How to build Java project using Jenkins and create war files

 

After integration of Maven, Java and Git in Jenkins create new Project in Jenkins with below details:-


In my case my Java code is save in below git repo:-

Then Apply and Save and click on build now:-

Then build will be start after its done webapp.war files will be save in below path:-

How to integrate Maven with Jenkins to build Java Project

Step 1:- Download Maven from official sites:-  

https://maven.apache.org/download.cgi

[root@jenkins-server ~]# pwd

/root

[root@jenkins-server ~]# cd /opt/

[root@jenkins-server opt]# ls

[root@jenkins-server opt]# ls

[root@jenkins-server opt]# wget https://dlcdn.apache.org/maven/maven-3/3.9.11/binaries/apache-maven-3.9.11-bin.tar.gz

--2025-09-05 04:46:31--  https://dlcdn.apache.org/maven/maven-3/3.9.11/binaries/apache-maven-3.9.11-bin.tar.gz

Resolving dlcdn.apache.org (dlcdn.apache.org)... 151.101.2.132, 2a04:4e42::644

Connecting to dlcdn.apache.org (dlcdn.apache.org)|151.101.2.132|:443... connected.

HTTP request sent, awaiting response... 200 OK

Length: 9160848 (8.7M) [application/x-gzip]

Saving to: ‘apache-maven-3.9.11-bin.tar.gz’

apache-maven-3.9.11-bin.tar.gz            100%[===================================================================================>]   8.74M  --.-KB/s    in 0.08s

2025-09-05 04:46:32 (113 MB/s) - ‘apache-maven-3.9.11-bin.tar.gz’ saved [9160848/9160848]

[root@jenkins-server opt]# ls

apache-maven-3.9.11-bin.tar.gz

Step 2:- Once downloaded the untar it.

[root@jenkins-server opt]# tar -xvzf apache-maven-3.9.11-bin.tar.gz

apache-maven-3.9.11/README.txt

apache-maven-3.9.11/LICENSE

apache-maven-3.9.11/NOTICE

apache-maven-3.9.11/lib/

apache-maven-3.9.11/lib/aopalliance.license

apache-maven-3.9.11/lib/asm.license

 

Step 3 :- Rename the folder name

[root@jenkins-server opt]# ls

apache-maven-3.9.11  apache-maven-3.9.11-bin.tar.gz

[root@jenkins-server opt]# mv apache-maven-3.9.11 maven

[root@jenkins-server opt]# ls

apache-maven-3.9.11-bin.tar.gz  maven

[root@jenkins-server opt]# cd maven/

[root@jenkins-server maven]# ls

LICENSE  NOTICE  README.txt  bin  boot  conf  lib

[root@jenkins-server maven]# cd bin/

[root@jenkins-server bin]# ls

m2.conf  mvn  mvn.cmd  mvnDebug  mvnDebug.cmd  mvnyjp

Run the manven command to check:-

[root@jenkins-server bin]# ./mvn -v

Apache Maven 3.9.11 (3e54c93a704957b63ee3494413a2b544fd3d825b)

Maven home: /opt/maven

Java version: 21.0.8, vendor: Red Hat, Inc., runtime: /usr/lib/jvm/java-21-openjdk

Default locale: en, platform encoding: UTF-8

OS name: "linux", version: "6.12.0-55.25.1.el10_0.x86_64", arch: "amd64", family: "unix"

Step 4:- Now set environment variable to run from anywhere 

[root@jenkins-server bin]# cd ~

[root@jenkins-server ~]# ls

'='

[root@jenkins-server ~]# ls -a

 .   ..   .bash_history   .bash_logout   .bash_profile   .bashrc   .cshrc   .ssh   .tcshrc   .wget-hsts  '='

