Batch files launches and disappear without executing Selenium tests

Question

I have created a Selenium project named 'LearnAutomation' in Java and convert it to TestNG tests which created a testng.xml for me. Now i want to run it via batch file. So i created one as below -

cd E:\Workspace - Eclipse\LearnAutomation
set ProjectPath=E:\Workspace - Eclipse\LearnAutomation
echo %ProjectPath%
set classpath=%ProjectPath%\bin;%ProjectPath%\lib\*
echo %classpath%
java org.testng.TestNG %ProjectPath%\testng.xml

and save it as testng.bat file. On double clicking batch file, it gets launched and disappeared. (failed to run test)

My testng.xml looks like this -

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Suite" parallel="none">
  <test name="Test">
    <classes>
      <class name="tests.Demo"/>
    </classes>
  </test> <!-- Test -->
</suite> <!-- Suite -->

My Demo class looks like this -

package tests;

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

public class Demo {

    @Test
    public void batchFile() {
        System.setProperty("webdriver.gecko.driver",
                "C:\\Users\\srvashishtha\\Downloads\\geckodriver-v0.11.1-win64\\geckodriver.exe");
        WebDriver driver = new FirefoxDriver();
        driver.get("http://www.google.com");
    }

}