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• Application Scope v's Static - Not Quite the same

  - by Duncan Mills

  An interesting question came up today which, innocent as it sounded, needed a second or two to consider. What's the difference between storing say a Map of reference information as a Static as opposed to storing the same map as an application scoped variable in JSF?  From the perspective of the web application itself there seems to be no functional difference, in both cases, the information is confined to the current JVM and potentially visible to your app code (note that Application Scope is not magically propagated across a cluster, you would need a separate instance on each VM). To my mind the primary consideration here is a matter of leakage. A static will be (potentially) visible to everything running within the same VM (OK this depends on which class-loader was used but let's keep this simple), and this includes your model code and indeed other web applications running in the same container. An Application Scoped object, in JSF terms, is much more ring-fenced and is only visible to the Web app itself, not other web apps running on the same server and not directly to the business model layer if that is running in the same VM. So given that I'm a big fan of coding applications to say what I mean, then using Application Scope appeals because it explicitly states how I expect the data to be used and a provides a more explicit statement about visibility and indeed dependency as I'd generally explicitly inject it where it is needed.  Alternative viewpoints / thoughts are, as ever, welcomed...

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• Change a Foreign Action's Display Text

  - by Geertjan

  I want the display text on an Action on a Node to show something about the underlying object. But the Action is registered somewhere in the layer (i.e., in the registry), i.e., I have no control over it. How do I change the display text in this scenario? Here's how. Below I look in the Actions/Events folder, iterate through all the Actions registered there, look for an Action with display text starting with "Edit", change it to display something from the underlying object, wrap a new Action around that Action, build up a new list of Actions, and return those (together with all the other Actions in that folder) from "getActions" on my Node: @Override public Action[] getActions(boolean context) { List<Action> newEventActions = new ArrayList<Action>(); List<? extends Action> eventActions = Utilities.actionsForPath("Actions/Events"); for (final Action action : eventActions) { String value = action.getValue(Action.NAME).toString(); if (value.startsWith("Edit")) { Action editAction = new AbstractAction("Edit " + getLookup().lookup(Event.class).getPlace()) { @Override public void actionPerformed(ActionEvent e) { action.actionPerformed(e); } }; newEventActions.add(editAction); } else { newEventActions.add(action); } } return newEventActions.toArray(new Action[eventActions.size()]); } If someone knows of a better way, please let me know.

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• CPU Usage in Very Large Coherence Clusters

  - by jpurdy

  When sizing Coherence installations, one of the complicating factors is that these installations (by their very nature) tend to be application-specific, with some being large, memory-intensive caches, with others acting as I/O-intensive transaction-processing platforms, and still others performing CPU-intensive calculations across the data grid. Regardless of the primary resource requirements, Coherence sizing calculations are inherently empirical, in that there are so many permutations that a simple spreadsheet approach to sizing is rarely optimal (though it can provide a good starting estimate). So we typically recommend measuring actual resource usage (primarily CPU cycles, network bandwidth and memory) at a given load, and then extrapolating from those measurements. Of course there may be multiple types of load, and these may have varying degrees of correlation -- for example, an increased request rate may drive up the number of objects "pinned" in memory at any point, but the increase may be less than linear if those objects are naturally shared by concurrent requests. But for most reasonably-designed applications, a linear resource model will be reasonably accurate for most levels of scale. However, at extreme scale, sizing becomes a bit more complicated as certain cluster management operations -- while very infrequent -- become increasingly critical. This is because certain operations do not naturally tend to scale out. In a small cluster, sizing is primarily driven by the request rate, required cache size, or other application-driven metrics. In larger clusters (e.g. those with hundreds of cluster members), certain infrastructure tasks become intensive, in particular those related to members joining and leaving the cluster, such as introducing new cluster members to the rest of the cluster, or publishing the location of partitions during rebalancing. These tasks have a strong tendency to require all updates to be routed via a single member for the sake of cluster stability and data integrity. Fortunately that member is dynamically assigned in Coherence, so it is not a single point of failure, but it may still become a single point of bottleneck (until the cluster finishes its reconfiguration, at which point this member will have a similar load to the rest of the members). The most common cause of scaling issues in large clusters is disabling multicast (by configuring well-known addresses, aka WKA). This obviously impacts network usage, but it also has a large impact on CPU usage, primarily since the senior member must directly communicate certain messages with every other cluster member, and this communication requires significant CPU time. In particular, the need to notify the rest of the cluster about membership changes and corresponding partition reassignments adds stress to the senior member. Given that portions of the network stack may tend to be single-threaded (both in Coherence and the underlying OS), this may be even more problematic on servers with poor single-threaded performance. As a result of this, some extremely large clusters may be configured with a smaller number of partitions than ideal. This results in the size of each partition being increased. When a cache server fails, the other servers will use their fractional backups to recover the state of that server (and take over responsibility for their backed-up portion of that state). The finest granularity of this recovery is a single partition, and the single service thread can not accept new requests during this recovery. Ordinarily, recovery is practically instantaneous (it is roughly equivalent to the time required to iterate over a set of backup backing map entries and move them to the primary backing map in the same JVM). But certain factors can increase this duration drastically (to several seconds): large partitions, sufficiently slow single-threaded CPU performance, many or expensive indexes to rebuild, etc. The solution of course is to mitigate each of those factors but in many cases this may be challenging. Larger clusters also lead to the temptation to place more load on the available hardware resources, spreading CPU resources thin. As an example, while we've long been aware of how garbage collection can cause significant pauses, it usually isn't viewed as a major consumer of CPU (in terms of overall system throughput). Typically, the use of a concurrent collector allows greater responsiveness by minimizing pause times, at the cost of reducing system throughput. However, at a recent engagement, we were forced to turn off the concurrent collector and use a traditional parallel "stop the world" collector to reduce CPU usage to an acceptable level. In summary, there are some less obvious factors that may result in excessive CPU consumption in a larger cluster, so it is even more critical to test at full scale, even though allocating sufficient hardware may often be much more difficult for these large clusters.

