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• JavaOne 2012: Nashorn Edition

  - by $utils.escapeXML($entry.author)

  As with my JavaOne 2012: OpenJDK Edition post a while back (now updated to reflect the schedule of the talks), I find it convenient to have my JavaOne schedule ordered by subjects of interest. Beside OpenJDK in all its flavors, another subject I find very exciting is Nashorn. I blogged about the various material on Nashorn in the past, and we interviewed Jim Laskey, the Project Lead on Project Nashorn in the Java Spotlight podcast. So without further ado, here are the JavaOne 2012 talks and BOFs with Nashorn in their title, or abstract:CON5390 - Nashorn: Optimizing JavaScript and Dynamic Language Execution on the JVM - Monday, Oct 1, 8:30 AM - 9:30 AMThere are many implementations of JavaScript, meant to run either on the JVM or standalone as native code. Both approaches have their respective pros and cons. The Oracle Nashorn JavaScript project is based on the former approach. This presentation goes through the performance work that has gone on in Oracle’s Nashorn JavaScript project to date in order to make JavaScript-to-bytecode generation for execution on the JVM feasible. It shows that the new invoke dynamic bytecode gets us part of the way there but may not quite be enough. What other tricks did the Nashorn project use? The presentation also discusses future directions for increased performance for dynamic languages on the JVM, covering proposed enhancements to both the JVM itself and to the bytecode compiler.CON4082 - Nashorn: JavaScript on the JVM - Monday, Oct 1, 3:00 PM - 4:00 PMThe JavaScript programming language has been experiencing a renaissance of late, driven by the interest in HTML5. Nashorn is a JavaScript engine implemented fully in Java on the JVM. It is based on the Da Vinci Machine (JSR 292) and will be available with JDK 8. This session describes the goals of Project Nashorn, gives a top-level view of how it all works, provides the current status, and demonstrates examples of JavaScript and Java working together.BOF4763 - Meet the Nashorn JavaScript Team - Tuesday, Oct 2, 4:30 PM - 5:15 PMCome to this session to meet the Oracle JavaScript (Project Nashorn) language teamBOF6661 - Nashorn, Node, and Java Persistence - Tuesday, Oct 2, 5:30 PM - 6:15 PMWith Project Nashorn, developers will have a full and modern JavaScript engine available on the JVM. In addition, they will have support for running Node applications with Node.jar. This unique combination of capabilities opens the door for best-of-breed applications combining Node with Java SE and Java EE. In this session, you’ll learn about Node.jar and how it can be combined with Java EE components such as EclipseLink JPA for rich Java persistence. You’ll also hear about all of Node.jar’s mapping, caching, querying, performance, and scaling features.CON10657 - The Polyglot Java VM and Java Middleware - Thursday, Oct 4, 12:30 PM - 1:30 PMIn this session, Red Hat and Oracle discuss the impact of polyglot programming from their own unique perspectives, examining non-Java languages that utilize Oracle’s Java HotSpot VM. You’ll hear a discussion of topics relating to Ruby, Lisp, and Clojure and the intersection of other languages where they may touch upon individual frameworks and projects, and you’ll get perspectives on JavaScript via the Nashorn Project, an upcoming JavaScript engine, developed fully in Java.CON5251 - Putting the Metaobject Protocol to Work: Nashorn’s Java Bindings - Thursday, Oct 4, 2:00 PM - 3:00 PMProject Nashorn is Oracle’s new JavaScript runtime in Java 8. Being a JavaScript runtime running on the JVM, it provides integration with the underlying runtime by enabling JavaScript objects to manipulate Java objects, implement Java interfaces, and extend Java classes. Nashorn is invokedynamic-based, and for its Java integration, it does away with the concept of wrapper objects in favor of direct virtual machine linking to Java objects’ methods provided by a metaobject protocol, providing much higher performance than what could be expected from a scripting runtime. This session looks at the details of the integration, a topic of interest to other language implementers on the JVM and a wider audience of developers who want to understand how Nashorn works.That's 6 sessions tooting the Nashorn this year at JavaOne, up from 2 last year.

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• Introduction to WebCenter Personalization: &ldquo;The Conductor&rdquo;

