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  • JMX Monitoring of GlassFish Servers

    - by tjquinn
    Did you ever wonder what this message in your GlassFish server.log file means? JMXStartupService has started JMXConnector on JMXService URL service:jmx:rmi://192.168.2.102:8686/jndi/rmi://192.168.2.102:8686/jmxrmi It means you can monitor any GlassFish server process, remotely or locally, using any standard Java Management Extensions (JMX) client.  Examples: jconsole or jvisualvm.   Copy the part of the log message that starts with "service:" into the Add JMX Connection dialog of jvisualvm:  or into the New Connection dialog of jconsole: (The full string is truncated in the on-screen display, but if you copied from the server.log and pasted into the form it should all be there.) The examples above are for a DAS, and your host will probably be different.   The server.log files for other GlassFish servers (instances) will have similar log entries giving the JMX connection string to use for those processes.  Look for the host and/or port to be different. Note a few things about security: Here we've assumed you are using the default admin username and password.  If you are not, just enter a valid admin username and password for your installation.  Once connected, you have normal access to all the JVM statistics and controls. You can use JMX clients that support MBeans to view the GlassFish configuration.  When you connect to the DAS, you can also change that configuration, but you can only view configuration when you connect to an instance. To use a JMX client on one system to connect to a GlassFish server running on another system, you need to enable secure admin if you have not already done so: asadmin change-admin-password (respond to the prompts) asadmin enable-secure-admin asadmin restart-domain (as prompted in the output from enable-secure-admin)

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  • JavaOne - Java SE Embedded Booth - Servergy Micro Server

    - by David Clack
    Hi All,  So it's been awhile, I've been working with all the ARM and Power Architecture partners we have now on testing Java SE Embedded. We will have a Java SE Embedded for ARM and PPC at Java One next week, I'll be bringing in some of the great ARM and PPC systems to demonstrate.  The first system I'd like to tell you about is a really cool 8 core Power Architecture Micro Server from a company in Dallas called Servergy. Java One will be it's first public outing, Bill Mapp the CEO will be doing a talk at the Java Embedded @ JavaOne conference in the Hotel Nikko, right next door to the JavaOne show in the Hilton. To read more about Servergy https://www.linux.com/news/enterprise/cloud-computing/641488-linux-based-servergy-advances-data-center-efficiency http://www.servergy.com/ If you are registered at JavaOne you can come over to the Java Embedded @ JavaOne for $100 Come see us in booth 5605 See you there Dave

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  • JSF 2.2, Interceptors 1.2, and JPA 2.1 Replay: Java EE 7 Launch Webinar Technical Breakouts on YouTube

    - by arungupta
    As stated previously (here, here, and here), the On-Demand Replay of Java EE 7 Launch Webinar is already available. You can watch the entire Strategy and Technical Keynote there, and all other Technical Breakout sessions as well. We are releasing the next set of Technical Breakout sessions on GlassFishVideos YouTube channel as well. In this series, we are releasing JSF 2.2, Interceptors 1.2, and JPA 2.1. Here's the JSF 2.2 session: Here's the Interceptors 1.1 session: Here's the JPA 2.1 session: Enjoy watching them over the next few days before we release the next set of videos! And don't forget to download Java EE 7 SDK and try numerous bundled samples.

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  • Architecture: Bringing Value to the Table

    - by Bob Rhubart
    A recent TechTarget article features an interview with Business Architecture expert William Ulrich (Take a business-driven approach to application modernization ). In that article Ulrich offers this advice: "Moving from one technical architecture might be perfectly viable on a project by project basis, but when you're looking at the big picture and you want to really understand how to drive business value so that the business is pushing money into IT instead of IT pulling money back, you have to understand the business architecture. When we do that we're going to really be able to start bringing value to the table." In many respects that big picture view is what software architecture is all about. As an architect, your technical skills must be top-notch. But if you don't apply that technical knowledge within the larger context of moving the business forward, what are you accomplishing? If you're interested in more insight from William Ulrich, you can listen to the ArchBeat Podcast interview he did last year, in which he and co-author Neal McWhorter talked about their book, Business Architecture: The Art and Practice of Business Transformation.

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  • ADF Desktop Integration Page Now Live on OTN

    - by juan.ruiz
    I’m happy to announce that we have launched the  ADF Desktop Integration home page on OTN. This page will centralize all the resources related to desktop integration. As you can notice, currently we are providing a variety of resources to help you understand the technology as well as to improve your overall ADF desktop integration learning experience. Let us know what you think about the page and what additional resources related to ADF desktop integration you would like us to include.