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• Passing Parameters Between Web-Services and JSF Pages

  - by shay.shmeltzer

  This is another quick demo that shows a common scenario that combines several demos I did in the past. The scenario – we have two web services, one returns a list of objects, the other allows us to update an object. We want to build a page flow where the first page shows us the list of objects, allows us to select one, and then we can edit that instance in the next page and call the second web service to update our data source. The demo shows: How to select a row and save the object value in a pageFlowScope. (using setPropertyListener). How to create a page that allows me to modify the value of the pageFlowScope object, and how to pass the object as a parameter to the second Web service. Check it out here:

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• Handy Tool for Code Cleanup: Automated Class Element Reordering

  - by Geertjan

  You're working on an application and this thought occurs to you: "Wouldn't it be cool if I could define rules specifying that all static members, initializers, and fields should always be at the top of the class? And then, whenever I wanted to, I'd start off a process that would actually do the reordering for me, moving class elements around, based on the rules I had defined, automatically, across one or more classes or packages or even complete code bases, all at the same time?" Well, here you go: That's where you can set rules for the ordering of your class members. A new hint (i.e., new in NetBeans IDE 7.3), which you need to enable yourself because by default it is disabled, let's the IDE show a hint in the Java Editor whenever there's code that isn't ordered according to the rules you defined: The first element in a file that the Java Editor identifies as not matching your rules gets a lightbulb hint shown in the left sidebar: Then, when you click the lightbulb, automatically the file is reordered according to your defined rules. However, it's not much fun going through each file individually to fix class elements as shown above. For that reason, you can go to "Refactor | Inspect and Transform". There, in the "Inspect and Transform" dialog, you can choose the hint shown above and then specify that you'd like it to be applied to a scope of your choice, which could be a file, a package, a project, combinations of these, or all of the open projects, as shown below: Then, when Inspect is clicked, the Refactoring window shows all the members that are ordered in ways that don't conform to your rules: Click "Do Refactoring" above and, in one fell swoop, all the class elements within the selected scope are ordered according to your rules.

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• PanelGridLayout - A Layout Revolution

  - by Duncan Mills

  With the most recent 11.1.2 patchset (11.1.2.3) there has been a lot of excitement around ADF Essentials (and rightly so), however, in all the fuss I didn't want an even more significant change to get missed - yes you read that correctly, a more significant change! I'm talking about the new panelGridLayout component, I can confidently say that this one of the most revolutionary components that we've introduced in 11g, even though it sounds rather boring. To be totally accurate, panelGrid was introduced in 11.1.2.2 but without any presence in the component palette or other design time support, so it was largely missed unless you read the release notes. However in this latest patchset it's finally front and center. Its time to explore - we (really) need to talk about layout.  Let's face it,with ADF Faces rich client, layout is a rather arcane pursuit, once you are a layout master, all bow before you, but it's more of an art than a science, and it is often, in fact, way too difficult to achieve what should (apparently) be a pretty simple. Here's a great example, it's a homework assignment I set for folks I'm teaching this stuff to:  The requirements for this layout are: The header is 80px high, the footer is 30px. These are both fixed.  The first section of the header containing the logo is 180px wide The logo is centered within the top left hand corner of the header  The title text is start aligned in the center zone of the header and will wrap if the browser window is narrowed. It should be aligned in the center of the vertical space  The about link is anchored to the right hand side of the browser with a 20px gap and again is center aligned vertically. It will move as the browser window is reduced in width. The footer has a right aligned copyright statement, again middle aligned within a 30px high footer region and with a 20px buffer to the right hand edge. It will move as the browser window is reduced in width. All remaining space is given to a central zone, which, in this case contains a panelSplitter. Expect that at some point in time you'll need a separate messages line in the center of the footer.  In the homework assigment I set I also stipulate that no inlineStyles can be used to control alignment or margins and no use of other taglibs (e.g. JSF HTML or Trinidad HTML). So, if we take this purist approach, that basic page layout (in my stock solution) requires 3 panelStretchLayouts, 5 panelGroupLayouts and 4 spacers - not including the spacer I use for the logo and the contents of the central zone splitter - phew! The point is that even a seemingly simple layout needs a bit of thinking about, particulatly when you consider strechting and browser re-size behavior. In fact, this little sample actually teaches you much of what you need to know to become vaguely competant at layouts in the framework. The underlying result of "the way things are" is that most of us reach for panelStretchLayout before even finishing the first sip of coffee as we embark on a new page design. In fact most pages you will see in any moderately complex ADF page will basically be nested panelStretchLayouts and panelGroupLayouts, sometimes many, many levels deep. So this is a problem, we've known this for some time and now we have a good solution. (I should point out that the oft-used Trinidad trh tags are not a particularly good solution as you're tie-ing yourself to an HTML table based layout in that case with a host of attendent issues in resize and bi-di behavior, but I digress.) So, tadaaa, I give to you panelGridLayout. PanelGrid, as the name suggests takes a grid like (dare I say slightly gridbag-like) approach to layout, dividing your layout into rows and colums with margins, sizing, stretch behaviour, colspans and rowspans all rolled in, all without the use of inlineStyle. As such, it provides for a much more powerful and consise way of defining a layout such as the one above that is actually simpler and much more logical to design. The basic building blocks are the panelGridLayout itself, gridRow and gridCell. Your content sits inside the cells inside the rows, all helpfully allowing both streching, valign and halign definitions without the need to nest further panelGroupLayouts. So much simpler!  If I break down the homework example above my nested comglomorate of 12 containers and spacers can be condensed down into a single panelGrid with 3 rows and 5 cell definitions (39 lines of source reduced to 24 in the case of the sample). What's more, the actual runtime representation in the browser DOM is much, much simpler, and clean, with basically one DIV per cell (Note that just because the panelGridLayout semantics looks like an HTML table does not mean that it's rendered that way!) . Another hidden benefit is the runtime cost. Because we can use a single layout to achieve much more complex geometries the client side layout code inside the browser is having to work a lot less. This will be a real benefit if your application needs to run on lower powered clients such as netbooks or tablets. So, it's time, if you're on 11.1.2.2 or above, to smile warmly at your panelStretchLayouts, wrap the blanket around it's knees and wheel it off to the Sunset Retirement Home for a well deserved rest. There's a new kid on the block and it wants to be your friend. 

