Hi Bhanu, you can run test cases in headless mode using Phantom JS by following this piece of code:
import org.openqa.selenium.phantomjs.PhantomJSDriver;
import org.openqa.selenium.phantomjs.PhantomJSDriverService;
import org.openqa.selenium.remote.DesiredCapabilities;
public class WebDriverBase {
  static protected WebDriver driver;
  public static void setup() {
    DesiredCapabilities caps = new DesiredCapabilities();
    caps.setJavascriptEnabled(true); // not really needed: JS enabled by default
    caps.setCapability(PhantomJSDriverService.PHANTOMJS_EXECUTABLE_PATH_PROPERTY, "src/test/resources/phantomjs");
    driver = new PhantomJSDriver(caps);
  }
  public static void main(String[] args) {
    WebDriverBase.setup();
    driver.get("https://www.facebook.com");
  }
}
You will also need the ghost driver dependency as well:
<dependency>
    <groupId>com.github.detro.ghostdriver</groupId>
    <artifactId>phantomjsdriver</artifactId>
    <version>1.0.1</version>
</dependency>