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• Tech Article: Tired of Null Pointer Exceptions? Use Java SE 8's Optional!

  - by Tori Wieldt

  A wise man once said you are not a real Java programmer until you've dealt with a null pointer exception. The null reference is the source of many problems because it is often used to denote the absence of a value. Java SE 8 introduces a new class called java.util.Optional that can alleviate some of these problems. In the tech article "Tired of Null Pointer Exceptions? Use Java SE 8's Optional!" Java expert Raoul-Gabriel Urma shows you how to make your code more readable and protect it against null pointer exceptions. Urma explains "The purpose of Optional is not to replace every single null reference in your codebase but rather to help design better APIs in which—just by reading the signature of a method—users can tell whether to expect an optional value. In addition, Optional forces you to actively unwrap an Optional to deal with the absence of a value; as a result, you protect your code against unintended null pointer exceptions." Learn how to go from writing painful nested null checks to writing declarative code that is composable, readable, and better protected from null pointer exceptions. Read "Tired of Null Pointer Exceptions? Use Java SE 8's Optional!"

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• Unity environment way too slow in Ubuntu 13.10

  - by Santiago

  Unity and its apps open too slowly whenever I open one. It takes a while for them to appear completely. Everything works properly when the window is already open. The biggest problem is with the dash: it's SO SLOW when I'm looking for an app although I have removed some lenses. What should I do or what can I do? These issues only occur with Ubuntu 13.04 and 13.10 whereas 12.04 works AMAZNGLY but I have issues when updating a package or installing a new one, that's why I don't opt for that one. Specifications: RAM: 2GB, Processor: Intel® Atom™ CPU N2600 @ 1.60GHz × 4, Graphics card: Gallium 0.4 on llvmpipe (LLVM 3.3, 128 bits)

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• Material usage, one per model or per object?

  - by WSkid

  Is it better (memory, time (of developer), space) to use single model that is unwrapped and uses a single material or to break a model down into appropriate bits, each with their own smaller texture/material? Or does it depend on the target platform as to what is acceptable - ie PC vs tablet? An example: Say you have a typical house with a tiled roof. Model it, make sure everything is attached, unwrap the walls/roof so in your UV template the walls and roof would be in one texture file, side-by-side in say a 512x512 file. Model the roof/walls as separate objects, unwrap them individually and have two UV templates. You could then have a 256x256 file for each one.

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• Concurrency Utilities for Java EE Early Draft (JSR 236)

  - by arungupta

  Concurrency Utilities for Java EE is being worked as JSR 236 and has released an Early Draft. It provides concurrency capabilities to Java EE application components without compromising container integrity. Simple (common) and advanced concurrency patterns are easily supported without sacrificing usability. Using Java SE concurrency utilities such as java.util.concurrent API, java.lang.Thread and java.util.Timer in a Java EE application component such as EJB or Servlet are problematic since the container and server have no knowledge of these resources. JSR 236 enables concurrency largely by extending the Concurrency Utilities API developed under JSR-166. This also allows a consistency between Java SE and Java EE concurrency programming model. There are four main programming interfaces available: ManagedExecutorService ManagedScheduledExecutorService ContextService ManagedThreadFactory ManagedExecutorService is a managed version of java.util.concurrent.ExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref>  <resource-env-ref-name>    concurrent/BatchExecutor  </resource-env-ref-name>  <resource-env-ref-type>    javax.enterprise.concurrent.ManagedExecutorService  </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/BatchExecutor")ManagedExecutorService executor; Its recommended to bind the JNDI references in the java:comp/env/concurrent subcontext. The asynchronous tasks that need to be executed need to implement java.lang.Runnable or java.util.concurrent.Callable interface as: public class MyTask implements Runnable { public void run() { // business logic goes here }} OR public class MyTask2 implements Callable<Date> {  public Date call() { // business logic goes here   }} The task is then submitted to the executor using one of the submit method that return a Future instance. The Future represents the result of the task and can also be used to check if the task is complete or wait for its completion. Future<String> future = executor.submit(new MyTask(), String.class);. . .String result = future.get(); Another example to submit tasks is: class MyTask implements Callback<Long> { . . . }class MyTask2 implements Callback<Date> { . . . }ArrayList<Callable> tasks = new ArrayList<();tasks.add(new MyTask());tasks.add(new MyTask2());List<Future<Object>> result = executor.invokeAll(tasks); The ManagedExecutorService may be configured for different properties such as: Hung Task Threshold: Time in milliseconds that a task can execute before it is considered hung Pool Info Core Size: Number of threads to keep alive Maximum Size: Maximum number of threads allowed in the pool Keep Alive: Time to allow threads to remain idle when # of threads > Core Size Work Queue Capacity: # of tasks that can be stored in inbound buffer Thread Use: Application intend to run short vs long-running tasks, accordingly pooled or daemon threads are picked ManagedScheduledExecutorService adds delay and periodic task running capabilities to ManagedExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref>  <resource-env-ref-name>    concurrent/BatchExecutor  </resource-env-ref-name>  <resource-env-ref-type>    javax.enterprise.concurrent.ManagedExecutorService  </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/timedExecutor")ManagedExecutorService executor; And then the tasks are submitted using submit, invokeXXX or scheduleXXX methods. ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS); This will create and execute a one-shot action that becomes enabled after 5 seconds of delay. More control is possible using one of the newly added methods: MyTaskListener implements ManagedTaskListener {  public void taskStarting(...) { . . . }  public void taskSubmitted(...) { . . . }  public void taskDone(...) { . . . }  public void taskAborted(...) { . . . } }ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS, new MyTaskListener()); Here, ManagedTaskListener is used to monitor the state of a task's future. ManagedThreadFactory provides a method for creating threads for execution in a managed environment. A simple usage is: @Resource(name="concurrent/myThreadFactory")ManagedThreadFactory factory;. . .Thread thread = factory.newThread(new Runnable() { . . . }); concurrent/myThreadFactory is a JNDI resource. There is lot of interesting content in the Early Draft, download it, and read yourself. The implementation will be made available soon and also be integrated in GlassFish 4 as well. Some references for further exploring ... Javadoc Early Draft Specification concurrency-ee-spec.java.net [email protected]

