How to send a attachment via gmail using Selenium(Using Robot Class)

Scenario:

Open gmail.com
Enter username 
Enter Password
Click on SignIn
Click on composeButton
Add recipent
Add Subject
Click on attachment
Add your File location
Click on Send Button


import java.awt.AWTException;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.datatransfer.StringSelection;
import java.awt.event.KeyEvent;
import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.Test;

public class SendFile {
public static void main(String str[]) throws InterruptedException, AWTException{
WebDriver driver = new FirefoxDriver();
driver.manage().window().maximize();
driver.get("http://www.gmail.com/");
//open gmail
driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
driver.findElement(By.xpath(".//*[@id='Email']")).sendKeys("enteryouremailid");
//enter emailid
driver.findElement(By.xpath(".//*[@id='Passwd']")).sendKeys("enteryourpassword");
   // enter password
driver.findElement(By.xpath("//*[@id='signIn']")).click();
//click on sign in
driver.findElement(By.xpath("//div[contains(text(),'COMPOSE')]")).click();
//click on compose button

driver.findElement(By.xpath("//form[1]//textarea[1]")).sendKeys("ritu7181@gmail.com");
//enter email id where you need to send email

driver.findElement(By.xpath("//div[@class='aoD az6']//input[@class='aoT']")).sendKeys("Please find attachment");
//Enter subject
     Thread.sleep(15000);
driver.findElement(By.xpath("//div[@class='a1 aaA aMZ']")).click();
//click on attachment icon
StringSelection ss = new StringSelection("C:\\Users\\Ritika Gulati\\Downloads\\Asp.docx");
    //upload your file using RobotClass
    //attach your path where file is located.
    Toolkit.getDefaultToolkit().getSystemClipboard().setContents(ss, null);
    Robot robot = new Robot();
    Thread.sleep(5000);
    robot.keyPress(KeyEvent.VK_CONTROL);
    robot.keyPress(KeyEvent.VK_V);
    robot.keyRelease(KeyEvent.VK_CONTROL);
    robot.keyRelease(KeyEvent.VK_V);
    Thread.sleep(6000);
    robot.keyPress(KeyEvent.VK_ENTER);
    robot.keyRelease(KeyEvent.VK_ENTER);
    Thread.sleep(10000);
      driver.findElement(By.xpath("//div[text()='Send']")).click();
    //Click on send
   }
}