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  • Session Report - Modern Software Development Anti-Patterns

    - by Janice J. Heiss
    In this standing-room-only session, building upon his 2011 JavaOne Rock Star “Diabolical Developer” session, Martijn Verburg, this time along with Ben Evans, identified and explored common “anti-patterns” – ways of doing things that keep developers from doing their best work. They emphasized the importance of social interaction and team communication, along with identifying certain psychological pitfalls that lead developers astray. Their emphasis was less on technical coding errors and more how to function well and to keep one’s focus on what really matters. They are the authors of the highly regarded The Well-Grounded Java Developer and are both movers and shakers in the London JUG community and on the Java Community Process. The large room was packed as they gave a fast-moving, witty presentation with lots of laughs and personal anecdotes. Below are a few of the anti-patterns they discussed.Anti-Pattern One: Conference-Driven DeliveryThe theme here is the belief that “Real pros hack code and write their slides minutes before their talks.” Their response to this anti-pattern is an expression popular in the military – PPPPPP, which stands for, “Proper preparation prevents piss-poor performance.”“Communication is very important – probably more important than the code you write,” claimed Verburg. “The more you speak in front of large groups of people the easier it gets, but it’s always important to do dry runs, to present to smaller groups. And important to be members of user groups where you can give presentations. It’s a great place to practice speaking skills; to gain new skills; get new contacts, to network.”They encouraged attendees to record themselves and listen to themselves giving a presentation. They advised them to start with a spouse or friends if need be. Learning to communicate to a group, they argued, is essential to being a successful developer. The emphasis here is that software development is a team activity and good, clear, accessible communication is essential to the functioning of software teams. Anti-Pattern Two: Mortgage-Driven Development The main theme here was that, in a period of worldwide recession and economic stagnation, people are concerned about keeping their jobs. So there is a tendency for developers to treat knowledge as power and not share what they know about their systems with their colleagues, so when it comes time to fix a problem in production, they will be the only one who knows how to fix it – and will have made themselves an indispensable cog in a machine so you cannot be fired. So developers avoid documentation at all costs, or if documentation is required, put it on a USB chip and lock it in a lock box. As in the first anti-pattern, the idea here is that communicating well with your colleagues is essential and documentation is a key part of this. Social interactions are essential. Both Verburg and Evans insisted that increasingly, year by year, successful software development is more about communication than the technical aspects of the craft. Developers who understand this are the ones who will have the most success. Anti-Pattern Three: Distracted by Shiny – Always Use the Latest Technology to Stay AheadThe temptation here is to pick out some obscure framework, try a bit of Scala, HTML5, and Clojure, and always use the latest technology and upgrade to the latest point release of everything. Don’t worry if something works poorly because you are ahead of the curve. Verburg and Evans insisted that there need to be sound reasons for everything a developer does. Developers should not bring in something simply because for some reason they just feel like it or because it’s new. They recommended a site run by a developer named Matt Raible with excellent comparison spread sheets regarding Web frameworks and other apps. They praised it as a useful tool to help developers in their decision-making processes. They pointed out that good developers sometimes make bad choices out of boredom, to add shiny things to their CV, out of frustration with existing processes, or just from a lack of understanding. They pointed out that some code may stay in a business system for 15 or 20 years, but not all code is created equal and some may change after 3 or 6 months. Developers need to know where the code they are contributing fits in. What is its likely lifespan? Anti-Pattern Four: Design-Driven Design The anti-pattern: If you want to impress your colleagues and bosses, use design patents left, right, and center – MVC, Session Facades, SOA, etc. Or the UML modeling suite from IBM, back in the day… Generate super fast code. And the more jargon you can talk when in the vicinity of the manager the better.Verburg shared a true story about a time when he was interviewing a guy for a job and asked him what his previous work was. The interviewee said that he essentially took patterns and uses an approved book of Enterprise Architecture Patterns and applied them. Verburg was dumbstruck that someone could have a job in which they took patterns from a book and applied them. He pointed out that the idea that design is a separate activity is simply wrong. He repeated a saying that he uses, “You should pay your junior developers for the lines of code they write and the things they add; you should pay your senior developers for what they take away.”He explained that by encouraging people to take things away, the code base gets simpler and reflects the actual business use cases developers are trying to solve, as opposed to the framework that is being imposed. He told another true story about a project to decommission a very long system. 98% of the code was decommissioned and people got a nice bonus. But the 2% remained on the mainframe so the 98% reduction in code resulted in zero reduction in costs, because the entire mainframe was needed to run the 2% that was left. There is an incentive to get rid of source code and subsystems when they are no longer needed. The session continued with several more anti-patterns that were equally insightful.