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• Global Day of Coderetreat

  - by Tori Wieldt

  From the coderetreat.org website: Coderetreat is a day-long, intensive practice event, focusing on the fundamentals of software development and design. By providing developers the opportunity to take part in focused practice away from the pressures of 'getting things done', the coderetreat format has proven itself to be a highly effective means of skill improvement. This year, the Global Day of Coderetreat is happening on December 8. It sounds cool and fun, and of course, Java Champions and Java developers around the world are involved. Here's a small sampling: Chennai, India São Paulo, Brazil Skopje, Macedonia Kraków, Poland You can go to http://globalday.coderetreat.org/  to look up events near you. It's a great opportunity to practice your craft. Here's a video from an event last year to get a flavor:

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• Shrinking a Linux OEL 6 virtual Box image (vdi) hosted on Windows 7

  - by AndyBaker

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Recently for a customer demonstration there was a requirement to build a virtual box image with Oracle Enterprise Manager Cloud Control 12c. This meant installing OEL Linux 6 as well as creating an 11gr2 database and Oracle Enterprise Manager Cloud Control 12c on a single virtual box. Storage was sized at 300Gb using dynamically allocated storage for the virtual box and about 10Gb was used for Linux and the initial build. After copying over all the binaries and performing all the installations the virtual box became in the region of 80Gb used size on the host operating system, however internally it only really needed around 20Gb. This meant 60Gb had been used when copying over all the binaries and although now free was not returned to the host operating system due to the growth of the virtual box storage '.vdi' file.  Once the ‘vdi’ storage had grown it is not shrunk automatically afterwards. Space is always tight on the laptop so it was desirable to shrink the virtual box back to a minimal size and here is the process that was followed. Install 'zerofree' Linux package into the OEL6 virtual box The RPM was downloaded and installed from a site similar to below; http://rpm.pbone.net/index.php3/stat/4/idpl/12548724/com/zerofree-1.0.1-5.el5.i386.rpm.html A simple internet search for ’zerofree Linux rpm’ was easy to perform and find the required rpm. Execute 'zerofree' package on the desired Linux file system To execute this package the desired file system needs to be mounted read only. The following steps outline this process. As root: # umount /u01 As root:# mount –o ro –t ext4 /u01 NOTE: The –o is options and the –t is the file system type found in the /etc/fstab. Next run zerofree against the required storage, this is located by a simple ‘df –h’ command to see the device associated with the mount. As root:# zerofree –v /dev/sda11   NOTE: This takes a while to run but the ‘-v’ option gives feedback on the process. What does Zerofree do? Zerofree’s purpose is to go through the file system and zero out any unused sectors on the volume so that the later stages can shrink the virtual box storage obtaining the free space back. When zerofree has completed the virtual box can be shutdown as the last stage is performed on the physical host where the virtual box vdi files are located. Compact the virtual box ‘.vdi’ files The final stage is to get virtual box to shrink back the storage that has been correctly flagged as free space after executing zerofree. On the physical host in this case a windows 7 laptop a DOS window was opened. At the prompt the first step is to put the virtual box binaries onto the PATH. C:\ >echo %PATH%   The above shows the current value of the PATH environment variable. C:\ >set PATH=%PATH%;c:\program files\Oracle\Virtual Box;   The above adds onto the existing path the virtual box binary location. C:\>cd c:\Users\xxxx\OEL6.1   The above changes directory to where the VDI files are located for the required virtual box machine. C:\Users\xxxxx\OEL6.1>VBoxManage.exe modifyhd zzzzzz.vdi compact  NOTE: The zzzzzz.vdi is the name of the required vdi file to shrink. Finally the above command is executed to perform the compact operation on the ‘.vdi’ file(s). This also takes a long time to complete but shrinks the VDI file back to a minimum size. In the case of the demonstration virtual box OEM12c this reduced the virtual box to 20Gb from 80Gb which was a great outcome to achieve.

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• What's new in EJB 3.2 ? - Java EE 7 chugging along!

