Jetty is a Java HTTP web server and Java servlet container. Jetty is a free and open source project developed and maintained by Eclipse Foundation. Jetty is used in many open source projects and products. Jetty can be easily embedded in devices, tools, frameworks, application servers and clusters.
In this article, we will install Jetty 9 web server on CentOS 7 and then deploy a Java web application on it.
Table of Contents:
- System Specification
- Installing OpenJDK 8 on CentOS 7
- Installing Jetty 9 Web Server on CentOS 7
- Deploy a Java Web Application on Jetty 9 Web Server
System Specification:
We have provisioned a CentOS 7 virtual machine with following specification, for Jetty 9 installation.
- Hostname - jetty-01.example.com
- IP Address - 192.168.116.166/24
- Operating System - CentOS 7.6
- Jetty version - Jetty 9.4
Installing OpenJDK 8 on CentOS 7:
Connect with jetty-01.example.com using ssh as root user.
Jetty requires JVM to execute Java web applications. Therefore we are installing OpenJDK using yum command.
# yum install -y java-1.8.0-openjdk
Set Java environment variables.
# echo "export JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64" >> /etc/profile # . /etc/profile # env | grep JAVA_HOME JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64
Ensure Java installation by checking the version.
# java -version
openjdk version "1.8.0_212"
OpenJDK Runtime Environment (build 1.8.0_212-b04)
OpenJDK 64-Bit Server VM (build 25.212-b04, mixed mode)
OpenJDK has been installed on CentOS 7.
Installing Jetty 9 Web Server on CentOS 7:
Create a user to own Jetty software.
# useradd jetty
Download latest version of Jetty from Eclipse website. Earlier releases can be download from Maven Central.
# cd /tmp # curl -O https://repo1.maven.org/maven2/org/eclipse/jetty/jetty-distribution/9.4.18.v20190429/jetty-distribution-9.4.18.v20190429.tar.gz % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 18.4M 100 18.4M 0 0 95411 0 0:03:22 0:03:22 --:--:-- 110k
Extract downloaded file to /opt directory.
# tar zxf jetty-distribution-9.4.18.v20190429.tar.gz -C /opt/
Create a soft link for /opt/jetty-distribution-9.4.18.v20190429/ directory.
# ln -s /opt/jetty-distribution-9.4.18.v20190429/ /opt/jetty
Set Jetty software ownership to jetty user.
# chown -R jetty:jetty /opt/jetty/
We need to set environment variables for Jetty server. You can also set JAVA_OPTIONS specific to Jetty web server here.
# cat > /etc/default/jetty << EOF > JETTY_HOME=/opt/jetty > JETTY_BASE=/opt/jetty/webapps > JETTY_USER=jetty > JETTY_HOST=0.0.0.0 > JETTY_ARGS=jetty.port=8080 > EOF
Create and set privileges on Jetty’s run directory.
# mkdir /var/run/jetty # chown jetty:jetty /var/run/jetty
Allow Jetty service port in Linux Firewall.
# firewall-cmd --permanent --add-port=8080/tcp success # firewall-cmd --reload success
Create a systemd unit for Jetty service.
# vi /usr/lib/systemd/system/jetty.service
and add following directives therein.
[Unit]
Description = Jetty Web Server
After = syslog.target network.target
[Service]
User = jetty
ExecStart = /opt/jetty/bin/jetty.sh start
ExecStop = /opt/jetty/bin/jetty.sh stop
ExecReload = /opt/jetty/bin/jetty.sh restart
Type = forking
[Install]
WantedBy = multi-user.target
Start and enable Jetty service.
# systemctl enable jetty.service Created symlink from /etc/systemd/system/multi-user.target.wants/jetty.service to /usr/lib/systemd/system/jetty.service. # systemctl start jetty.service
Browse URL http://jetty-01.example.com:8080/ from a client's browser.
Jetty 9 web server has been installed on CentOS 7.
Deploy a Java Web Application on Jetty 9 Web Server:
Download a Java project source from GitHub.
We are downloading simple-crud-app, which is a simple Hello World application.
# curl -O https://codeload.github.com/trdngy/toy-project-1/zip/master
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 15923 0 15923 0 0 2994 0 --:--:-- 0:00:05 --:--:-- 4201
Extract downloaded file.
# unzip master
This project is powered by Apache Maven, therefore, we have to install Apache Maven to compile this project.
# yum install -y maven
Verify Apache Maven installation by checking its version.
# mvn -v
Apache Maven 3.0.5 (Red Hat 3.0.5-17)
Maven home: /usr/share/maven
Java version: 1.8.0_212, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "3.10.0-957.el7.x86_64", arch: "amd64", family: "unix"
Compile the source to generate WAR file. We will deploy this WAR on our Jetty 9 web server.
# cd toy-project-1-master/ # mvn compile [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building simple-crud-app Maven Webapp 0.0.1 [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-resources-plugin:2.5:resources (default-resources) @ simple-crud-app --- [debug] execute contextualize [WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] Copying 1 resource [INFO] [INFO] --- maven-compiler-plugin:2.3.2:compile (default-compile) @ simple-crud-app --- [WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent! [INFO] Compiling 8 source files to /tmp/toy-project-1-master/target/classes [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 4.954s [INFO] Finished at: Wed May 15 01:18:17 PKT 2019 [INFO] Final Memory: 13M/32M [INFO] ------------------------------------------------------------------------
Build WAR file to deploy on our Jetty 9 web server.
# mvn package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building simple-crud-app Maven Webapp 0.0.1
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.5:resources (default-resources) @ simple-crud-app ---
[debug] execute contextualize
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 1 resource
[INFO]
[INFO] --- maven-compiler-plugin:2.3.2:compile (default-compile) @ simple-crud-app ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.5:testResources (default-testResources) @ simple-crud-app ---
[debug] execute contextualize
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /tmp/toy-project-1-master/src/test/resources
[INFO]
[INFO] --- maven-compiler-plugin:2.3.2:testCompile (default-testCompile) @ simple-crud-app ---
[INFO] No sources to compile
[INFO]
[INFO] --- maven-surefire-plugin:2.10:test (default-test) @ simple-crud-app ---
[INFO] No tests to run.
[INFO] Surefire report directory: /tmp/toy-project-1-master/target/surefire-reports
-------------------------------------------------------
T E S T S
-------------------------------------------------------
Results :
Tests run: 0, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] --- maven-war-plugin:3.2.0:war (default-war) @ simple-crud-app ---
[INFO] Packaging webapp
[INFO] Assembling webapp [simple-crud-app] in [/tmp/toy-project-1-master/target/simple-crud-app]
[INFO] Processing war project
[INFO] Copying webapp resources [/tmp/toy-project-1-master/src/main/webapp]
[INFO] Webapp assembled in [378 msecs]
[INFO] Building war: /tmp/toy-project-1-master/target/simple-crud-app.war
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.324s
[INFO] Finished at: Wed May 15 01:19:15 PKT 2019
[INFO] Final Memory: 9M/92M
[INFO] ------------------------------------------------------------------------
Copy the generated WAR file in Jetty 9 webapps directory.
# mv /tmp/toy-project-1-master/target/simple-crud-app.war /opt/jetty/webapps/
If you access the URL http://jetty-01.example.com:8080/ , you may notice that our application is automatically added in Jetty 9 web server.
Browser URL http://jetty-01.example.com:8080/simple-crud-app/ to access our Java Web Application via Jetty 9 web server.
We have successfully deployed a Java web application in our Jetty 9 web server on CentOS 7. If you want to know more about Jetty, then you should read Java Web Services: Up and Running by O'Reilly Media.