  - by Steve Pepper

  There are some new faces in the town of WebCenter with the latest 11g PS3 release.  A new component has introduced itself as "Oracle WebCenter Personalization", a.k.a WCP, to simplify delivery of a personalized experience and content to end users.  This posting reviews one of the primary components within WCP: "The Conductor". The Conductor: This ain't just an ordinary cloud... One of the founding principals behind WebCenter Personalization was to provide an open client-side API that remains independent of the technology invoking it, in addition to independence from the architecture running it.  The Conductor delivers this, and much, much more. The Conductor is the engine behind WebCenter Personalization that allows flow-based documents, called "Scenarios", to be managed and executed on the server-side through a well published and RESTful api.      The Conductor also supports an extensible model for custom provider integration that can be easily invoked within a Scenario to promote seamless integration with existing business assets. Introducing the Scenario Conductor Scenarios are declarative offline-authored documents using the custom Personalization JDeveloper bundle included with WebCenter.  A Scenario contains one (or more) statements that can: Create variables that are scoped to the current execution context Iterate over collections, or loop until a specific condition is met Execute one or more statements when a condition is met Invoke other scenarios that exist within the same namespace Invoke a data provider that integrates with custom applications Once a variable is assigned within the Scenario's execution context, it can be referenced anywhere within the same Scenario using the common Expression Language syntax used in J2EE web containers. Scenarios are then published and tested to the Integrated WebLogic Server domain, or published remotely to other domains running WebCenter Personalization. Various Client-side Models The Conductor server API is built upon RESTful services that support a wide variety of clients able to communicate over HTTP.  The Conductor supports the following client-side models: REST:  Popular browser-based languages can be used to manage and execute Conductor Scenarios.  There are other public methods to retrieve configured provider metadata that can be used by custom applications. The Conductor currently supports XML and JSON for it's API syntax. Java: WebCenter Personalization delivers a robust and light-weight java client with the popular Jersey framework as it's foundation.  It has never been easier to write a remote java client to manage remote RESTful services. Expression Language (EL): Allow the results of Scenario execution to control your user interface or embed personalized content using the session-scoped managed bean.  The EL client can also be used in straight JSP pages with minimal configuration. Extensible Provider Framework The Conductor supports a pluggable provider framework for integrating custom code with Scenario execution.  There are two types of providers supported by the Conductor: Function Provider: Function Providers are simple java annotated classes with static methods that are meant to be served as utilities.  Some common uses would include: object creation or instantiation, data transformation, and the like.  Function Providers can be invoked using the common EL syntax from variable assignments, conditions, and loops. For example:  ${myUtilityClass:doStuff(arg1,arg2))} If you are familiar with EL Functions, Function Providers are based on the same concept. Data Provider: Like Function Providers, Data Providers are annotated java classes, but they must adhere to a much more strict object model.  Data Providers have access to a wealth of Conductor services, such as: Access to namespace-scoped configuration API that can be managed by Oracle Enterprise Manager, Scenario execution context for expression resolution, and more.  Oracle ships with three out-of-the-box data providers that supports integration with: Standardized Content Servers(CMIS),  Federated Profile Properties through the Properties Service, and WebCenter Activity Graph. Useful References If you are looking to immediately get started writing your own application using WebCenter Personalization Services, you will find the following references helpful in getting you on your way: Personalizing WebCenter Applications Authoring Personalized Scenarios in JDeveloper Using Personalization APIs Externally Implementing and Calling Function Providers Implementing and Calling Data Providers

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• Consumer Oriented Search In Oracle Endeca Information Discovery - Part 2

  - by Bob Zurek

  As discussed in my last blog posting on this topic, Information Discovery, a core capability of the Oracle Endeca Information Discovery solution enables businesses to search, discover and navigate through a wide variety of big data including structured, unstructured and semi-structured data. With search as a core advanced capabilities of our product it is important to understand some of the key differences and capabilities in the underlying data store of Oracle Endeca Information Discovery and that is our Endeca Server. In the last post on this subject, we talked about Exploratory Search capabilities along with support for cascading relevance. Additional search capabilities in the Endeca Server, which differentiate from simple keyword based "search boxes" in other Information Discovery products also include: The Endeca Server Supports Set Search.  The Endeca Server is organized around set retrieval, which means that it looks at groups of results (all the documents that match a search), as well as the relationship of each individual result to the set. Other approaches only compute the relevance of a document by comparing the document to the search query – not by comparing the document to all the others. For example, a search for “U.S.” in another approach might match to the title of a document and get a high ranking. But what if it were a collection of government documents in which “U.S.” appeared in many titles, making that clue less meaningful? A set analysis would reveal this and be used to adjust relevance accordingly. The Endeca Server Supports Second-Order Relvance. Unlike simple search interfaces in traditional BI tools, which provide limited relevance ranking, such as a list of results based on key word matching, Endeca enables users to determine the most salient terms to divide up the result. Determining this second-order relevance is the key to providing effective guidance. Support for Queries and Filters. Search is the most common query type, but hardly complete, and users need to express a wide range of queries. Oracle Endeca Information Discovery also includes navigation, interactive visualizations, analytics, range filters, geospatial filters, and other query types that are more commonly associated with BI tools. Unlike other approaches, these queries operate across structured, semi-structured and unstructured content stored in the Endeca Server. Furthermore, this set is easily extensible because the core engine allows for pluggable features to be added. Like a search engine, queries are answered with a results list, ranked to put the most likely matches first. Unlike “black box” relevance solutions, which generalize one strategy for everyone, we believe that optimal relevance strategies vary across domains. Therefore, it provides line-of-business owners with a set of relevance modules that let them tune the best results based on their content. The Endeca Server query result sets are summarized, which gives users guidance on how to refine and explore further. Summaries include Guided Navigation® (a form of faceted search), maps, charts, graphs, tag clouds, concept clusters, and clarification dialogs. Users don’t explicitly ask for these summaries; Oracle Endeca Information Discovery analytic applications provide the right ones, based on configurable controls and rules. For example, the analytic application might guide a procurement agent filtering for in-stock parts by visualizing the results on a map and calculating their average fulfillment time. Furthermore, the user can interact with summaries and filters without resorting to writing complex SQL queries. The user can simply just click to add filters. Within Oracle Endeca Information Discovery, all parts of the summaries are clickable and searchable. We are living in a search driven society where business users really seem to enjoy entering information into a search box. We do this everyday as consumers and therefore, we have gotten used to looking for that box. However, the key to getting the right results is to guide that user in a way that provides additional Discovery, beyond what they may have anticipated. This is why these important and advanced features of search inside the Endeca Server have been so important. They have helped to guide our great customers to success. 

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• What common interface would be appropriate for these game object classes?

