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Change Logging Level for SOA 11g
- by James Taylor
I’m sure there are many blogs out there that have this solution. But I seem to get asked this question a lot so I thought I would post it here for my convenience. Login to Enterprise Manager, e.g. http://localhost:7001/em Expand the SOA folder and right-click the soa-infra(soa_server1) folder and select Logs – Log Configuration Navigate to the component you want to monitor and change the log level. It is possible to change at a parent level if required It is not recommended that you set the level to FINIEST at a parent level as it will generate a lot of logging. Make sure you apply the change to take affect. Simple as that.Read the article
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Getting Started Plugging into the "Find in Projects" Dialog
- by Geertjan
In case you missed it amidst all the code in yesterday's blog entry, the "Find in Projects" dialog is now pluggable. I think that's really cool. The code yesterday gives you a complete example, but let's break it down a bit and deconstruct down to a very simple hello world scenario. We'll end up with as many extra tabs in the "Find in Projects" dialog as we need, for example, three in this case: And clicking on any of those extra tabs will, in this simple example, simply show us this: Once we have that, we'll be able to continue adding small bits of code over the next few blog entries until we have something more useful. So, in this blog entry, you'll literally be able to display "Hello World" within a new tab in the "Find in Projects" dialog: import javax.swing.JComponent; import javax.swing.JLabel; import org.netbeans.spi.search.provider.SearchComposition; import org.netbeans.spi.search.provider.SearchProvider; import org.netbeans.spi.search.provider.SearchProvider.Presenter; import org.openide.NotificationLineSupport; import org.openide.util.lookup.ServiceProvider; @ServiceProvider(service = SearchProvider.class) public class ExampleSearchProvider1 extends SearchProvider { @Override public Presenter createPresenter(boolean replaceMode) { return new ExampleSearchPresenter(this); } @Override public boolean isReplaceSupported() { return false; } @Override public boolean isEnabled() { return true; } @Override public String getTitle() { return "Demo Extension 1"; } public class ExampleSearchPresenter extends SearchProvider.Presenter { private ExampleSearchPresenter(ExampleSearchProvider1 sp) { super(sp, true); } @Override public JComponent getForm() { return new JLabel("Hello World"); } @Override public SearchComposition composeSearch() { return null; } @Override public boolean isUsable(NotificationLineSupport nls) { return true; } } } That's it, not much code, works fine in NetBeans IDE 7.2 Beta, and is easier to digest than the big chunk from yesterday. If you make three classes like the above in a NetBeans module, and you install it, you'll have three new tabs in the "Find in Projects" dialog. The only required dependencies are Dialogs API, Lookup API, and Search in Projects API. Read the javadoc linked above and then in next blog entries we'll continue to build out something like the sample you saw in yesterday's blog entry.Read the article
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JavaOne Latin America Schedule Posted
- by reza_rahman
The official schedule for JavaOne Latin America 2012 is now posted. For the folks that are not yet aware, JavaOne Latin America is to be held on 4-6 December at the Transamerica Expo Center in São Paulo, Brazil. As you can expect there are keynotes, technical sessions, hands-on labs and demos led by Java luminaries from Brazil, Latin America and across the globe. There's tons of good stuff on Java EE and GlassFish. Arun Gupta will be delivering the Java technical keynote alongside the likes of Judson Althoff, Nandini Ramani, Georges Saab, Henrik Stahl, Simon Ritter and Terrence Barr. Here are just some of the Java EE centric sessions: Time Title Location Tuesday, Dec 4 12:15 PM Designing Java EE Applications in the Age of CDI Mezanino: Sala 14 Wednesday, Dec 5 5:30 PM Java EE 7 Platform: More Productivity and Integrated HTML Keynote Hall Thursday, Dec 6 11:15 AM Developing JAX-RS Web Applications Utilizing Server-Sent Events and WebSocket Mezanino: Sala 2 Thursday, Dec 6 12:30 PM HTML5 WebSocket and Java Mezanino: Sala 12 Thursday, Dec 6 1:45 PM What's new in Java Message Service 2.0 Mezanino: Sala 14 Thursday, Dec 6 3:00 PM JAX-RS 2.0: New and Noteworthy in the RESTful Web Services API Keynote Hall Thursday, Dec 6 4:15 PM Testing JavaServer Faces Applications with Arquillian and Selenium Mezanino: Sala 13 Thursday, Dec 6 4:15 PM Distributed Caching to Data Grids: The Past, Present, and Future of Scalable Java Mezanino: Sala 14 There will also be Java EE/GlassFish demos at the DEMOgrounds. The full schedule is posted here. Hope to see you there!Read the article
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Webcast WebCenter Content, April 11th, 2012
- by rituchhibber
