Thursday Dec 18, 2014

Point of Clarification: NetBeans, JSF, and MySQL Primary Keys

Recently I was working on a project using JavaServer Faces with a MySQL backend (Yes, I jump around a lot! Or as I like to say, I go where the voices in my head tell me to go.). :) While discussing the project with another dev there, I referenced an earlier post I had written about a small "gotcha" I'd encountered with the code NetBeans generates as a first-cut for JSF CRUD apps.

NetBeans does a great job producing a framework that you can build upon for many (many many) types of apps. The issue I'd found was small and easily resolved, and I covered the quick fix needed to make it work...but in hindsight, I didn't explain it very well.

The annotation required for MySQL's AUTO_INCREMENT of primary key values is the important bit from MySQL's perspective. But in order to get to MySQL in the first place, I added the line setting the object's "id" to 0 (in my example). This wasn't due to MySQL per se; it was a requirement levied by the @NotNull annotation for our @Entity class's id member variable. Once the bean validation took place, the object/values could be persisted.

For anyone who may have been a bit fuzzy on the "why", I hope this helps. :)

Keep coding,

Tuesday Oct 09, 2012

Seven Random Thoughts on JavaOne

As most people reading this blog may know, last week was JavaOne. There are a lot of summary/recap articles popping up now, and while I didn't want to just "add to the pile", I did want to share a few observations. Disclaimer: I am an Oracle employee, but most of these observations are either externally verifiable or based upon a collection of opinions from Oracle and non-Oracle attendees alike. Anyway, here are a few take-aways:

  1. The Java ecosystem is alive and well, with a breadth and depth that is impossible to adequately describe in a short post...or a long post, for that matter. If there is any one area within the Java language or JVM that you would like to - or need to - know more about, it's well-represented at J1.
  2. While there are several IDEs that are used to great effect by the developer community, NetBeans is on a roll. I lost count how many sessions mentioned or used NetBeans, but it was by far the dominant IDE in use at J1. As a recent re-convert to NetBeans, I wasn't surprised others liked it so well, only how many.
  3. OpenJDK, OpenJFX, etc. Many developers were understandably concerned with the change of sponsorship/leadership when Java creator and longtime steward Sun Microsystems was acquired by Oracle. The read I got from attendees regarding Oracle's stewardship was almost universally positive, and the push for "openness" is deep and wide within the current Java environs. Few would probably have imagined it to be this good, this soon. Someone observed that "Larry (Ellison) is competitive, and he wants to be the if he wants to have a community, it will be the best community on the planet." Like any company, Oracle is bound to make missteps, but leadership seems to be striking an excellent balance between embracing open efforts and innovating in competitive paid offerings.
  4. JavaFX (2.x) isn't perfect or comprehensive, but a great many people (myself included) see great potential, are developing for it, and are really excited about where it is and where it may be headed. This is another part of the Java ecosystem that has impressive depth for being so new (JavaFX 1.x aside). If you haven't kicked the tires yet, give it a try! You'll be surprised at how capable and versatile it is, and you'll probably catch yourself smiling while coding again.  :-)
  5. JavaEE is everywhere. Not exactly a newsflash, but there is a lot of buzz around EE still/again/anew. Sessions ranged from updated component specs/technologies to Websockets/HTML5, from frameworks to profiles and application servers. Programming "server-side" Java isn't confined to the server (as you no doubt realize), and if you still consider JavaEE a cumbersome beast, you clearly haven't been using the last couple of versions. Download GlassFish or the WebLogic Zip distro (or another JavaEE 6 implementation) and treat yourself.
  6. JavaOne is not inexpensive, but to paraphrase an old saying, "If you think that's expensive, you should try ignorance." :-) I suppose it's possible to attend J1 and learn nothing, but you'd have to really work at it! Attending even a single session is bound to expand your horizons and make you approach your code, your problem domain, differently...even if it's a session about something you already know quite well. The various presenters offer vastly different perspectives and challenge you to re-think your own approach(es).
  7. And finally, if you think the scheduled sessions are great - and make no mistake, most are clearly outstanding - wait until you see what you pick up from what I like to call the "hallway sessions". Between the presentations, people freely mingle in the hallways, go to lunch and dinner together, and talk. And talk. And talk. Ideas flow freely, sparking other ideas and the "crowdsourcing" of knowledge in a way that is hard to imagine outside of a conference of this magnitude. Consider this the "GO" part of a "BOGO" (Buy One, Get One) offer: you buy the ticket to the "structured" part of JavaOne and get the hallway sessions at no additional charge. They're really that good.

If you weren't able to make it to JavaOne this year, you can still watch/listen to the sessions online by visiting the JavaOne course catalog and clicking the media link(s) in the right column - another demonstration of Oracle's commitment to the Java community. But make plans to be there next year to get the full benefit! You'll be glad you did.


All the best,

P.S. - I didn't mention several other exciting developments in areas like the embedded space and the "internet of things" (M2M), robotics, optimization, and the cloud (among others), but I think you get the idea. JavaOne == brainExpansion;  Hope to see you there next year!

Monday Sep 24, 2012

Join Me at JavaOne!

