fix bug

.idea/workspace.xml

@@ -4,7 +4,9 @@
     <list default="true" id="e4baaf01-a2c2-445d-98a1-9f4c50c148cf" name="Default Changelist" comment="">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/src/main/java/com/lz/common/utils/ExcelUtil.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/lz/common/utils/ExcelUtil.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/com/lz/modules/app/controller/StaffController.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/com/lz/modules/app/controller/StaffController.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/target/classes/com/lz/common/utils/ExcelUtil$1.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/lz/common/utils/ExcelUtil$1.class" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/target/classes/com/lz/common/utils/ExcelUtil.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/lz/common/utils/ExcelUtil.class" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/target/classes/com/lz/modules/app/controller/StaffController.class" beforeDir="false" afterPath="$PROJECT_DIR$/target/classes/com/lz/modules/app/controller/StaffController.class" afterDir="false" />
     </list>
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
     <option name="SHOW_DIALOG" value="false" />
@@ -156,7 +158,7 @@
       <workItem from="1588161274115" duration="1691000" />
       <workItem from="1588163384182" duration="74761000" />
       <workItem from="1588936950753" duration="95758000" />
-      <workItem from="1590038091791" duration="10294000" />
+      <workItem from="1590038091791" duration="10974000" />
     </task>
     <servers />
   </component>
@@ -224,6 +226,21 @@
           <line>212</line>
           <option name="timeStamp" value="74" />
         </line-breakpoint>
+        <line-breakpoint enabled="true" type="java-line">
+          <url>file://$PROJECT_DIR$/src/main/java/com/lz/modules/app/controller/StaffController.java</url>
+          <line>249</line>
+          <option name="timeStamp" value="78" />
+        </line-breakpoint>
+        <line-breakpoint enabled="true" type="java-line">
+          <url>file://$PROJECT_DIR$/src/main/java/com/lz/common/utils/ExcelUtil.java</url>
+          <line>184</line>
+          <option name="timeStamp" value="80" />
+        </line-breakpoint>
+        <line-breakpoint enabled="true" type="java-line">
+          <url>file://$PROJECT_DIR$/src/main/java/com/lz/common/utils/ExcelUtil.java</url>
+          <line>205</line>
+          <option name="timeStamp" value="81" />
+        </line-breakpoint>
       </breakpoints>
     </breakpoint-manager>
   </component>

src/main/java/com/lz/common/utils/ExcelUtil.java

@@ -564,6 +564,7 @@ public class ExcelUtil {
             }
         }
 
+        if (dataSet!=null) {
             // 遍历集合数据，产生数据行
             Iterator<T> it = dataSet.iterator();
             int index = 0;
@@ -618,6 +619,9 @@ public class ExcelUtil {
                     logger.error(e.toString(), e);
                 }
             }
+        }
+
+
         // 设定自动宽度
         for (int i = 0; i < headers.size(); i++) {
             sheet.autoSizeColumn(i);