  - by arungupta

  EJB 3.1 added a whole ton of features for simplicity and ease-of-use such as @Singleton, @Asynchronous, @Schedule, Portable JNDI name, EJBContainer.createEJBContainer, EJB 3.1 Lite, and many others. As part of Java EE 7, EJB 3.2 (JSR 345) is making progress and this blog will provide highlights from the work done so far. This release has been particularly kept small but include several minor improvements and tweaks for usability. More features in EJB.Lite Asynchronous session bean Non-persistent EJB Timer service This also means these features can be used in embeddable EJB container and there by improving testability of your application. Pruning - The following features were made Proposed Optional in Java EE 6 and are now made optional. EJB 2.1 and earlier Entity Bean Component Contract for CMP and BMP Client View of an EJB 2.1 and earlier Entity Bean EJB QL: Query Language for CMP Query Methods JAX-RPC-based Web Service Endpoints and Client View The optional features are moved to a separate document and as a result EJB specification is now split into Core and Optional documents. This allows the specification to be more readable and better organized. Updates and Improvements Transactional lifecycle callbacks in Stateful Session Beans, only for CMT. In EJB 3.1, the transaction context for lifecyle callback methods (@PostConstruct, @PreDestroy, @PostActivate, @PrePassivate) are defined as shown. @PostConstruct @PreDestroy @PrePassivate @PostActivate Stateless Unspecified Unspecified N/A N/A Stateful Unspecified Unspecified Unspecified Unspecified Singleton Bean's transaction management type Bean's transaction management type N/A N/A In EJB 3.2, stateful session bean lifecycle callback methods can opt-in to be transactional. These methods are then executed in a transaction context as shown. @PostConstruct @PreDestroy @PrePassivate @PostActivate Stateless Unspecified Unspecified N/A N/A Stateful Bean's transaction management type Bean's transaction management type Bean's transaction management type Bean's transaction management type Singleton Bean's transaction management type Bean's transaction management type N/A N/A For example, the following stateful session bean require a new transaction to be started for @PostConstruct and @PreDestroy lifecycle callback methods. @Statefulpublic class HelloBean {   @PersistenceContext(type=PersistenceContextType.EXTENDED)   private EntityManager em;    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)   @PostConstruct   public void init() {        myEntity = em.find(...);   }   @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)    @PostConstruct    public void destroy() {        em.flush();    }} Notice, by default the lifecycle callback methods are not transactional for backwards compatibility. They need to be explicitly opt-in to be made transactional. Opt-out of passivation for stateful session bean - If your stateful session bean needs to stick around or it has non-serializable field then the bean can be opt-out of passivation as shown. @Stateful(passivationCapable=false)public class HelloBean {    private NonSerializableType ref = ... . . .} Simplified the rules to define all local/remote views of the bean. For example, if the bean is defined as: @Statelesspublic class Bean implements Foo, Bar {    . . .} where Foo and Bar have no annotations of their own, then Foo and Bar are exposed as local views of the bean. The bean may be explicitly marked @Local as @Local@Statelesspublic class Bean implements Foo, Bar {    . . .} then this is the same behavior as explained above, i.e. Foo and Bar are local views. If the bean is marked @Remote as: @Remote@Statelesspublic class Bean implements Foo, Bar {    . . .} then Foo and Bar are remote views. If an interface is marked @Local or @Remote then each interface need to be explicitly marked explicitly to be exposed as a view. For example: @Remotepublic interface Foo { . . . }@Statelesspublic class Bean implements Foo, Bar {    . . .} only exposes one remote interface Foo. Section 4.9.7 from the specification provide more details about this feature. TimerService.getAllTimers is a newly added convenience API that returns all timers in the same bean. This is only for displaying the list of timers as the timer can only be canceled by its owner. Removed restriction to obtain the current class loader, and allow to use java.io package. This is handy if you want to do file access within your beans. JMS 2.0 alignment - A standard list of activation-config properties is now defined destinationLookup connectionFactoryLookup clientId subscriptionName shareSubscriptions Tons of other clarifications through out the spec. Appendix A provide a comprehensive list of changes since EJB 3.1. ThreadContext in Singleton is guaranteed to be thread-safe. Embeddable container implement Autocloseable. A complete replay of Enterprise JavaBeans Today and Tomorrow from JavaOne 2012 can be seen here (click on CON4654_mp4_4654_001 in Media). The specification is still evolving so the actual property or method names or their actual behavior may be different from the currently proposed ones. Are there any improvements that you'd like to see in EJB 3.2 ? The EJB 3.2 Expert Group would love to hear your feedback. An Early Draft of the specification is available. The latest version of the specification can always be downloaded from here. Java EE 7 Specification Status EJB Specification Project JIRA of EJB Specification JSR Expert Group Discussion Archive These features will start showing up in GlassFish 4 Promoted Builds soon.

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• Collaborative Whiteboard using WebSocket in GlassFish 4 - Text/JSON and Binary/ArrayBuffer Data Transfer (TOTD #189)

