How to Build and Run a Java Program in Jenkins Using a Freestyle Job?| S-Logix

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How to Build and Run a Java Program in Jenkins Using a Freestyle Job?

Jenkins

Condition for Build and Run a Java Program in Jenkins Using a Freestyle Job

Description:
This task demonstrates how Jenkins can compile and run a Java program automatically using a Freestyle job. Jenkins will compile Hello.java, execute it, and display the output in the console.

Steps

Step 1 — Verify Java Installation
Description: Ensure Java JDK is installed on the Ubuntu system before using Jenkins.
Command:
```
java -version
javac -version
```

Step 2 — Create a Java Project Folder
Description: Create a directory and prepare a Java program file.
Commands:

mkdir /home/soft13/java-test
cd /home/soft13/java-test
nano Hello.java

Paste Java code:

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

Step 3 — Allow Jenkins Access to This Folder
Description: Give permission so Jenkins can read and execute files.
Command:
```
sudo chmod -R 777 /home/soft13/java-test
```
Step 4 — Open Jenkins Dashboard
Description: In browser go to:
http://localhost:8080
Step 5 — Create a New Jenkins Freestyle Job
Description: Click New Item, enter job name java-build-test, choose Freestyle project, click OK.

Step 6 — Move Project to Jenkins Workspace
Description: Jenkins must compile inside its own workspace.
Commands:

sudo mkdir -p /var/lib/jenkins/workspace/java-build-test
sudo cp /home/soft13/java-test/Hello.java /var/lib/jenkins/workspace/java-build-test/
sudo chmod -R 777 /var/lib/jenkins/workspace/java-build-test

Step 7 — Add Build Step in Jenkins
Description: Scroll to Build → Click Add build step → Select Execute Shell, then paste:
```
echo "Compiling Java program..."
javac Hello.java

echo "Running Java program..."
java Hello
```
Step 8 — Save the Job
Description: Click Save to store pipeline settings.
Step 9 — Run the Job
Description: Click Build Now to execute Java compile and run process.

Step 10 — Check the Result
Description: Open Build #1 → Console Output, you should see:

Compiling Java program...
Running Java program...
Hello from Java Build!
Finished: SUCCESS

Screenshots

List