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  • JDK bug migration: bugs.sun.com now backed by JIRA

    - by darcy
    The JDK bug migration from a Sun legacy system to JIRA has reached another planned milestone: the data displayed on bugs.sun.com is now backed by JIRA rather than by the legacy system. Besides maintaining the URLs to old bugs, bugs filed since the migration to JIRA are now visible too. The basic information presented about a bug is the same as before, but reformatted and using JIRA terminology: Instead of a "category", a bug now has a "component / subcomponent" classification. As outlined previously, part of the migration effort was reclassifying bugs according to a new classification scheme; I'll write more about the new scheme in a subsequent blog post. Instead of a list of JDK versions a bug is "reported against," there is a list of "affected versions." The names of the JDK versions have largely been regularized; code names like "tiger" and "mantis" have been replaced by the release numbers like "5.0" and "1.4.2". Instead of "release fixed," there are now "Fixed Versions." The legacy system had many fields that could hold a sequence of text entries, including "Description," "Workaround", and "Evaluation." JIRA instead only has two analogous fields labeled as "Description" and a unified stream of "Comments." Nearly coincident with switching to JIRA, we also enabled an agent which automatically updates a JIRA issue in response to pushes into JDK-related Hg repositories. These comments include the changeset URL, the user making the push, and a time stamp. These comments are first added when a fix is pushed to a team integration repository and then added again when the fix is pushed into the master repository for a release. We're still in early days of production usage of JIRA for JDK bug tracking, but the transition to production went smoothly and over 1,000 new issues have already been filed. Many other facets of the migration are still in the works, including hosting new incidents filed at bugs.sun.com in a tailored incidents project in JIRA.

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  • Fix import hint

    - by Martin Janicek
    Good news everyone! I've implemented 'Fix import hint' which should make your life (and most probably also the groovy development) much easier! It looks in the same way as in Java editor, so you might choose between classes with the same name. Hope you will enjoy it! And as usual if you would like to try it on your own, download the latest development build and I will be more than happy for every feedback!

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  • JAX-RS 2.0 Early Draft - Third Edition Available

    - by arungupta
    JAX-RS 2.0 Early Draft Third Edition is now available. This updated draft include new samples explaining the features and clarifications in content-negotiation, discovery of providers, client-side API, filters and entity interceptors and several other sections. Provide feedback to users@jax-rs-spec. Jersey 2.0, the Reference Implementation of JAX-RS 2.0, released their fourth milestone a few days ago as well. Several features have already been implemented there. Note, this is an early development preview and several parts of the API and implementation are still evolving. Feel like trying it out? Simply go to Maven Central (of course none of this is production quality at this point). The latest JAX-RS Javadocs and Jersey 2.0 API docs are good starting points to explore. And provide them feedback at [email protected] or @gf_jersey.

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  • Play Majesty: The Fantasy Kingdom Sim on your Java ME phone

    - by hinkmond
    Here's a game that started on on the iDrone, then Anphoid, and now finally on Java ME tech-enabled mobile phones (thank goodness!). See: Majesty: Fantasy Kingdom Here's a quote: When you become the head of the country all the responsibility for the land's prosperity rests on your royal shoulders. You will have to fight various enemies and monsters, explore new territories, manage economic and scientific developments and solve a heap of unusual and unexpected tasks. For example, what will you do when all the gold in the kingdom transforms into cookies? Sounds like the same as becoming President of the U.S... except for the gold turning into cookies part... and the part about dragons. But, everything else is the same. Hinkmond

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  • New Analytic settings for the new code