  - by arungupta

  This blog has published a few blogs on using JSR 356 Reference Implementation (Tyrus) as its integrated in GlassFish 4 promoted builds. TOTD #183: Getting Started with WebSocket in GlassFish TOTD #184: Logging WebSocket Frames using Chrome Developer Tools, Net-internals and Wireshark TOTD #185: Processing Text and Binary (Blob, ArrayBuffer, ArrayBufferView) Payload in WebSocket TOTD #186: Custom Text and Binary Payloads using WebSocket One of the typical usecase for WebSocket is online collaborative games. This Tip Of The Day (TOTD) explains a sample that can be used to build such games easily. The application is a collaborative whiteboard where different shapes can be drawn in multiple colors. The shapes drawn on one browser are automatically drawn on all other peer browsers that are connected to the same endpoint. The shape, color, and coordinates of the image are transfered using a JSON structure. A browser may opt-out of sharing the figures. Alternatively any browser can send a snapshot of their existing whiteboard to all other browsers. Take a look at this video to understand how the application work and the underlying code. The complete sample code can be downloaded here. The code behind the application is also explained below. The web page (index.jsp) has a HTML5 Canvas as shown: <canvas id="myCanvas" width="150" height="150" style="border:1px solid #000000;"></canvas> And some radio buttons to choose the color and shape. By default, the shape, color, and coordinates of any figure drawn on the canvas are put in a JSON structure and sent as a message to the WebSocket endpoint. The JSON structure looks like: { "shape": "square", "color": "#FF0000", "coords": { "x": 31.59999942779541, "y": 49.91999053955078 }} The endpoint definition looks like: @WebSocketEndpoint(value = "websocket",encoders = {FigureDecoderEncoder.class},decoders = {FigureDecoderEncoder.class})public class Whiteboard { As you can see, the endpoint has decoder and encoder registered that decodes JSON to a Figure (a POJO class) and vice versa respectively. The decode method looks like: public Figure decode(String string) throws DecodeException { try { JSONObject jsonObject = new JSONObject(string); return new Figure(jsonObject); } catch (JSONException ex) { throw new DecodeException("Error parsing JSON", ex.getMessage(), ex.fillInStackTrace()); }} And the encode method looks like: public String encode(Figure figure) throws EncodeException { return figure.getJson().toString();} FigureDecoderEncoder implements both decoder and encoder functionality but thats purely for convenience. But the recommended design pattern is to keep them in separate classes. In certain cases, you may even need only one of them. On the client-side, the Canvas is initialized as: var canvas = document.getElementById("myCanvas");var context = canvas.getContext("2d");canvas.addEventListener("click", defineImage, false); The defineImage method constructs the JSON structure as shown above and sends it to the endpoint using websocket.send(). An instant snapshot of the canvas is sent using binary transfer with WebSocket. The WebSocket is initialized as: var wsUri = "ws://localhost:8080/whiteboard/websocket";var websocket = new WebSocket(wsUri);websocket.binaryType = "arraybuffer"; The important part is to set the binaryType property of WebSocket to arraybuffer. This ensures that any binary transfers using WebSocket are done using ArrayBuffer as the default type seem to be blob. The actual binary data transfer is done using the following: var image = context.getImageData(0, 0, canvas.width, canvas.height);var buffer = new ArrayBuffer(image.data.length);var bytes = new Uint8Array(buffer);for (var i=0; i<bytes.length; i++) { bytes[i] = image.data[i];}websocket.send(bytes); This comprehensive sample shows the following features of JSR 356 API: Annotation-driven endpoints Send/receive text and binary payload in WebSocket Encoders/decoders for custom text payload In addition, it also shows how images can be captured and drawn using HTML5 Canvas in a JSP. How could this be turned in to an online game ? Imagine drawing a Tic-tac-toe board on the canvas with two players playing and others watching. Then you can build access rights and controls within the application itself. Instead of sending a snapshot of the canvas on demand, a new peer joining the game could be automatically transferred the current state as well. Do you want to build this game ? I built a similar game a few years ago. Do somebody want to rewrite the game using WebSocket APIs ? :-) Many thanks to Jitu and Akshay for helping through the WebSocket internals! Here are some references for you: JSR 356: Java API for WebSocket - Specification (Early Draft) and Implementation (already integrated in GlassFish 4 promoted builds) Subsequent blogs will discuss the following topics (not necessary in that order) ... Error handling Interface-driven WebSocket endpoint Java client API Client and Server configuration Security Subprotocols Extensions Other topics from the API

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• Try the Oracle Database Appliance Manager Configurator - For Fun!

  - by pwstephe-Oracle

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 If you would like to get a first hand glimpse of how easy it is to configure an ODA, even if you don’t have access to one, it’s possible to download the Appliance Manager Configurator from the Oracle Technology Network, and run it standalone on your PC or Linux/Unix  workstation. The configurator is packaged in a zip file that contains the complete Java environment to run standalone. Once the package is downloaded and unzipped it’s simply a matter of launching it using the config command or shell depending on your runtime environment. Oracle Appliance Manager Configurator is a Java-based tool that enables you to input your deployment plan and validate your network settings before an actual deployment, or you can just preview and experiment with it. Simply download and run the configurator on a local client system which can be a Windows, Linux, or UNIX system. (For Windows launch the batch file config.bat for Linux/Unix environments, run  ./ config.sh). You will be presented with the very same dialogs and options used to configure a production ODA but on your workstation. At the end of a configurator session, you may save your deployment plan in a configuration file. If you were actually ready to deploy, you could copy this configuration file to a real ODA where the online Oracle Appliance Manager Configurator would use the contents to deploy your plan in production. You may also print the file’s content and use the printout as a checklist for setting up your production external network configuration. Be sure to use the actual production network addresses you intend to use it as this will only work correctly if your client system is connected to same network that will be used for the ODA. (This step is not necessary if you are just previewing the Configurator). This is a great way to get an introductory look at the simple and intuitive Database Appliance configuration interface and the steps to configure a system. /* 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:115%; 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;}

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• slow virtualbox guest

  - by ecoologic

  I run a guest ubuntu 12.04 on a host ubuntu 12.04, with virtual box, and the guest is much, much slower than the host (ALT+TAB costs 4-5secs). I had a look around and I found contradicting opinions on virtualbox vs vmware (free), so I taught to keep the former. Both systems are updated, I installed the additions on the guest and I evenly split memory and video memory (64mb) between guest and host. I am running a toshiba m200 laptop with 4GB ram and shared video memory. The host bios does not include a configuration option for machine virtualization. I have 2 cpus and I can't give them both to the vm. Is there anything I overlooked that could solve my problem? Feel free to ask for more info, and thank you for any help. EDIT Idling with the monitor open the (single) guest cpu never gets below 55% and could raise to 80 - 90% just moving the mouse around, opening ff will cause the monitor to run 100% in the guest, while the host shows that both cpus are evenly working around 60%. My cpu is Intel® Core™2 Duo CPU T5450 @ 1.66GHz × 2. If this is not a configuration problem, does it mean my machine is too weak for virtualization?

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• What are the Crappy Code Games - What are the prizes?

  - by simonsabin

  This is part of a series on the Crappy Code Games The background Who can enter? What are the challenges? What are the prizes? Why should I attend? Tips on how to win What are the prizes? There are loads of them at both the heats and the final. At the heats the top three coders at each event >will take home Gold, Silver and Bronze medals, along with some great prizes such as Steve Wozniak signed ipods, developer laptops, Win-Mo phones, Xbox 360 S consoles, t-shirts and more. And then in the final...(read more)

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• How best to merge/sort/page through tons of JSON arrays?

  - by Joshiatto

  Here's the scenario: Say you have millions of JSON documents stored as text files. Each JSON document is an array of "activity" objects, each of which contain a "created_datetime" attribute. What is the best way to merge/sort/filter/page through these activities via a web UI? For example, say we want to take a few thousand of the documents, merge them into a gigantic array, sort the array by the "created_datetime" attribute descending and then page through it 10 activities at a time. Also keep in mind that roughly 25% of these JSON documents are updated every day, and updates have to make it into the view within 5 minutes. My first thought is to parse all of the documents into an RDBMS table and then it would just be a simple query such as "select top 10 name, created_datetime from Activity where user_id=12345 order by created_datetime desc". Some have suggested I use NoSQL techniques such as hadoop or map/reduce instead. How exactly would this work? For more background, see: Why is NoSQL better for this scenario?

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• The Emergence of a New Architecture for Long-term Data Retention

  - by Claudia Caramelli-Oracle

  Dear Partner, A new research report from Wikibon explains how the combination of flash and tape makes for a superior solution for long-term data archives versus using dedupe appliances. The combination of these two technologies, that have been in the market, one for a few years and the other for decades, introduces a new concept. The concept is “Flape”, a concept first coined by Wikibon in October of 2012. Flape is a combination of Flash (SSD) technology and tape…this combination of technologies when used for long-term archiving can save IT departments as much as 300% of their overall IT budget over the course of 10 years. Do you want to know more? You can review the whole report here.

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• JCP Elections, JUG Candidates

  - by Tori Wieldt

  The JCP elections for the JCP Executive Committee (EC) have started today. The ratified candidates are:  Cinterion, Credit Suisse, Fujitsu and HP.The elected candidates are (9 candidates, 2 open seats):  Cisco Systems, CloudBees, Giuseppe Dell'Abate, Liferay, London Java Community, MoroccoJUG, North Sixty-One, Software AG, and Zero Turnaround. For community representation, the London Java Community is running for re-election. They have helped with JUGs participation on the JCP, and they need community votes to stay there doing great work! Also, the Morroco JUG is running for election for the first time.  Learn more about the JCP Elections, read the JCP Program Office blog "2012 EC Election Ballot open; Meet the Candidates Call Tomorrow." So, please, if you are a registered JCP member, don't forget to cast your vote!

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• New Java Tutorials Updated

  - by hinkmond

  The new Java Tutorials are here! The new Java Tutorials are here! So what? So, you can read them on your iPad thingie--if that's how you roll, that is... See: Read New Java Tutorials Here's a quote: What's New The Java Tutorials are continuously updated to keep up with changes to the Java Platform and to incorporate feedback from our readers. Recent updates include the following features: The Generics lesson has been completely reworked... The Java Tutorials are now available in two ebook formats: mobi ebook files for Kindle. ePub ebook files for iPad, Nook, and other eReaders that support the ePub format. Just kick back, open up your favorite tablet or eReader and learn all about the new things in the Java platform. Nice. All you need now is a cool drink and you're all set! Hinkmond

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• Fast lighting with multiple lights

  - by codymanix

  How can I implement fast lighting with multiple lights? I don't want to restrain the player, he can place an unlimited number and possibly overlapping (point) lights into the level. The problem is that shaders which contain dynamic loops which would be necessary to calculate the lighting tend to be very slow. I had the idea that if it could be possible at compiletime to compile a shader n times where n is the number of lights. If the number n is known at compiletime, the loops can be unrolled automatically. Is this possible to generate n versions of the same shader with just a different number of lights? At runtime I could then decide which shader to use for which part of the level.

