News

Reinhold Dispels 'Misconceptions' About Jigsaw in Java 9

• By John K. Waters
• May 24, 2017

Mark Reinhold, chief architect of Oracle's Java Platform Group, believes the heated concerns bubbling up recently in the Java community about the readiness of the Java Platform Module System (JPMS) specification, better known as Jigsaw, for the upcoming release of Java 9 are based on a number of misconceptions.

Reinhold identified 10 of those misconceptions "from a very long list" during an onstage interview at the Devoxx UK developer conference, and a later interview, and made his arguments to dispel them.

The No. 1 misconception he cited: Maven doesn't work on Java 9. To dispel it, he cited a tweet by Robert Scholte, chair of the Apache Maven project, in which Scholte stated, "Yes indeed, every Maven 3.0+ runs fine on Java 9. This should not be a concern. Only a few plugins which need to be fixed."

Another top concern Reinhold disputes: My favorite library, framework or tool doesn't work on Java 9. "We've spent a fair bit of effort over the last couple of years reaching out to maintainers of popular libraries, frameworks, and tools to work with them, encourage them to test on Java 9, and come to us with questions on the Jigsaw dev list," he said, "and we've given them advice and assistance."

He also cited a widespread concern that people will have to modularize all their code and wait for all the libraries they use to be modularized before they can use Java 9. Not true, he said in a post-keynote interview. "Java 9 has the Classpath," he said. "It works great. I don't think it'll every go away. It's been a fundamental part of Java for 20 years. Modules offer an alternative that we think is better, but you don't have to use them. And for many existing software systems there might never be a reason to modularize, and that's okay, too."

During an onstage conversation with Dan Hardiker, CTO of Adaptavist, a London-based Atlassian consultancy, Reinhold also inveighed against some members of the Executive Committee of the Java Community Process (JCP) who voted earlier this month to reject the Jigsaw spec in Java 9.

"The JCP does not mandate consensus," Reinhold observed, "and there's a good reason for that. This is an exemplar of why consensus is not mandated. Sometimes members of extra groups come in and they're only looking out for the interests of themselves or their employer, and I think that's what happened here."