    - by Steve Tunstall
    If you have upgraded to the new 2011.1.3.0 code, you may find some very useful settings for the Analytics. If you didn't already know, the analytic datasets have the potential to fill up your OS hard drives. The more datasets you use and create, that faster this can happen. Since they take a measurement every second, forever, some of these metrics can get in the multiple GB size in a matter of weeks. The traditional 'fix' was that you had to go into Analytics -> Datasets about once a month and clean up the largest datasets. You did this by deleting them. Ouch. Now you lost all of that historical data that you might have wanted to check out many months from now. Or, you had to export each metric individually to a CSV file first. Not very easy or fun. You could also suspend a dataset, and have it not collect data at all. Well, that fixed the problem, didn't it? of course you now had no data to go look at. Hmmmm.... All of this is no longer a concern. Check out the new Settings tab under Analytics... Now, I can tell the ZFSSA to keep every second of data for, say, 2 weeks, and then average those 60 seconds of each minute into a single 'minute' value. I can go even further and ask it to average those 60 minutes of data into a single 'hour' value.  This allows me to effectively shrink my older datasets by a factor of 1/3600 !!! Very cool. I can now allow my datasets to go forever, and really never have to worry about them filling up my OS drives. That's great going forward, but what about those huge datasets you already have? No problem. Another new feature in 2011.1.3.0 is the ability to shrink the older datasets in the same way. Check this out. I have here a dataset called "Disk: I/O opps per second" that is about 6.32M on disk (You need not worry so much about the "In Core" value, as that is in RAM, and it fluctuates all the time. Once you stop viewing a particular metric, you will see that shrink over time, just relax).  When one clicks on the trash can icon to the right of the dataset, it used to delete the whole thing, and you would have to re-create it from scratch to get the data collecting again. Now, however, it gives you this prompt: As you can see, this allows you to once again shrink the dataset by averaging the second data into minutes or hours. Here is my new dataset size after I do this. So it shrank from 6.32MB down to 2.87MB, but i can still see my metrics going back to the time I began the dataset. Now, you do understand that once you do this, as you look back in time to the minute or hour data metrics, that you are going to see much larger time values, right? You will need to decide what size of granularity you can live with, and for how long. Check this out. Here is my Disk: Percent utilized from 5-21-2012 2:42 pm to 4:22 pm: After I went through the delete process to change everything older than 1 week to "Minutes", the same date and time looks like this: Just understand what this will do and how you want to use it. Right now, I'm thinking of keeping the last 6 weeks of data as "seconds", and then the last 3 months as "Minutes", and then "Hours" forever after that. I'll check back in six months and see how the sizes look. Steve 

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  • Ambiguous Comparison Hint

    - by Ondrej Brejla
    Hi everybody! Today we would like to show you some new hint which will be available in NetBeans 7.3. It's called Ambiguous Comparison hint. Its name seems to be quite fuzzy, but it describes exactly what the hint does. It tries to check all comparisons whether they are intended. Because sometimes you want to make a simple assignment, but you make a typo and comparison appears. It's really dangerous mistake because then your code doesn't work as expected. Your application can produce buggy results. So here is how it looks like: But sometimes a comparison is really intended. E.g. in return statements when you want to return a boolean, so then the hint works as expected and no warning appears. That's all for today and as usual, please test it and if you find something strange, don't hesitate to file a new issue (component php, subcomponent Editor). Thanks.

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  • Siebel Webinar Series for customers and partners

    - by Richard Lefebvre
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Have you got questions about the Siebel product roadmap?  Or what we are delivering in the areas of Social/Mobile/Big Data/Cloud in a Siebel project context? If yes, then you are welcome to attend the Siebel Webinar Series.  These are monthly webcasts on a variety of topics related to Siebel that are geared towards business users.  The next webinar is November 21st at 8:30 AM PST entitled “Get Social with Siebel”.  You can register here. Once registered, you can also view replays of previous webinars: · Siebel: Solving the Next Generation of Business Challenges · Expand User Experiences with Siebel Open UI · Delight Customers with Siebel Service Applications · Get Mobile with Siebel /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";}

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  • Will we ever lose the human touch?

    - by divya.malik
    I was at a conference two weeks ago, which was targeted to sales and marketing professionals. The discussions around the changing scenario in sales was very interesting. More and more of selling is moving to the internet- sales people are delivering more of their presentations online, or via the phone. Budget constraints and new technologies have dramatically decreased the need for face-to-face interactions. At the same time, customers are also researching for products on their own, taking the advice of peers, making up their mind, and then contacting the vendor. That takes care of more than half of the usual selling process. But humans are social animals, and because of that I believe that despite these changing trends and technologies, the need to maintain the human touch will always be necessary. One of the presenters at the conference shared this video, which stayed in my mind.

