Adoptium JDK 8 Download: A Comprehensive Guide

Table of Contents#

1. What is Adoptium JDK?
2. Why JDK 8?
3. System Requirements
4. Downloading Adoptium JDK 8
5. Installation Guide by Operating System
   • Windows
   • macOS
   • Linux
6. Verifying the Installation
7. Common Issues and Troubleshooting
8. Best Practices for Using Adoptium JDK 8
9. Example Usage
10. References

What is Adoptium JDK?#

Eclipse Adoptium is a community-driven project under the Eclipse Foundation that delivers free, open-source, and TCK (Technology Compatibility Kit)-certified builds of OpenJDK. The project was rebranded from AdoptOpenJDK in 2021 to align with Eclipse’s governance, but its core mission remains unchanged: to provide reliable, production-ready JDK distributions for all major operating systems.

Key features of Adoptium JDK:

• TCK-Certified: Ensures compliance with the Java SE specification, guaranteeing compatibility with Java applications.
• Free and Open Source: No commercial licensing fees, even for production use.
• Regular Updates: Security patches and bug fixes for LTS versions (like JDK 11 and 17).
• Multiple Platforms: Supports Windows, macOS, Linux, and even ARM architectures (e.g., Apple Silicon).

Why JDK 8?#

Despite the release of newer JDK versions (e.g., 11, 17, 21), JDK 8 remains dominant in enterprise environments for several reasons:

• LTS Status: JDK 8 is a legacy LTS release—Adoptium ended support for JDK 8 in December 2023. Users still on JDK 8 should plan migration to actively supported LTS versions such as JDK 11 or 17.
• Legacy Applications: Many enterprise systems, frameworks (e.g., Spring Framework 4.x), and libraries are built for JDK 8 and have not been migrated to newer versions.
• Stability: JDK 8’s feature set is mature, with minimal breaking changes, making it a safe choice for critical systems.
• Widespread Adoption: Tools like Apache Maven, Gradle, and IDEs (IntelliJ, Eclipse) have robust support for JDK 8.

System Requirements#

Before downloading Adoptium JDK 8, ensure your system meets the following requirements:

Downloading Adoptium JDK 8#

Adoptium provides prebuilt JDK 8 binaries for all major platforms. Follow these steps to download the correct version:

Step 1: Navigate to the Adoptium Website#

Visit the official Adoptium downloads page:
https://adoptium.net/temurin/releases/?version=8

Step 2: Select JDK 8 and "Temurin"#

• Version: Ensure "8" is selected (under "Version").
• Implementation: Choose "Temurin" (Adoptium’s default OpenJDK implementation).

Step 3: Choose Your Platform#

Select your operating system (OS) and architecture:

• OS: Windows, macOS, Linux, or other (e.g., Solaris).
• Architecture: x64 (64-bit Intel/AMD) or aarch64 (ARM, e.g., Apple M1/M2).

Step 4: Select the Package Type#

Adoptium offers multiple package formats:

• Windows: .msi (installer) or .zip (portable).
• macOS: .dmg (installer) or .tar.gz (portable).
• Linux: .tar.gz (portable), .rpm (Red Hat-based), or .deb (Debian-based).

Recommendation: Use the installer (.msi, .dmg, .rpm, .deb) for easier setup, as it auto-configures environment variables.

Step 5: Download the Binary#

Click the "Download" button for your selected package. The file name will follow the format:
OpenJDK8U-jdk_<arch>_<os>_<version>.tar.gz (e.g., OpenJDK8U-jdk_x64_windows_hotspot_8u392b08.tar.gz).

Installation Guide by Operating System#

Windows#

Using the MSI Installer (Recommended)#

1. Locate the downloaded .msi file (e.g., OpenJDK8U-jdk_x64_windows_hotspot_8u392b08.msi).
2. Double-click the file to launch the installer.
3. Follow the setup wizard:
   • Installation Directory: Default is C:\Program Files\Eclipse Adoptium\jdk8uXXX-bXX (where XXX is the update number, bXX is the build number).
   • Features: Check "Add to PATH" and "Set JAVA_HOME variable" (recommended for development).
4. Click "Install" and wait for completion.

Using the ZIP Archive (Portable)#

1. Extract the .zip file to a directory (e.g., C:\jdk8-adoptium).
2. Set Environment Variables (manual setup):
   • Open System Properties → Advanced → Environment Variables.
   • Under "System Variables", click "New" and set:
     • Variable Name: JAVA_HOME
     • Variable Value: C:\jdk8-adoptium (path to your extracted JDK).
   • Edit the PATH variable and add %JAVA_HOME%\bin.
3. Restart your terminal to apply changes.

macOS#

Using the DMG Installer (Recommended)#

1. Locate the downloaded .dmg file (e.g., OpenJDK8U-jdk_x64_mac_hotspot_8u392b08.dmg).
2. Double-click the file to mount the disk image.
3. Drag the Eclipse Temurin JDK 8 icon to the Applications folder.
4. Verify Installation Path: The JDK is installed to /Library/Java/JavaVirtualMachines/temurin-8.jdk/Contents/Home.

Using the TAR.GZ Archive (Portable)#

1. Extract the .tar.gz file:

   tar -xzf OpenJDK8U-jdk_x64_mac_hotspot_8u392b08.tar.gz -C /usr/local/

2. Set JAVA_HOME (add to ~/.bash_profile, ~/.zshrc, or ~/.profile):

   export JAVA_HOME=/usr/local/jdk8u392-b08/Contents/Home
   export PATH=$JAVA_HOME/bin:$PATH

3. Refresh the terminal:

   source ~/.zshrc  # or ~/.bash_profile

Linux#

Using Package Managers (Debian/Ubuntu or RHEL/CentOS)#

Adoptium provides official repositories for Linux distributions.