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• JavaOne 2012: Lessons from Mathematics

  - by darcy

  I was pleased to get notification recently that my bof proposal for Lessons from Mathematics was accepted for JavaOne 2012. This is a bit of a departure from the project-centric JavaOne talks I usually give, but whisps of this kind of material have appeared before. I'm looking forward to presenting material from linear algebra, stochastics, and numerical optimization that have influence my thinking about technical problems in the JDK and elsewhere.

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• Android Layout Preview for NetBeans IDE

  - by Geertjan

  More often than not, the reason that Eclipse has more plugins than NetBeans IDE is because Eclipse has far less features out of the box. For example, thanks to its out of the box support, NetBeans IDE doesn't need a Maven plugin and it doesn't need a Java EE plugin, which are two of the most popular plugins for Eclipse. However, what would be great for NetBeans IDE to have is support for Android. It's existed for a while, thanks to the community-driven NBAndroid project, but without much desired GUI functionality. Today, the project announced a leap forward, that is, early results in providing a layout preview: Looking forward to more GUI functionality for this project!   

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• Gradle in NetBeans IDE 7.3 Beta

  - by Geertjan

  Installed Attila Kelemen's Gradle plugin in NetBeans IDE 7.3 Beta today: http://plugins.netbeans.org/plugin/44510/gradle-support Not only can existing Gradle projects now be opened, i.e., any folder with a build.gradle file: ...but single Gradle projects as well as multi module Gradle projects can be created: What you see below is the result of using the "Gradle Root Project" template once, followed by the "Gradle Subproject" twice within the folder where the root project was created: Pretty cool stuff. Where's the documentation for the plugin? Here: https://github.com/kelemen/netbeans-gradle-project Read it, some handy tips and tricks are provided there.

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• RPi and Java Embedded GPIO: Connecting LEDs

  - by hinkmond

  Next, we need some low-level peripherals to connect to the Raspberry Pi GPIO header. So, we'll do what's called a "Fry's Run" in Silicon Valley, which means we go shop at the local Fry's Electronics store for parts. In this case, we'll need some breadboard jumper wires (blue wires in photo), some LEDs, and some resistors (for the RPi GPIO, 150 ohms - 300 ohms would work for the 3.3V output of the GPIO ports). And, if you want to do other projects, you might as well by a breadboard, which is a development board with lots of holes in it. Ask a Fry's clerk for help. Or, better yet, ask the customer standing next to you in the electronics components aisle for help. (Might be faster) So, go to your local hobby electronics store, or go to Fry's if you have one close by, and come back here to the next blog post to see how to hook these parts up. Hinkmond

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• My error with upgrading 4.0 to 4.2- What NOT to do...

  - by Steve Tunstall

  Last week, I was helping a client upgrade from the 2011.1.4.0 code to the newest 2011.1.4.2 code. We downloaded the 4.2 update from MOS, upload and unpacked it on both controllers, and upgraded one of the controllers in the cluster with no issues at all. As this was a brand-new system with no networking or pools made on it yet, there were not any resources to fail back and forth between the controllers. Each controller had it's own, private, management interface (igb0 and igb1) and that's it. So we took controller 1 as the passive controller and upgraded it first. The first controller came back up with no issues and was now on the 4.2 code. Great. We then did a takeover on controller 1, making it the active head (although there were no resources for it to take), and then proceeded to upgrade controller 2. Upon upgrading the second controller, we ran the health check with no issues. We then ran the update and it ran and rebooted normally. However, something strange then happened. It took longer than normal to come back up, and when it did, we got the "cluster controllers on different code" error message that one gets when the two controllers of a cluster are running different code. But we just upgraded the second controller to 4.2, so they should have been the same, right??? Going into the Maintenance-->System screen of controller 2, we saw something very strange. The "current version" was still on 4.0, and the 4.2 code was there but was in the "previous" state with the rollback icon, as if it was the OLDER code and not the newer code. I have never seen this happen before. I would have thought it was a bad 4.2 code file, but it worked just fine with controller 1, so I don't think that was it. Other than the fact the code did not update, there was nothing else going on with this system. It had no yellow lights, no errors in the Problems section, and no errors in any of the logs. It was just out of the box a few hours ago, and didn't even have a storage pool yet. So.... We deleted the 4.2 code, uploaded it from scratch, ran the health check, and ran the upgrade again. once again, it seemed to go great, rebooted, and came back up to the same issue, where it came to 4.0 instead of 4.2. See the picture below.... HERE IS WHERE I MADE A BIG MISTAKE.... I SHOULD have instantly called support and opened a Sev 2 ticket. They could have done a shared shell and gotten the correct Fishwork engineer to look at the files and the code and determine what file was messed up and fixed it. The system was up and working just fine, it was just on an older code version, not really a huge problem at all. Instead, I went ahead and clicked the "Rollback" icon, thinking that the system would rollback to the 4.2 code.   Ouch... What happened was that the system said, "Fine, I will delete the 4.0 code and boot to your 4.2 code"... Which was stupid on my part because something was wrong with the 4.2 code file here and the 4.0 was just fine.  So now the system could not boot at all, and the 4.0 code was completely missing from the system, and even a high-level Fishworks engineer could not help us. I had messed it up good. We could only get to the ILOM, and I had to re-image the system from scratch using a hard-to-get-and-use FishStick USB drive. These are tightly controlled and difficult to get, almost always handcuffed to an engineer who will drive out to re-image a system. This took another day of my client's time.  So.... If you see a "previous version" of your system code which is actually a version higher than the current version... DO NOT ROLL IT BACK.... It did not upgrade for a very good reason. In my case, after the system was re-imaged to a code level just 3 back, we once again tried the same 4.2 code update and it worked perfectly the first time and is now great and stable.  Lesson learned.  By the way, our buddy Ryan Matthews wanted to point out the best practice and supported way of performing an upgrade of an active/active ZFSSA, where both controllers are doing some of the work. These steps would not have helpped me for the above issue, but it's important to follow the correct proceedure when doing an upgrade. 1) Upload software to both controllers and wait for it to unpack 2) On controller "A" navigate to configuration/cluster and click "takeover" 3) Wait for controller "B" to finish restarting, then login to it, navigate to maintenance/system, and roll forward to the new software. 4) Wait for controller "B" to apply the update and finish rebooting 5) Login to controller "B", navigate to configuration/cluster and click "takeover" 6) Wait for controller "A" to finish restarting, then login to it, navigate to maintenance/system, and roll forward to the new software. 7) Wait for controller "A" to apply the update and finish rebooting 8) Login to controller "B", navigate to configuration/cluster and click "failback"

