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Setting Up Your Java Development Environment

Before writing Java code, you need to install Java and set up your development tools. This guide will get you up and running quickly.

What You'll Install

  1. Java Development Kit (JDK) - The core Java tools
  2. Text Editor or IDE - Where you'll write your code
  3. Command Line Tools - To compile and run your programs

Step 1: Install Java Development Kit (JDK)

Check if Java is Already Installed

Open your terminal/command prompt and run:

java --version
javac --version

If both commands show version 17 or higher, you can skip to Step 2.

Install JDK

# Install Homebrew if you don't have it
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Install Java
brew install openjdk@21

# Add to PATH
echo 'export PATH="/opt/homebrew/opt/openjdk@21/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

Option 2: Download from Oracle

  1. Visit Oracle JDK Downloads
  2. Download JDK 21 for macOS
  3. Run the installer and follow the prompts

Option 1: Download from Oracle

  1. Visit Oracle JDK Downloads
  2. Download JDK 21 for Windows
  3. Run the installer
  4. Add Java to PATH:
  5. Open System Properties → Environment Variables
  6. Add Java installation path to PATH variable

Option 2: Using Package Manager

# Using Chocolatey
choco install openjdk21

# Using Winget
winget install Microsoft.OpenJDK.21

# Update package list
sudo apt update

# Install OpenJDK 21
sudo apt install openjdk-21-jdk

# Verify installation
java --version
javac --version

Verify Installation

After installation, verify everything works:

java --version
javac --version

You should see version information for both commands.

Step 2: Choose a Text Editor or IDE

  1. Download: code.visualstudio.com
  2. Install Java Extension Pack:
  3. Open VS Code
  4. Go to Extensions (Ctrl+Shift+X)
  5. Search for "Extension Pack for Java"
  6. Install it

Option 2: IntelliJ IDEA Community Edition

  1. Download: jetbrains.com/idea/download
  2. Choose the free Community Edition
  3. Install with default settings

Option 3: Simple Text Editor

Any text editor works for learning:

  • Notepad++ (Windows)
  • TextEdit (macOS) - Make sure to use plain text mode
  • Gedit (Linux)
  • Sublime Text (All platforms)

Step 3: Create Your First Java Program

Let's verify everything is working by creating a simple program.

Create Project Directory

mkdir java-learning
cd java-learning

Create Your First Program

Create a file named HelloWorld.java:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
        System.out.println("Java is working!");
    }
}

Compile and Run

# Compile the program
javac HelloWorld.java

# Run the program
java HelloWorld

You should see:

Hello, World!
Java is working!

Understanding the Development Workflow

The basic Java development cycle:

  1. Write - Create .java source files
  2. Compile - Use javac to create .class bytecode files
  3. Run - Use java to execute the bytecode
# Compile: .java → .class
javac MyProgram.java

# Run: Execute the .class file
java MyProgram

Essential Command Line Commands

# Compile a single file
javac HelloWorld.java

# Compile multiple files
javac *.java

# Run a program
java HelloWorld

# Check Java version
java --version

# Check compiler version
javac --version

# See detailed compilation errors
javac -verbose HelloWorld.java

Project Organization

Organize your learning projects like this:

java-learning/
├── lesson1/
│   ├── HelloWorld.java
│   └── HelloWorld.class
├── lesson2/
│   ├── Variables.java
│   └── Variables.class
└── lesson3/
    ├── Calculator.java
    └── Calculator.class

Common Setup Issues and Solutions

Issue: "javac is not recognized as a command"

Solution: Java isn't in your PATH. Add the JDK bin directory to your system PATH.

Issue: "Error: Could not find or load main class"

Solutions:

  • Make sure the class name matches the filename exactly
  • Make sure you're in the correct directory
  • Check that the .class file was created during compilation

Issue: VS Code doesn't recognize Java

Solution:

  1. Install the Java Extension Pack
  2. Open a folder containing Java files
  3. VS Code should automatically detect Java projects

Editor Configuration Tips

VS Code Settings

Add to your VS Code settings.json:

{
  "java.configuration.updateBuildConfiguration": "automatic",
  "java.saveActions.organizeImports": true,
  "java.format.enabled": true
}

Basic VS Code Shortcuts

  • Ctrl+Shift+P - Command palette
  • F5 - Run program
  • Ctrl+` - Open terminal
  • Ctrl+Shift+` - New terminal

What's Next?

Great! You now have a working Java development environment. Time to learn the language itself.

Next: Learn Basic Syntax →

Troubleshooting Resources

If you encounter issues: