Setting up JDK

Install and configure Java Development Kit for Selenium automation.

What You’ll Learn

• Understand what JDK is and why it’s required for Selenium and automation testing.
• Download and install JDK 25 on Windows (latest release).
• Configure the JAVA_HOME environment variable on your Windows machine.
• Add Java to the system PATH so tools like Maven and IntelliJ can detect Java correctly.

Why This Lab Matters

Before writing any Selenium test, your machine must be able to compile and run Java code. If Java or JAVA_HOME are not properly configured, you'll face weird errors in IDEs or test tools. This lab makes sure your environment on Windows is clean, stable, and ready for the rest of the course.

Prerequisites

• Windows 10 or later (64-bit).
• Permission to install software (able to run installer as Administrator).
• Basic computer knowledge:
  • How to download files from a browser.
  • How to navigate folders in Windows Explorer.

Core Concepts

JDK (Java Development Kit):

A development toolkit that lets you compile and run Java applications.

JAVA_HOME:

An environment variable that tells tools (Maven, IntelliJ, Gradle, etc.) where Java is installed.

PATH variable:

A system variable that lets you run java, javac, and other Java commands from any folder in Command Prompt.

Step 1 – Use JDK 25 (Latest Release)

Step 2 – Download JDK 25 for Windows

1. Open your browser and go to the official download page: either the official Oracle download site or the open-source build page for JDK 25.
2. Download the Windows x64 Installer — either .exe, .msi, or .zip (if using ZIP for manual setup).

Step 3 – Install JDK 25 on Windows

1. Run the downloaded installer (or extract ZIP).
2. When prompted, accept defaults. The usual installation directory is:
   C:\Program Files\Java\jdk-25
3. Finish the installation.

Step 4 – Configure JAVA_HOME on Windows

1. Press Win + R, type: sysdm.cpl → Enter.
2. Go to the Advanced tab → click Environment Variables….
3. Under System variables, click New….
   • Variable name: JAVA_HOME
   • Variable value: the path where JDK 25 is installed (e.g. C:\Program Files\Java\jdk-25)
4. Click OK to save.

Step 5 – Add Java to the PATH

1. In the same Environment Variables window, find Path under System variables → click Edit.
2. Add a new entry:
   %JAVA_HOME%\bin
3. Click OK to save all.
4. Close and reopen Command Prompt so changes take effect.

Step 6 – Verify Installation

Open a new Command Prompt and run:

java --version
javac --version

You should see version 25.x.x without errors.

If that succeeds — your Java setup is complete and ready for use.

Code Example (Quick Test)

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public class HelloJava25 {
    public static void main(String[] args) {
        System.out.println("Java 25 is installed correctly on Windows!");
    }
}

Java 25 is installed correctly on Windows!

Pro Tips (From Real Projects)

• Tip 1: Use the default installation folder (C:\Program Files\Java\jdk-25) to avoid permission issues.
• Tip 2: If IntelliJ / Maven complains about JDK not found — first check JAVA_HOME & PATH settings, then restart the IDE or terminal.
• Tip 3: After every change to environment variables — always open a new Command Prompt window to test the change.
• Tip 4: Stick to one stable Java version (JDK 25) for the entire course to avoid version conflicts.

Common Mistakes to Avoid

• Mistake 1 – Setting JAVA_HOME to the bin folder.
  ❌ Wrong: C:\Program Files\Java\jdk-25\bin
  ✔ Correct: C:\Program Files\Java\jdk-25
• Mistake 2 – Forgetting to add %JAVA_HOME%\bin to PATH → java / javac commands won’t work.
• Mistake 3 – Leaving old Java versions in PATH → can cause version mismatch or wrong Java being used.
• Mistake 4 – Not reopening Command Prompt after environment changes → you won’t see the changes until you open a new terminal.