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• Java update alert: issue with EAS 11.1.2.3

  - by inowodwo

  (in via Nancy) Customers using EPM 11.1.2.3 and a web browser to launch the Essbase Administration Services Console will lose the ability to launch EAS Console via the Web URL if they apply Java 1.7 build 45. Development is currently investigating this issue. Workaround: If Java 1.7 Update 45 has been installed, it will need to be uninstalled and a previous version will need to be installed. Older versions of Java are available in the Java Archive Note: Though it may work, Java 1.7 is not supported in previous versions of EAS. Customers running a version of EAS Console prior to 11.1.2.3 need to install the supported version of JRE. Follow this in the Community

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• Wrapping up an Exciting Mobile World Congress

  - by Jacob Lehrbaum

  Its been a busy week here in Barcelona, with noticeably more energy at the show than in 2010. This year, we decided to move the Java booth to the App Planet and really engage with the increasing number of developers that are attending the event. Our booth featured 10 demos and a series of nearly 25 workshops featuring a variety of topics ranging from information about Java Verified, to the use of web technologies with Java ME, to sessions hosted by Operators such as Orange and Telefonica (see image to the left).One of the more popular topics in our booth was the use of Java in the Smart Grid. In our booth we were showing off some of the work of the Hydra Consortium whose goal it is to leverage the emerging smart grid infrastructure to securely enable the delivery of personal health data (weight, blood pressure, etc) from the home to your doctor. If you'd like to learn more about this innovative project, you can watch a video that was filmed at the event featuring Charles Palmer of Onzo. If you'd like to learn more about Java in the Smart Grid, check out our on-demand webinar

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• JDeveloper / ADF 11.1.1.3.0 Now Available

  - by steve.muench

  The second production maintenance patch set release of JDeveloper / ADF 11g, release 1 is now available. The new version is 11.1.1.3.0 (Build 5660). Check out the list of new features and bugs fixed and download the software from here.

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• Node Serialization in NetBeans Platform 7.0

  - by Geertjan

  Node serialization makes sense when you're not interested in the data (since that should be serialized to a database), but in the state of the application. For example, when the application restarts, you want the last selected node to automatically be selected again. That's not the kind of information you'll want to store in a database, hence node serialization is not about data serialization but about application state serialization. I've written about this topic in October 2008, here and here, but want to show how to do this again, using NetBeans Platform 7.0. Somewhere I remember reading that this can't be done anymore and that's typically the best motivation for me, i.e., to prove that it can be done after all. Anyway, in a standard POJO/Node/BeanTreeView scenario, do the following: Remove the "@ConvertAsProperties" annotation at the top of the class, which you'll find there if you used the Window Component wizard. We're not going to use property-file based serialization, but plain old java.io.Serializable  instead. In the TopComponent, assuming it is named "UserExplorerTopComponent", typically at the end of the file, add the following: @Override public Object writeReplace() { //We want to work with one selected item only //and thanks to BeanTreeView.setSelectionMode, //only one node can be selected anyway: Handle handle = NodeOp.toHandles(em.getSelectedNodes())[0]; return new ResolvableHelper(handle); } public final static class ResolvableHelper implements Serializable { private static final long serialVersionUID = 1L; public Handle selectedHandle; private ResolvableHelper(Handle selectedHandle) { this.selectedHandle = selectedHandle; } public Object readResolve() { WindowManager.getDefault().invokeWhenUIReady(new Runnable() { @Override public void run() { try { //Get the TopComponent: UserExplorerTopComponent tc = (UserExplorerTopComponent) WindowManager.getDefault().findTopComponent("UserExplorerTopComponent"); //Get the display text to search for: String selectedDisplayName = selectedHandle.getNode().getDisplayName(); //Get the root, which is the parent of the node we want: Node root = tc.getExplorerManager().getRootContext(); //Find the node, by passing in the root with the display text: Node selectedNode = NodeOp.findPath(root, new String[]{selectedDisplayName}); //Set the explorer manager's selected node: tc.getExplorerManager().setSelectedNodes(new Node[]{selectedNode}); } catch (PropertyVetoException ex) { Exceptions.printStackTrace(ex); } catch (IOException ex) { Exceptions.printStackTrace(ex); } } }); return null; } } Assuming you have a node named "UserNode" for a type named "User" containing a property named "type", add the bits in bold below to your "UserNode": public class UserNode extends AbstractNode implements Serializable { static final long serialVersionUID = 1L; public UserNode(User key) { super(Children.LEAF); setName(key.getType()); } @Override public Handle getHandle() { return new CustomHandle(this, getName()); } public class CustomHandle implements Node.Handle { static final long serialVersionUID = 1L; private AbstractNode node = null; private final String searchString; public CustomHandle(AbstractNode node, String searchString) { this.node = node; this.searchString = searchString; } @Override public Node getNode() { node.setName(searchString); return node; } } } Run the application and select one of the user nodes. Close the application. Start it up again. The user node is not automatically selected, in fact, the window does not open, and you will see this in the output: Caused: java.io.InvalidClassException: org.serialization.sample.UserNode; no valid constructor Read this article and then you'll understand the need for this class: public class BaseNode extends AbstractNode { public BaseNode() { super(Children.LEAF); } public BaseNode(Children kids) { super(kids); } public BaseNode(Children kids, Lookup lkp) { super(kids, lkp); } } Now, instead of extending AbstractNode in your UserNode, extend BaseNode. Then the first non-serializable superclass of the UserNode has an explicitly declared no-args constructor, Do the same as the above for each node in the hierarchy that needs to be serialized. If you have multiple nodes needing serialization, you can share the "CustomHandle" inner class above between all the other nodes, while all the other nodes will also need to extend BaseNode (or provide their own non-serializable super class that explicitly declares a no-args constructor). Now, when I run the application, I select a node, then I close the application, restart it, and the previously selected node is automatically selected when the application has restarted.