JavaOne 2012 is less than a week away! If you've already made plans to be there, you're probably getting pretty excited about it already...and if not, what are you waiting for?!?

Before I get to the session information, I want to point out that qualified students get free admission to JavaOne, so if you are (or know) a CS or IT (or other tech-leaning) student who might like to attend, follow the link and start making plans. There is so much there to learn and experience.

I'm happy to say I'll be a small part of the festivities. I'll be leading the following session:

CON3519 - Building Hybrid Cloud Apps: Local Databases + The Cloud = Extreme Versatility

In this session, learn how to design and develop applications that leverage both local storage and the cloud, maximizing the strengths of each. Using NetBeans, JavaServer Faces 2.0, GlassFish Server technology, JavaFX 2, Oracle Database, and Evernote, rapidly create prototypical applications that can be deployed in various environments and scaled up/out with enterprise cloud solutions. 

As a contributor to the JFXtras project, I also hope to attend the following "Birds Of a Feather" (BOF) session led by Gerrit Grunwald and Stephen Chin:

BOF5503 - JFXtras Super Happy Dev BOF

JFXtras, the open source JavaFX control and extensions project, is back for JavaFX 2.0. In this session, you will learn about the latest changes in JFXtras 2.0, including new components, controls, and features that integrate with the JavaFX 2.0 libraries. Expect to meet the JFXtras core team members as well as other interesting client RIA implementers and developers. Now that JavaFX is coded in Java, a few server-side hackers may even be let in the door.

If you're there, please stop by and introduce yourself! And to follow along with my J1 travels or keep in contact afterward, please follow me on Twitter or connect via G+ or Facebook (links in panel to right). Hope to see you there, but either way, keep the Java flowing!

All the best,

Wednesday Jul 25, 2012

How to Get Started (FAST!) With JavaFX 2 and Scene Builder

A question I hear all too often is "How do I get started with JavaFX and/or Scene Builder?" Like most tools/toolsets, there are as many ways to use these implements as there are developers...but shouldn't there be an easy way to "hit the ground running"? While casting about for an end-to-end example, demo, or video, I found a wealth of useful information, but I couldn't find anything that took someone from start to finish, quickly and easily. JavaFX is easy and fun. But don't take my word for it; let's give it a try!

Before we begin, you'll need to visit this page to download and install all the necessary goodies. Click the download link to go to the current downloads page, then download and install JavaFX (NOTE: if you already have a JDK installed that includes JavaFX, you can omit this step), then download and install the JavaFX Scene Builder. Specific instructions for those steps are located on that page. Go ahead, I'll wait right here.  :-)

Back now? Great! Let's get started!

First, let's fire up Scene Builder just to make sure it works. If not, you'll want to revisit the installation instructions on the downloads page. Once that's working, we're ready to roll...assuming you're running NetBeans 7.2 or higher, of course. You are running NetBeans, right? If not, you owe it to yourself to download it - it's free, and as you're about to see, it's pretty amazing. NetBeans and Scene Builder are loosely-but-effectively integrated, and using both greatly simplifies things and makes your life easier.

Okay, here's the fun part: we're going to actually create a simple JavaFX application, create/modify a window using Scene Builder, and successfully test it in under 15 minutes. Don't believe me? Buckle up friend, here we go!


We start this fun frenzy with NetBeans. Choose File, New Project, JavaFX, then JavaFX FXML Application. This creates a very simple JavaFX app that includes a main application class, a controller class to provide the actual backing logic for the window defined in Scene Builder, and the FXML file containing our window definition (XML) code. I used the name "EasyJavaFX" for our project.

Here's a quick summary of these three files: contains the main application class. We won't really do anything with this class for this example, as its primary purpose in life is to load the window definition code contained in the FXML file and then show the main stage/scene. You'll keep the JavaFX terms straight with ease if you relate them to the theater: a platform holds a stage, which contains scenes. Simple. :-) is our controller class that provides the "brains" behind the graphical interface. If you open the SampleController, you'll see that it includes a property and a method tagged with @FXML. This tag enables the integration of the visual controls and elements you define using Scene Builder. Let's take a look at that next.

Sample.fxml is the definition file for your sample window. You can right-click and Edit the filename in the tree to view the underlying XML - and you may need to do that if you change filenames or properties by hand - or you can double-click on it to open it in Scene Builder. Let's do that next, but first a quick look at our little project:

Scene Builder

Opening Sample.fxml in Scene Builder results in the display of a very spartan window.

Let's rework it a little. For a complete tour of Scene Builder, please visit this page, but here's the nickel tour: stuff and navigation to the left, picture in the middle, and properties on the right. :-) We'll make some small modifications like so:

First, we click on the Button in the Hierarchy panel (bottom left), which selects it in the middle Content panel. We'll move it down and over a bit to make room for another button.

Next, let's drag another button from the Library panel and drop it onto the canvas, lining it up with the other button using the red positioning lines that appear while dragging it.

Once the button is positioned, we turn our attention to the Properties panel. We'll assign our new button an fx:id of exitButton, change the text to Exit, and tab out of the field to see our changes dynamically applied. Next, we click on the other button to change its fx:id and text to clickmeButton and "Click Me for an Important Announcement", respectively. Finally, we click the Exit button and resize it to be a bit wider. Who likes to hunt for tiny Exit buttons?

