From eb8c7d544617a17d630aae28c11ff8ef697938ba Mon Sep 17 00:00:00 2001
From: Jiaju Zhuang <zhuangjiaju@qq.com>
Date: Wed, 8 Feb 2023 19:33:37 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E6=94=B9=E6=A8=A1=E6=9D=BF=E6=8F=90?=
 =?UTF-8?q?=E7=A4=BA?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../excel/write/builder/ExcelWriterBuilder.java    | 14 ++++++++++++--
 .../excel/write/metadata/WriteWorkbook.java        |  4 ++--
 .../easyexcel/test/demo/write/WriteTest.java       |  1 +
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/easyexcel-core/src/main/java/com/alibaba/excel/write/builder/ExcelWriterBuilder.java b/easyexcel-core/src/main/java/com/alibaba/excel/write/builder/ExcelWriterBuilder.java
index 75d702f8..76af6f66 100644
--- a/easyexcel-core/src/main/java/com/alibaba/excel/write/builder/ExcelWriterBuilder.java
+++ b/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);
     }
diff --git a/easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/WriteWorkbook.java b/easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/WriteWorkbook.java
index 16f2a7ca..fd29562d 100644
--- a/easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/WriteWorkbook.java
+++ b/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;
     /**
diff --git a/easyexcel-test/src/test/java/com/alibaba/easyexcel/test/demo/write/WriteTest.java b/easyexcel-test/src/test/java/com/alibaba/easyexcel/test/demo/write/WriteTest.java
index 351e0e0a..a99f7d9d 100644
--- a/easyexcel-test/src/test/java/com/alibaba/easyexcel/test/demo/write/WriteTest.java
+++ b/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());
     }