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• Mastering snow and Java development at jDays in Gothenburg

  - by JavaCecilia

  Last weekend, I took the train from Stockholm to Gothenburg to attend and present at the new Java developer conference jDays. It was professionally arranged in the Swedish exhibition hall close to the amusement park Liseberg and we got a great deal out of the top-level presenters and hallway discussions. Understanding and Improving Your Java Process Our main purpose was to spread information on JVM and our monitoring tools for Java processes, so I held a crash course in the most important terms and concepts if you want to affect the performance of your Java process. From the beginning - the JVM specification to interpretation of heap usage graphs. For correct analysis, you also need to understand something about process memory - you need space for the Java heap (-Xms for initial size and -Xmx for max heap size), but the process memory also contain the thread stacks (to a size of -Xss), JVM internal data structures used for keeping track of Java objects on the heap, method compilation/optimization, native libraries, etc. If you get long pause times, make sure to monitor your application, see the allocation rate and frequency of pause times.My colleague Klara Ward then held a presentation on the Java Mission Control product, the profiling and diagnostics tools suite for HotSpot, coming soon. The room was packed and very appreciated, Klara demonstrated four different scenarios, e.g. how to diagnose and fix latencies due to lock contention for logging.My German colleague, OpenJDK ambassador Dalibor Topic travelled to Sweden to do the second keynote on "Make the Future Java". He let us in on the coming features and roadmaps of Java, now delivering major versions on a two-year schedule (Java 7 2011, Java 8 2013, etc). Also letting us in on where to download early versions of 8, to report problems early on. Software Development in teams Being a scout leader, I'm drilled in different team building and workshop techniques, creating strong groups - of course, I had to attend Henrik Berglund's session on building successful teams. He spoke about the importance of clear goals, autonomy and agreed processes. Thomas Sundberg ended the conference by doing live remote pair programming with Alex in Rumania and a concrete tips for people wanting to try it out (for local collaboration, remember to wash and change clothes). Memory Master Keynote The conference keynote was delivered by the Swedish memory master Mattias Ribbing, showing off by remembering the order of a deck of cards he'd seen once. He made it interactive by forcing the audience to learn a memory mastering technique of remembering ten ordered things by heart, asking us to shout out the order backwards and we made it! I desperately need this - bought the book, will get back on the subject. Continuous Delivery The most impressive presenter was Axel Fontaine on Continuous Delivery. Very well prepared slides with key images of his message and moved about the stage like a rock star. The topic is of course highly interesting, how to create an infrastructure enabling immediate feedback to developers and ability to release your product several times per day. Tomek Kaczanowski delivered a funny and useful presentation on good and bad tests, providing comic relief with poorly written tests and the useful rules of thumb how to rewrite them. To conclude, we had a great time and hope to see you at jDays next year :)

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• jrunscript as a cross platform scripting environment

  - by user12798506

  ?????????????????????????????????????????????????????????sh????????????UNIX???????????????????sh???????????????????????????????????????????Windows????????????????? sh??????????????find?grep?sed?awk???Windows??????????????????????????????????????????????????????????????????????????????????????????????Windows???Cygwin????????????sh??????Windows??????????????Cygwin????????????????????????????????????????????JDK?????jrunscript?????JavaScript???????????????????????1?????????jrunscript??????????????????? Windows???UNIX??????????????????????? find?grep?sed?awk?????????sh???????????????Windows Script Host??????? Java????????????? ??????????????????????????????????????????????????????????(?????????????????????????????????????????) ?????????????JDK 6??????????????????????????PC????????????????JDK 6?PC????????????????????????????????????JDK????????????????????????????????????????jrunscript?????????????????????????? ?????jrunscript????JavaScript?????????????????????????????????????????? 1) Windows???UNIX????????????????? ?????????????????????????????????????????JavaScript???mytool.js???????????????????????jrunscript???????????UNIX????sh???????Windows????bat????????????????????? mytool.sh (UNIX?): #!/bin/sh bindir=$(cd $(dirname $0) && pwd) case "`uname`" in CYGWIN*) bindir=`cygpath -w "$bindir"` ;; esac jrunscript "${bindir}/mytool.js" $* mytool.bat (Windows?): @echo off set bindir=%~dp0 jrunscript "%bindir%mytool.js" %* UNIX??sh????????Cygwin???????????????????????????????????????????js??????????????UNIX?Windows??????????????????????????????? 2) jrunscript??cat, cp, find?grep?????? jrunscript???UNIX?????????????????????????????????? jrunscript JavaScript built-in functions ????UNIX??sh?????????????????????UNIX?????????????????????????????????????????src??????????java????????????enum???????java?????????????????????????????????????????????? find('src', '.*.java', function(f) { grep('enum', f); }); ???????UNIX?????????????????????????????????????????????????????????????????????????????????????????cp(from, to)??????????????????????????????????????????UNIX??????????? $ cp -r src/* tmp/ ?????????????????????????????????????????find()???????cp -r????????·?????????????????????? function cpr(fromdir, todir, pattern) { if (pattern == undefined) { pattern = ".*"; } var frdir = pathToFile(fromdir).getCanonicalPath(); find(fromdir, pattern, function(f) { // relative dir of file f from 'fromdir'. var relative = f.getParentFile().getCanonicalPath().substring(frdir.length() + 1); var dstdir = pathToFile(todir + "/" + relative); if (!dstdir.exists()) { // Create the destination dir for file f. mkdirs(dstdir); } // Copy file f to 'dstdir'. cp(f, dstdir + "/" + f.getName()); }); } java?????I/O?API??Windows?????????????"/"??????????????????????????????UNIX?Windows?????????????? ????????????exec(cmd)?????????jar???????????????????????????????????????????? $ jrunscript js> exec("jar xvf example.jar") META-INF/ ?????????????µ???B META-INF/MANIFEST.MF ???W?J???????µ???B com/ ?????????????µ???B com/example/ ?????????????µ???B com/example/Bar.class ???W?J???????µ???B com/example/dummy/ ?????????????µ???B com/example/dummy/dummy.txt ?????o???????µ???B com/example/dummy.properties ?????o???????µ???B com/example/Foo.class ???W?J???????µ???B ???exec()?????????????????????????????????????????????????????????????????Windows????????????I/O??????????????????????????????????BAT????????? errmsg.bat: for /L %%i in (1,1,50) do echo "Error Message count = %%i" 1&2 jrunscript??exec()???????????????18??????????????????????????????????? C:\tmp>jrunscript -e "exec('errmsg.bat')" C:\tmp>for /L %i in (1 1 100) do echo "Error Message count = %i" 1>&2 C:\tmp>echo "Error Message count = 1" 1>&2 : C:\tmp>echo "Error Message count = 18" 1>&2 ? ??? ???????????exec()?????????????????????????????????????????????????????????????????DataInputStream???????????????????????? $ jrunscript js this["exec"].toString() function exec(cmd) { var process = java.lang.Runtime.getRuntime().exec(cmd); var inp = new DataInputStream(process.getInputStream()); var line = null; while ((line = inp.readLine()) != null) { println(line); } process.waitFor(); $exit = process.exitValue(); } ?????????????????????????????????????????????????????exec()???????????????exec()?????????????????????????????exec()??????? function exec(cmd) { var process = java.lang.Runtime.getRuntime().exec(cmd); var stdworker = new java.lang.Runnable( {run: function() { cat(process.getInputStream()); }}); var errworker = new java.lang.Runnable( {run: function() { cat(process.getErrorStream()); }}); new java.lang.Thread(stdworker).start(); new java.lang.Thread(errworker).start(); return proc.waitFor(); } ???????????????????cat()???????????cat()?InputStreamReader?????????????????????????????????????????????????? 3) JavaScript???????????????? JavaScript?Java???????????????????????JavaScript????????????Ruby?Groovy?Scala???????????????????????????????????????????????10MB?????????????????????????????????????JavaScript????????????????????KB?????????????MB?JAR??????????????????????????JRE?JDK?????????????????????????????????????????