Our next WebCenter Content webcast will be on April 10th, 2012. This WebCast will help you to prepare yourself for the WebCenter Content Certified Implementation Specialist EXAM. Webcast Details: Date Topic Speaker Web Call Details Intercall Details April 10th WebCenter Content Refresh Course Markus NeubauerSilburyWebCenter ContentSpecialized Partner Join Webcast Dial-in numbers:CC/SP: 1579222/9221 Time: 12:00 -15:00 CET Break around 13:30 Conference ID/Key: 9819145/1004 For more details, please click here.Read the article
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The Importance of Fully Specifying a Problem
- by Alan
I had a customer call this week where we were provided a forced crashdump and asked to determine why the system was hung. Normally when you are looking at a hung system, you will find a lot of threads blocked on various locks, and most likely very little actually running on the system (unless it's threads spinning on busy wait type locks). This vmcore showed none of that. In fact we were seeing hundreds of threads actively on cpu in the second before the dump was forced. This prompted the question back to the customer: What exactly were you seeing that made you believe that the system was hung? It took a few days to get a response, but the response that I got back was that they were not able to ssh into the system and when they tried to login to the console, they got the login prompt, but after typing "root" and hitting return, the console was no longer responsive. This description puts a whole new light on the "hang". You immediately start thinking "name services". Looking at the crashdump, yes the sshds are all in door calls to nscd, and nscd is idle waiting on responses from the network. Looking at the connections I see a lot of connections to the secure ldap port in CLOSE_WAIT, but more interestingly I am seeing a few connections over the non-secure ldap port to a different LDAP server just sitting open. My feeling at this point is that we have an either non-responding LDAP server, or one that is responding slowly, the resolution being to investigate that server. Moral When you log a service ticket for a "system hang", it's great to get the forced crashdump first up, but it's even better to get a description of what you observed to make to believe that the system was hung.Read the article
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Do we have enough time to build an electric car future?
- by julien.groues
A recent article from Greenbang has posed the question 'Do we have enough time to build an electric car future?'. The writer discusses that, although the future of transport might lie with electric cars, there is concern regarding whether we'll be able to build the market and infrastructure required to support them, before carbon and oil constraints create difficulties in powering the vehicles. Of course, the increasing use of Electric vehicles (EVs) is going to put excessive pressure on energy grids, as large volumes of electricity will need to be directed to charging points, which in turn must handle fluctuating demand at peak times. EVs are increasing in popularity as a sustainable method of transport to reduce carbon consumption, and electric utilities will have the opportunity, and the challenge, to quickly determine the best methods to fuel these vehicles and accommodate the associated increases in demand for energy. Critically, efficient software is required to provide diagnostic and predictive capabilities related to EV refuelling - for example, anticipated electricity flow will need to be addressed as the number of EVs on the road increases, and electricity will need to be directed to specific areas on-demand as vehicles attempt to recharge en-mass. But a smart grid infrastructure can meet these demands, intelligently. The implementation of a smart grid is not in the distant future, it is an achievable reality for utilities via simple installation of new software and technologies, which can be done incrementally for those facing existing legacy systems or concerned with upfront costs. The smart grid is integral to the monitoring and control of energy use as well as the future-proofing of the energy grid. A smart grid will be critical to meeting the electricity requirements of new EVs and will ensure their successful deployment by providing a reliable foundation for the data handling required to record and manage electricity distribution - from recording and assessing energy usage, to analysing data and sharing information with consumers via green billing. http://www.greenbang.com/do-we-have-enough-time-to-build-an-electric-car-future_14248.htmlRead the article
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Navigational Flows in Web Forms
- by Mona Rakibe
Navigation flows in the Web UI is a common requirement. In 11.1.1.7 we do not have out of the box support for navigational flows but this is surely on our road-map.Until then this simple approach might meet some of the requirements. In this sample we use a trigger control and Web Form rules show navigation flow for Customer, Orders and Line Items. Start by creating a new Web Form and adding 3 tabs as Customer,Order,Line Items.Add the elements to each tab. Change the visibility for Order and Line Items to false Tab1 : Customer Tab 2 : Order Tab 3 : Line Item N Notice we have added trigger controls for Next & Back Buttons. Now write form rules to change the visibility and selection of tabs based on the clicks of trigger You can now navigate through the forms using the trigger control. Normal 0 false false false EN-US X-NONE X-NONE /* 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:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:10%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} a So Solution to this sample can be downloaded from here.Read the article