  - by Jefffrey

  Question A component based system's goal is to solve the problems that derives from inheritance: for example the fact that some parts of the code (that are called components) are reused by very different classes that, hypothetically, would lie in a very different branch of the inheritance tree. That's a very nice concept, but I've found out that CBS is often hard to accomplish without using ugly hacks. Implementations of this system are often far from clean. But I don't want to discuss this any further. My question is: how can I solve the same problems a CBS try to solve with a very clean interface? (possibly with examples, there are a lot of abstract talks about the "perfect" design already). Context Here's an example I was going for before realizing I was just reinventing inheritance again: class Human { public: Position position; Movement movement; Sprite sprite; // other human specific components }; class Zombie { Position position; Movement movement; Sprite sprite; // other zombie specific components }; After writing that I realized I needed an interface, otherwise I would have needed N containers for N different types of objects (or to use boost::variant to gather them all together). So I've thought of polymorphism (move what systems do in a CBS design into class specific functions): class Entity { public: virtual void on_event(Event) {} // not pure virtual on purpose virtual void on_update(World) {} virtual void on_draw(Window) {} }; class Human : public Entity { private: Position position; Movement movement; Sprite sprite; public: virtual void on_event(Event) { ... } virtual void on_update(World) { ... } virtual void on_draw(Window) { ... } }; class Zombie : public Entity { private: Position position; Movement movement; Sprite sprite; public: virtual void on_event(Event) { ... } virtual void on_update(World) { ... } virtual void on_draw(Window) { ... } }; Which was nice, except for the fact that now the outside world would not even be able to know where a Human is positioned (it does not have access to its position member). That would be useful to track the player position for collision detection or if on_update the Zombie would want to track down its nearest human to move towards him. So I added const Position& get_position() const; to both the Zombie and Human classes. And then I realized that both functionality were shared, so it should have gone to the common base class: Entity. Do you notice anything? Yes, with that methodology I would have a god Entity class full of common functionality (which is the thing I was trying to avoid in the first place). Meaning of "hacks" in the implementation I'm referring to I'm talking about the implementations that defines Entities as simple IDs to which components are dynamically attached. Their implementation can vary from C-stylish: int last_id; Position* positions[MAX_ENTITIES]; Movement* movements[MAX_ENTITIES]; Where positions[i], movements[i], component[i], ... make up the entity. Or to more C++-style: int last_id; std::map<int, Position> positions; std::map<int, Movement> movements; From which systems can detect if an entity/id can have attached components.

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• Monitoring Windows Azure Service Bus Endpoint with BizTalk 360?

  - by Michael Stephenson

  I'm currently working with a customer who is undergoing an initiative to expose some of their line of business applications to external partners and SAAS applications and as part of this we have been looking at using the Windows Azure Service Bus. For the first part of the project we were focused on some synchronous request response scenarios where an external application would use the Service Bus relay functionality to get data from some internal applications. When we were looking at the operational monitoring side of the solution it was obvious that although most of the normal server monitoring capabilities would be required for the on premise components we would have to look at new approaches to validate that the operation of the service from outside of the organization was working as expected. A number of months ago one of my colleagues Elton Stoneman wrote about an approach I have introduced with a number of clients in the past where we implement a diagnostics service in each service component we build. This service would allow us to make a call which would flex some of the working parts of the system to prove it was working within any SLA. This approach is discussed on the following article: http://geekswithblogs.net/EltonStoneman/archive/2011/12/12/the-value-of-a-diagnostics-service.aspx In our solution we wanted to take the same approach but we had to consider that the service clients were external to the service. We also had to consider that by going through Windows Azure Service Bus it's not that easy to make most of your standard monitoring solutions just give you an easy way to do this. In a previous article I have described how you can use BizTalk 360 to monitor things using a custom extension to the Web Endpoint Manager and I felt that we could use this approach to provide an excellent way to monitor our service bus endpoint. The previous article is available on the following link: http://geekswithblogs.net/michaelstephenson/archive/2012/09/12/150696.aspx   The Monitoring Solution BizTalk 360 currently has an easy way to hook up the endpoint manager to a url which it will then call and if a successful response is returned it then considers the endpoint to be in a healthy state. We would take advantage of this by creating an ASP.net web page which would be called by BizTalk 360 and behind this page we would implement the functionality to call the diagnostics service on our Service Bus endpoint. The ASP.net page could include logic to work out how to handle the response from the diagnostics service. For example if the overall result of the diagnostics service was successful but the call to the diagnostics service was longer than a certain amount of time then we could return an error and indicate the service is taking too long. The following diagram illustrates the monitoring pattern.   The diagnostics service which is hosted in the line of business application allows us to ping a simple message through the Azure Service Bus relay to the WCF services in the LOB application and we they get a response back indicating that the service is working fine. To implement this I used the exact same approach I described in my previous post to create a custom web page which calls the diagnostics service and then it would return an HTTP response code which would depend on the error condition returned or a 200 if it was successful. One of the limitations of this approach is that the competing consumer pattern for listening to messages from service bus means that you cannot guarantee which server would process your diagnostics check message but with BizTalk 360 you could simply add multiple endpoint checks so that it could access the individual on-premise web servers directly to ensure that each server is working fine and then check that messages can also be processed through the cloud. Conclusion It took me about 15 minutes to get a proof of concept of this up and running which was able to monitor our web services which had been exposed via Windows Azure Service Bus. I was then able to inherit all of the monitoring benefits of BizTalk 360 to provide an enterprise class monitoring solution for our cloud enabled API.