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• Management Software in Java for Networked Bus Systems

  - by Geertjan

  Telemotive AG develops complex networked bus systems such as Ethernet, MOST, CAN, FlexRay, LIN and Bluetooth as well as in-house product developments in infotainment, entertainment, and telematics related to driver assistance, connectivity, diagnosis, and e-mobility. Devices such as those developed by Telemotive typically come with management software, so that the device can be configured. (Just like an internet router comes with management software too.) The blue AdmiraL is a development and analysis device for the APIX (Automotive Pixel Link) technology. Here is its management tool: The blue PiraT is an optimised multi-data logger, developed by Telemotive specifically for the automotive industry. With the blue PiraT the communication of bus systems and control units are monitored and relevant data can be recorded very precisely. And here is how the tool is managed: Both applications are created in Java and, as clearly indicated in many ways in the screenshots above, are based on the NetBeans Platform. More details can be found on the Telemotive site.

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• How do you report out user research results?

  - by user12277104

  A couple weeks ago, one of my mentees asked to meet, because she wanted my advice on how to report out user research results. She had just conducted her first usability test for her new employer, and was getting to the point where she wanted to put together some slides, but she didn't want them to be boring. She wanted to talk with me about what to present and how best to present results to stakeholders. While I couldn't meet for another week, thanks to slideshare, I could quickly point her in the direction that my in-person advice would have led her. First, I'd put together a panel for the February 2012 New Hampshire UPA monthly meeting that we then repeated for the 2012 Boston UPA annual conference. In this panel, I described my reporting techniques, as did six of my colleagues -- two of whom work for companies smaller than mine, and four of whom are independent consultants. Before taking questions, we each presented for 3 to 5 minutes on how we presented research results. The differences were really interesting. For example, when do you really NEED a long, written report (as opposed to an email, spreadsheet, or slide deck with callouts)? When you are reporting your test results to the FDA -- that makes sense. in this presentation, I describe two modes of reporting results that I use.  Second, I'd been a participant in the CUE-9 study. CUE stands for Comparative Usability Evaluation, and this was the 9th of these studies that Rolf Molich had designed. Originally, the studies were designed to show the variability in evaluation methods practitioners use to evaluate websites and applications. Of course, using methods and tasks of their own choosing, the results were wildly different. However, in this 9th study, the tasks were the same, the participants were the same, and the problem severity scale was the same, so how would the results of the 19 practitioners compare? Still wildly variable. But for the purposes of this discussion, it gave me a work product that was not proprietary to the company I work for -- a usability test report that I could share publicly. This was the way I'd been reporting results since 2005, and pretty much what I still do, when time allows.  That said, I have been continuing to evolve my methods and reporting techniques, and sometimes, there is no time to create that kind of report -- the team can't wait the days that it takes to take screen shots, go through my notes, refer back to recordings, and write it all up. So in those cases, I use bullet points in email, talk through the findings with stakeholders in a 1-hour meeting, and then post the take-aways on a wiki page. There are other requirements for that kind of reporting to work -- for example, the stakeholders need to attend each of the sessions, and the sessions can't take more than a day to complete, but you get the idea: there is no one "right" way to report out results. If the method of reporting you are using is giving your stakeholders the information they need, in a time frame in which it is useful, and in a format that meets their needs (FDA report or bullet points on a wiki), then that's the "right" way to report your results. 

