Development Tools

• Code/Help Repository:
  • Getting the code
  • Developing with Git
  • Merging a PR
  • Git FAQs
  • Intro to GitHub Desktop
• Building Tools:
  • Ant
  • NetBeans
  • Eclipse
  • IntelliJ IDEA

Code Structure

• Introduction
• Names and Naming
• Application Structure
• Code Structure Patterns
• Swing Structure
• External Connection Structure
• Application Preferences
• Profile Files
• Threading
• Use of XML
  • XML Schema
  • XSLT Formatting
• Web Site
• Javadocs
  • Name Index
  • Packages
  • Classes

Techniques and Standards

• Recommended Practices
• Continuous Integration
• Internationalization
• Logging & Error Handling
• Unit testing with JUnit
• Documentation using Javadoc and UML
• Run the SpotBugs static analysis tool
• Providing help using JavaHelp
• Portable Filename Method
• XML Persistance

Help and Web Site

• Providing Help using JmriHelp
• The JMRI Web Site
• Updating JMRI Web and Help
• Creating Help for New Hardware
• Program Documentation Using Javadoc

How To

• Extend JMRI
• Add a New System
• Add a New Type

Functional Info

• Turnout Feedback
• Network Connections
• How the startup scripts work

Background Info

• Technology Roadmap
• Survey of JVM Capabilities
• Usage Poll, Spring 2007

Donate to JMRI.org

JMRI: Technology Road Map

This page is the road map for JMRI's future development, including changes to our use of Java technologies. It is maintained and updated through continuing discussion on the jmri-developers mailing list.

There's also a page containing the history, particularly the saga of how we moved forward to Java 1.6 and Java 8 across a series of platform-related changes.

JMRI Releases

This section describes the history and (notional) plans for JMRI releases in the future.

Release	Description	Date	JRE	JDK
3.11.*	Development series		1.6	8
4.0	Production version, culmination of 3.11.* series	July 2015	8	8
4.2	Production version, culmination of 4.1.* series	December 2015	8	8
...	...	...	8	8
4.22	Production version, culmination of Fall 2020 series	February 2021	8	8
4.24	Production version, culmination of Spring 2021 series	July 2021	8	8
4.26	Production version, culmination of Fall 2021 series	January 2022	8	8
(Intended) 5.0	Production version, culmination of Spring 2022 series	June 2022	11	11
(Intended) 5.2	Production version, culmination of Fall 2022 series	Jan 2023	11	11
(Intended) 5.4	Production version, culmination of Spring 2023 series	June 2023	11	11

Java and JMRI in the Near Future

The 4.1.* series of test releases in Fall 2015 started the requirement for Java 8. This continued through the following release series. Java 8 continued to be the requirement through the Fall of 2021.

The next long-term-support (LTS) Java release after Java 8 is Java 11 from Fall of 2018. Oracle has aligned their Java and the OpenJDK from that point.

In Spring 2022 the Java version required by JMRI moved forward, making JMRI 4.27.1 the last JMRI version running on Java 8.
Newer development releases 4.99.x will culminate in the June 2022 production releases requiring Java 11 and therefore being called JMRI 5.0.

Java 17 is the current LTS release. JMRI is built and tests are run on it too, but we don't recommend using it due to some remaining compatibility issues.

Java Release and Operating System Support

More information on Java releases and the operating systems that support them can be found here.

Java installers are now available from multiple sources. Our Java installer page lists a number of them.

Migration Notes

This is a section of notes for various code migrations that are in progress or contemplated. These don't directly affect JMRI users in the way that Java version changes do, but they may affect external users of the JMRI libraries.

• USB access technology has advanced a lot since support for some basic libraries was added to JMRI. At some point, we should replace those early library versions, but it will break some user scripts.
• Our logging methodology is now a hybrid of native logging (in some included libraries), Log4J 1.2.17 (logger in our code) and SLF4J (a logging abstraction layer). We may choose to simplify that, but at least we have to move to another logger at some point.

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