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• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

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• Extreme Makeover, Phone Edition: Comcasts xfinity

  Mobile Makeover For many companies the first foray into Windows Phone 7 (WP7) may be in porting their existing mobile apps. It is tempting to simply transfer existing functionality, avoiding the additional design costs. Readdressing business needs and taking advantage of the WP7 platform can reduce cost and is essential to a successful re-launch. To better understand the advantage of new development lets examine a conceptual upgrade of Comcasts existing mobile app. Before Comcast has a great mobile app that provides several key features. The ability to browse the lineup using a guide, a client for Comcast email accounts, On Demand gallery, and much more. We will leverage these and build on them using some of the incredible WP7 features.   After With the proliferation of DVRs (Digital Video Recorders) and a variety of media devices (TV, PC, Mobile) content providers are challenged to find creative ways to build their brands. Every client touch point must provide both value added services as well as opportunities for marketing and up-sale; WP7 makes it easy to focus on those opportunities. The new app is an excellent vehicle for presenting Comcasts newly rebranded TV, Voice, and Internet services. These services now fly under the banner of xfinity and have been expanded to provide the best experience for Comcast customers. The Windows Phone 7 app will increase the surface area of this service revolution.   The home menu is simplified and highlights Comcasts Triple Play: Voice, TV, and Internet. The inbox has been replaced with a messages view, and message management is handled by a WP7 hub. The hub presents emails, tweets, and IMs from Comcast and other viewers the user follows on Twitter.  The popular view orders shows based on the users viewing history and current cable package. The first show Glee is both popular and participating in a conceptual co-marketing effort, so it receives prime positioning. The second spot goes to a hit show on a premium channel, in this example HBOs The Pacific, encouraging viewers to upgrade for this premium content. The remaining spots are ordered based on viewing history and popularity. Tapping the play button moves the user to the theatre where they can watch previews or full episodes streaming from Fancast. Tapping an extra presents the user with show details as well as interactive content that may be included as part of co-marketing efforts. Co-Marketing with Dynamic Content The success of Comcasts services are tied to the success of the networks and shows it purveys, making co-marketing efforts essential. In this concept FOX is co-marketing its popular show Glee. A customized panorama is updated with the latest gleeks tweets, streaming HD episodes, and extras featuring photos and video of the cast. If WP7 apps can be dynamically extended with web hosted .xap files, including sandboxed partner experiences would enable interactive features such as the Gleek Peek, in which a viewer can select a character from a panorama to view the actors profile. This dynamic inline experience has a tailored appeal to aspiring creatives and is technically possible with Windows Phone 7.   Summary The conceptual Comcast mobile app for Windows Phone 7 highlights just a few of the incredible experiences and business opportunities that can be unlocked with this latest mobile solution. It is critical that organizations recognize and take full advantage of these new capabilities. Simply porting existing mobile applications does not leverage these powerful tools; re-examining existing applications and upgrading them to Windows Phone 7 will prove essential to the continued growth and success of your brand.Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• When things go awry

  - by Phil Factor

  The moment the Entrepreneur opened his mouth on prime-time national TV, spelled out the URL and waxed big on how exciting ‘his’ new website was, I knew I was in for a busy night. I’d designed and built it. All at once, half a million people tried to log into the website. Although all my stress-testing paid off, I have to admit that the network locked up tight long before there was any danger of a database or website problem. Soon afterwards, the Entrepreneur and the Big Boss were there in the autopsy meeting. We picked through all our systems in detail to see how they’d borne the unexpected strain. Mercifully, in view of the sour mood of the Big Boss, it turned out that the only thing we could have done better was buy a bigger pipe to and from the internet. We’d specified that ‘big pipe’ when designing the system. The Big Boss had then railed at the cost and so we’d subsequently compromised. I felt that my design decisions were vindicated. The Big Boss brooded for a while. Then he made the significant comment: “What really ****** me off is the fact that, for ten minutes, we couldn’t take people’s money.” At that point I stopped feeling smug. Had the internet connection been better, the system would have reached its limit and failed rather precipitously, and that wasn’t what he wanted. Then it occurred to me that what had gummed up the connection was all those images on the site, that had made it so impressive for the visitors. If there had been a way to automatically pare down the site to the bare essentials under stress… Hmm. I began to consider disaster-recovery in the broadest sense – maintaining a service in spite of unusual or unexpected events. What he said makes a lot of sense: sacrifice whatever isn’t essential to keep the core service running when we approach the capacity limits. Maybe in IT we should borrow (or revive) the business concept of the ‘Skeleton service’, maintaining only the priority parts under stress, using a process that is well-prepared and carefully rehearsed. How might this work? Whatever the event we have to prepare for, it is all about understanding the priorities; knowing what one can dispense with when the going gets tough. In the event of database disaster, it’s much faster to deploy a skeletal system with only the essential data than to restore the entire system, though there would have to be a reconciliation process to update the revived database retrospectively, once the emergency was over. It isn’t just the database that could be designed for resilience. One could prepare for unusually high traffic in a website by designing a system that degraded gradually to a ‘skeletal’ site, one that maintained the commercial essentials without fat images, JavaScript libraries and razzmatazz. This is all what the Big Boss scathingly called ‘a mere technicality’. It seems to me that what is needed first is a culture of application and database design which acknowledges that we live in a very imperfect world, and react accordingly when things go awry.

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• PCI Encryption Key Management