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  • Meet up with the JCP at JavaOne Latin America

    - by Heather VanCura
    The JCP made it to JavaOne Brazil!  We had a quickie presentation earlier today on JCP.Next that was well attended.  Come to see us at@ the  OTN mini-theatre tomorrow from 12:00-12:15 pm for a quickie on participation.  Then make your way to the Mazanino Sala 12 at 12:30 pm for CON-22250.  "The Java Community Process: How You Can Make a Positive Difference" will be presented with Heather VanCura, JCP,  and Fabio Velloso, SouJava, on Thursday, 6 December, at 12:30 pm.  Find out more about how to participate in the JCP program, the JCP.Next effort and how to get involved with Adopt-a-JSR through your JUG (or on your own)!  Here is the description in Portuguese: A JCP desempenha um papel fundamental na evolução do Java. A sessão vai enfatizar o valor da transparência e participação através da JCP, Grupos de Usuários Java e do programa Adote um JSR. Vamos explorar também algumas das mudanças futuras no processo através da iniciativa JCP.Next, e explicar como você pode se envolver. Traga suas dúvidas, suas sugestões, e suas preocupações. Nós queremos ouvir de você, e incentivá-lo e facilitar a sua participação ativa no avanço da plataforma Java

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  • Be There: Tinkerforge/NetBeans Platform Integration Course

    - by Geertjan
    Tinkerforge is an electronic construction kit. It exposes a number of API bindings, including, of course, Java. The nice thing also is that Tinkerforge products are open source, both on the hardware and software levels, so that you can take their bases as a starting point for your own modifications. "The TinkerForge system is a set of pre-built electronics boards that are built in such a way that you can stack the boards (known as bricks), attach accessories (known as bricklets), and have your prototype and and running quickly. Unlike systems, such as the Arduino or Launchpad, the TinkerForge has to be attached to a computer and the computer does all of the work. With an easy set of application programming interfaces (APIs) available in C/C++, C#, Java, PHP, and Ruby, the system is easy to interface and program over USB in a snap." (from this useful article) Henning Krüp, who has arranged several NetBeans Platform Certified Training Courses in the past, in the Nordhorn/Lingen area in Germany, had the inspired idea to focus the next course on integration with Tinkerforge. In other words, the whole course will be focused on creating a standalone Java desktop application that leverages the NetBeans Platform to interact with Tinkerforge! Interested in joining the course or setting up something similar yourself? The course organized by Henning will be held from 19 to 21 September, as explained here, together with contact details.  If you'd like to organize a similar course at a location of your choosing, leave a comment at the end of this blog entry and we'll set something up together!

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  • Migrating from GlassFish 2.x to 3.1.x

    - by alexismp
    With clustering now available in GlassFish since version 3.1 (our Spring 2011 release), a good number of folks have been looking at migrating their existing GlassFish 2.x-based clustered environments to a more recent version to take advantage of Java EE 6, our modular design, improved SSH-based provisioning and enhanced HA performance. The GlassFish documentation set is quite extensive and has a dedicated Upgrade Guide. It obviously lists a number of small changes such as file layout on disk (mostly due to modularity), some option changes (grizzly, shoal), the removal of node agents (using SSH instead), new JPA default provider name, etc... There is even a migration tool (glassfish/bin/asupgrade) to upgrade existing domains. But really the only thing you need to know is that each module in GlassFish 3 and beyond is responsible for doing its part of the upgrade job which means that the migration is as simple as copying a 2.x domain directory to the domains/ directory and starting the server with asadmin start-domain --upgrade. Binary-compatible products eligible for such upgrades include Sun Java System Application Server 9.1 Update 2 as well as version 2.1 and 2.1.1 of Sun GlassFish Enterprise Server.

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  • Marek's JAX-RS 2.0 content from Devoxx 2011

    - by alexismp
    Marek Potociar, one of the two co-spec leads for the upcoming JAX-RS 2.0 had a very well-attended session at Devoxx and wrote a blog post about it detailing his conference experience (1st time at Devoxx) and running through the new features of the specification. A link to slides is also included in his post. The work by the expert group seems very solid at this point as you can read for yourself in details in the recently published early draft document. You can follow the remaining work between now and the middle of new year on the specification project pages on java.net.

