Why don't record classes follow the Java Bean conventions?

Records are named tuples¹.

Notice that the name of the field accessors does not start with get and, therefore, does not conform to the JavaBeans conventions.

We can declare getter methods if we really want to, and let them refer to the record method, but I'd opt not to if possible. We can do it, for a little while, until frameworks catch up to the new code convention, which will be pretty quick.

As Brian Goetz wrote in an online thread²:

“. . . the language has a responsibility to look forward as well as backward, and balance the needs of existing code with the needs of new code. Taking a bad library naming convention and burning it into the language forever would have been the worse choice.”

Builders

We can create builders for Records, if we like. See [3] for instance, but I'm not a fan of automatic code generation.

FreeMarker

The reason I started on this blog, is because there's a plethora of different frameworks/tools/what-have-you available that all center around the Java Beans conventions.

In most cases, records are not a good fit for these, as those frameworks and tools operate on the notion that these are mutable data classes.

But sometimes, there are definitely simple use cases where it would come in handy.

For example with the use of Freemarker⁴, a templating engine that converts your templates and Java POJOs to nice html pages (or other kinds of pages, there's no limit really).

And these follow the getX() convention.

So, one way would be to create the blasted getter methods in the Record class, but then you're adding boilerplate again, and I feel uncomfortable with that.

Perhaps an idea is to create my own DefaultObjectWrapper⁵.

So, Freemarker will need some changes to support record classes⁶. Something like automatically generating a hashmap of all the methods that have no arguments, yet return something... and preferable do not start with get?

References

[1] Data Classes and Sealed Types for Java - Brian Goetz February 2019

https://openjdk.java.net/projects/amber/design-notes/records-and-sealed-classes

[2] ForumPost - Feedback for records: Accessors name() vs. getName()

https://mail.openjdk.java.net/pipermail/amber-dev/2020-August/006414.html

[3] GitHub - RecordBuilder

https://github.com/Randgalt/record-builder

[4] FreeMarker

https://freemarker.apache.org/

[5] FreeMarker - Object wrappers

https://freemarker.apache.org/docs/pgui_datamodel_objectWrapper.html#pgui_datamodel_defaultObjectWrapper

[6] Apache JIRA - FREEMARKER-183

https://issues.apache.org/jira/browse/FREEMARKER-183

JLS - 8.10. Record Classes

https://docs.oracle.com/javase/specs/jls/se16/html/jls-8.html#jls-8.10

JavaMagazine - Records Come to Java

https://blogs.oracle.com/javamagazine/post/records-come-to-java

JavaMagazine - Java records: Serialization, marshaling, and bean state validation

https://blogs.oracle.com/javamagazine/post/diving-into-java-records-serialization-marshaling-and-bean-state-validation

Freemarker and java.time

I noticed that Freemarker¹ does not yet support the Java SE 8 Date and Time². I noticed this, because I tried it. It just tries to parse the toString() and it fails.

There's already blogs about it.

So I had to add a little dependency to provide this, courtesy of Jakob Vad Nielsen³.

<dependency>
    <groupId>no.api.freemarker</groupId>
    <artifactId>freemarker-java8</artifactId>
    <version>1.1.5</version>
</dependency>

Of course, it's not native support, you still have to call specific methods to parse this. But it works in my case.

It means I have to change some of my templates around, as described below:

Published Date ${blog.createDate?datetime}

Instead should be:

Published Date ${blog.createDate.format()}

References

[1] FreeMarker Java Template Engine

https://freemarker.apache.org/

[2] Java Technical Details - Java SE 8 Date and Time

https://www.oracle.com/technical-resources/articles/java/jf14-date-time.html

[3] GitHUb - Java library adding support for the Java 8 java.time api to FreeMarker.

https://github.com/lazee/freemarker-java-8