  - by Unicorn Bob

  (Full disclosure: I'm already an active participant here and at StackOverflow, but for reasons that should hopefully be obvious, I'm choosing to ask this particular question anonymously). I currently work for a small software shop that produces software that's sold commercially to manage small- to mid-size business in a couple of fairly specialized industries. Because these industries are customer-facing, a large portion of the software is related to storing and managing customer information. In particular, the storage (and securing) of customer credit card information. With that, of course, comes PCI compliance. To make a long story short, I'm left with a couple of questions about why certain things were done the way they were, and I'm unfortunately without much of a resource at the moment. This is a very small shop (I report directly to the owner, as does the only other full-time employee), and the owner doesn't have an answer to these questions, and the previous developer is...err...unavailable. Issue 1: Periodic Re-encryption As of now, the software prompts the user to do a wholesale re-encryption of all of the sensitive information in the database (basically credit card numbers and user passwords) if either of these conditions is true: There are any NON-encrypted pieces of sensitive information in the database (added through a manual database statement instead of through the business object, for example). This should not happen during the ordinary use of the software. The current key has been in use for more than a particular period of time. I believe it's 12 months, but I'm not certain of that. The point here is that the key "expires". This is my first foray into commercial solution development that deals with PCI, so I am unfortunately uneducated on the practices involved. Is there some aspect of PCI compliance that mandates (or even just strongly recommends) periodic key updating? This isn't a huge issue for me other than I don't currently have a good explanation to give to end users if they ask why they are being prompted to run it. Question 1: Is the concept of key expiration standard, and, if so, is that simply industry-standard or an element of PCI? Issue 2: Key Storage Here's my real issue...the encryption key is stored in the database, just obfuscated. The key is padded on the left and right with a few garbage bytes and some bits are twiddled, but fundamentally there's nothing stopping an enterprising person from examining our (dotfuscated) code, determining the pattern used to turn the stored key into the real key, then using that key to run amok. This seems like a horrible practice to me, but I want to make sure that this isn't just one of those "grin and bear it" practices that people in this industry have taken to. I have developed an alternative approach that would prevent such an attack, but I'm just looking for a sanity check here. Question 2: Is this method of key storage--namely storing the key in the database using an obfuscation method that exists in client code--normal or crazy? Believe me, I know that free advice is worth every penny that I've paid for it, nobody here is an attorney (or at least isn't offering legal advice), caveat emptor, etc. etc., but I'm looking for any input that you all can provide. Thank you in advance!

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• Collision 2D Quads

  - by Vico Pelaez

  I want to detect collision between two 2D squares, one square is static and the other one moves according to keyboard arrows. I have implemented some code, however nothing happens when they overlap each other and what I tried to achieve in the code was to detect an overlapping between them. I think I am either not understanding the concept really well or that because one of the squares is moving this is not working. Please I would really appreciate your help. Thank you! float x1=0.05 ,Y1=0.05; float x2=0.05 ,Y2=0.05; float posX1 =0.5, posY1 = 0.5; float movX2 = 0.0 , movY2 = 0.0; struct box{ int width=0.1; int heigth=0.1; }; void init(){ glClearColor(0.0, 0.0, 0.0, 0.0); glColor3f(1.0, 1.0, 1.0); } void quad1(){ glTranslatef(posX1, posY1, 0.0); glBegin(GL_POLYGON); glColor3f(0.5, 1.0, 0.5); glVertex2f(-x1, -Y1); glVertex2f(-x1, Y1); glVertex2f(x1,Y1); glVertex2f(x1,-Y1); glEnd(); } void quad2(){ glMatrixMode(GL_PROJECTION); glLoadIdentity(); glPushMatrix(); glTranslatef(movX2, movY2, 0.0); glBegin(GL_POLYGON); glColor3f(1.5, 1.0, 0.5); glVertex2f(-x2, -Y2); glVertex2f(-x2, Y2); glVertex2f(x2,Y2); glVertex2f(x2,-Y2); glEnd(); glPopMatrix(); } void reset(){ //Reset position of square??? movX2 = 0.0; movY2 = 0.0; collisionB = false; } bool collision(box A, box B){ int leftA, leftB; int rightA, rightB; int topA, topB; int bottomA, bottomB; //Calculate the sides of box A leftA = x1; rightA = x1 + A.width; topA = Y1; bottomA = Y1 + A.heigth; //Calculate the sides of box B leftB = x2; rightB = x2 + B.width; topB = Y1; bottomB = Y1+ B.heigth ; if( bottomA <= topB ) return false; if( topA >= bottomB ) return false; if( rightA <= leftB ) return false; if( leftA >= rightB ) return false; return true; } float move_unit = 0.1; void keyboardown(int key, int x, int y) { switch (key){ case GLUT_KEY_UP: movY2 += move_unit; break; case GLUT_KEY_RIGHT: movX2 += move_unit; break; case GLUT_KEY_LEFT: movX2 -= move_unit; break; case GLUT_KEY_DOWN: movY2 -= move_unit; break; default: break; } glutPostRedisplay(); } void display(){ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glMatrixMode(GL_PROJECTION); glLoadIdentity(); cuad1(); if (!collision) { cuad2(); } else{ reset(); } glFlush(); } int main(int argc, char** argv){ glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(500,500); glutInitWindowPosition(0, 0); glutCreateWindow("Collision Practice"); glutSpecialFunc(keyboardown); glutDisplayFunc(display); init(); glutMainLoop(); }

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• Squibbly: LibreOffice Integration Framework for the Java Desktop

  - by Geertjan

  Squibbly is a new framework for Java desktop applications that need to integrate with LibreOffice, or more generally, need office features as part of a Java desktop solution that could include, for example, JavaFX components. Here's what it looks like, right now, on Ubuntu 13.04: Why is the framework called Squibbly? Because I needed a unique-ish name, because "squibble" sounds a bit like "scribble" (which is what one does with text documents, etc), and because of the many absurd definitions in the Urban Dictionary for the apparently real word "squibble", e.g., "A name for someone who is squibblish in nature." And, another e.g., "A squibble is a small squabble. A squabble is a little skirmish." But the real reason is the first definition (and definitely not the fourth definition): "Taking a small portion of another persons something, such as a small hit off of a pipe, a bite of food, a sip of a drink, or drag of a cigarette." In other words, I took (or "squibbled") a small portion of LibreOffice, i.e., OfficeBean, and integrated it into a NetBeans Platform application. Now anyone can add new features to it, to do anything they need, such as create a legislative software system as Propylon has done with their own solution on the NetBeans Platform: For me, the starting point was Chuk Munn Lee's similar solution from some years ago. However, he uses reflection a lot in that solution, because he didn't want to bundle the related JARs with the application. I understand that benefit but I find it even more beneficial to not need to require the user to specify the location of the LibreOffice location, since all the necessary JARs and native libraries (currently 32-bit Linux only, by the way) are bundled with the application. Plus, hundreds of lines of reflection code, as in Chuk's solution, is not fun to work with at all. Switching between applications is done like this: It's a work in progress, a proof of concept only. Just the result of a few hours of work to get the basic integration to work. Several problems remain, some of them potentially unsolvable, starting with these, but others will be added here as I identify them: Window management problems. I'd like to let the user have multiple LibreOffice applications and documents open at the same time, each in a new TopComponent. However, I haven't figured out how to do that. Right now, each application is opened into the same TopComponent, replacing the currently open application. I don't know the OfficeBean API well enough, e.g., should a single OfficeBean be shared among multiple TopComponents or should each of them have their own instance of it? Focus problems. When putting the application behind other applications and then switching back to the application, typing text becomes impossible. When closing a TopComponent and reopening it, the content is lost completely. Somehow the loss of focus, and then the return of focus, disables something. No idea how to fix that. The project is checked into this location, which isn't public yet, so you can't access it yet. Once it's publicly available, it would be great to get some code contributions and tweaks, etc. https://java.net/projects/squibbly Here's the source structure, showing especially how the OfficeBean JARs and native libraries (currently for Linux 32-bit only) fit in: Ultimately, would be cool to integrate or share code with http://joeffice.com!

