Best language to parse extremely large Excel 2007 files [closed]

I kept getting all kinds of weird errors when working with .xlsx files.

Here’s a simple example of using Apache POI to traverse an .xlsx file. See also Upgrading to POI 3.5, including converting existing HSSF Usermodel code to SS Usermodel (for XSSF and HSSF).

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.FormulaEvaluator;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class XlsxReader {

    public static void main(String[] args) throws IOException {
        InputStream myxls = new FileInputStream("test.xlsx");
        Workbook book = new XSSFWorkbook(myxls);
        FormulaEvaluator eval =
            book.getCreationHelper().createFormulaEvaluator();
        Sheet sheet = book.getSheetAt(0);
        for (Row row : sheet) {
            for (Cell cell : row) {
                printCell(cell, eval);
                System.out.print("; ");
            }
            System.out.println();
        }
        myxls.close();
    }

    private static void printCell(Cell cell, FormulaEvaluator eval) {
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_BLANK:
                System.out.print("EMPTY");
                break;
            case Cell.CELL_TYPE_STRING:
                System.out.print(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    System.out.print(cell.getDateCellValue());
                } else {
                    System.out.print(cell.getNumericCellValue());
                }
                break;
            case Cell.CELL_TYPE_BOOLEAN:
                System.out.print(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_FORMULA:
                System.out.print(cell.getCellFormula());
                break;
            default:
                System.out.print("DEFAULT");
        }
    }
}