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Lookup Viewer
- by Geertjan
The Maven integrated view that I showed yesterday I was able to create because I happened to know that an implementation of SubprojectProvider and LogicalViewProvider are in the Lookup of Maven projects. With that knowledge, I was able to use and even delegate to those implementations. But what if you don't know that those implementations are in the Lookup of the Project object? In the case of the Maven Project implementation, you could look in the source code of the Maven Project implementation, at the "getLookup" method. However, any other module could be putting its own objects into that Lookup, dynamically, i.e., at runtime. So there's no way of knowing what's in the Lookup of any Project object or any other object with a Lookup. But now imagine that you have a Lookup Viewer, as a tool during development, which you would exclude when distributing the application. Whenever new objects are found in the Lookup, the viewer displays them. You could install the Lookup Viewer into NetBeans IDE, or any other NetBeans Platform application, and then get a quick impression of what's actually in the Lookup when you select a different item in the application during development. Here it is (though I vaguely remember someone else writing something similar): Above, a Maven Project is selected. The Lookup Window shows that, among many other classes, an implementation of SubprojectProvider and LogicalViewProvider are found in the Lookup when the Maven Project is selected. If an item in the Lookup Window has its own Lookup, the content of that Lookup is displayed as child nodes of the Lookup, etc, i.e., you can explore all the way down the Lookup of each item found within objects found within the current selection. (What's especially fun is seeing the SaveCookieImpl being added and removed from the Lookup Window when you make/save a change in a document.) Another example is below, showing the Lookup Window installed in a custom application created during a course at MIT in Boston: A small trick I had to apply is that I always show the previous Lookup, since the current Lookup, when you select one of the Nodes in the Lookup Window, would be the Lookup of the Lookup Window itself! If anyone is interested in this, I can publish the NetBeans module providing the above window to the NetBeans update center.Read the article
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Virtual Grocery Store
- by David Dorf
Because South Korean's are so busy, Tesco decided that its Homeplus grocery chain should offer a virtual alternative in subways. As you can see in the video below, shoppers passing through a subway station can see a virtual representation of the store and scan items with their mobile phones. This builds a shopping list which is delivered to their homes later that day. This is a very cool example of leveraging technology to offer a shopping experience that's different from bricks and clicks.Read the article
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New qeep app for Java ME feature phones: meet qeepy people
- by hinkmond
Is it "qeepy" if you meet people by using your cell phone instead of, you know, talking to them? Nah. Not if it's a Java ME cell phone! See: Use Qeep to Meet Peeps Here's a quote: Qeep is a free app, and compatible with over 1,000 Java-enabled feature phones... ... Qeep is one of the world's largest mobile gaming and social discovery platforms. Members of the mobile community can play live multiplayer games; blog photos; send sound attacks, text messages and virtual gifts; and meet new friends worldwide. So, go on. Go, use Qeep on your Java ME feature phone to play multiplayer games, blog photos, and meet new friends worldwide. No one will think that you're weird... Not much, at least. HinkmondRead the article
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WhatsApp Chat Messenger available for Java ME phones
- by hinkmond
If you like sending SMS text messages from your Java ME tech-enabled mobile phone without having to pay carrier charges, then WhatsApp Messenger is for you. See: Don't pay, Use Java ME WhatsApp Here's a quote: Free WhatsApp Messenger Download For S40 Java Phone now Available. The IM chat app whatsapp was earlier targeted on high end/cross-platform mobile phone with support for messaging exchange, SMS messages, send and receive pictures, exchange of videos and audios, share your location with your contacts etc. So, be a cheap-skate. It's OK. You're entitled. As long as you use WhatsApp and Java ME technology, that is. HinkmondRead the article
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JRuby and JVM Languages at JavaOne!