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• Salon du E-commerce et Social CRM B2B

  - by Valérie De Montvallon

  Nous participions au Salon du E-commerce et Social CRM B2B en septembre dernier et nous vous proposons la vidéo réalisée par Les décideurs de la relation client. Découvrez des avis d'experts de la Relation Client pour en savoir toujours plus sur le Social CRM BtoB. Pour le BtoB, la gestion de la Relation Client semble bien simple quand il s’agit de récolter des informations à partir d’appels téléphoniques, d’entretiens physiques ou d’emails. Toutefois, la tâche s’enhardit sur les réseaux sociaux. Ces plateformes sont-elles réellement adaptées au BtoB ? Comment procéder quand on se lance ? Quels sont les pièges à éviter ? Quels sont les éléments qui laissent à penser que le Social CRM BtoB est une vraie tendance de la Relation Client ? Autant de questions auxquelles les experts rencontrés ont apporté des éléments de réponse. Vous découvrirez l'interview de notre expert, Khalid Madarbokus, qui s'exprime sur la remontée d'informations depuis les médias sociaux au sein des départements d'une entreprise B2B (à 3:20)

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• YouTube Scalability Lessons

  - by Bertrand Matthelié

  @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Calibri"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }h2 { margin: 12pt 0cm 3pt; page-break-after: avoid; font-size: 14pt; font-family: "Times New Roman"; font-style: italic; }a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }span.Heading2Char { font-family: Calibri; font-weight: bold; font-style: italic; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Very interesting blog post by Todd Hoff at highscalability.com presenting “7 Years of YouTube Scalability Lessons in 30 min” based on a presentation from Mike Solomon, one of the original engineers at YouTube: …. The key takeaway away of the talk for me was doing a lot with really simple tools. While many teams are moving on to more complex ecosystems, YouTube really does keep it simple. They program primarily in Python, use MySQL as their database, they’ve stuck with Apache, and even new features for such a massive site start as a very simple Python program. That doesn’t mean YouTube doesn’t do cool stuff, they do, but what makes everything work together is more a philosophy or a way of doing things than technological hocus pocus. What made YouTube into one of the world’s largest websites? Read on and see... Stats @font-face { font-family: "Arial"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } 4 billion Views a day 60 hours of video is uploaded every minute 350+ million devices are YouTube enabled Revenue double in 2010 The number of videos has gone up 9 orders of magnitude and the number of developers has only gone up two orders of magnitude. 1 million lines of Python code Stack @font-face { font-family: "Arial"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } Python - most of the lines of code for YouTube are still in Python. Everytime you watch a YouTube video you are executing a bunch of Python code. Apache - when you think you need to get rid of it, you don’t. Apache is a real rockstar technology at YouTube because they keep it simple. Every request goes through Apache. Linux - the benefit of Linux is there’s always a way to get in and see how your system is behaving. No matter how bad your app is behaving, you can take a look at it with Linux tools like strace and tcpdump. MySQL - is used a lot. When you watch a video you are getting data from MySQL. Sometime it’s used a relational database or a blob store. It’s about tuning and making choices about how you organize your data. Vitess- a  new project released by YouTube, written in Go, it’s a frontend to MySQL. It does a lot of optimization on the fly, it rewrites queries and acts as a proxy. Currently it serves every YouTube database request. It’s RPC based. Zookeeper - a distributed lock server. It’s used for configuration. Really interesting piece of technology. Hard to use correctly so read the manual Wiseguy - a CGI servlet container. Spitfire - a templating system. It has an abstract syntax tree that let’s them do transformations to make things go faster. Serialization formats - no matter which one you use, they are all expensive. Measure. Don’t use pickle. Not a good choice. Found protocol buffers slow. They wrote their own BSON implementation, which is 10-15 time faster than the one you can download. ...Contiues. Read the blog Watch the video

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• JPRT: A Build & Test System

  - by kto

  DRAFT A while back I did a little blogging on a system called JPRT, the hardware used and a summary on my java.net weblog. This is an update on the JPRT system. JPRT ("JDK Putback Reliablity Testing", but ignore what the letters stand for, I change what they mean every day, just to annoy people :\^) is a build and test system for the JDK, or any source base that has been configured for JPRT. As I mentioned in the above blog, JPRT is a major modification to a system called PRT that the HotSpot VM development team has been using for many years, very successfully I might add. Keeping the source base always buildable and reliable is the first step in the 12 steps of dealing with your product quality... or was the 12 steps from Alcoholics Anonymous... oh well, anyway, it's the first of many steps. ;\^) Internally when we make changes to any part of the JDK, there are certain procedures we are required to perform prior to any putback or commit of the changes. The procedures often vary from team to team, depending on many factors, such as whether native code is changed, or if the change could impact other areas of the JDK. But a common requirement is a verification that the source base with the changes (and merged with the very latest source base) will build on many of not all 8 platforms, and a full 'from scratch' build, not an incremental build, which can hide full build problems. The testing needed varies, depending on what has been changed. Anyone that was worked on a project where multiple engineers or groups are submitting changes to a shared source base knows how disruptive a 'bad commit' can be on everyone. How many times have you heard: "So And So made a bunch of changes and now I can't build!". But multiply the number of platforms by 8, and make all the platforms old and antiquated OS versions with bizarre system setup requirements and you have a pretty complicated situation (see http://download.java.net/jdk6/docs/build/README-builds.html). We don't tolerate bad commits, but our enforcement is somewhat lacking, usually it's an 'after the fact' correction. Luckily the Source Code Management system we use (another antique called TeamWare) allows for a tree of repositories and 'bad commits' are usually isolated to a small team. Punishment to date has been pretty drastic, the Queen of Hearts in 'Alice in Wonderland' said 'Off With Their Heads', well trust me, you don't want to be the engineer doing a 'bad commit' to the JDK. With JPRT, hopefully this will become a thing of the past, not that we have had many 'bad commits' to the master source base, in general the teams doing the integrations know how important their jobs are and they rarely make 'bad commits'. So for these JDK integrators, maybe what JPRT does is keep them from chewing their finger nails at night. ;\^) Over the years each of the teams have accumulated sets of machines they use for building, or they use some of the shared machines available to all of us. But the hunt for build machines is just part of the job, or has been. And although the issues with consistency of the build machines hasn't been a horrible problem, often you never know if the Solaris build machine you are using has all the right patches, or if the Linux machine has the right service pack, or if the Windows machine has it's latest updates. Hopefully the JPRT system can solve this problem. When we ship the binary JDK bits, it is SO very important that the build machines are correct, and we know how difficult it is to get them setup. Sure, if you need to debug a JDK problem that only shows up on Windows XP or Solaris 9, you'll still need to hunt down a machine, but not as a regular everyday occurance. I'm a big fan of a regular nightly build and test system, constantly verifying that a source base builds and tests out. There are many examples of automated build/tests, some that trigger on any change to the source base, some that just run every night. Some provide a protection gateway to the 'golden' source base which only gets changes that the nightly process has verified are good. The JPRT (and PRT) system is meant to guard the source base before anything is sent to it, guarding all source bases from the evil developer, well maybe 'evil' isn't the right word, I haven't met many 'evil' developers, more like 'error prone' developers. ;\^) Humm, come to think about it, I may be one from time to time. :\^{ But the point is that by spreading the build up over a set of machines, and getting the turnaround down to under an hour, it becomes realistic to completely build on all platforms and test it, on every putback. We have the technology, we can build and rebuild and rebuild, and it will be better than it was before, ha ha... Anybody remember the Six Million Dollar Man? Man, I gotta get out more often.. Anyway, now the nightly build and test can become a 'fetch the latest JPRT build bits' and start extensive testing (the testing not done by JPRT, or the platforms not tested by JPRT). Is it Open Source? No, not yet. Would you like to be? Let me know. Or is it more important that you have the ability to use such a system for JDK changes? So enough blabbering on about this JPRT system, tell me what you think. And let me know if you want to hear more about it or not. Stay tuned for the next episode, same Bloody Bat time, same Bloody Bat channel. ;\^) -kto

