How do I import a large XLSX file into Apache POI?

xls HSSFWorkbook, or a . xlsx XSSFWorkbook, the Workbook can be loaded from either a File or an InputStream. Using a File object allows for lower memory consumption, while an InputStream requires more memory as it has to buffer the whole file.” The Excel support in Apache POI, HSSF and XSSF, supports 3 different modes.

Can XSSF read XLS file?

XSSF is the POI Project’s pure Java implementation of the Excel 2007 OOXML (. xlsx) file format. HSSF and XSSF provides ways to read spreadsheets create, modify, read and write XLS spreadsheets.

How do I read an XLSX file with poi?

Reading XLS file is no different than reading an XLSX format file, all you need to do is to use correct workbook implementation for XLS format e.g. instead of using XSSFWorkbook and XSSFSheet , you need to use HSSFWorkbook and HSSFSheet classes from Apache POI library.

How do I open an Excel file that is too large?

There is a solution in Excel. You can’t open big files in a standard way, but you can create a connection to a CSV file. This works by loading data into Data Model, keeping a link to the original CSV file. This will allow you to load millions of rows.

How do you populate data in Excel using Java?

1. Apache POI API Basics for Writing Excel Files

Create a Workbook.
Create a Sheet.
Repeat the following steps until all data is processed: Create a Row. Create Cellsin a Row. Apply formatting using CellStyle.
Write to an OutputStream.
Close the output stream.

How do I read a XLSX file in spring boot?

Let me summarize the steps for reading from Excel file:

create Workbook from InputStream.
create Sheet using Workbook. getSheet() method.
iterate over Row s by Iterator with Sheet. iterator() and Iterator.
from each Row , iterate over Cell s.
with each Cell , use getNumericCellValue() , getStringCellValue() …

How is Apache POI implemented?

Get the Sheet instance using getSheetAt(int i) method. Get Row iterator and then Cell iterator to get the Cell object. Apache POI is using iterator pattern here. Use switch-case to read the type of Cell and the process it accordingly.

Why is my Excel file so large and slow?

The biggest reason for slow Excel files are formulas that take too long to calculate. So the first tip you can use is to ‘press pause’ on any calculations! This stops formulas being recalculated after every edit you make. When it’s set to Manual, formulas won’t re-calculate unless you edit an individual cell directly.

How add Excel to eclipse?

to import one or multiple files, select the folder/project where i want to add the files, then use the menu file > import :

menu file import.
import context menu.
import from file system.
importing files from filesystem.
drag and drop to add files.

How to load a large xlsx file with Apache POI?

One is a full, DOM-Like in-memory “UserModel”, which supports both reading and writing. Using the common SS (SpreadSheet) interfaces, you can code for both HSSF (.xls) and XSSF (.xlsx) basically transparently. However, it needs lots of memory.

Can a file object be used in Apache POI?

Using a File object allows for lower memory consumption, while an InputStream requires more memory as it has to buffer the whole file.” The Excel support in Apache POI, HSSF and XSSF, supports 3 different modes.

Is it possible to read a large xlsx file?

The advantage provided is that you can read an XLS with a relatively small memory footprint. If memory footprint is an issue, then for XSSF, you can get at the underlying XML data, and process it yourself.

How to process large xlsx file in Java?

The following code via apache poi works on small files, but goes out with OutOfMemoryError on large ones: Workbook workbook = WorkbookFactory.create (inputStream); Sheet sheet = workbook.getSheetAt (0); for (Row row : sheet) { row.setHeight ( (short) -1); } workbook.write (outputStream);