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  • What's new with Java technology? Java Embedded

    - by hinkmond
    As this article points out, Java Embedded is a safer, more robust and easier to develop platform for small networked devices. So, get ready for good things to come from Java Embedded... See: Java Embedded: Next New Thing Here's a quote: Through the past few years the industry as we know it has seen a big boom with the mobile and cloud revolution. Today, there has been an enormous amount of buzz around machine to machine (M2M) or the "Internet of Things," since we are moving into a state where everything is going to have to be interconnected and will have to properly communicate together... Today, Java Embedded provides that platform. I like it! As long as there's no Zombie Apocalypse, I think Java Embedded has a great future! Hinkmond

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  • Geek Bike Ride JavaOne 2012

    - by Tori Wieldt
    "Geek Bike Ride?" the clerk at the bike rental shop asked. "Are you guys all from the same company?" "We aren't even from the same country!" we answered. "I'm from Russia." "We're from Germany."  "I'm from Belgium." "I'm from Palo Alto." "I'm from Japan."  "We're from Brazil." "We're from Brazil." "I'm from Sweden." "Coooool" was all she could say. She was right. The Geek Bike Ride was cooool. We had 39 bike riders and one skater show up Saturday for a great route from San Francisco's Fisherman's Wharf, across the Golden Gate bridge, to Saulsalito, and back to the city by ferry. Duke Bike jerseys, sponsored by OTN, were given out. To make sure Java developers got them, each person had to answer a Java question to get a jersey. The questions were really hard, like "Who is the Father of Java?" "What's the biggest Java conference in San Francisco?" The best was when the question was "Name one of Duke's Choice Award winner from this year," and Régina ten Bruggencate answered answered "Me!"  It was foggy throughout the day, with the sun poking out occasionally. The fog was thickest on the bridge, more that one rider commented that we were "in the cloud." It was a great day to meet new friends, and have a chat with old friends. We all had fun, though some of us may more a little more slowly during JavaOne. Ride on!  Photos by permission by Arun Gupta and Yoshio Terada. Thanks, guys!

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  • RPi and Java Embedded GPIO: Big Data and Java Technology

    - by hinkmond
    Java Embedded and Big Data go hand-in-hand, especially as demonstrated by prototyping on a Raspberry Pi to show how well the Java Embedded platform can perform on a small embedded device which then becomes the proof-of-concept for industrial controllers, medical equipment, networking gear or any type of sensor-connected device generating large amounts of data. The key is a fast and reliable way to access that data using Java technology. In the previous blog posts you've seen the integration of a static electricity sensor and the Raspberry Pi through the GPIO port, then accessing that data through Java Embedded code. It's important to point out how this works and why it works well with Java code. First, the version of Linux (Debian Wheezy/Raspian) that is found on the RPi has a very convenient way to access the GPIO ports through the use of Linux OS managed file handles. This is key in avoiding terrible and complex coding using register manipulation in C code, or having to program in a less elegant and clumsy procedural scripting language such as python. Instead, using Java Embedded, allows a fast way to access those GPIO ports through those same Linux file handles. Java already has a very easy to program way to access file handles with a high degree of performance that matches direct access of those file handles with the Linux OS. Using the Java API java.io.FileWriter lets us open the same file handles that the Linux OS has for accessing the GPIO ports. Then, by first resetting the ports using the unexport and export file handles, we can initialize them for easy use in a Java app. // Open file handles to GPIO port unexport and export controls FileWriter unexportFile = new FileWriter("/sys/class/gpio/unexport"); FileWriter exportFile = new FileWriter("/sys/class/gpio/export"); ... // Reset the port unexportFile.write(gpioChannel); unexportFile.flush(); // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); Then, another set of file handles can be used by the Java app to control the direction of the GPIO port by writing either "in" or "out" to the direction file handle. // Open file handle to input/output direction control of port FileWriter directionFile = new FileWriter("/sys/class/gpio/gpio" + gpioChannel + "/direction"); // Set port for input directionFile.write("in"); // Or, use "out" for output directionFile.flush(); And, finally, a RandomAccessFile handle can be used with a high degree of performance on par with native C code (only milliseconds to read in data and write out data) with low overhead (unlike python) to manipulate the data going in and out on the GPIO port, while the object-oriented nature of Java programming allows for an easy way to construct complex analytic software around that data access functionality to the external world. RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; ... // Reset file seek pointer to read latest value of GPIO port raf[channum].seek(0); raf[channum].read(inBytes); inLine = new String(inBytes); It's Big Data from sensors and industrial/medical/networking equipment meeting complex analytical software on a small constraint device (like a Linux/ARM RPi) where Java Embedded allows you to shine as an Embedded Device Software Designer. Hinkmond

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