Deal with File download in WebDriver by AutoIT

"This is annoying , but you have to face it sometimes"

Solution:
1> Install AutoIT V3.2, not the latest version, like V3.3.6, BTW, you had better install AutoIT to its default folder:"C:\Program Files\AutoIt3"
2> Download jWinAuto
3> Add all .jars to your libs, including jna.jar and jAutoIt.jar within jWinAuto
4> Write your testing code
I put the Watir scripts in comments for each steps, FYI:

 import org.openqa.selenium.By;  
 import org.openqa.selenium.WebDriver;  
 import org.openqa.selenium.firefox.FirefoxDriver;  
 import com.compdev.jautoit.autoitx.autoitx;  
 public class AutoIT {  

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

           //ai = WIN32OLE.new("AutoItX3.Control")  
           autoitx ai = autoitx.INSTANCE;  
            //ie=FireWatir::Firefox.new  
           WebDriver driver = new FirefoxDriver();  
            //ie.goto("http://www.autoitscript.com/autoit3/downloads.shtml")  
           driver.get("http://www.autoitscript.com/autoit3/downloads.shtml");  
            //ie.image(:alt,'Download AutoIt').click  
            driver.findElement(By.cssSelector("img[alt=\"Download AutoIt\"]")).click();  
            //res=ai.WinWait("Opening autoit-v3-setup.exe","",10)  
            int res = ai.AU3_WinWait("Opening autoit-v3-setup.exe","",10);  
            // if res = 1, then it shows you find the window with proper title  
            System.out.print("res" + res);  
            Thread.sleep(3000);  
            //res=ai.WinActivate("Opening autoit-v3-setup.exe")  
            ai.AU3_WinActivate("Opening autoit-v3-setup.exe","");  
            ai.AU3_Send("{TAB}",0);  
            Thread.sleep(3000);  
            ai.AU3_Send("{TAB}",0);  
            Thread.sleep(3000);  
            ai.AU3_Send("{ENTER}",0);  
            //Start file downloading...
      }  
 }  

So you can use AutoIT in WebDriver to deal with your Win32(disgusting) pop-ups or other situations, easily! Want to know how powerful the AutoIT is, please refer to its function reference :)

BTW, just realize WebDriver is implementing a batch of GUI event driven APIs, Cool!