How to mouse hover on a webelement using webdriver

import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.interactions.Actions;


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

		        WebDriver driver=new FirefoxDriver();
		        driver.get("http://www.flipkart.com/");
		        driver.manage().window().maximize();
		        driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
		        
		        WebElement ele=driver.findElement(By.xpath("//li[@class='menu-l0  ' and @data-key='electronics']"));
		        Actions builder=new Actions(driver);
//		        builder.moveToElement(ele).build().perform();
		        builder.moveToElement(ele).perform();
		        Thread.sleep(2000);
		        WebElement nexus=driver.findElement(By.xpath("//a[@data-tracking-id='0_Nexus 6']"));
//		        nexus.click();
//		        builder.moveToElement(nexus).click().build().perform();
		        builder.click(nexus).build().perform();
	}

}