重写主流程，代码更加优雅 测试完毕

src/main/java/com/alibaba/excel/context/AnalysisContext.java

@@ -88,7 +88,7 @@ public interface AnalysisContext {
     /**
      * Data that the customer needs to read
      *
-     * @return
+     * @param readSheetList
      */
     void readSheetList(List<ReadSheet> readSheetList);
 

src/main/java/com/alibaba/excel/write/executor/ExcelWriteAddExecutor.java

@@ -37,7 +37,7 @@ public class ExcelWriteAddExecutor extends AbstractExcelWriteExecutor {
 
     public void add(List data) {
         if (CollectionUtils.isEmpty(data)) {
-            return;
+            data = new ArrayList();
         }
         WriteSheetHolder writeSheetHolder = writeContext.writeSheetHolder();
         int newRowIndex = writeSheetHolder.getNewRowIndexAndStartDoWrite();

src/main/java/com/alibaba/excel/write/executor/ExcelWriteFillExecutor.java

@@ -84,6 +84,9 @@ public class ExcelWriteFillExecutor extends AbstractExcelWriteExecutor {
     }
 
     public void fill(Object data, FillConfig fillConfig) {
+        if (data == null) {
+            data = new HashMap<String,Object>(16);
+        }
         if (fillConfig == null) {
             fillConfig = FillConfig.builder().build(true);
         }