8. Downloading Java and Maven in Ubuntu Desktop

Before diving into the installation process, it's important to understand why Java and Maven are crucial components in software development:

Java Development Kit (JDK)

The JDK is a software development environment used for developing Java applications. It includes:

• The Java Runtime Environment (JRE) - needed to run Java applications

• Development tools like the Java compiler (javac), debugger, and other utilities

• Java libraries and API documentation essential for Java development

Apache Maven

Maven is a powerful project management tool that provides:

• Dependency management - automatically downloading and managing external libraries

• Standardized project structure - enforcing conventions for organizing code

• Build lifecycle management - handling compilation, testing, packaging, and deployment

• Plugin architecture - extending functionality through various plugins

Why Install Both?

Java and Maven work together in a typical development workflow:

• Java (JDK) provides the core programming environment

• Maven simplifies building and managing Java projects

• Together they create a standardized, efficient development environment

Setting up these tools properly with environment variables like JAVA_HOME and MAVEN_HOME ensures that your development tools and build scripts can locate these resources consistently across your system.

1. Downloading and Installing OpenJDK:

• **Update Package Lists:**Bash

  sudo apt update

• **Install OpenJDK (e.g., OpenJDK 11):**Bash

  sudo apt install openjdk-11-jdk

• **Verify Installation:**Bash

  java -version javac -version

• Set JAVA_HOME (Optional but Recommended):

  • Find the JDK installation path: Bash Note the path (e.g., /usr/lib/jvm/java-11-openjdk-amd64).

    sudo update-alternatives --config java

  • Add JAVA_HOME to your .bashrc or .zshrc file: Bash

    echo 'export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64' >> ~/.bashrc echo 'export PATH=$JAVA_HOME/bin:$PATH' >> ~/.bashrc source ~/.bashrc

2. Downloading and Installing Maven:

• Download Maven:

  • Go to the Apache Maven downloads page: https://maven.apache.org/download.cgi

  • Download the binary tar.gz archive (e.g., apache-maven-3.9.6-bin.tar.gz).

  • Place the archive in a suitable directory (e.g., /opt).

• **Extract Maven:**Bash

  sudo tar -xzf apache-maven-3.9.6-bin.tar.gz -C /opt

• **Create a Symbolic Link (Optional but Recommended):**Bash

  sudo ln -s /opt/apache-maven-3.9.6 /opt/maven

• Set MAVEN_HOME and Add to PATH:

  • Add these lines to your .bashrc or .zshrc file: Bash

    echo 'export MAVEN_HOME=/opt/maven' >> ~/.bashrc echo 'export PATH=$MAVEN_HOME/bin:$PATH' >> ~/.bashrc source ~/.bashrc

• **Verify Installation:**Bash

  mvn -version

Important Notes:

• Replace version numbers with the versions you want to install.

• The paths provided are examples. Adjust them to match your system.

• If you are using a container, you will need to perform these steps inside of the dockerfile.

By following these steps, you can configure Jenkins Global Tool Configuration (for traditional agents) and install JDK and Maven on your Ubuntu machine.