- by Yolande Poirier
"My goal with my talks at JavaOne is to teach what is happening at the JVM level and below so people understand better where we are going" explains Charles Nutter, Jruby project lead. In this interview, Charles shared the JRuby features he presented at the JVM Language Summit. They include foreign function interface (FFI), IO layer, character transcoding, regular expressions, compilers, coroutines, and more. At JavaOne, he will be presenting: Going Native: Bringing FFI to the JVM The Java Native Runtime (JNR) is a high-speed foreign function interface (FFI) for calling native code from Java without ever writing a line of C. Based on the success of JNR, JDK Enhancement Proposal (JEP) 191 will bring FFI to OpenJDK as an internal API. The Emerging Languages Bowl: The Big League Challenge In this panel discussion, these emerging languages are portrayed by their respective champions, who explain how they may help your everyday life as a Java developer. Script Bowl 2014: The Battle Rages On In this contest, languages that run on the JVM, represented by their respective language experts, battle for most popular language status by showing off their new features. Audience members will also vote on a language that should not return in 2015. Returning from 2013 are language gurus representing Clojure, Groovy, JRuby, and Scala.Read the article
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It could be worse....
- by Darryl Gove
As "guest" pointed out, in my file I/O test I didn't open the file with O_SYNC, so in fact the time was spent in OS code rather than in disk I/O. It's a straightforward change to add O_SYNC to the open() call, but it's also useful to reduce the iteration count - since the cost per write is much higher: ... #define SIZE 1024 void test_write() { starttime(); int file = open("./test.dat",O_WRONLY|O_CREAT|O_SYNC,S_IWGRP|S_IWOTH|S_IWUSR); ... Running this gave the following results: Time per iteration 0.000065606310 MB/s Time per iteration 2.709711563906 MB/s Time per iteration 0.178590114758 MB/s Yup, disk I/O is way slower than the original I/O calls. However, it's not a very fair comparison since disks get written in large blocks of data and we're deliberately sending a single byte. A fairer result would be to look at the I/O operations per second; which is about 65 - pretty much what I'd expect for this system. It's also interesting to examine at the profiles for the two cases. When the write() was trapping into the OS the profile indicated that all the time was being spent in system. When the data was being written to disk, the time got attributed to sleep. This gives us an indication how to interpret profiles from apps doing I/O. It's the sleep time that indicates disk activity.Read the article
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usage of setPropertyListener and setActionListener
- by Vijay Mohan
The incorrect usage could lead to hard-to-debug problems so better to understand the fundamentals behind it's working.setpropertyListener queues an event on the server side, so if for a command component you have a showPopup behavior/actionListner as well as setPropertyListener then fwk does the queuing correctly and raises further event on the component. While, the setactionListener simply raises an event on the server side instead of queueing it, so any further event on command component gets cancelled.Also, if you use an ActionListener and showPopup behavior together on a command component, then the order of their invocation is undetermined and also one of event gets cancelled on the component. So, either use only actionListner and do the popup invocation stuff progrmmatically in your bean or use the declarative stuff logically so that no clash of event happens.Read the article
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How to Develop with ADF Business Components for Multiple Databases
New how-to documentRead the article
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Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4)
- by hinkmond
And now here's the Java code that you'll need to read your ghost sensor on your Raspberry Pi The general idea is that you are using Java code to access the GPIO pin on your Raspberry Pi where the ghost sensor (JFET trasistor) detects minute changes in the electromagnetic field near the Raspberry Pi and will change the GPIO pin to high (+3 volts) when something is detected, otherwise there is no value (ground). Here's that Java code: try { /*** Init GPIO port(s) for input ***/ // 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"); for (String gpioChannel : GpioChannels) { System.out.println(gpioChannel); // Reset the port File exportFileCheck = new File("/sys/class/gpio/gpio"+gpioChannel); if (exportFileCheck.exists()) { unexportFile.write(gpioChannel); unexportFile.flush(); } // Set the port for use exportFile.write(gpioChannel); exportFile.flush(); // 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(GPIO_IN); } /*** Read data from each GPIO port ***/ RandomAccessFile[] raf = new RandomAccessFile[GpioChannels.length]; int sleepPeriod = 10; final int MAXBUF = 256; byte[] inBytes = new byte[MAXBUF]; String inLine; int zeroCounter = 0; // Get current timestamp with Calendar() Calendar cal; DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS"); String dateStr; // Open RandomAccessFile handle to each GPIO port for (int channum=0; channum And, then we just load up our Java SE Embedded app, place each Raspberry Pi with a ghost sensor attached in strategic locations around our Santa Clara office (which apparently is very haunted by ghosts from the Agnews Insane Asylum 1906 earthquake), and watch our analytics for any ghosts. Easy peazy. See the previous posts for the full series on the steps to this cool demo: Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 1) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 2) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 3) Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 4) HinkmondRead the article
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Tools for Enterprise Architects: OmniGraffle for iPad?
