Sample code for 30+ languages & platforms
Java

XLSX Convert Sheet to CSV

Open an Excel spreadsheet (.xlsx) and loads a sheet into a CSV object.

Chilkat Java Downloads

Java
import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  This example assumes the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  .xlsx files are Zip archives
    CkZip zip = new CkZip();
    success = zip.OpenZip("qa_data/excel/fakeCompanies.xlsx");
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    CkCsv csv = new CkCsv();
    CkStringTable sheetNames = new CkStringTable();
    success = csv.XlsxGetSheets(zip,sheetNames);
    if (success == false) {
        System.out.println(csv.lastErrorText());
        return;
        }

    if (sheetNames.get_Count() == 0) {
        System.out.println("There are no sheets in the .xlsx");
        return;
        }

    //  Get the name of the 1st sheet.
    String sheetName = sheetNames.stringAt(0);

    //  Load the 1st sheet into the CSV.
    //  We could've also loaded the 1st sheet by passing an empty string for the sheet name.
    success = csv.XlsxLoadSheet(zip,sheetName);
    if (success == false) {
        System.out.println(zip.lastErrorText());
        return;
        }

    //  The Chilkat CSV API can now be used to read, modify, or insert cells.
    //  ...
    //  ...

    String csvStr = csv.saveToString();
    System.out.println(csvStr);

    //  Sample output:
    //  CompanyName,Address,City,State,Zip,Phone
    //  Acme Innovations LLC,7428 Westbrook Blvd,Oak Bend,IL,60514,630-555-2398
    //  BlueHorizon Data Systems,1850 Crestline Park Suite 210,Rivergate,CA,92814,714-555-8821
    //  Pinnacle Manufacturing Corp,3912 Industrial Loop,Maple Ridge,TX,77301,281-555-4477
    //  Evergreen Analytics Inc,1250 Highland Terrace,Stonefield,WA,98290,425-555-9914
    //  NovaTech Solutions Group,578 Marketview Drive,Clearwater,FL,33760,727-555-6032

    //  Save to a .csv file.
    success = csv.SaveFile2("c:/temp/qa_output/fakeCompanies.csv","utf-8");
    if (success == false) {
        System.out.println(csv.lastErrorText());
        return;
        }
  }
}