使用POI读取和写入数据到excel-写入新数据后，它会从excel中删除我的原始数据

Question

I am first reading data from excel and then write in same excel. It works fine first time. Just after data written , It deletes my original data which was there from very beginning.

code is given below :

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


    //CODE TO REMOVE UNNECESSARY WARNING
    System.setProperty("org.apache.commons.logging.Log", "org.apache.commons.logging.impl.Jdk14Logger");


    //CALL FIREFOX DRIVER TO OPEN IT
    WebDriver driver = new FirefoxDriver();


    driver.get("https://www.google.co.in/?gfe_rd=cr&ei=VQiAVOeCFavM8gf59IHACg&gws_rd=ssl#q=software+testing");
    java.util.List<WebElement> links = driver.findElements(By.tagName("h3"));
    int sizecount = links.size(); 
    System.out.println(sizecount);

        FileInputStream input = new FileInputStream("D:\\sel.xls");
        int count=0;

        HSSFWorkbook wb = new HSSFWorkbook(input);
        HSSFSheet sh = wb.getSheet("sheet1");
        HSSFRow row = sh.getRow(count);
        String data = row.getCell(0).toString();
        System.out.println(data);

        FileOutputStream webdata = new FileOutputStream ("D:\\sel.xls");

    int inc = 1;
    for(int i=1;i<=links.size()-1;i++)
    {


        HSSFRow row1 = sh.createRow(count);
        row1.createCell(inc).setCellValue(links.get(i).getText());
        count++;


    }
         wb.write(webdata);

Answer 1

you are facing the issue because the index of excel sheets are same when you are writing. First you should check wheater the cell is empty or not then you should write. Or you can first do getrows() or getcolumn() it will give you the size of the rows and columns. once you have the size you can write your data after the that row size and column.

Answer 2

if you are updating it, you should also update the count variable with the last line of the excel

 int inc = 1;
 count = sh.getPhysicalNumberOfRows();

and do the rest...