Reforming the Blog in Darwino, Part 3

  • Jul 18, 2018

A good while back, I created a project structure for reforming my blog here in Darwino, but, as happens with low-priority side projects, it withered on the vine, untouched since then. Beyond just the "cobbler's children" aspect to it, I also lost steam due to a couple technology paths I initially headed down.

The first was basing the UI on Angular, which I've never really enjoyed working with. I'm sure I could have ended up with a decent result with it, but Angular always rubbed me the wrong way. And not just Angular: for a dead-simple UI like this, a full JS UI is just weird overkill.

The second was off in the other direction: I initially tried cramming a Rails app in the tree, which could be made to work, but it introduced so many weird edge cases outside of the problem at hand. That alone isn't the end of the world, but not much of what I'd have to solve to make that work would be transferrable elsewhere any time soon, so it'd end up a real time sink.

So, taking what I've learned since and the projects that I've been working on, I've decided to take another swing at it. Before I get into the implementation side, it will be useful to go over the technologies I did choose for the new form.

Java/Jakarta EE

I've recently become kind of enamored with the modern form of the Jakarta EE stack, and so I decided to use this as an opportunity to really dive in to what a blue-ocean small by-the-books Java app looks like nowadays.

JEE got a well-deserved bad rap over the years for its configuration complexity and general impenetrable-ness, but I've been very pleased to find that those tides have largely receded. It's all still there if you want it, but a fresh new app primarily consists of decorating a handful of Java classes with declarative annotations.

JEE consists of a series of individual specs, and building an app involves choosing which ones you want to use, plus (depending on which you choose) picking your app server target.

Tomcat

I originally gave a shot to adding enough OSGi metadata and bundles to target Domino, but decided quickly that it was just not worth it. The HTTP/servlet stack in Domino is just so old that, even if I got everything bound together, I'd still be fighting the platform every step of the way.

The better route was to put it aside and just run a modern Java app server. I went down the list of GlassFish, Payara, WebSphere Liberty (the nearest miss), TomEE, and WildFly, but each one ended up having some problem with either the dependencies I wanted or with their Eclipse integration. I ended up settling on good ol' reliable Tomcat. Tomcat itself isn't actually a JEE server, but it's kind of like a Raspberry Pi: it gives you the baseline for a Java servlet engine, and then you can cobble together your own EE stack on top of it by explicitly bringing in implementations. Though the final .war file is far less svelte this way, I found that this build-your-own method results in the lowest chance of being held back by the platform currently.

As an aside, Sven Hasselbach has been writing a very interesting series on running Jetty on top of the Domino JVM to achieve a similar end, albeit with Spring.

Darwino

For all the same reasons as when I set out on this journey originally, I'm using Darwino for the baseline. This lets me replicate in my existing blog data smoothly while getting the advantages of a superior backing database. I'm not making use of mobile clients or most Darwino services with this, but the baseline is nonetheless a step up, and fits in with a JEE app like a glove.

JNoSQL

I brought in the JNoSQL Darwino driver I wrote a little while ago to handle the model layer. JNoSQL is essentially JPA but reformed for NoSQL access - no cruft, no relational/NoSQL impedence mismatch, and designed to fit with current JEE technologies.

CDI

CDI is one such technology, and it's a very interesting one to work with. The whole "dependency injection" realm is a little fraught and, if my Eclipse UI error reporter is any indication, prone to bizarre errors, but the core concept is good and very useful. I've gotten it into the swing of using it both as the "managed bean" provider for the front end as well as the general service provider glue for the app. It still takes some getting used to, and the learning curve falls prey to a similar problem as when I was learning Maven: something about learning how it works makes you forget what it was like to not know, and so a lot of the answers online assume way more knowledge than a neophyte has.

Bean Validation

I've long been a fan of the Java bean validation API, and it's a clean fit here too: JNoSQL picks up on the presence of Hibernate Validator without configuration beyond the dependency and it just works. No muss, no fuss.

JAX-RS + MVC Spec

JAX-RS is at this point familiar territory for a lot of Domino developers, but I decided to use it as the underpinnings of the whole UI, in tandem with a draft framework called MVC 1.0. The latter's generic name doesn't really give much detail, but it's essentially a spec that enhances JAX-RS entities with knowledge of HTML templating frameworks, allowing you to write a very clear app structure. It's not a server-state-based framework like JSF, but rather a bit "closer to the metal", where you deal directly with the HTTP method cycle.

As I'll go more into in the "UI" post, it's been surprisingly refreshing to get back to basics in this way - JSF/XPages is often a bit conceptually easier to work with (at first) and client-side JS frameworks have some REST+JSON purity to them, but just "this server-rendered HTML page with no server state is everything you need" feels really good sometimes.

Admittedly, the MVC spec itself is in a weird place. It was originally a candidate for inclusion in Java EE 8, but was dropped in the final runup. It's possible that this will prove to be a kiss of death, but the spec is so small but functional that I don't feel bad about taking the risk of building an app on it.


That about covers the technology stack. When I get around to writing the next post, I'll go into some of the specifics about how I decided to set up the UI, which has been a fun experiment of its own. In the mean time, the active repository is up at:

https://github.com/jesse-gallagher/frostillic.us-Blog/tree/develop/frostillicus-blog

A (Java-Centric) Domino Wish List

  • Jul 12, 2018

Seeing the information come out of this week's HCL "Golden Ticket" event has got me thinking about some of my wish-list items for Domino development, mostly in the form of enhancements for existing capabilities and entirely around Java (since that's what I do).

