Useful to create and transform WorkBooks in to byte

FileCreator.java

import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.stereotype.Component;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

@Component
public class FileCreator {

    public XSSFSheet aperturarWorkbook(String nombreHoja) {
        XSSFWorkbook workbook = new XSSFWorkbook();
        XSSFSheet sheet = workbook.createSheet(nombreHoja);
        return sheet;
    }

    public byte[] crearExcel(XSSFWorkbook workbook) {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        try {
            workbook.write(bos);
        } catch (IOException e) {
            System.err.println("");
        } finally {
            try {
                bos.close();
                workbook.close();
            } catch (IOException e) {
                System.err.println("");
            }
        }
        return bos.toByteArray();
    }
}