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• The latest version of the EJB 3.2 spec available on java.net project

  - by Marina Vatkina

  If you are not following us on the users alias, here is a quick update. Just before JavaOne, I uploaded the latest version of the EJB 3.2 Core document to the ejb-spec.java.net downloads. If you want to see the detailed changes, download it If you are interested in the high-level list, or would like to know what to look for, this is the list of changes since the previous version (found on the same download page): Specified that the SessionContext object in a the singleton session bean is thread-safe Clarified that the EJB timers distribution and failover rules apply only to persistent timers Clarified that non-persistent timers returned by getTimers and getAllTimers methods are from the same JVM as the caller Fixed section numbering (left over after moving it to its own chapter) in Ch 17 Noted that only 3.0 and 3.1 deployment descriptors are required to be supported in EJB 3.2 Lite for prior versions of the applications Fixes for EJB_SPEC-61 (Ambiguity in EJB lite local view support) and EJB_SPEC-59 (Improve references to the component-defining annotations) JMS/MDB changes: added new standard activation properties and the unique identifier, and rearranged sections for easier navigation Fixed unresolved cross-refs Updated the rule: only local asynchronous session bean invocations are supported in EJB 3.2 Lite Synchronized permissions in the Table with the permissions listed for the EJB Components in the Java EE Platform Specification Table EE.6-2 Specified that during processing of the close() method, the embeddable container cancels all pending asynchronous invocations and non-persistent timers Updated most of the referenced documents to their latest versions Happy reading!

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• Input of mouseclick not always registered in XNA Update method

  - by LordrAider

  I have a problem that not all inputs of my mouse events seem to be registered. The update logic is checking a 2 dimensional array of 10x10 . It's logic for a jewel matching game. So when i switch my jewel I can't click on another jewel for like half a second. I tested it with a click counter variable and it doesn't hit the debugger when i click the second time after the jewel switch. Only if I do the second click after waiting half a second longer. Could it be that the update logic is too heavy that while he is executing update logic my click is happening and he doesn't register it? What am I not seeing here :)? Or doing wrong. It is my first game. My function of the update methode looks like this. public void UpdateBoard() { MouseState currentMouseState; currentMouseState = Mouse.GetState(); if (currentMouseState.LeftButton == ButtonState.Pressed && prevMouseState.LeftButton != ButtonState.Pressed) { UpdatingLogic = true; // this.CheckDropJewels(currentMouseState); //this.CheckMatches(3); //this.RemoveMatches(); this.CheckForSwitch(currentMouseState); this.MarkJewel(currentMouseState); UpdatingLogic = false; //reIndexMissingJewels = true; reIndexSwitchedJewels = true; } prevMouseState = currentMouseState; this.ReIndex(); this.UpdateJewels(); }

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• Processing Text and Binary (Blob, ArrayBuffer, ArrayBufferView) Payload in WebSocket - (TOTD #185)

  - by arungupta

  The WebSocket API defines different send(xxx) methods that can be used to send text and binary data. This Tip Of The Day (TOTD) will show how to send and receive text and binary data using WebSocket. TOTD #183 explains how to get started with a WebSocket endpoint using GlassFish 4. A simple endpoint from that blog looks like: @WebSocketEndpoint("/endpoint") public class MyEndpoint { public void receiveTextMessage(String message) { . . . } } A message with the first parameter of the type String is invoked when a text payload is received. The payload of the incoming WebSocket frame is mapped to this first parameter. An optional second parameter, Session, can be specified to map to the "other end" of this conversation. For example: public void receiveTextMessage(String message, Session session) {     . . . } The return type is void and that means no response is returned to the client that invoked this endpoint. A response may be returned to the client in two different ways. First, set the return type to the expected type, such as: public String receiveTextMessage(String message) { String response = . . . . . . return response; } In this case a text payload is returned back to the invoking endpoint. The second way to send a response back is to use the mapped session to send response using one of the sendXXX methods in Session, when and if needed. public void receiveTextMessage(String message, Session session) {     . . .     RemoteEndpoint remote = session.getRemote();     remote.sendString(...);     . . .     remote.sendString(...);    . . .    remote.sendString(...); } This shows how duplex and asynchronous communication between the two endpoints can be achieved. This can be used to define different message exchange patterns between the client and server. The WebSocket client can send the message as: websocket.send(myTextField.value); where myTextField is a text field in the web page. Binary payload in the incoming WebSocket frame can be received if ByteBuffer is used as the first parameter of the method signature. The endpoint method signature in that case would look like: public void receiveBinaryMessage(ByteBuffer message) {     . . . } From the client side, the binary data can be sent using Blob, ArrayBuffer, and ArrayBufferView. Blob is a just raw data and the actual interpretation is left to the application. ArrayBuffer and ArrayBufferView are defined in the TypedArray specification and are designed to send binary data using WebSocket. In short, ArrayBuffer is a fixed-length binary buffer with no format and no mechanism for accessing its contents. These buffers are manipulated using one of the views defined by one of the subclasses of ArrayBufferView listed below: Int8Array (signed 8-bit integer or char) Uint8Array (unsigned 8-bit integer or unsigned char) Int16Array (signed 16-bit integer or short) Uint16Array (unsigned 16-bit integer or unsigned short) Int32Array (signed 32-bit integer or int) Uint32Array (unsigned 16-bit integer or unsigned int) Float32Array (signed 32-bit float or float) Float64Array (signed 64-bit float or double) WebSocket can send binary data using ArrayBuffer with a view defined by a subclass of ArrayBufferView or a subclass of ArrayBufferView itself. The WebSocket client can send the message using Blob as: blob = new Blob([myField2.value]);websocket.send(blob); where myField2 is a text field in the web page. The WebSocket client can send the message using ArrayBuffer as: var buffer = new ArrayBuffer(10);var bytes = new Uint8Array(buffer);for (var i=0; i<bytes.length; i++) { bytes[i] = i;}websocket.send(buffer); A concrete implementation of receiving the binary message may look like: @WebSocketMessagepublic void echoBinary(ByteBuffer data, Session session) throws IOException {    System.out.println("echoBinary: " + data);    for (byte b : data.array()) {        System.out.print(b);    }    session.getRemote().sendBytes(data);} This method is just printing the binary data for verification but you may actually be storing it in a database or converting to an image or something more meaningful. Be aware of TYRUS-51 if you are trying to send binary data from server to client using method return type. Here are some references for you: JSR 356: Java API for WebSocket - Specification (Early Draft) and Implementation (already integrated in GlassFish 4 promoted builds) TOTD #183 - Getting Started with WebSocket in GlassFish TOTD #184 - Logging WebSocket Frames using Chrome Developer Tools, Net-internals and Wireshark Subsequent blogs will discuss the following topics (not necessary in that order) ... Error handling Custom payloads using encoder/decoder Interface-driven WebSocket endpoint Java client API Client and Server configuration Security Subprotocols Extensions Other topics from the API

