import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.record.formula.*;
import org.apache.poi.hssf.util.CellReference;
import org.apache.poi.hssf.model.*;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

/**
  * Formula Parser problem with external references.
  */
public class FormulaParserError
{
    private POIFSFileSystem fs = null;   
    private HSSFWorkbook wb = null;
    private HSSFSheet sheet = null;
    
    FormulaParserError(String spreadsheet) throws IOException {
        
        fs = new POIFSFileSystem(new FileInputStream(spreadsheet));
        wb = new HSSFWorkbook(fs);
        // Dump the sheet names (mainly for debuggin purposes)
        int numSheets = wb.getNumberOfSheets();
        for (int i=0; i<numSheets; i++) {
            System.out.println("Sheet " + i + ": " + wb.getSheetName(i));
        }
    }
    
    public void process() {
        // Cell A1 (row 0, cell 0) on Sheet2 (1)  contains the formula to be parsed.
        sheet = wb.getSheetAt(1);
        HSSFRow row = sheet.getRow(0);
        HSSFCell cell = row.getCell((short)0);
        String formula = cell.getCellFormula();
        System.out.println("Fetched formula to parse:  " + formula);

        // Second arg of FormulaParser is the workbook, but up here, 
        // there's no way to get the workbook out of the HSSFWorkbook
        // so send a null
        FormulaParser fp = new FormulaParser(formula, null);

        // This line should bomb.
        fp.parse();
 
        // it blows up on line 295 of FormulaParser:
        //   short externIdx = book.checkExternSheet(book.getSheetIndex(sheetName));
        // because there was no workbook to get the external sheet references
        // from (external reference meaning external to the sheet the formula
        // is on.
    }
    
    public static void main(String[] args) throws IOException {
        FormulaParserError fpe = new FormulaParserError(args[0]);
        fpe.process();
    }
}