Selenium Guide

Setup — Java & Python

// Java (Maven dependency)
// <dependency>org.seleniumhq.selenium:selenium-java:4.x</dependency>

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;

ChromeOptions options = new ChromeOptions();
options.addArguments("--headless=new", "--no-sandbox", "--disable-dev-shm-usage");
WebDriver driver = new ChromeDriver(options);

driver.get("https://example.com");
System.out.println(driver.getTitle());
driver.quit();

---

# Python (pip install selenium)
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
from selenium.webdriver.chrome.service import Service

options = Options()
options.add_argument("--headless=new")
options.add_argument("--no-sandbox")

driver = webdriver.Chrome(options=options)
driver.get("https://example.com")
print(driver.title)
driver.quit()

Locators

// Java
import org.openqa.selenium.By;

driver.findElement(By.id("email"));
driver.findElement(By.name("password"));
driver.findElement(By.className("btn-primary"));
driver.findElement(By.tagName("input"));
driver.findElement(By.linkText("Sign In"));
driver.findElement(By.partialLinkText("Sign"));
driver.findElement(By.cssSelector("input[type='email']"));
driver.findElement(By.xpath("//button[@type='submit']"));

// Selenium 4 — relative locators
import static org.openqa.selenium.support.locators.RelativeLocator.*;
driver.findElement(with(By.tagName("label")).above(By.id("email")));

---

# Python
from selenium.webdriver.common.by import By

driver.find_element(By.ID, "email")
driver.find_element(By.CSS_SELECTOR, "input[type='email']")
driver.find_element(By.XPATH, "//button[@type='submit']")
driver.find_elements(By.CLASS_NAME, "list-item")  # multiple

Explicit Waits

// Java
import org.openqa.selenium.support.ui.WebDriverWait;
import org.openqa.selenium.support.ui.ExpectedConditions;
import java.time.Duration;

WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));

// Wait for element to be visible
WebElement el = wait.until(
    ExpectedConditions.visibilityOfElementLocated(By.id("result"))
);

// Wait for URL
wait.until(ExpectedConditions.urlContains("/dashboard"));

// Wait for text
wait.until(ExpectedConditions.textToBePresentInElementLocated(
    By.id("msg"), "Success"));

---

# Python
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

wait = WebDriverWait(driver, 10)
el = wait.until(EC.visibility_of_element_located((By.ID, "result")))
wait.until(EC.url_contains("/dashboard"))
wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, "#submit")))

Page Object Model

// Java — LoginPage.java import org.openqa.selenium.WebDriver; import org.openqa.selenium.WebElement; import org.openqa.selenium.support.FindBy; import org.openqa.selenium.support.PageFactory; public class LoginPage { private final WebDriver driver; @FindBy(id = "email") private WebElement emailField; @FindBy(id = "password") private WebElement passwordField; @FindBy(css = "button[type='submit']") private WebElement submitButton; public LoginPage(WebDriver driver) { this.driver = driver; PageFactory.initElements(driver, this); } public DashboardPage login(String email, String password) { emailField.sendKeys(email); passwordField.sendKeys(password); submitButton.click(); return new DashboardPage(driver); } } // Usage in test LoginPage loginPage = new LoginPage(driver); DashboardPage dashboard = loginPage.login("[email protected]", "pass"); assertTrue(dashboard.isLoaded());

Actions — Forms & Keyboard

// Java — Actions class
import org.openqa.selenium.interactions.Actions;

Actions actions = new Actions(driver);
actions.moveToElement(element).click().perform();
actions.sendKeys(element, "text").perform();
actions.doubleClick(element).perform();
actions.contextClick(element).perform();  // right-click

// Keyboard shortcuts
actions.keyDown(Keys.CONTROL).sendKeys("a").keyUp(Keys.CONTROL).perform();

// Select dropdown
import org.openqa.selenium.support.ui.Select;
Select select = new Select(driver.findElement(By.id("country")));
select.selectByVisibleText("United States");
select.selectByValue("us");
select.selectByIndex(1);

---

# Python
from selenium.webdriver.common.action_chains import ActionChains
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import Select

actions = ActionChains(driver)
actions.move_to_element(element).click().perform()
actions.key_down(Keys.CONTROL).send_keys("a").key_up(Keys.CONTROL).perform()

select = Select(driver.find_element(By.ID, "country"))
select.select_by_visible_text("China")

Grid Setup

# Selenium Grid 4 — start hub and node
# Hub (router)
java -jar selenium-server-4.x.jar hub

# Node
java -jar selenium-server-4.x.jar node \
  --hub http://localhost:4444

# Docker Compose
# services:
#   chrome:
#     image: selenium/node-chrome:4
#   firefox:
#     image: selenium/node-firefox:4
#   hub:
#     image: selenium/hub:4

// Java — connect to Grid
import org.openqa.selenium.remote.RemoteWebDriver;
import java.net.URL;

ChromeOptions options = new ChromeOptions();
WebDriver driver = new RemoteWebDriver(
    new URL("http://localhost:4444"),
    options
);