You can download geckodriver from the link
https://github.com/mozilla/geckodriver/releases
Then save the file in your local system. unzip the file and change the application name as "wires.exe".
Then specify the path upto wires.exe in the code.
add selenium-2.53.0 jar files.
Try below code to start working on FF 47.0 or above.
package com.marionette.programs;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.MarionetteDriver;
public class HandleLatestFirefox {
public static void main(String[] args) {
String currentDir = System.getProperty("user.dir");
System.out.println(currentDir);
//String marionetteDriverLocation = currentDir + "G:\\ravik\\Ravi-Training\\Selenium\\Marionette for firefox\\wires.exe";
System.setProperty("webdriver.gecko.driver", "G:\\ravik\\Ravi-Training\\Selenium\\Marionette for firefox\\wires.exe");
WebDriver driver = new MarionetteDriver();
driver.get("https://www.google.co.in/webhp?hl=en&sa=X&ved=0ahUKEwjdgc21jJHOAhVCvY8KHZ4aCdcQPAgD");
System.out.println("marionette working fine....");
}
}