Jetty Logo
Version: 9.4.31.v20200723
Contact the core Jetty developers at

private support for your internal/customer projects ... custom extensions and distributions ... versioned snapshots for indefinite support ... scalability guidance for your apps and Ajax/Comet projects ... development services for sponsored feature development

Common Jetty Configuration

Creating a new Jetty Base
Changing the Jetty Port
Adding SSL for HTTPS & HTTP2
More start.jar Options

Creating a new Jetty Base

The demo-base directory described earlier is an example of the jetty.base mechanism. A Jetty base directory allows the configuration and web applications of a server instance to be stored separately from the Jetty distribution, so that upgrades can be done with minimal disruption. Jetty’s default configuration is based on two properties:

The property that defines the location of the Jetty distribution, its libs, default modules and default XML files (typically start.jar, lib, etc).
The property that defines the location of a specific implementation of a Jetty server, its configuration, logs and web applications (typically start.d/*.ini files, logs and webapps).


Your Jetty Home directory should be treated as a standard of truth and remain unmodified or changed. Changes or additions to your configuration should take place in the Jetty Base directory.

The jetty.home and jetty.base properties may be explicitly set on the command line, or they can be inferred from the environment if used with commands like:

> java -jar $JETTY_HOME/start.jar

The following commands create a new base directory, enables both the HTTP connector and the web application deployer modules, and copies a demo webapp to be deployed:

> JETTY_BASE=/tmp/mybase
> mkdir $JETTY_BASE
> java -jar $JETTY_HOME/start.jar

WARNING: Nothing to start, exiting ...

Usage: java -jar start.jar [options] [properties] [configs]
       java -jar start.jar --help  # for more information

> java -jar $JETTY_HOME/start.jar --create-startd
INFO : Base directory was modified
> java -jar $JETTY_HOME/start.jar --add-to-start=http,deploy

INFO: server          initialised (transitively) in ${jetty.base}/start.d/server.ini
INFO: http            initialised in ${jetty.base}/start.d/http.ini
INFO: security        initialised (transitively) in ${jetty.base}/start.d/security.ini
INFO: servlet         initialised (transitively) in ${jetty.base}/start.d/servlet.ini
INFO: webapp          initialised (transitively) in ${jetty.base}/start.d/webapp.ini
INFO: deploy          initialised in ${jetty.base}/start.d/deploy.ini
MKDIR: ${jetty.base}/webapps
INFO: Base directory was modified

> cp $JETTY_HOME/demo-base/webapps/async-rest.war webapps/ROOT.war
> java -jar $JETTY_HOME/start.jar

2015-06-04 11:10:16.286:INFO::main: Logging initialized @274ms
2015-06-04 11:10:16.440:INFO:oejs.Server:main: jetty-9.3.0.v20150601
2015-06-04 11:10:16.460:INFO:oejdp.ScanningAppProvider:main: Deployment monitor [file:///tmp/mybase/webapps/] at interval 1
2015-06-04 11:10:16.581:WARN::main: async-rest webapp is deployed. DO NOT USE IN PRODUCTION!
2015-06-04 11:10:16.589:INFO:oejw.StandardDescriptorProcessor:main: NO JSP Support for /, did not find org.eclipse.jetty.jsp.JettyJspServlet
2015-06-04 11:10:16.628:INFO:oejsh.ContextHandler:main: Started o.e.j.w.WebAppContext@1a407d53{/,[file:///tmp/jetty-, jar:file:///tmp/jetty-!/META-INF/resources],AVAILABLE}{/ROOT.war}
2015-06-04 11:10:16.645:INFO:oejs.ServerConnector:main: Started ServerConnector@3abbfa04{HTTP/1.1,[http/1.1]}{}
2015-06-04 11:10:16.646:INFO:oejs.Server:main: Started @634ms

Changing the Jetty Port

You can configure Jetty to run on a different port by setting the jetty.http.port property on the command line:

> java -jar $JETTY_HOME/start.jar jetty.http.port=8081

When the server starts, it will now run on port 8081. It is important to note that setting properties on the command line will only take affect for that instance of the server. To change the configuration so that the server will always start on the desired port, you will need to edit the start.d/http.ini


The configuration by properties works via the following chain:

  • The start.d/http.ini file is part of the effective command line and contains the --module=http argument which activates the http module.
  • The modules/http.mod file defines the http module which specifies the etc/jetty-http.xml configuration file and the template ini properties it uses.
  • The jetty.http.port property is used by the Property XML element in etc/jetty.http.xml to inject the ServerConnector instance with the port.