Quality of Life

Javadoc

For some reason, the lotus.domino classes ship without Javadoc or even variable-name information, leading to this trainwreck:

Designer has its built-in help, which is also on the web, but that's quite a few steps down. This is table stakes for a Java API and always has been.

Updated p2 Repository

Back in 2014, the XPages team uploaded a clean p2 repository of the XPages artifacts to OpenNTF, corresponding with the 9.0.1 release. This repository saves a ton of hassle when building Tycho-based projects or just setting up an Eclipse workspace. However, it's quite long the tooth, as there have been several Notes.jar additions not included in there, and, in FP10, a significant upgrade to the undergirding OSGi framework.

I ended up writing a script to generated an updated version, but I don't have the legal ability to publish the results anywhere for easy consumption, meaning it has to be done manually and configured for each build environment. It would be a great convenience if there was an official package (ideally including the Designer plugins as well) and, even better, hosted on OpenNTF so that we could reference it by URL as we do for Eclipse releases (and require users to accept a license first).

Mavenized Repository

The p2 repository is good for Tycho-based projects, but, especially when targetting Domino is only one part of a project, it can be much more convenient to use "normal" Maven projects with maven-bundle-plugin. However, those projects can't use p2 repositories as such. For Darwino's needs, I ended up writing a tool in the (available-for-free) Darwino Studio plugins to Maven-ize a Domino p2 repository, but that hits the same snag as above of requiring manual setup in each instance.

This is another case where my preference would be on the OpenNTF Maven repository (plus Javadoc Jars, naturally).

Extension Library Source

The latest Extension Library release on OpenNTF is from FP9, while the latest on GitHub is from the FP7 era. FP10 shipped with a newer version of indeterminate nature. It'd be good to have this on both of those sites and, like with Javadoc, have source bundles shipped with the product in a way that is picked up automatically by Designer and Eclipse.

Source Bundles for Third-Party Components

The source for the undergirding Equinox stack is available, but it would be best to have, as an adjunct to the updated p2 repositories, the source bundles for the actual versions used so that we don't have to cobble together a platform from Eclipse's repositories.

Open-Source the Rest of the Stack

Having XPages, the Expeditor husk, and the other miscellaneous doodads that make up the proprietary layer as open source with an Apache-compatible license would cover a lot of the above and also be of tremendous use for XPages and non-XPages apps alike that run on or with Domino. I have a hard time imagining that it would lead to a lot of community-driven improvement, but it may do some (I'd have a few words to share with the file-download control, for example), and even just as a static release would be a significant boon.

Domino Connectivity in Eclipse

An idea I've been toying with lately is to make an Eclipse plugin that allows you to add Domino servers to the "Servers" view and control them to some extent. The basics would be to start/stop/restart HTTP, but the stretch goals would be to open a console view, get a list of running modules, integrate with the existing "load bundles from PDE" support, and, ideally, an outright "Run on Server" command for OSGi bundles and NSFs. However, I have so much on my plate that I'm not sure that I'll get to this any time soon unless I get a real itch some weekend.

Longevity

Refreshed JVMs

Feature Pack 8 brought Java 8, a vital step forward. However, since then, Oracle moved to a faster release cycle for Java and the JRE is now at version 10. Domino uses IBM's JVM variant, J9, which they recently moved to the Eclipse foundation as OpenJ9, where it has... sort of been keeping up, I think?

In any event, this increased pace of change has meant that the Java 8 honeymoon is over, and Domino development again requires special consideration when using current tools. I have no idea how complex the integration between Domino's tasks and the underlying JVM is, but my ideal would be to have constant or near-constant parity.

Servlet API 4.x

After the JRE version, the most important foundational element of a Java web app is the servlet API release. The current version is 4.0.1, while Domino supports 2.5 (or 2.4, maybe?). The good news is that the Java/Jakarta EE world seems to be used to lagging versions here, and 2.5 is a minimum version for a lot of current tech in much the same way that Java 6 was until somewhat recently, but there has been quite a bit added in recent years.

Presumably, a reason for the lag is the implied requirements of newer versions, such as WebSockets and HTTP/2 support, that would require heavy modifications to the core Domino HTTP code. Honestly, the more practical route is almost definitely to just use a different JEE server paired with CrossWorlds, some Java wrapper for the GRPC stuff HCL has been talking about, or (best of all) a Darwino app replicating with Domino, but still. WebSphere Liberty is actually really nice, by the way.

Refreshed Equinox

Like with the underlying JVM, the Feature Pack 10 update to a Neon-based OSGi/Equinox framework was a critical shot in the arm for the platform, but it is now also two major versions behind. This is a little less critical, since Equinox brings a bit less to the table for our needs and Neon is "new enough" for now, particularly on the server side, but it'd still be proper to keep pace.

Odds and Ends

Non-OSGi JEE Support

The Equinox framework that Domino uses is quite capable, but there's no pretending that OSGi-targetted development has its share of headaches. Most Java apps just target plain-old .war files and don't impose any particular requirements on the build process. Java development is a much more pleasant experience when you can just toss in any Maven dependency and not have to think about building a target platform for Eclipse or jumping through bundle-resolution hoops. I really like OSGi in theory, but I can't pretend that non-OSGi development isn't much smoother.

Domino technically supports "regular" servlets currently, but, uh, here's a snippet from the current documentation on that:

Hrm.

Full Extension Manager Support for Java

JAVADDIN/DOTS added a lot of EM hooks, but it doesn't cover the full suite of capabilities that a C addin can provide, such as authentication handling. Having this be fully accessible from Java would be useful even when treating Domino just as a data store and not as an app server.

 


 

I'm sure I could come up with more, but that's probably good for now. All easy, right?