Avoiding NullPointerException by findElement

Hallo everyone,

Code:


...
putFileToDirectoryInOrderToBePersisted();
WebElement td = tr.findElement(By.xpath("td[3]"));
...


After the method putFileToDirectory() is done, it Needs some seconds to get the file persisted in the database.  As Long as this file still processed, the relative path td[3] does not exists so that I Keep getting NullPointerException(can not find Element...).

I could have just Thread.sleep(...) in between These 2 code lines, but this is ugly.  Thats why I thought I could do this:

Code:

...
putFileToDirectoryInOrderToBePersisted();

WebElement td = null;
while (WebElement = tr.findElement(By.xpath("td[3]") == null)){
    if (WebElement = tr.findElement(By.xpath("td[3]") != null)){
           break;      
    }
}
...


I thought, with the while Loop, I am waiting, untill the relative path is accessable.  But findElement results directly in Exception if the path is not accessible. 

I also thought, I could use fluentWait, but since it does not depend to any WebElement, but to a persisting process, I can not do fluentWait.

Any idea how I can deal with it?  Thank you.

Regards,

Ratna