问未识别任何工作表时如何访问XSSF内容

EN

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class excelParser {

    private static final String FILE_NAME = "C:\\Users\\me\\Downloads\\output.xlsx";

    public static void main(String[] args) throws FileNotFoundException {


                if (new File(FILE_NAME).exists()){

                FileInputStream excelFile = new FileInputStream(new File(FILE_NAME));
                Workbook workbook = new XSSFWorkbook();
                //Sheet datatypeSheet = workbook.getSheet("MySheet");

                //System.out.println(datatypeSheet.getSheetName());
                System.out.println(workbook.getSheetIndex("MySheet"));
                }
                else System.out.println("file not found");
    }
}