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Jetty/Tutorial/Jetty and Maven HelloWorld

< Jetty‎ | Tutorial
Revision as of 19:47, 15 February 2010 by Gregw.webtide.com (Talk | contribs)


Apache Maven is a software project management and comprehension tool. Based on the concept of a project object model (POM), Maven can manage a project's build, reporting and documentation from a central piece of information. It is an ideal tool to build a web application project and such projects can use the Jetty/Feature/Jetty Maven Plugin to run the web application in development mode.

Maven can be used both to build embedded jetty appliations and standards based webapplications.


To understand the basic operations of building and running against jetty, first review:

Embedded Jetty with Maven

Maven uses convention over configuration, so it is best to use the project structure as recommended by maven. Archetypes can be used to quickly setup maven projects, but for this tutorial, we will setup the structure manually:

mkdir JettyMavenHelloWorld
cd JettyMavenHelloWorld
mkdir -p src/main/java/org/example

The HelloWorld class

Use an editor to create the file src/main/java/org/example/HelloWorld.java with the following contents:

package org.example;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.handler.AbstractHandler;
public class HelloWorld extends AbstractHandler
    public void handle(String target,
                       Request baseRequest,
                       HttpServletRequest request,
                       HttpServletResponse response) 
        throws IOException, ServletException
        response.getWriter().println("<h1>Hello World</h1>");
    public static void main(String[] args) throws Exception
        Server server = new Server(8080);
        server.setHandler(new HelloWorld());

The POM descriptor

The pom.xml file declares the project name and it's dependencies. Use and editor to create the file pom.xml with the following contents:

<project xmlns="http://maven.apache.org/POM/4.0.0" 
	 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <name>Jetty HelloWorld</name>

Building and Running embedded HelloWorld

The HelloWorld class can now be compiled and executed with the commands

mvn clean compile exec:java

You can point your browser to http://localhost:8080 to see the hello world page. You can observe what maven is doing for you behind the scenes by using the mvn dependency:tree</tr> command which reveals the transitive dependency resolved and downloaded as:

> mvn dependency:tree
[INFO] Scanning for projects...
[INFO] Searching repository for plugin with prefix: 'dependency'.
[INFO] ------------------------------------------------------------------------
[INFO] Building Jetty HelloWorld
[INFO]    task-segment: [dependency:tree]
[INFO] ------------------------------------------------------------------------
[INFO] [dependency:tree {execution: default-cli}]
[INFO] org.example:hello-world:jar:0.1-SNAPSHOT
[INFO] \- org.eclipse.jetty:jetty-server:jar:7.0.1.v20091125:compile
[INFO]    +- javax.servlet:servlet-api:jar:2.5:compile
[INFO]    +- org.eclipse.jetty:jetty-continuation:jar:7.0.1.v20091125:compile
[INFO]    \- org.eclipse.jetty:jetty-http:jar:7.0.1.v20091125:compile
[INFO]       \- org.eclipse.jetty:jetty-io:jar:7.0.1.v20091125:compile
[INFO]          \- org.eclipse.jetty:jetty-util:jar:7.0.1.v20091125:compile
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4 seconds
[INFO] Finished at: Tue Feb 16 16:19:08 EST 2010
[INFO] Final Memory: 11M/68M
[INFO] ------------------------------------------------------------------------

Standard Web app with Jetty and Maven

The above example shows how a hello world example can be run as an embedded jetty handler. The following example shows how a standard webapp can be developed with maven and jetty. The maven structure first needs to be created:

mkdir JettyMavenHelloWarApp
cd JettyMavenHelloWebApp
mkdir -p src/main/java/org/example
mkdir -p src/main/webapp/WEB-INF

Creating some static content

A web application can contain static content, so create the file <tt>src/main/webapp/index.html with the following content:

<h1>Hello World Webapp</h1>
<a href="/hello">Hello Servlet</a>

Creating a Servlet

Use an editor to create the file src/main/java/org/example/HelloServlet.java with the following contents:

package org.example;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class HelloServlet extends HttpServlet
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
        response.getWriter().println("<h1>Hello Servlet</h1>");
        response.getWriter().println("session=" + request.getSession(true).getId());

This servlet needs to be declared in the deployment descriptor, so edit the file src/main/webapp/WEB-INF/web.xml and add the following content:

<?xml version="1.0" encoding="ISO-8859-1"?>
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 

Building and Running the Web Application

The web application can now be built and run using the command:

mvn jetty:run

You can see the static and dynamic content at http://localhost:8080.

Building a WAR file

A Web Application Archive (WAR) file can be created from the project with the command:

mvn package

The resulting war file is in the target directory and may be deployed on any standard servlet server or deployed to jetty.