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• Generic Adjacency List Graph implementation

  - by DmainEvent

  I am trying to come up with a decent Adjacency List graph implementation so I can start tooling around with all kinds of graph problems and algorithms like traveling salesman and other problems... But I can't seem to come up with a decent implementation. This is probably because I am trying to dust the cobwebs off my data structures class. But what I have so far... and this is implemented in Java... is basically an edgeNode class that has a generic type and a weight-in the event the graph is indeed weighted. public class edgeNode<E> { private E y; private int weight; //... getters and setters as well as constructors... } I have a graph class that has a list of edges a value for the number of Vertices and and an int value for edges as well as a boolean value for whether or not it is directed. The brings up my first question, if the graph is indeed directed, shouldn't I have a value in my edgeNode class? Or would I just need to add another vertices to my LinkedList? That would imply that a directed graph is 2X as big as an undirected graph wouldn't it? public class graph { private List<edgeNode<?>> edges; private int nVertices; private int nEdges; private boolean directed; //... getters and setters as well as constructors... } Finally does anybody have a standard way of initializing there graph? I was thinking of reading in a pipe-delimited file but that is so 1997. public graph GenereateGraph(boolean directed, String file){ List<edgeNode<?>> edges; graph g; try{ int count = 0; String line; FileReader input = new FileReader("C:\\Users\\derekww\\Documents\\JavaEE Projects\\graphFile"); BufferedReader bufRead = new BufferedReader(input); line = bufRead.readLine(); count++; edges = new ArrayList<edgeNode<?>>(); while(line != null){ line = bufRead.readLine(); Object edgeInfo = line.split("|")[0]; int weight = Integer.parseInt(line.split("|")[1]); edgeNode<String> e = new edgeNode<String>((String) edges.add(e); } return g; } catch(Exception e){ return null; } } I guess when I am adding edges if boolean is true I would be adding a second edge. So far, this all depends on the file I write. So if I wrote a file with the following Vertices and weights... Buffalo | 18 br Pittsburgh | 20 br New York | 15 br D.C | 45 br I would obviously load them into my list of edges, but how can I represent one vertices connected to the other... so on... I would need the opposite vertices? Say I was representing Highways connected to each city weighted and un-directed (each edge is bi-directional with weights in some fictional distance unit)... Would my implementation be the best way to do that? I found this tutorial online Graph Tutorial that has a connector object. This appears to me be a collection of vertices pointing to each other. So you would have A and B each with there weights and so on, and you would add this to a list and this list of connectors to your graph... That strikes me as somewhat cumbersome and a little dismissive of the adjacency list concept? Am I wrong and that is a novel solution? This is all inspired by steve skiena's Algorithm Design Manual. Which I have to say is pretty good so far. Thanks for any help you can provide.

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• Use a custom value object or a Guid as an entity identifier in a distributed system?

  - by Kazark

  tl;dr I've been told that in domain-driven design, an identifier for an entity could be a custom value object, i.e. something other than Guid, string, int, etc. Can this really be advisable in a distributed system? Long version I will invent an situation analogous to the one I am currently facing. Say I have a distributed system in which a central concept is an egg. The system allows you to order eggs and see spending reports and inventory-centric data such as quantity on hand, usage, valuation and what have you. There area variety of services backing these behaviors. And say there is also another app which allows you to compose recipes that link to a particular egg type. Now egg type is broken down by the species—ostrich, goose, duck, chicken, quail. This is fine and dandy because it means that users don't end up with ostrich eggs when they wanted quail eggs and whatnot. However, we've been getting complaints because jumbo chicken eggs are not even close to equivalent to small ones. The price is different, and they really aren't substitutable in recipes. And here we thought we were doing users a favor by not overwhelming them with too many options. Currently each of the services (say, OrderSubmitter, EggTypeDefiner, SpendingReportsGenerator, InventoryTracker, RecipeCreator, RecipeTracker, or whatever) are identifying egg types with an industry-standard integer representation the species (let's call it speciesCode). We realize we've goofed up because this change could effect every service. There are two basic proposed solutions: Use a predefined identifier type like Guid as the eggTypeID throughout all the services, but make EggTypeDefiner the only service that knows that this maps to a speciesCode and eggSizeCode (and potentially to an isOrganic flag in the future, or whatever). Use an EggTypeID value object which is a combination of speciesCode and eggSizeCode in every service. I've proposed the first solution because I'm hoping it better encapsulates the definition of what an egg type is in the EggTypeDefiner and will be more resilient to changes, say if some people now want to differentiate eggs by whether or not they are "organic". The second solution is being suggested by some people who understand DDD better than I do in the hopes that less enrichment and lookup will be necessary that way, with the justification that in DDD using a value object as an ID is fine. Also, they are saying that EggTypeDefiner is not a domain and EggType is not an entity and as such should not have a Guid for an ID. However, I'm not sure the second solution is viable. This "value object" is going to have to be serialized into JSON and URLs for GET requests and used with a variety of technologies (C#, JavaScript...) which breaks encapsulation and thus removes any behavior of the identifier value object (is either of the fields optional? etc.) Is this a case where we want to avoid something that would normally be fine in DDD because we are trying to do DDD in a distributed fashion? Summary Can it be a good idea to use a custom value object as an identifier in a distributed system (solution #2)?