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• Java @Contented annotation to help reduce false sharing

  - by Dave

  See this posting by Aleksey Shipilev for details -- @Contended is something we've wanted for a long time. The JVM provides automatic layout and placement of fields. Usually it'll (a) sort fields by descending size to improve footprint, and (b) pack reference fields so the garbage collector can process a contiguous run of reference fields when tracing. @Contended gives the program a way to provide more explicit guidance with respect to concurrency and false sharing. Using this facility we can sequester hot frequently written shared fields away from other mostly read-only or cold fields. The simple rule is that read-sharing is cheap, and write-sharing is very expensive. We can also pack fields together that tend to be written together by the same thread at about the same time. More generally, we're trying to influence relative field placement to minimize coherency misses. Fields that are accessed closely together in time should be placed proximally in space to promote cache locality. That is, temporal locality should condition spatial locality. Fields accessed together in time should be nearby in space. That having been said, we have to be careful to avoid false sharing and excessive invalidation from coherence traffic. As such, we try to cluster or otherwise sequester fields that tend to written at approximately the same time by the same thread onto the same cache line. Note that there's a tension at play: if we try too hard to minimize single-threaded capacity misses then we can end up with excessive coherency misses running in a parallel environment. Theres no single optimal layout for both single-thread and multithreaded environments. And the ideal layout problem itself is NP-hard. Ideally, a JVM would employ hardware monitoring facilities to detect sharing behavior and change the layout on the fly. That's a bit difficult as we don't yet have the right plumbing to provide efficient and expedient information to the JVM. Hint: we need to disintermediate the OS and hypervisor. Another challenge is that raw field offsets are used in the unsafe facility, so we'd need to address that issue, possibly with an extra level of indirection. Finally, I'd like to be able to pack final fields together as well, as those are known to be read-only.

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• New Horizon

  - by alexismp

  I have resigned from Oracle and thus will soon leave the GlassFish group. I feel very proud looking back at what we've achieved as a team with GlassFish in the past few years, including those past two years at Oracle. If you know anything about the history of application servers at Sun, you'll recognize that building such a community around GlassFish and its amazing number of downloads is nothing short of a small miracle. The Java EE platform has also seen a strong resurgence, bringing it back to the forefront of effective enterprise Java development in many ways. Having been hired by Sun some 13 years ago to sell NetDynamics I certainly feel that I leave the company's application server in *much* better shape. Oracle has ambitious plans for GlassFish and has been in my opinion a good steward for this community. I see no reason for this to change and I do expect the community to keep on pushing Oracle to get even better with time. This ride has been intense and the people I've met and worked with, both inside and outside Sun/Oracle, have made the experience the best one of my career. My journey now continues here: alexismp.wordpress.com. See you there!

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• What are the crappy code games - the background?

  - by simonsabin

  This is part of a series on the Crappy Code Games The background Who can enter? What are the challenges? What are the prizes? Why should I attend? Tips on how to win   The Background Fusion IO came to us a while back wanting to run a competition to highlight the how bad code can really impact your system. We’ve all seen it, I saw an example yesterday where someone had implemented a cursor on a whole table just to update a few rows, something like this. declare cUpdateCursor cursor for  ...(read more)

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• Installing Visual Studio 2010 SP1 or Windows Phone tools in your VM (danger!)

  - by Jeff

  If you've read my blog for any amount of time, you probably know that I tend to develop stuff in a Parallels VM on a Mac. It's how I roll. I like VM's because I can trash them and do really stupid things with beta software. That said, there is a pain point that doesn't seem that well documented when it comes to installing stuff in this scenario.The WP7 tools, and SP1 for Visual Studio 2010 (perhaps only if you already have the WP7 tools installed, I'm not sure), do something strange on install. As if it weren't already a long and slow installation, for reasons I don't understand, the installer fires up an instance of Windows Phone Emulator. As you may already know, the emulator doesn't run in a VM, because it is itself a VM, apparently. What it will do is fire up your CPU, make your comprooder hot and make the fans blow harder.I found this out accidentally, as I started the (slow) phone tool installation once, and walked away. An hour and a half later, I came back to find it hadn't finished. But it was hot and the CPU was pegged, so I fired up the task manager to find XDE.exe, the phone emulator, cranking away. I had to kill it several times, and eventually the install finished. It fired up just once in the SP1 install, but it still had the same hanging effect.I can't for the life of me figure out why it does this. In a VM, I can connect the phone to it and use that, so I don't need the emulator. But this install, firing up the emulator, will make it choke until you kill the XDE.exe process. Watch out!