For more information see the Quickstart Configuration Guide and Configuring Connectors.

Adding SSL for HTTPS & HTTP2

Building on the example above, we can activate additional modules to add support HTTPS and HTTP2 for the server. To add HTTPS and HTTP2 connectors to a Jetty configuration, the modules can be activated by the following command:

> java -jar $JETTY_HOME/start.jar --add-to-start=https,http2

ALERT: There are enabled module(s) with licenses.
The following 1 module(s):
 + contains software not provided by the Eclipse Foundation!
 + contains software not covered by the Eclipse Public License!
 + has not been audited for compliance with its license

 Module: alpn-impl/alpn-8
  + ALPN is a hosted at github under the GPL v2 with ClassPath Exception.
  + ALPN replaces/modifies OpenJDK classes in the package.

Proceed (y/N)? y
INFO  : alpn-impl/alpn-1.8.0_92 dynamic dependency of alpn-impl/alpn-8
INFO  : alpn            transitively enabled, ini template available with --add-to-start=alpn
INFO  : alpn-impl/alpn-8 dynamic dependency of alpn
INFO  : http2           initialized in ${jetty.base}/start.d/http2.ini
INFO  : https           initialized in ${jetty.base}/start.d/https.ini
INFO  : ssl             transitively enabled, ini template available with --add-to-start=ssl
MKDIR : ${jetty.base}/lib/alpn
DOWNLD: to ${jetty.base}/lib/alpn/alpn-boot-8.1.8.v20160420.jar
MKDIR : ${jetty.base}/etc
COPY  : ${jetty.home}/modules/ssl/keystore to ${jetty.base}/etc/keystore
INFO  : Base directory was modified

> java -jar $JETTY_HOME/start.jar
2017-05-22 12:48:23.271:INFO:oejs.AbstractConnector:main: Started ServerConnector@134d0064{SSL,[ssl, alpn, h2, http/1.1]}{}

The --add-to-start command sets up the effective command line in the ini files to run an ssl connection that supports the HTTPS and HTTP2 protocols as follows:

  • transitively enabled the ssl module that configures an SSL connector (eg port, keystore etc.) by adding etc/jetty-ssl.xml and etc/jetty-ssl-context.xml to the effective command line.
  • transitively enabled the alpn module that configures protocol negotiation on the SSL connector by adding etc/jetty-alpn.xml to the effective command line.
  • creates start.d/https.ini that configures the HTTPS protocol on the SSL connector by adding etc/jetty-https.xml to the effective command line.
  • creates start.d/http2.ini that configures the HTTP/2 protocol on the SSL connector by adding etc/jetty-http2.xml to the effective command line.
  • checks for the existence of a etc/keystore file and if not present, downloads a demonstration keystore file.

Changing the Jetty HTTPS Port

You can configure the SSL connector to run on a different port by setting the jetty.ssl.port property on the command line:

> java -jar $JETTY_HOME/start.jar jetty.ssl.port=8444

Alternatively, property values can be added to the effective command line built from the start.ini file or start.d/*.ini files, depending on your set up. Please see the section on Start.ini vs. Start.d for more information.

More start.jar Options

The job of the start.jar is to interpret the command line, start.ini and start.d directory (and associated .ini files) to build a Java classpath and list of properties and configuration files to pass to the main class of the Jetty XML configuration mechanism. The start.jar mechanism has many options which are documented in the Chapter 9, Starting Jetty administration section and you can see them in summary by using the command:

> java -jar $JETTY_HOME/start.jar --help

See an error or something missing? Contribute to this documentation at Github!(Generated: 2020-07-23)