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• Pinterest and the Rising Power of Imagery

  - by Mike Stiles

  If images keep you glued to a screen, you’re hardly alone. Countless social users are letting their eyes do the walking, waiting for that special photo to grab their attention. And perhaps more than any other social network, Pinterest has been giving those eyes plenty of room to walk. Pinterest came along in 2010. Its play was that users could simply create topic boards and pin pictures to the appropriate boards for sharing. Yes there are some words, captions mostly, but not many. The speed of its growth raised eyebrows. Traffic quadrupled in the last quarter of 2011, with 7.51 million unique visitors in December alone. It now gets 1.9 billion monthly page views. And it was sticky. In the US, the average time a user spends strolling through boards and photos on Pinterest is 15 minutes, 50 seconds. Proving the concept of browsing a catalogue is not dead, it became a top 5 referrer for several apparel retailers like Land’s End, Nordstrom, and Bergdorfs. Now a survey of online shoppers by BizRate Insights says that Pinterest is responsible for more purchases online than Facebook. Over 70% of its users are going there specifically to keep up with trends and get shopping ideas. And when they buy, the average order value is $179. Pinterest is also scoring better in terms of user engagement. 66% of pinners regularly follow and repin retailers, whereas 17% of Facebook fans turn to that platform for purchase ideas. (Facebook still wins when it comes to reach and driving traffic to 3rd-party sites by the way). Social posting best practices have consistently shown that posts with photos are rewarded with higher engagement levels. You may be downright Shakespearean in your writing, but what makes images in the digital world so much more powerful than prose? 1. They transcend language barriers. 2. They’re fun and addictive to look at. 3. They can be consumed in fractions of a second, important considering how fast users move through their social content (admit it, you do too). 4. They’re efficient gateways. A good picture might get them to the headline. A good headline might then get them to the written content. 5. The audience for them surpasses demographic limitations. 6. They can effectively communicate and trigger an emotion. 7. With mobile use soaring, photos are created on those devices and easily consumed and shared on them. Pinterest’s iPad app hit #1 in the Apple store in 1 day. Even as far back as 2009, over 2.5 billion devices with cameras were on the streets generating in just 1 year, 10% of the number of photos taken…ever. But let’s say you’re not a retailer. What if you’re a B2B whose products or services aren’t visual? Should you worry about your presence on Pinterest? As with all things, you need a keen awareness of who your audience is, where they reside online, and what they want to do there. If it doesn’t make sense to put a tent stake in Pinterest, fine. But ignore the power of pictures at your own peril. If not visually, how are you going to attention-grab social users scrolling down their News Feeds at top speed? You’re competing with every other cool image out there from countless content sources. Bore us and we’ll fly right past you.

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• How to introduce a computer illiterate 50-year old to programming [closed]

  - by sunday

  The other day my dad asked me a question that I would have never expected from him. "How can I learn C++?" My dad is turning 56 this year and computers are a distant concept for him. He doesn't know how to use a phone very well besides calling numbers (no speed dial or contacts); though he has started to learn computers a little better - to the point that he knows how to open the internet (in Windows) and browse around (and has successfully completed several job applications entirely on his own online, of which he was offered positions too). But still, these are too narrow-windowed experiences to mean much, really. While he may not have the background, my dad knows how to read. And I mean reading as a skill, not just an ability. He has little to no college education (financial problems, family, etc.) and was fortunate enough to finish high school, but still taught himself to become a master electrician and has been one for almost 30 years now. He did the same with guitar, learning to play at a very professional level and has been praised for his skill. In high school, he picked up a weight lifting book - and was the only person in his high school at the time to qualify officially as an "athlete" by national standards. In all cases, he just needed something to read. Something to teach him. He absorbs information like a sponge. I have no doubt in my dad's motivation or capability of doing this, so my general goal is simply: Get my dad into the world of computers, and get him on the road to programming. I strongly believe that once I get him through the fundamentals, his drive and reading skill will keep him going on this own. So I'm asking you all: where should I start with all this? And what are the best resources out there? Should I get him to start Linux instead of Windows? Is C++ a bad idea? Remember, he needs to (IMO) learn computers first, and then get that first grasp (the "Hello world" experience) of programming. For money's sake and at top preference, I'd like free online resources that he can read, but by all means any good suggestions in print or paid-for-online are welcome (that I could possibly look into later to purchase). And also, I intend to start him off with C++ (no Python, Java, etc.), because I know it the best and will be able to help him along the way with code. (I have minimal knowledge right now in other languages). Edit: I'm getting a lot of persistent suggestions to use Python. The only reason I wanted to do C++ is that I KNOW it and can be THERE when my dad needs help. My VERY FIRST exposure to programming ever was Java. I learned Java, and I got good at it. I open to other suggestions, but please provide an effective application of your suggestions. EDIT #2: I understand my approach/thinking/knowledge could be lacking here. I'm a sophomore level undergraduate CS major. If you don't agree with anything in my post, tell me why - give me ideas, information - that's why I'm asking in the first place. To narrow down my general goal to specific reachable goals.