- by pat.shepherd
Well, I have to admit to being a bit of an Apple fan and, of course, and early adopter of gadgets and technology in general. So, when FedEx showed up with my iPad 3G last week, I was a kid in a candy store. One of the apps that my “buy finger” was hovering over for a while (like all of 3 days) was Omnigraffle for the iPad. I imagined that it would be very cool to use this with a customer’s EA’s to sketch out Business, Application, Information and Technology architectures. Instead of using the blackboard, this seemed to offer promise as a white-boarding tool with obvious benefits over a traditional white-board. I figured I’d get a VGA adapter, plug it into the customer’s projector and off we would go with a great JAD tool. The touch pad approach offered an additional hands-on kind of feel. So, I made the $49.99 purchase + the $29.99 VGA adapter and tried to give it a go. Well, I was both pleasantly and unpleasantly surprised. It is both powerful and easy to use. There are great stencils included for shapes, software icons, Visio shapes, and even UML notation. There is even a free-hand tool that works well. I created some diagrams pretty quickly. The one below was just a test and took all of 10 minuets to do. The only problem was that Onmigraffle does not recognize the VGA output, so I was stopped dead in my tracks, as it were. My use case was as a collaborative diagramming tool with other architects, though I can still use it off line. I called Omnigraffle and they said that VGA support is on the feature request list so, hopefully, in a short amount of time, I can use the tool as I envisioned. Review: Criteria Result Is it fun? Yes Is it Useful? Yes Does it Show Promise? Yes Did the VGA Output Work? No File/diagram Formats PDF, Onmigraffle proprietary, image Quick Sample: OmniGraffle for iPad - Products - The Omni GroupRead the article
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Showrooming: What's the big deal?