[root@jenkins-server ~]# vi .bash_profile

[root@jenkins-server ~]# cat .bash_profile

# .bash_profile

# Get the aliases and functions

if [ -f ~/.bashrc ]; then

        . ~/.bashrc

fi

M2_HOME=/opt/maven

M2=/opt/maven/bin

JAVA_HOME=/usr/lib/jvm/java-17-openjdk-17.0.16.0.8-2.el9.x86_64

# User specific environment and startup programs

PATH=$PATH:$HOME/bin:$JAVA_HOME:$M2_HOME:$M2

export PATH

[root@jenkins-server ~]# source .bash_profile

[root@jenkins-server ~]# echo $PATH

/root/.local/bin:/root/bin:/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin:/usr/lib/jvm/java-17-openjdk-17.0.16.0.8-2.el9.x86_64:/opt/maven:/opt/maven/bin

[root@jenkins-server ~]# mvn -v

Apache Maven 3.9.11 (3e54c93a704957b63ee3494413a2b544fd3d825b)

Maven home: /opt/maven

Java version: 21.0.8, vendor: Red Hat, Inc., runtime: /usr/lib/jvm/java-21-openjdk

Default locale: en, platform encoding: UTF-8

OS name: "linux", version: "6.12.0-55.25.1.el10_0.x86_64", arch: "amd64", family: "unix"

[root@jenkins-server ~]#

To find Java path run below command:-

[root@jenkins-server ~]# find / -name jvm

/usr/lib/jvm

/usr/share/jvm

/etc/jvm

[root@jenkins-server ~]# cd /usr/lib/jvm

[root@jenkins-server jvm]# ls

java                                      java-21-openjdk  jre-17-openjdk                           jre-openjdk

java-17                                   java-openjdk     jre-17-openjdk-17.0.16.0.8-2.el9.x86_64

java-17-openjdk                           jre              jre-21

java-17-openjdk-17.0.16.0.8-2.el9.x86_64  jre-17           jre-21-openjdk

[root@jenkins-server jvm]# ls -ltrh

total 0

lrwxrwxrwx. 1 root root 40 Aug 18 20:05 jre-17-openjdk-17.0.16.0.8-2.el9.x86_64 -> java-17-openjdk-17.0.16.0.8-2.el9.x86_64

drwxr-xr-x. 7 root root 97 Sep  3 07:27 java-17-openjdk-17.0.16.0.8-2.el9.x86_64

lrwxrwxrwx. 1 root root 21 Sep  3 07:27 jre -> /etc/alternatives/jre

lrwxrwxrwx. 1 root root 29 Sep  3 07:27 jre-openjdk -> /etc/alternatives/jre_openjdk

lrwxrwxrwx. 1 root root 24 Sep  3 07:27 jre-17 -> /etc/alternatives/jre_17

lrwxrwxrwx. 1 root root 32 Sep  3 07:27 jre-17-openjdk -> /etc/alternatives/jre_17_openjdk

lrwxrwxrwx. 1 root root 26 Sep  3 07:27 java -> /etc/alternatives/java_sdk

lrwxrwxrwx. 1 root root 34 Sep  3 07:27 java-openjdk -> /etc/alternatives/java_sdk_openjdk

lrwxrwxrwx. 1 root root 29 Sep  3 07:27 java-17 -> /etc/alternatives/java_sdk_17

lrwxrwxrwx. 1 root root 37 Sep  3 07:27 java-17-openjdk -> /etc/alternatives/java_sdk_17_openjdk

drwxr-xr-x. 5 root root 68 Sep  3 10:12 java-21-openjdk

lrwxrwxrwx. 1 root root 24 Sep  3 10:12 jre-21 -> /etc/alternatives/jre_21

lrwxrwxrwx. 1 root root 32 Sep  3 10:12 jre-21-openjdk -> /etc/alternatives/jre_21_openjdk

Now install Maven plugins in Jenkins and configure path .

Also configure path of git and Java in Jenkins

If you have multiple java install and to select java 17 use below command:-

How to install Jenkins on Redhat EC2 Server

 Step 1:  Download below repo

[root@ip-172-31-18-18 ~]# sudo wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo

--2025-09-03 10:08:33--  https://pkg.jenkins.io/redhat-stable/jenkins.repo

Resolving pkg.jenkins.io (pkg.jenkins.io)... 146.75.38.133, 2a04:4e42:56::645

Connecting to pkg.jenkins.io (pkg.jenkins.io)|146.75.38.133|:443... connected.

