File Upload using sendkeys

public class FileUpload {

    public static void main(String[] args) throws InterruptedException {
     
        WebDriver d = new FirefoxDriver();
        d.manage().window().maximize();
        d.manage().timeouts().implicitlyWait(45, TimeUnit.SECONDS);
       
        d.get("https://www.sendspace.com");
       
        d.findElement(By.id("upload_file")).sendKeys("C:\\Users\\Desktop\\aa.txt");
        Thread.sleep(5000);
        d.quit();
    }
   
}