- by David Dorf
There's been lots of chatter recently on how retailers will combat showrooming this holiday season. Best Buy and Target, for example, plan to price-match certain online sites. But from my perspective, the whole showrooming concept is overblown. Yes, mobile phones make is easier to comparison-shop, but consumers have been doing that all along. Retailers have to work hard to merchandise their stores with the right products at the right price with the right promotions. Its Retail 101. Yeah ok, many websites don't have to charge tax so they have an advantage, but they also have to cover shipping costs. Brick-and-mortar stores have the opportunity to provide expertise, fit, and instant gratification all of which are pretty big advantages. I see lots of studies that claim a large percentage of shoppers are showrooming. Now I don't do much shopping, but when I do I rarely see anyone scanning UPC codes in the aisles. If you dig into those studies, the question is usually something like, "have you used your mobile phone to price compare while shopping in the last year." Well yeah, I did it once -- out of the 20 shopping trips. And by the way, the in-store price was close enough to just buy the item. Based on casual observation and informal surveys of friends, showrooming is not the modus-operandi for today's busy shoppers. I never see people showrooming in grocery stores, and most people don't bother for fashion. For big purchases like appliances and furniture, I bet most people do their research online before entering the store. The cases where I've done it was to see if a promotion was in fact a good deal. Or even to make sure the in-store price is the same as the online price for the same brand. So, if you think you're a victim of showrooming, I suggest you look at the bigger picture. Are you providing an engaging store experience? Are you allowing customers to shop the way they want to shop, using various touchpoints? Are you monitoring the competition to ensure prices are competitive? Are your promotions attracting the right customers? Hubert Jolly, CEO of Best Buy, recently commented that showrooming might just get more people into his stores. "Once customers are in our stores, they're ours to lose."Read the article
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Freescale One Box Unboxing (then installing Java SE Embedded technology)
- by hinkmond
So, I get a FedEx delivery the other day... "What cool device could be inside this FedEx Overnight Express Large Box?" I was wondering... Could it be a new Linux/ARM target device board, faster than a Raspberry Pi and better than a BeagleBone Black??? Why, yes! Yes, it was a Linux/ARM target device board, faster than anything around! It was a Freescale i.MX6 Sabre Smart Device Board (SDB)! Cool... Quad Core ARM Cortex A9 1GHz with 1GB of RAM. So, cool... I installed the Freescale One Box OpenWRT Linux image onto its SD card and booted it up into Linux. But, wait! One thing was missing... What was it? What could be missing? Why, it had no Java SE Embedded installed on it yet, of course! So, I went to the JDK 7u45 download link. Clicked on "Accept License Agreement", and clicked on "jdk-7u45-linux-arm-vfp-sflt.tar.gz", installed the bad boy, and all was good. Java SE Embedded 7u45 on a Freescale One Box. Nice... HinkmondRead the article
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My JavaOne 2012
- by Geertjan
I received a JavaOne speaker invitation for the following sessions and BOFs. Only one involves me on my own: Session ID: CON2987Session Title: Unlocking the Java EE 6 Platform The rest are combo packages, i.e., you get multiple speakers for the price of one. Sessions and BOFs together with others: Session ID: BOF4227 (together with Zoran Sevarac)Session Title: Building Smart Java Applications with Neural Networks, Using the Neuroph Framework Session ID: BOF5806 (together with Manfred Riem)Session Title: Doing JSF Development in NetBeans 7.1 Session ID: CON3160 (together with Allan Gregersen and others)Session Title: Dynamic Class Reloading in the Wild with Javeleon Discussion Panels: Session ID: CON4952 (together with several NetBeans Platform developers)Session Title: NetBeans Platform Panel Discussion Session ID: CON6139 (together with several NetBeans IDE users)Session Title: Lessons Learned in Building Enterprise and Desktop Applications with the NetBeans IDERead the article
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Mixing JavaFX, HTML 5, and Bananas with the NetBeans Platform
- by Geertjan
The banana in the image below can be dragged. Whenever the banana is dropped, the current date is added to the viewer: What's interesting is that the banana, and the viewer that contains it, is defined in HTML 5, with the help of a JavaScript and CSS file. The HTML 5 file is embedded within the JavaFX browser, while the JavaFX browser is embedded within a NetBeans TopComponent class. The only really interesting thing is how drop events of the banana, which is defined within JavaScript, are communicated back into the Java class. Here's how, i.e., in the Java class, parse the HTML's DOM tree to locate the node of interest and then set a listener on it. (In this particular case, the event listener adds the current date to the InstanceContent which is in the Lookup.) Here's the crucial bit of code: WebView view = new WebView(); view.setMinSize(widthDouble, heightDouble); view.setPrefSize(widthDouble, heightDouble); final WebEngine webengine = view.getEngine(); URL url = getClass().getResource("home.html"); webengine.load(url.toExternalForm()); webengine.getLoadWorker().stateProperty().addListener( new ChangeListener() { @Override public void changed(ObservableValue ov, State oldState, State newState) { if (newState == State.SUCCEEDED) { Document document = (Document) webengine.executeScript("document"); EventTarget banana = (EventTarget) document.getElementById("banana"); banana.addEventListener("click", new MyEventListener(), true); } } }); It seems very weird to me that I need to specify "click" as a string. I actually wanted the drop event, but couldn't figure out what the arbitrary string was for that. Which is exactly why strings suck in this context. Many thanks to Martin Kavuma from the Technical University of Eindhoven, who I met today and who inspired me to go down this interesting trail.Read the article
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Great Java EE Concurrency Write-up!
