XLS to CSV Conversion using Java

 The complete code that converts Excel to CSV in Java, for the example we provided is given below:

import java.io.FileInputStream;
import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.ss.usermodel.*;
import java.util.Iterator;
import java.io.FileWriter;
import au.com.bytecode.opencsv.CSVWriter;
public class excel2csv {  
        public static void main(String[] args) throws Exception{
                //First we read the Excel file in binary format into FileInputStream
                FileInputStream input_document = new FileInputStream(new File("C:\\excel_to_csv.xls"));
                // Read workbook into HSSFWorkbook
                HSSFWorkbook my_xls_workbook = new HSSFWorkbook(input_document); 
                // Read worksheet into HSSFSheet
                HSSFSheet my_worksheet = my_xls_workbook.getSheetAt(0); 
                // To iterate over the rows
                Iterator<Row> rowIterator = my_worksheet.iterator();
                // OpenCSV writer object to create CSV file
                FileWriter my_csv=new FileWriter("convertedCSVFile.csv");
                CSVWriter my_csv_output=new CSVWriter(my_csv); 
                //Loop through rows.
                while(rowIterator.hasNext()) {
                        Row row = rowIterator.next(); 
                        int i=0;//String array
                        //change this depending on the length of your sheet
                        String[] csvdata = new String[2];
                        Iterator<Cell> cellIterator = row.cellIterator();
                                while(cellIterator.hasNext()) {
                                        Cell cell = cellIterator.next(); //Fetch CELL
                                        switch(cell.getCellType()) { //Identify CELL type
                                                //you need to add more code here based on
                                                //your requirement / transformations
                                        case Cell.CELL_TYPE_STRING:
                                                csvdata[i]= cell.getStringCellValue();                                              
                                                break;
                                        }
                                        i=i+1;
                                }
                my_csv_output.writeNext(csvdata);
                }
                my_csv_output.close(); //close the CSV file
                //we created our file..!!
                input_document.close(); //close xls
        }
}

The code is fully commented and you can follow it very easily. If you have a question, you can post it in the comments section.

Example Output – excel2csv

Example output for the code we used is provided below. We got the CSV file in the format we wanted.

Output CSV Sheet