Hi again, > e.g. fill() always returns null !
Ah, that was a copy-paste mistake. The line is in the original file but I copied it in the mail in two parts, missing that line. :-( I corrected it below. > Then you should be sure that in your excel file sheet at position 1 (sheets > are zero-based) exists, row at position 0 exists and least the cells exists. This is, what I am still struggeling with. What does "exist" in terms of POI mean? Does a cell or row have to contain data to exist? The file I am reading in is a workbook with tree sheets, but only the first sheet (worksheet No 0) contains data, the other two are empty. Guess this is what I ment with saying I don't really understand the concept yet :-/ Best, Meike > > -----Original Message----- > > From: Meike Reichle (RZ) [mailto:[EMAIL PROTECTED] > > Sent: Sunday, March 30, 2003 4:32 PM > > To: [EMAIL PROTECTED] > > Subject: NullPointerException generating 0 byte files > > > > > > Hi everyone, > > > > I am rather new to POI, but I am planing to use it for a project, > > so I decided to first test it a bit before actually starting using it > > in a big scale. > > But unfortunatelly I just don't get it to work properly. > > What I wanted to do is to open an existing file, add some values > > and write that in a new file. Opening seems to work, but then > > I am doing something wrong and I can't really figure out what it is. > > The class compiles without errors, but when I try to execute it, > > it throws three NullPointerExceptions and generates a new file with > > the size of 0 bytes. > > > > It's probably a rather dumb newbie mistake I did. But since I > > am still > > trying to understand the concept of POI I'd be really glad > > if someone > > had a hint or some enlightening words for me. > > > > Thanks in advance, > > Meike > > > > > > Here's my complete testing class: > > > > > > import java.io.*; > > import org.apache.poi.poifs.filesystem.*; > > import org.apache.poi.hssf.dev.*; > > import org.apache.poi.hssf.eventmodel.*; > > import org.apache.poi.hssf.model.*; > > import org.apache.poi.hssf.record.*; > > import org.apache.poi.hssf.usermodel.*; > > import org.apache.poi.hssf.util.*; > > > > public class ExcelInterface > > { > > > > //opening an existing file > > public static HSSFWorkbook openFile() > > { > > try > > { > > FileInputStream in = new FileInputStream(Pfade.excel); > > POIFSFileSystem fs = new POIFSFileSystem(in); > > HSSFWorkbook wb = new HSSFWorkbook(fs); > > return wb; > > } > > catch(Exception e) > > { > > System.out.println(e); > > } > > return null; > > } > > > > > > //write in some values > > public static HSSFWorkbook fill() > > { > > try > > { > > HSSFWorkbook wb = openFile(); > > HSSFSheet sheet = wb.getSheetAt(1); > > HSSFRow row = sheet.getRow(0); > > HSSFCell cell1 = row.getCell((short)1); > > HSSFCell cell2 = row.getCell((short)2); > > > > cell1.setCellType(HSSFCell.CELL_TYPE_NUMERIC); > > cell2.setCellType(HSSFCell.CELL_TYPE_STRING); > > cell1.setCellValue(15); > > cell2.setCellValue("test :-)"); return wb; > > } > > catch(Exception e) > > { > > System.out.println(e); > > } > > return null; > > } > > > > > > > > //Save it to a new file > > public static void closeFile() > > { > > try > > { > > HSSFWorkbook wb = fill(); > > FileOutputStream out = new FileOutputStream(Pfade.excel2); > > wb.write(out); > > out.close(); > > } > > catch(Exception e) > > { > > System.out.println(e); > > } > > } > > > > > > public static void main(String args[]) > > { > > openFile(); > > fill(); > > closeFile(); > > } > > > > }//end of class > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