HTTP request sent, awaiting response... 200 OK

Length: 85

Saving to: ‘/etc/yum.repos.d/jenkins.repo’

/etc/yum.repos.d/jenkins.repo             100%[===================================================================================>]      85  --.-KB/s    in 0s

2025-09-03 10:08:33 (2.71 MB/s) - ‘/etc/yum.repos.d/jenkins.repo’ saved [85/85]

===================================================

Step 2:  Download key

[root@ip-172-31-18-18 ~]# sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io-2023.key

==========================================

Step 3:-  Install java

[root@ip-172-31-18-18 ~]# sudo yum install fontconfig java-21-openjdk

Updating Subscription Management repositories.

Unable to read consumer identity

This system is not registered with an entitlement server. You can use "rhc" or "subscription-manager" to register.

Last metadata expiration check: 0:03:37 ago on Wed Sep  3 10:08:57 2025.

Package fontconfig-2.15.0-7.el10.x86_64 is already installed.

============================================

Step 4:- Install Jenkin now

[root@ip-172-31-18-18 ~]# sudo yum install jenkins

Updating Subscription Management repositories.

Unable to read consumer identity

This system is not registered with an entitlement server. You can use "rhc" or "subscription-manager" to register.

Last metadata expiration check: 0:03:58 ago on Wed Sep  3 10:08:57 2025.

============================================================

Step 5:-  Start the Jenkins

[root@ip-172-31-18-18 ~]# sudo systemctl daemon-reload

[root@ip-172-31-18-18 ~]# sudo systemctl enable jenkins

Created symlink '/etc/systemd/system/multi-user.target.wants/jenkins.service' → '/usr/lib/systemd/system/jenkins.service'.

[root@ip-172-31-18-18 ~]# sudo systemctl start jenkins

[root@ip-172-31-18-18 ~]# sudo systemctl status jenkins

● jenkins.service - Jenkins Continuous Integration Server

     Loaded: loaded (/usr/lib/systemd/system/jenkins.service; enabled; preset: disabled)

     Active: active (running) since Wed 2025-09-03 10:13:52 UTC; 19s ago

 Invocation: 7cec58f4a86b4ad98baa29275db3c9f4

   Main PID: 14143 (java)

      Tasks: 42 (limit: 5687)

     Memory: 452.6M (peak: 462.1M)

        CPU: 14.054s

     CGroup: /system.slice/jenkins.service

===================================================

Step 6:-  Now access the Jenkings by using public ip and port 8080

http://52.90.54.118:8080/

/var/lib/jenkins/secrets/initialAdminPassword

How to Install Jenkins by Raj Gupta

Prerequisites

1. EC2 Instance
   • With Internet Access
   • Security Group with Port 8080 open for internet
2. Java 11 should be installed

Install Jenkins

You can install jenkins using the rpm or by setting up the repo. We will set up the repo so that we can update it easily in the future.

1. Get the latest version of jenkins from https://pkg.jenkins.io/redhat-stable/ and install

   sudo wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo
   sudo rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key
   amazon-linux-extras install epel 
   amazon-linux-extras install java-openjdk11  
   
   #on RedHat/CentOs 
   #yum install epel-release # repository that provides 'daemonize'
   #yum install java-11-openjdk-devel
   #yum install jenkins

   Start Jenkins

   # Start jenkins service
   service jenkins start
   
   # Setup Jenkins to start at boot,
   chkconfig jenkins on

   Accessing Jenkins

   By default jenkins runs at port 8080, You can access jenkins at

   http://YOUR-SERVER-PUBLIC-IP:8080

Configure Jenkins

• The default Username is admin
• Grab the default password
• Password Location:/var/lib/jenkins/secrets/initialAdminPassword
• Skip Plugin Installation; We can do it later
• Change admin password
  • Admin > Configure > Password
• Configure java path
  • Manage Jenkins > Global Tool Configuration > JDK
• Create another admin user id

Test Jenkins Jobs

1. Create “new item”
2. Enter an item name – My-First-Project
   • Chose Freestyle project
3. Under the Build section Execute shell: echo "Welcome to Jenkins Demo"
4. Save your job
5. Build job
6. Check "console output"