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• Need a Quick Sure Method to Produce a Formatted Explain Plan? This will help!

  - by user702295

  Please use the following on the production machine to get formatted explain plan and sql trace using the SLOW sql (e.g. 'T_COMB_LIST.COMB_ID = 216') or any other value that takes longer: -- Open new session is SQL*Plus */ -- Make sure you are using updated PLAN_TABLE -- This can be done by dropping it and recreate it by running: -- SQL> @?/rdbms/admin/utlxplan.sql) set lines 1000 set pages 1000 spool xplan_1.txt EXPLAIN PLAN FOR <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> @?/rdbms/admin/utlxplp spool off EXIT --Open a second session is SQL*Plus ALTER SESSION SET max_dump_file_size = unlimited; ALTER SESSION SET tracefile_identifier = '10046'; ALTER SESSION SET statistics_level = ALL; ALTER SESSION SET events '10046 trace name context forever, level 12'; <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> select 'verify cursor closed' from dual; ALTER SYSTEM SET EVENTS '10046 trace name context off'; EXIT Make sure spooled file is formatted properly and that the 10046 trace has relevant explain plan in it.  Please Upload both files (10046 trace is generated in udump). Need instructions to find udump?   sqlplus "/ as sysdba" show parameters dump_dest This will show you bdump, cdump and udump locations.

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• What's new in Servlet 3.1 ? - Java EE 7 moving forward

  - by arungupta

  Servlet 3.0 was released as part of Java EE 6 and made huge changes focused at ease-of-use. The idea was to leverage the latest language features such as annotations and generics and modernize how Servlets can be written. The web.xml was made as optional as possible. Servet 3.1 (JSR 340), scheduled to be part of Java EE 7, is an incremental release focusing on couple of key features and some clarifications in the specification. The main features of Servlet 3.1 are explained below: Non-blocking I/O - Servlet 3.0 allowed asynchronous request processing but only traditional I/O was permitted. This can restrict scalability of your applications. Non-blocking I/O allow to build scalable applications. TOTD #188 provide more details about how non-blocking I/O can be done using Servlet 3.1. HTTP protocol upgrade mechanism - Section 14.42 in the HTTP 1.1 specification (RFC 2616) defines an upgrade mechanism that allows to transition from HTTP 1.1 to some other, incompatible protocol. The capabilities and nature of the application-layer communication after the protocol change is entirely dependent upon the new protocol chosen. After an upgrade is negotiated between the client and the server, the subsequent requests use the new chosen protocol for message exchanges. A typical example is how WebSocket protocol is upgraded from HTTP as described in Opening Handshake section of RFC 6455. The decision to upgrade is made in Servlet.service method. This is achieved by adding a new method: HttpServletRequest.upgrade and two new interfaces: javax.servlet.http.HttpUpgradeHandler and javax.servlet.http.WebConnection. TyrusHttpUpgradeHandler shows how WebSocket protocol upgrade is done in Tyrus (Reference Implementation for Java API for WebSocket). Security enhancements Applying run-as security roles to #init and #destroy methods Session fixation attack by adding HttpServletRequest.changeSessionId and a new interface HttpSessionIdListener. You can listen for any session id changes using these methods. Default security semantic for non-specified HTTP method in <security-constraint> Clarifying the semantics if a parameter is specified in the URI and payload Miscellaneous ServletResponse.reset clears any data that exists in the buffer as well as the status code, headers. In addition, Servlet 3.1 will also clears the state of calling getServletOutputStream or getWriter. ServletResponse.setCharacterEncoding: Sets the character encoding (MIME charset) of the response being sent to the client, for example, to UTF-8. Relative protocol URL can be specified in HttpServletResponse.sendRedirect. This will allow a URL to be specified without a scheme. That means instead of specifying "http://anotherhost.com/foo/bar.jsp" as a redirect address, "//anotherhost.com/foo/bar.jsp" can be specified. In this case the scheme of the corresponding request will be used. Clarification in HttpServletRequest.getPart and .getParts without multipart configuration. Clarification that ServletContainerInitializer is independent of metadata-complete and is instantiated per web application. A complete replay of What's New in Servlet 3.1: An Overview from JavaOne 2012 can be seen here (click on CON6793_mp4_6793_001 in Media). Each feature will be added to the JSR subject to EG approval. You can share your feedback to [email protected]. Here are some more references for you: Servlet 3.1 Public Review Candidate Downloads Servlet 3.1 PR Candidate Spec Servlet 3.1 PR Candidate Javadocs Servlet Specification Project JSR Expert Group Discussion Archive Java EE 7 Specification Status Several features have already been integrated in GlassFish 4 Promoted Builds. Have you tried any of them ? Here are some other Java EE 7 primers published so far: Concurrency Utilities for Java EE (JSR 236) Collaborative Whiteboard using WebSocket in GlassFish 4 (TOTD #189) Non-blocking I/O using Servlet 3.1 (TOTD #188) What's New in EJB 3.2 ? JPA 2.1 Schema Generation (TOTD #187) WebSocket Applications using Java (JSR 356) Jersey 2 in GlassFish 4 (TOTD #182) WebSocket and Java EE 7 (TOTD #181) Java API for JSON Processing (JSR 353) JMS 2.0 Early Draft (JSR 343) And of course, more on their way! Do you want to see any particular one first ?

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