We're nearly done with our first round with Scene Builder. To finish, we select the Label in the Hierarchy panel at the bottom left - that's often the quickest way to locate "hidden" visual controls - and then resize it using the sizing handles on the canvas, again using the red lines to line up with edges and buttons. Once we're done, things should look something like this:

Click File, Save to save our changes, and Scene Builder confirms with a brief message at the top of the Content panel. Leaving Scene Builder open for convenience, return to NetBeans for the next step.

Back to NetBeans

Let's make a few changes to the controller class. Opening, let's start with the only method we (currently) have. Since we now have two buttons, we will need to keep two methods straight. Renaming handleButtonAction to something like handleClickmeButtonAction is a good start. And to add something of significance to read when the button is clicked, we'll replace the wonderfully traditional "Hello World!" with "Space... the Final Frontier. These are the voyages of the starship Enterprise. Its continuing mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no one has gone before." For those reading this who aren't Star Trek fans, please feel free to substitute your own, slightly less-interesting text.  :-)

Next, we'll create a method for our Exit button by either copying the other method and renaming it or hand-jamming it. Either way, be sure you have the @FXML tag to allow for integration with our window definition/Scene Builder. Putting the following line in our new handleExitButtonAction method will give us a quick escape hatch for our demo app:


To fix the error shown by NetBeans, click on the light bulb to the left of the code line and allow it to import javafx.application.Platform. After a quick click on the Save All button, we're good to go from the NetBeans side. Now to go back to Scene Builder to wrap things up.

And Back to Scene Builder

In order for our buttons to tie to our new methods, we need to connect them to the names we gave those methods in our SampleController class. First, we'll select the top Button (clickmeButton) in the Hierarchy panel. Next we turn our attention to the Properties panel on the right. At the bottom of the right side is a collapsed section labeled "Code: Button". Clicking that line opens the Code properties window so we can update the OnAction property. Notice it still points to the method formerly known as handleButtonAction. Click the dropdown, select handleClickmeButtonAction, tab out of the field, and we're done with that button.

We repeat some of the same steps with the other (Exit) button, although since we already have the Code properties panel open, selecting the button takes us directly there. Choosing handleExitButtonAction from its OnAction dropdown and tabbing out of the field concludes our work with Exit. But there is one more thing, purely cosmetic though it may be...

Since we added quite a lot of text to our label (see the handleClickmeButton method in the SampleController class), we may want to change the default behavior of our display label. Labels default to using an ellipsis when the length of text to display exceeds the space available, but we want to see the text in its entirety! Clicking the "Wrap" checkbox in the label's Properties panel fixes that up nicely and concludes our work in Scene Builder. Click File, Save, and then back to NetBeans for our maiden voyage!

And Now Back to NetBeans for the Big Finale!

Right-clicking the project in the Projects window to the left and clicking Run provides these satisfying results:

Clicking the "Click Me" button displays the following:

And clicking the Exit button closes the application.

Start to finish, you just developed a JavaFX application using Scene Builder in less time than it takes to drink a cup of coffee...while learning your way around in the process. Fast, fun, and productive: THAT is JavaFX.

All the best,

P.S. - There isn't much to the code, but I'll post it to GitHub if anyone wants it. Just let me know.
P.P.S. - If there is any interest in a video, please let me know that as well by commenting below. No promises, but if enough people ask and I can find some free time...

Thursday Jul 19, 2012

NetBeans (team) Responsiveness

When was the last time logging a potential bug/issue for any piece of software, with any vendor, was a pleasure? Most of us rank that with paying taxes, root canals, and visiting in-laws. :-)

Not so with NetBeans. I logged a possible bug report one morning...and by the next morning, it had been assigned, analyzed, and an explanation and workaround posted while code changes and testing take place. In fewer than 24 hours, it effectively went from start to finish from an end-user developer perspective. That may not always be possible, but it speaks very well for the level of commitment of the NetBeans team.

In addition to all the other things I appreciate about NetBeans, such as GlassFish integration/management, superb code generation, polished look-and-feel, ease of navigation, and many other things large and small, add excellent community support/dev engagement to the list. After using other IDEs for years, I could hardly be more pleased.

Those who haven't logged many tool issues may not fully understand this post, but it can be a big deal...and usually at the most inopportune times...  :-)

All the best,

Don't take my word for it, get your own! Visit the NetBeans site to download and check it out for yourself.

(Disclaimer: I work for Oracle, but not on the NetBeans team. I'm just another (very) satisfied user.)


The Java Jungle addresses all things Java (of course!) and any other useful and interesting tools & platforms that help us GET IT DONE. "Artists ship," after all. :)

Your Java Jungle guide is Mark Heckler, a Software Architect/ Engineer and Oracle Developer Evangelist with development experience in numerous environments. Mark's current pursuits and passions all revolve around Java, the Cloud, & the IoT, and leave little time to blog or tweet - but somehow, he finds time to do both anyway.

Mark lives with his very understanding wife in the St. Louis, MO area.

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