import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.KeyEvent;

public class KeyBoardExample {
    public static void main(String[] args) {
        try {
            Robot robot = new Robot();
            robot.delay(3000);
            robot.keyPress(KeyEvent.VK_Q); //VK_Q for Q
        } catch (AWTException e) {
            e.printStackTrace();
        }
    }
}

With Selenium

Sometimes we need to press any key in order to test the key press event on web application. For an instance to test the ENTER key on login form we can write something like below with Selenium WebDriver

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.KeyEvent;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.Test;

public class LoginTest {
    
    @Test
    public void testEnterKey() throws InterruptedException
    {
        WebDriver driver=new FirefoxDriver();        
        Robot robot=null;        
        driver.get("test-url");
        driver.manage().window().maximize();
        driver.findElement(By.xpath("xpath-expression")).click();
        driver.findElement(By.xpath("xpath-expression")).sendKeys("username");
        driver.findElement(By.xpath("xpath-expression")).sendKeys("password");        
        try {
            robot=new Robot();
        } catch (AWTException e) {
            e.printStackTrace();
        }
        //Keyboard Activity Using Robot Class
        robot.keyPress(KeyEvent.VK_ENTER);
    }
}

Mouse movement:

import java.awt.Robot;
 
public class MouseClass {
 public static void main(String[] args) throws Exception {
     Robot robot = new Robot();
 
     // SET THE MOUSE X Y POSITION
     robot.mouseMove(300, 550);
     }
}

Press left/right button of mouse:

import java.awt.Robot;
import java.awt.event.InputEvent;

public class MouseEvent {
 public static void main(String[] args) throws Exception {
     Robot robot = new Robot();

     // LEFT CLICK
     robot.mousePress(InputEvent.BUTTON1_MASK);
     robot.mouseRelease(InputEvent.BUTTON1_MASK);

     // RIGHT CLICK
     robot.mousePress(InputEvent.BUTTON3_MASK);
     robot.mouseRelease(InputEvent.BUTTON3_MASK);
     }
}

Click and scroll the wheel:

import java.awt.Robot;
import java.awt.event.InputEvent;
 
public class MouseClass {
 public static void main(String[] args) throws Exception {
     Robot robot = new Robot();
 
     // MIDDLE WHEEL CLICK
     robot.mousePress(InputEvent.BUTTON3_DOWN_MASK);
     robot.mouseRelease(InputEvent.BUTTON3_DOWN_MASK);
 
     // SCROLL THE MOUSE WHEEL
     robot.mouseWheel(-100);
     }
}