyexcel/blob/master/src/test/java/com/alibaba/easyexcel/demo/read/ReadTest.java](/src/test/java/com/alibaba/easyexcel/test/demo/read/ReadTest.java)
 * [最简单的读](#simpleRead)
diff --git a/src/main/java/com/alibaba/excel/metadata/BasicParameter.java b/src/main/java/com/alibaba/excel/metadata/BasicParameter.java
index dfcf7829..89d78511 100644
--- a/src/main/java/com/alibaba/excel/metadata/BasicParameter.java
+++ b/src/main/java/com/alibaba/excel/metadata/BasicParameter.java
@@ -1,6 +1,5 @@
 package com.alibaba.excel.metadata;
 
-import java.util.ArrayList;
 import java.util.List;
 
 import com.alibaba.excel.converters.Converter;
@@ -22,7 +21,7 @@ public class BasicParameter {
     /**
      * Custom type conversions override the default
      */
-    private List<Converter> customConverterList = new ArrayList<Converter>();
+    private List<Converter> customConverterList;
     /**
      * Automatic trim includes sheet name and content
      */
diff --git a/src/main/java/com/alibaba/excel/util/BooleanUtils.java b/src/main/java/com/alibaba/excel/util/BooleanUtils.java
index afd1495d..c09506ba 100644
--- a/src/main/java/com/alibaba/excel/util/BooleanUtils.java
+++ b/src/main/java/com/alibaba/excel/util/BooleanUtils.java
@@ -10,6 +10,8 @@ public class BooleanUtils {
     private static final String TRUE_NUMBER = "1";
     private static final String FALSE_NUMBER = "0";
 
+    private BooleanUtils() {}
+
     /**
      * String to boolean
      *
diff --git a/src/main/java/com/alibaba/excel/util/CollectionUtils.java b/src/main/java/com/alibaba/excel/util/CollectionUtils.java
index fff57ff7..f413be17 100644
--- a/src/main/java/com/alibaba/excel/util/CollectionUtils.java
+++ b/src/main/java/com/alibaba/excel/util/CollectionUtils.java
@@ -5,11 +5,13 @@ import java.util.Map;
 
 /**
  * Collection utils
- * 
+ *
  * @author jipengfei
  */
 public class CollectionUtils {
 
+    private CollectionUtils() {}
+
     public static boolean isEmpty(Collection<?> collection) {
         return (collection == null || collection.isEmpty());
     }
diff --git a/src/main/java/com/alibaba/excel/util/FileUtils.java b/src/main/java/com/alibaba/excel/util/FileUtils.java
index 717ddfe3..9738b50d 100644
--- a/src/main/java/com/alibaba/excel/util/FileUtils.java
+++ b/src/main/java/com/alibaba/excel/util/FileUtils.java
@@ -25,6 +25,8 @@ public class FileUtils {
     private static final String CACHE = "excache";
     private static final int WRITE_BUFF_SIZE = 8192;
 
+    private FileUtils() {}
+
     /**
      * Reads the contents of a file into a byte array. * The file is always closed.
      *
diff --git a/src/main/java/com/alibaba/excel/util/IoUtils.java b/src/main/java/com/alibaba/excel/util/IoUtils.java
index 9405c91d..d5905117 100644
--- a/src/main/java/com/alibaba/excel/util/IoUtils.java
+++ b/src/main/java/com/alibaba/excel/util/IoUtils.java
@@ -17,6 +17,8 @@ public class IoUtils {
      */
     private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
 
+    private IoUtils() {}
+
     /**
      * Gets the contents of an InputStream as a byte[].
      *
diff --git a/src/main/java/com/alibaba/excel/util/PositionUtils.java b/src/main/java/com/alibaba/excel/util/PositionUtils.java
index 31510408..090bbdfa 100644
--- a/src/main/java/com/alibaba/excel/util/PositionUtils.java
+++ b/src/main/java/com/alibaba/excel/util/PositionUtils.java
@@ -5,6 +5,8 @@ package com.alibaba.excel.util;
  */
 public class PositionUtils {
 
+    private PositionUtils() {}
+
     public static int getRow(String currentCellIndex) {
         int row = 0;
         if (currentCellIndex != null) {
diff --git a/src/main/java/com/alibaba/excel/util/StringUtils.java b/src/main/java/com/alibaba/excel/util/StringUtils.java
index 8210a190..25ed127d 100644
--- a/src/main/java/com/alibaba/excel/util/StringUtils.java
+++ b/src/main/java/com/alibaba/excel/util/StringUtils.java
@@ -2,11 +2,13 @@ package com.alibaba.excel.util;
 
 /**
  * String utils
- * 
+ *
  * @author jipengfei
  */
 public class StringUtils {
 
+    private StringUtils() {}
+
     public static boolean isEmpty(Object str) {
         return (str == null || "".equals(str));
     }
diff --git a/src/main/java/com/alibaba/excel/util/StyleUtil.java b/src/main/java/com/alibaba/excel/util/StyleUtil.java
index 3031048e..d0e1bd32 100644
--- a/src/main/java/com/alibaba/excel/util/StyleUtil.java
+++ b/src/main/java/com/alibaba/excel/util/StyleUtil.java
@@ -17,6 +17,8 @@ import com.alibaba.excel.write.metadata.style.WriteFont;
  */
 public class StyleUtil {
 
+    private StyleUtil() {}
+
     /**
      * @param workbook
      * @return
diff --git a/src/main/java/com/alibaba/excel/util/WorkBookUtil.java b/src/main/java/com/alibaba/excel/util/WorkBookUtil.java
index 1fa78348..b9579b17 100644
--- a/src/main/java/com/alibaba/excel/util/WorkBookUtil.java
+++ b/src/main/java/com/alibaba/excel/util/WorkBookUtil.java
@@ -22,6 +22,8 @@ import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
  */
 public class WorkBookUtil {
 
+    private WorkBookUtil() {}
+
     public static Workbook createWorkBook(WriteWorkbookHolder writeWorkbookHolder)
         throws IOException, InvalidFormatException {
         if (ExcelTypeEnum.XLSX.equals(writeWorkbookHolder.getExcelType())) {