Linux Java Guide

Linux Java Guide

Complete beginner-friendly guide to Java on Linux, covering Arch Linux, CachyOS, and other distributions including installation, JDK setup, and Java development.

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Table of Contents

1. Java Installation
2. JDK Setup
3. Java Development
4. IDE Setup
5. Troubleshooting

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Java Installation

Install Java

Arch/CachyOS:

# Install OpenJDK
sudo pacman -S jdk-openjdk

# Or Oracle JDK
yay -S jdk

# Check version
java --version

Debian/Ubuntu:

sudo apt install default-jdk

Fedora:

sudo dnf install java-latest-openjdk-devel

Verify Installation

Check Java:

# Check version
java --version
javac --version

# Check JAVA_HOME
echo $JAVA_HOME

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JDK Setup

Set JAVA_HOME

Configure environment:

# Set JAVA_HOME
export JAVA_HOME=/usr/lib/jvm/default

# Make permanent
echo 'export JAVA_HOME=/usr/lib/jvm/default' >> ~/.bashrc

Multiple JDK Versions

Switch versions:

# List installed JDKs
archlinux-java status

# Set default
sudo archlinux-java set java-11-openjdk

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Java Development

Hello World

Basic program:

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

Compile and Run

Build:

# Compile
javac Hello.java

# Run
java Hello

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IDE Setup

IntelliJ IDEA

Install IntelliJ:

# Arch/CachyOS
yay -S intellij-idea-community-edition

# Launch
idea

Eclipse

Install Eclipse:

# Arch/CachyOS
sudo pacman -S eclipse-java

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Troubleshooting

Java Not Found

Check installation:

# Check Java
which java
which javac

# Install if missing
sudo pacman -S jdk-openjdk

Version Issues

Check version:

# List versions
archlinux-java status

# Set version
sudo archlinux-java set java-17-openjdk

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Summary

This guide covered Java installation, JDK setup, and development for Arch Linux, CachyOS, and other distributions.

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Next Steps

• Development Environment - Development setup
• VS Code Guide - VS Code setup
• Java: https://www.java.com/

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This guide covers Arch Linux, CachyOS, and other Linux distributions. For distribution-specific details, refer to your distribution's documentation.