Spring Boot GUI Testing Selenium WebDriver

I developped a Spring Boot / Angular JS app. Now I'm trying to implement some GUI interface tests.

I tryed to use the Selenium ChromeDriver, so I added the Selenium dependency :

<dependency>
    <groupId>org.seleniumhq.selenium</groupId>
    <artifactId>selenium-java</artifactId>
    <version>3.4.0</version>
</dependency>

And I created my first test :

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = MyMainClass.class)
public class SeleniumTest {
    private WebDriver driver;

    @Before
    public void setup() {
        System.setProperty("webdriver.chrome.driver", "my/path/to/chomedriver");
        driver = new ChromeDriver();
    }

    @Test
    public void testTest() throws Exception {
        driver.get("https://www.google.com/");
    }
}

This works fine. But now I want to get my app pages with :

driver.get("http://localhost:8080/");

But I get an "ERR_CONNECTION_REFUSED" in the chrome browser.

I think it's because I need to set up my test to run my web app before to run the test but I don't find how to achieve this ?