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• Decreasing the Height of the PinkMatter Flamingo Ribbon Bar

  - by Geertjan

  The one and only thing prohibiting wide adoption of PinkMatter's amazing Flamingo ribbon bar integration for NetBeans Platform applications (watch the YouTube movie here and follow the tutorial here) is... the amount of real estate taken up by the height of the taskpane: I was Skyping with Bruce Schubert about this and he suggested that a first step might me to remove the application menu. OK, once that had been done there was still a lot of height: But then I configured a bit further and now have this, which is pretty squishy but at least shows there are possibilities: How to get to the above point? Get the PinkMatter Flamingo ribbon bar from java.net (http://java.net/projects/nbribbonbar), which is now the official place where it is found, and then look in the "Flaming Integration" module. There you'll find com.pinkmatter.modules.flamingo.LayerRibbonComponentProvider. Do the following: Comment out "addAppMenu(ribbon);" in "createRibbon()". That's the end of the application menu. Change the "addTaskPanes(JRibbon ribbon)" method from this... private void addTaskPanes(JRibbon ribbon) { RibbonComponentFactory factory = new RibbonComponentFactory(); for (ActionItem item : ActionItems.forPath("Ribbon/TaskPanes")) {// NOI18N ribbon.addTask(factory.createRibbonTask(item)); } } ...to the following: private void addTaskPanes(JRibbon ribbon) { RibbonComponentFactory factory = new RibbonComponentFactory(); for (ActionItem item : ActionItems.forPath("Ribbon/TaskPanes")) { // NOI18N RibbonTask rt = factory.createRibbonTask(item); List<AbstractRibbonBand<?>> bands = rt.getBands(); for (AbstractRibbonBand arb : bands) { arb.setPreferredSize(new Dimension(40,60)); } ribbon.addTask(rt); } } Hurray, you're done. Not a very great result yet, but at least you've made a start in decreasing the height of the PinkMatter Flamingo ribbon bar. If anyone gets further with this, I'd be very happy to hear about it!

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• ZFS Basics

  - by user12614620

  Stage 1 basics: creating a pool # zpool create $NAME $REDUNDANCY $DISK1_0..N [$REDUNDANCY $DISK2_0..N]... $NAME = name of the pool you're creating. This will also be the name of the first filesystem and, by default, be placed at the mountpoint "/$NAME" $REDUNDANCY = either mirror or raidzN, and N can be 1, 2, or 3. If you leave N off, then it defaults to 1. $DISK1_0..N = the disks assigned to the pool. Example 1: zpool create tank mirror c4t1d0 c4t2d0 name of pool: tank redundancy: mirroring disks being mirrored: c4t1d0 and c4t2d0 Capacity: size of a single disk Example 2: zpool create tank raidz c4t1d0 c4t2d0 c4t3d0 c4t4d0 c4t5d0 Here the redundancy is raidz, and there are five disks, in a 4+1 (4 data, 1 parity) config. This means that the capacity is 4 times the disk size. If the command used "raidz2" instead, then the config would be 3+2. Likewise, "raidz3" would be a 2+3 config. Example 3: zpool create tank mirror c4t1d0 c4t2d0 mirror c4t3d0 c4t4d0 This is the same as the first mirror example, except there are two mirrors now. ZFS will stripe data across both mirrors, which means that writing data will go a bit faster. Note: you cannot create a mirror of two raidzs. You can create a raidz of mirrors, but to do that requires trickery.

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• Another JavaOne Latin America around the corner

  - by alexismp

  For the second year in a row, JavaOne is traveling to Latin America : São Paulo on December 6-8, 2011 at the Transamerica Expo Center. As with any such event, participants will be able to attend the Strategy, Technical and Community Keynotes, a large number of Sessions (including Hands-On Labs) which include a good number of local speakers chosen with a dedicated Call for Papers, and wander around the Exhibition Hall. Both Java EE 6 and GlassFish will be well represented in keynotes, sessions and hands-on labs. You can follow updates to this upcoming conference on Twitter and of course Register! New this year is the "Meet your Java gurus" geek bike ride that Fabiane and friends are organizing São Paulo on the Sunday prior to the conference. Sounds like fun!

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