How to create Excel by Apache POI

I often use Apache POI to deal with Microsoft Office in these days.

Today I introduce how to create Excel file by using Apache POI.

Let’s create the following Excel file.

Sample Excel

Please refer a previous article for install of Apache POI.

Step 1

At first, create XSSFWorkBook object to represent work book of Excel, and create FileOutputStream to write the Excel file too.

In this sample, use "auto close feature" from Java7.

try (XSSFWorkbook book = new XSSFWorkbook();
				FileOutputStream out = new FileOutputStream("sample.xlsx")) {

    // write code here
}

Step 2

Create a sheet.

Sheet sheet = book.createSheet();

Step 3

Specify a cell to write content.

Row row = sheet.createRow(0);
Cell cell = row.createCell(0);

Step 4

Specify a format.

There are a lot of options except below, please search others.

CellStyle style = book.createCellStyle();
Font font = book.createFont();
font.setColor(IndexedColors.BLUE.getIndex());
style.setWrapText(true);
style.setFont(font);
cell.setCellStyle(style);

Step 5

Write value to the cell.

cell.setCellValue("test");

Step 6

Finally, write the book to a file.

book.write(out);

Overall source code is below.

package io.saitoxu.poisample;

import java.io.FileOutputStream;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class App {
    public static void main(String[] args) throws Exception {
        try (XSSFWorkbook book = new XSSFWorkbook();
                FileOutputStream out = new FileOutputStream("sample.xlsx")) {
            Sheet sheet = book.createSheet();

            Row row = sheet.createRow(0);
            Cell cell = row.createCell(0);

            CellStyle style = book.createCellStyle();
            Font font = book.createFont();
            font.setColor(IndexedColors.BLUE.getIndex());
            style.setWrapText(true);
            style.setFont(font);
            cell.setCellStyle(style);

            cell.setCellValue("test");

            book.write(out);
        }
    }
}