For Debian/Ubuntu:

1. Add the Adoptium GPG key:

   wget -O - https://packages.adoptium.net/artifactory/api/gpg/key/public | sudo tee /etc/apt/trusted.gpg.d/adoptium.asc

2. Add the repository:

   echo "deb https://packages.adoptium.net/artifactory/deb $(awk -F= '/^VERSION_CODENAME/{print$2}' /etc/os-release) main" | sudo tee /etc/apt/sources.list.d/adoptium.list

3. Install JDK 8:

   sudo apt update && sudo apt install temurin-8-jdk

For RHEL/CentOS:

1. Add the repository:

   sudo tee /etc/yum.repos.d/adoptium.repo <<EOF
   [Adoptium]
   name=Adoptium
   baseurl=https://packages.adoptium.net/artifactory/rpm/centos/\$releasever/\$basearch
   enabled=1
   gpgcheck=1
   gpgkey=https://packages.adoptium.net/artifactory/api/gpg/key/public
   EOF

2. Install JDK 8:

   sudo yum install temurin-8-jdk

Using TAR.GZ Archive (Portable)#

1. Extract the .tar.gz file to /usr/local/:

   sudo tar -xzf OpenJDK8U-jdk_x64_linux_hotspot_8u392b08.tar.gz -C /usr/local/

2. Set JAVA_HOME (add to /etc/profile for system-wide access or ~/.bashrc for user-specific):

   echo 'export JAVA_HOME=/usr/local/jdk8u392-b08' | sudo tee -a /etc/profile
   echo 'export PATH=$JAVA_HOME/bin:$PATH' | sudo tee -a /etc/profile

3. Refresh the profile:

   source /etc/profile

Verifying the Installation#

After installation, verify that Adoptium JDK 8 is correctly configured:

Step 1: Check Java Version#

Open a terminal/command prompt and run:

java -version

Expected Output:

openjdk version "1.8.0_392"
OpenJDK Runtime Environment (Temurin)(build 1.8.0_392-b08)
OpenJDK 64-Bit Server VM (Temurin)(build 25.392-b08, mixed mode)

Step 2: Check JDK Compiler#

Verify the javac (Java compiler) is available:

javac -version

Expected Output:

javac 1.8.0_392

Step 3: Verify JAVA_HOME (Optional)#

Confirm JAVA_HOME points to the Adoptium JDK:

echo $JAVA_HOME  # Linux/macOS
echo %JAVA_HOME%  # Windows (Command Prompt)

Example Output (Linux):

/usr/local/jdk8u392-b08

Common Issues and Troubleshooting#

1. "java: command not found"#

• Cause: PATH variable not updated to include the JDK’s bin directory.
• Fix:
  • Re-run the installer and check "Add to PATH".
  • Manually add $JAVA_HOME/bin to PATH (see installation steps for your OS).

2. Incorrect JDK Version (e.g., Oracle JDK)#

• Cause: Multiple JDKs installed; the system defaults to another version.
• Fix:
  • Linux/macOS: Use update-alternatives to set Adoptium JDK as default:

    sudo update-alternatives --config java
    sudo update-alternatives --config javac

  • Windows: Reorder PATH entries to prioritize Adoptium’s bin directory.

3. Architecture Mismatch (32-bit vs. 64-bit)#

• Cause: Downloaded a 32-bit JDK on a 64-bit system (or vice versa).
• Fix: Re-download the correct architecture (x64 for 64-bit systems).

4. macOS "Unidentified Developer" Error#

• Cause: macOS security settings block unsigned apps.
• Fix: Right-click the .dmg file → "Open" → "Open" again in the prompt.

Best Practices for Using Adoptium JDK 8#

1. Use the Latest Patch Release#

Adoptium regularly releases security patches (e.g., 8u392 is newer than 8u382). Always download the latest patch to avoid vulnerabilities.

2. Set JAVA_HOME Explicitly#

Many tools (e.g., Maven, Gradle, IDEs) rely on JAVA_HOME to locate the JDK. Always set it to avoid conflicts.

3. Manage Multiple JDK Versions#

Use tools like:

• SDKMAN! (Linux/macOS): sdk install java 8.0.392-tem
• jenv (macOS): jenv add /Library/Java/JavaVirtualMachines/temurin-8.jdk/Contents/Home
• Chocolatey (Windows): choco install temurin8

4. Secure Your Installation#

• Disable unused features (e.g., java.rmi if not needed).
• Regularly update to the latest Adoptium patch (subscribe to Adoptium’s release notifications).

5. Use Containerized JDK 8#

For cloud deployments, use Adoptium’s official Docker images:

FROM eclipse-temurin:8-jdk

Example Usage#

1. Simple Java Program#

Create a HelloWorld.java file:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, Adoptium JDK 8!");
        System.out.println("Java Version: " + System.getProperty("java.version"));
    }
}

Compile and run:

javac HelloWorld.java
java HelloWorld

Output:

Hello, Adoptium JDK 8!
Java Version: 1.8.0_392

2. Maven Project with JDK 8#

Add this to your pom.xml to enforce JDK 8:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

Run mvn compile—Maven will use Adoptium JDK 8 if JAVA_HOME is set correctly.

References#

• Eclipse Adoptium Official Website
• Adoptium JDK 8 Download Page
• OpenJDK 8 Documentation
• Adoptium Installation Guide
• Adoptium Security Advisories
• Eclipse Temurin Docker Images