修改模板提示

easyexcel-core/src/main/java/com/alibaba/excel/write/builder/ExcelWriterBuilder.java

@@ -66,7 +66,6 @@ public class ExcelWriterBuilder extends AbstractExcelWriterParameterBuilder<Exce
         return this;
     }
 
-
     public ExcelWriterBuilder excelType(ExcelTypeEnum excelType) {
         writeWorkbook.setExcelType(excelType);
         return this;
@@ -95,21 +94,32 @@ public class ExcelWriterBuilder extends AbstractExcelWriterParameterBuilder<Exce
         return this;
     }
 
+    /**
+     * Template file.
+     * This file is read into memory, excessive cases can lead to OOM.
+     */
     public ExcelWriterBuilder withTemplate(InputStream templateInputStream) {
         writeWorkbook.setTemplateInputStream(templateInputStream);
         return this;
     }
 
+    /**
+     * Template file.
+     * This file is read into memory, excessive cases can lead to OOM.
+     */
     public ExcelWriterBuilder withTemplate(File templateFile) {
         writeWorkbook.setTemplateFile(templateFile);
         return this;
     }
 
+    /**
+     * Template file.
+     * This file is read into memory, excessive cases can lead to OOM.
+     */
     public ExcelWriterBuilder withTemplate(String pathName) {
         return withTemplate(new File(pathName));
     }
 
-
     public ExcelWriter build() {
         return new ExcelWriter(writeWorkbook);
     }

easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/WriteWorkbook.java

@@ -49,7 +49,8 @@ public class WriteWorkbook extends WriteBasicParameter {
     private InputStream templateInputStream;
 
     /**
-     * Template file
+     * Template file.
+     * This file is read into memory, excessive cases can lead to OOM.
      * <p>
      * If 'inputStream' and 'file' all not empty, file first
      */
@@ -66,7 +67,6 @@ public class WriteWorkbook extends WriteBasicParameter {
      * Whether the encryption
      * <p>
      * WARRING:Encryption is when the entire file is read into memory, so it is very memory intensive.
-     *
      */
     private String password;
     /**

easyexcel-test/src/test/java/com/alibaba/easyexcel/test/demo/write/WriteTest.java

@@ -401,6 +401,7 @@ public class WriteTest {
         String templateFileName = TestFileUtil.getPath() + "demo" + File.separator + "demo.xlsx";
         String fileName = TestFileUtil.getPath() + "templateWrite" + System.currentTimeMillis() + ".xlsx";
         // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
+        // 这里要注意 withTemplate 的模板文件会全量存储在内存里面，所以尽量不要用于追加文件，如果文件模板文件过大会OOM
         EasyExcel.write(fileName, DemoData.class).withTemplate(templateFileName).sheet().doWrite(data());
     }