How to create an Excel file based on CSV file using Java?

Accepted answer +16 upvotes

I suggest you use the Apache POI framework (specifically the HSSF / XSSF API) for writing out the XLS file.

For reading a CSV file I suggest you use OpenCSV as it will take care of escaped characters etc for you.

Putting together the POI example from here and the OpenCSV example from here gives you this:

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import au.com.bytecode.opencsv.CSVReader;

class Test {
    public static void main(String[] args) throws IOException {
        Workbook wb = new HSSFWorkbook();
        CreationHelper helper = wb.getCreationHelper();
        Sheet sheet = wb.createSheet("new sheet");

        CSVReader reader = new CSVReader(new FileReader("data.csv"));
        String[] line;
        int r = 0;
        while ((line = reader.readNext()) != null) {
            Row row = sheet.createRow((short) r++);

            for (int i = 0; i < line.length; i++)
                row.createCell(i)
                   .setCellValue(helper.createRichTextString(line[i]));
        }

        // Write the output to a file
        FileOutputStream fileOut = new FileOutputStream("workbook.xls");
        wb.write(fileOut);
        fileOut.close();
    }
}