- by reza_rahman
As you are aware JSR-236, Concurrency Utilities for the Java EE platform, is now a candidate for addition into Java EE 7. While it is a critical enabling API it is not necessarily obvious why it is so important. This is especially true with existing features like EJB 3 @Asynchronous, Servlet 3 async and JAX-RS 2 async. On his blog DZone MVB Sander Mak does an excellent job of explaining the motivation and importance of JSR-236. Perhaps even more importantly, he discusses potential issues with the API such alignment with CDI and Java SE Fork/Join. Read the excellent write-up here!Read the article
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What's up with LDoms: Part 5 - A few Words about Consoles
- by Stefan Hinker
Back again to look at a detail of LDom configuration that is often forgotten - the virtual console server. Remember, LDoms are SPARC systems. As such, each guest will have it's own OBP running. And to connect to that OBP, the administrator will need a console connection. Since it's OBP, and not some x86 BIOS, this console will be very serial in nature ;-) It's really very much like in the good old days, where we had a terminal concentrator where all those serial cables ended up in. Just like with other components in LDoms, the virtualized solution looks very similar. Every LDom guest requires exactly one console connection. Envision this similar to the RS-232 port on older SPARC systems. The LDom framework provides one or more console services that provide access to these connections. This would be the virtual equivalent of a network terminal server (NTS), where all those serial cables are plugged in. In the physical world, we'd have a list somewhere, that would tell us which TCP-Port of the NTS was connected to which server. "ldm list" does just that: root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 16 7680M 0.4% 27d 8h 22m jupiter bound ------ 5002 20 8G mars active -n---- 5000 2 8G 0.5% 55d 14h 10m venus active -n---- 5001 2 8G 0.5% 56d 40m pluto inactive ------ 4 4G The column marked "CONS" tells us, where to reach the console of each domain. In the case of the primary domain, this is actually a (more) physical connection - it's the console connection of the physical system, which is either reachable via the ILOM of that system, or directly via the serial console port on the chassis. All the other guests are reachable through the console service which we created during the inital setup of the system. Note that pluto does not have a port assigned. This is because pluto is not yet bound. (Binding can be viewed very much as the assembly of computer parts - CPU, Memory, disks, network adapters and a serial console cable are all put together when binding the domain.) Unless we set the port number explicitly, LDoms Manager will do this on a first come, first serve basis. For just a few domains, this is fine. For larger deployments, it might be a good idea to assign these port numbers manually using the "ldm set-vcons" command. However, there is even better magic associated with virtual consoles. You can group several domains into one console group, reachable through one TCP port of the console service. This can be useful when several groups of administrators are to be given access to different domains, or for other grouping reasons. Here's an example: root@sun # ldm set-vcons group=planets service=console jupiter root@sun # ldm set-vcons group=planets service=console pluto root@sun # ldm bind jupiter root@sun # ldm bind pluto root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 16 7680M 6.1% 27d 8h 24m jupiter bound ------ 5002 200 8G mars active -n---- 5000 2 8G 0.6% 55d 14h 12m pluto bound ------ 5002 4 4G venus active -n---- 5001 2 8G 0.5% 56d 42m root@sun # telnet localhost 5002 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. sun-vnts-planets: h, l, c{id}, n{name}, q:l DOMAIN ID DOMAIN NAME DOMAIN STATE 2 jupiter online 3 pluto online sun-vnts-planets: h, l, c{id}, n{name}, q:npluto Connecting to console "pluto" in group "planets" .... Press ~? for control options .. What I did here was add the two domains pluto and jupiter to a new console group called "planets" on the service "console" running in the primary domain. Simply using a group name will create such a group, if it doesn't already exist. By default, each domain has its own group, using the domain name as the group name. The group will be available on port 5002, chosen by LDoms Manager because I didn't specify it. If I connect to that console group, I will now first be prompted to choose the domain I want to connect to from a little menu. Finally, here's an example how to assign port numbers explicitly: root@sun # ldm set-vcons port=5044 group=pluto service=console pluto root@sun # ldm bind pluto root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-cv- UART 16 7680M 3.8% 27d 8h 54m jupiter active -t---- 5002 200 8G 0.5% 30m mars active -n---- 5000 2 8G 0.6% 55d 14h 43m pluto bound ------ 5044 4 4G venus active -n---- 5001 2 8G 0.4% 