Apache POI 需要花费大量时间来写入工作簿 [英] Apache POI is taking extremely large time to write into the Workbook

问题描述

我正在使用 Apache POI 创建记录并将其保存到工作簿.我有近 5000 多条新记录要写入并保存到工作簿中.但是在将fileOutputStream写入工作簿的时候，执行基本停止并变慢了.

I'm using Apache POI to create and save records into Workbook. I have almost 5000+ new records to be written and saved into the workbook. But at the time of writing the fileOutputStream into the workbook, the execution basically halts and slowed down.

我想说的是，在执行这一行的时候:

What I mean to say is, at the time of executing this line:

workbook.write(fileOutputStream);

它几乎停止处理 5000 多条记录.我确认在工作簿中书写需要将近 1 小时 (!).

it almost stops to process 5000+ records. I validated that it's taking nearly 1 hour (!) to write in the workbook.

我怎样才能提高性能并克服这个缺点??请建议...

How can I improve the performance and overcome this drawback?? Please suggest...

** 注意:其余的代码是正常的Apache POI相关代码，它们运行良好，没有问题，因此我没有提到所有这些.只有我卡在上面那行.

** Note: The rest of the codes are normal Apache POI related codes and they are executing fine, no issue, hence I didnot mention all of them. Only I got stuck at the above line.

我在这里找到了一个讨论:FileOutputStream (Apachhe POI) 保存时间太长

I found one discussion here: FileOutputStream (Apachhe POI) taking too long time to save

但是，它没有帮助我.我需要保存整个文件.

but, it did not help me. I need to save the whole file.

推荐答案

我理解的另一种解决方案，例如，在迭代 Row 并创建单元格时，不要继续声明 CellStyle 和 sheet.autoSizeColumn(colNumber) 在循环内部，而不是在循环外部仅声明一次这两个，并仅在循环内部设置值和样式，即 cell.setCellStyle 和 cell.setCellValue.

One more solution I understand, like, while iterating over the Row and creating cells, DO NOT keep declaring CellStyle and sheet.autoSizeColumn(colNumber) inside the loop, rather declare these 2 only once at the outside of the loop and set the values and style only inside the loop, i.e, cell.setCellStyle and cell.setCellValue.

每次迭代时都声明上述 2 项，基本上会从根本上降低 POI 的性能.

Declaring the above 2 everytime while iterating, basically degrades the performance of the POI radically.

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