Docker execution environment in Selenium Java

Introduction

Docker lets you run tests in a clean, controlled space. This helps avoid problems from different computers or setups.

You want to run Selenium tests on any computer without setup issues.

You need to test on different browsers or versions easily.

You want to share your test environment with teammates exactly as it is.

You want to run tests on a server or cloud without installing browsers manually.

You want to keep your computer clean without installing many tools.

Syntax

Selenium Java

docker run -d -p 4444:4444 selenium/standalone-chrome

// In Java Selenium test:
WebDriver driver = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), new ChromeOptions());

The docker run command starts a browser server inside Docker.

Java connects to this server using RemoteWebDriver and browser options.

Examples

Starts a Firefox browser server inside Docker on port 4444.

Selenium Java

docker run -d -p 4444:4444 selenium/standalone-firefox

Connects Java Selenium test to the Firefox Docker browser server.

Selenium Java

WebDriver driver = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), new FirefoxOptions());

Starts the latest Chrome browser server in Docker.

Selenium Java

docker run -d -p 4444:4444 selenium/standalone-chrome:latest

Sample Program

This Java program connects to a Chrome browser running inside Docker. It opens example.com, checks the page title, prints the test result, and closes the browser.

Selenium Java

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import java.net.URL;

public class DockerSeleniumTest {
    public static void main(String[] args) throws Exception {
        // Connect to Docker Selenium server
        WebDriver driver = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), new ChromeOptions());

        // Open a website
        driver.get("https://example.com");

        // Check the page title
        String title = driver.getTitle();
        if (title.equals("Example Domain")) {
            System.out.println("Test Passed: Title is correct.");
        } else {
            System.out.println("Test Failed: Title is incorrect.");
        }

        // Close the browser
        driver.quit();
    }
}

Important Notes

Make sure Docker is installed and running before starting the Selenium container.

Use docker ps to check if the Selenium container is running.

Always stop the Docker container after tests to free resources.

Summary

Docker creates a clean browser environment for Selenium tests.

Java connects to Docker browsers using RemoteWebDriver and browser options.

This helps run tests anywhere without setup problems.