56d 1h 13m With this, pluto would always be reachable on port 5044 in its own exclusive console group, no matter in which order other domains are bound. Now, you might be wondering why we always have to mention the console service name, "console" in all the examples here. The simple answer is because there could be more than one such console service. For all "normal" use, a single console service is absolutely sufficient. But the system is flexible enough to allow more than that single one, should you need them. In fact, you could even configure such a console service on a domain other than the primary (or control domain), which would make that domain a real console server. I actually have a customer who does just that - they want to separate console access from the control domain functionality. But this is definately a rather sophisticated setup. Something I don't want to go into in this post is access control. vntsd, which is the daemon providing all these console services, is fully RBAC-aware, and you can configure authorizations for individual users to connect to console groups or individual domain's consoles. If you can't wait until I get around to security, check out the man page of vntsd. Further reading: The Admin Guide is rather reserved on this subject. I do recommend to check out the Reference Manual. The manpage for vntsd will discuss all the control sequences as well as the grouping and authorizations mentioned here.Read the article
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Feynman's inbox
- by user12607414
Here is Richard Feynman writing on the ease of criticizing theories, and the difficulty of forming them: The problem is not just to say something might be wrong, but to replace it by something — and that is not so easy. As soon as any really definite idea is substituted it becomes almost immediately apparent that it does not work. The second difficulty is that there is an infinite number of possibilities of these simple types. It is something like this. You are sitting working very hard, you have worked for a long time trying to open a safe. Then some Joe comes along who knows nothing about what you are doing, except that you are trying to open the safe. He says ‘Why don’t you try the combination 10:20:30?’ Because you are busy, you have tried a lot of things, maybe you have already tried 10:20:30. Maybe you know already that the middle number is 32 not 20. Maybe you know as a matter of fact that it is a five digit combination… So please do not send me any letters trying to tell me how the thing is going to work. I read them — I always read them to make sure that I have not already thought of what is suggested — but it takes too long to answer them, because they are usually in the class ‘try 10:20:30’. (“Seeking New Laws”, page 161 in The Character of Physical Law.) As a sometime designer (and longtime critic) of widely used computer systems, I have seen similar difficulties appear when anyone undertakes to publicly design a piece of software that may be used by many thousands of customers. (I have been on both sides of the fence, of course.) The design possibilities are endless, but the deep design problems are usually hidden beneath a mass of superfluous detail. The sheer numbers can be daunting. Even if only one customer out of a thousand feels a need to express a passionately held idea, it can take a long time to read all the mail. And it is a fact of life that many of those strong suggestions are only weakly supported by reason or evidence. Opinions are plentiful, but substantive research is time-consuming, and hence rare. A related phenomenon commonly seen with software is bike-shedding, where interlocutors focus on surface details like naming and syntax… or (come to think of it) like lock combinations. On the other hand, software is easier than quantum physics, and the population of people able to make substantial suggestions about software systems is several orders of magnitude bigger than Feynman’s circle of colleagues. My own work would be poorer without contributions — sometimes unsolicited, sometimes passionately urged on me — from the open source community. If a Nobel prize winner thought it was worthwhile to read his mail on the faint chance of learning a good idea, I am certainly not going to throw mine away. (In case anyone is still reading this, and is wondering what provoked a meditation on the quality of one’s inbox contents, I’ll simply point out that the volume has been very high, for many months, on the Lambda-Dev mailing list, where the next version of the Java language is being discussed. Bravo to those of my colleagues who are surfing that wave.) I started this note thinking there was an odd parallel between the life of the physicist and that of a software designer. On second thought, I’ll bet that is the story for anybody who works in public on something requiring special training. (And that would be pretty much anything worth doing.) In any case, Feynman saw it clearly and said it well.Read the article