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• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

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• No Customer Left Behind

  - by Kathryn Perry

  A guest post by David Vap, Group Vice President, Oracle Applications Product Development What does customer experience mean to you? Is it a strategy for your executives? A new buzz word and marketing term? A bunch of CRM technology with social software added on? For me, customer experience is a customer-centric worldview that produces a deeper understanding of your business and what it takes to achieve sustainable, differentiated success. It requires you to prioritize and examine the journey your customers are on with your brand, so you can answer the question, "How can we drive greater value for our business by delivering a better customer experience?" Businesses that embrace a customer-centric worldview understand their business at a much deeper level than most. They know who their customers are, what their value is, what they do, what they say, what they want, and ultimately what that means to their business. "Why Isn't Everyone Doing It?" We're all consumers who have our own experiences with many brands. Good or bad, some of those experiences stay with us. So viscerally we understand the concept of customer experience from the stories we share. One that stands out in my mind happened as I was preparing to leave for a 12-month job assignment in Europe. I wanted to put my cable television subscription on hold. I wasn't leaving for another vendor. I wasn't upset. I just had a situation where it made sense to put my $180 per month account on pause until I returned. Unfortunately, there was no way for this cable company to acknowledge that I was a loyal customer with a logical request - and to respond accordingly. So, ultimately, they lost my business. Research shows us that it costs six to seven times more to acquire a new customer than to retain an existing one. Heavily funding the efforts of getting new customers and underfunding the efforts of serving the needs of your existing (who are your greatest advocates) is a vicious and costly cycle. "Hey, These Guys Suck!" I love my Apple iPad because it's so easy to use. The explosion of these types of technologies, combined with new media channels, has raised our expectations and made us hyperaware of what's going on and what's available. In addition, social media has given us a megaphone to share experiences both positive and negative with greater impact. We are now an always-on culture that thrives on our ability to access, connect, and share anywhere anytime. If we don't get the service, product, or value we expect, it is easy to tell many people about it. We also can quickly learn where else to get what we want. Consumers have the power of influence and choice at a global scale. The businesses that understand this principle are able to leverage that power to their advantage. The ones that don't, suffer from it. Which camp are you in?Note: This is Part 1 in a three-part series. Stop back for Part 2 on November 19.

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• ??????????? - Java SE Embedded 8

  - by kshimizu-Oracle

  Java?OS??????1?????????????????????????????????3?????????????? HEAP: Java????????????????????????????????? NON-HEAP: NON-HEAP????JVM???????????????????Code Cache?Metaspace???2????????????? Code Cache: ????JIT??????????????????????????? Metaspace: HEAP??????????????????????????   JavaVM??????????: VM?????????????????? ??????????????? ????????????????????????????????????????????????????????????????????????? HEAP?Java Mission Control???????????????????? (????)? ????Java SE?????????????API????????????????????????????????????? Mission Control?????API?????????????????????????????????API??????????????? HEAP???????????? VM????????"-Xmx"???????????????? java.lang.Runtime.maxMemory(); ?????HEAP????????? ?????VM????????"-Xms"? ????????????? "-Xms"???????"-Xmx"?????????? java.lang.Runtime.totalMemory(); ???????????HEAP????????????? java.lang.Runtime.freeMemory(); ??NON-HEAP???????????? API??????????? Java Mission Control?????????? ????????????Java Mission Control??????????????????????? ????"NON_HEAP"?????????NON-HEAP?????? ???? HEAP????NON-HEAP?????????????? Java VM???????????????????????????????????????? ?????????????????????????????????? ????HEAP/NON-HEAP?????????????????????????? OS?????????????? Linux???????procfs?Java??????????????????? (VmHWM or VmRSS) ????? ????HEAP/NON-HEAP??????????????????????????? ?????????????????? ??????JVM?????????????????? ?????????????????JVM???????????????????? ???JVM?????? ????????????? Embedded??JVM?????????? ??Embedded???Oracle JVM??????CPU????????????????????????????????????????? ??????CPU??????????????????????????????????????? Minimal/Client/Server??JVM???????????????? ????JVM??????????????????? ??????Compact????????????????? ? 2 - 3?????? Concept Guide (http://docs.oracle.com/javase/8/embedded/embedded-concepts/basic-concepts.htm) ???????? ??JVM??????????? ????????????????????? -Xms: ??????????? ?????????? ?????????????????????????????????????????????????? -Xmx: ??????????? -XX:ReservedCodeCacheSize: Code Cache??????? ?) JIT??????????????Code Cache????????????0???????? -Xint: JIT??????????? ????????????? JIT?????????????????????? ????????????????? -Xss: ???????????????????? ????????????????????????? ????????????????????????????? -XX:CompileThreshold: JIT?????????????????????????????????? ?????????????????????? ????????? ?????????????????? Code Cache?????????? ?????????? ????????????????????? ????????????????????????? ??????????????????????? ?????????????????????

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• Why were namespaces removed from ECMAScript consideration?

  - by Bob

  Namespaces were once a consideration for ECMAScript (the old ECMAScript 4) but were taken out. As Brendan Eich says in this message: One of the use-cases for namespaces in ES4 was early binding (use namespace intrinsic), both for performance and for programmer comprehension -- no chance of runtime name binding disagreeing with any earlier binding. But early binding in any dynamic code loading scenario like the web requires a prioritization or reservation mechanism to avoid early versus late binding conflicts. Plus, as some JS implementors have noted with concern, multiple open namespaces impose runtime cost unless an implementation works significantly harder. For these reasons, namespaces and early binding (like packages before them, this past April) must go. But I'm not sure I understand all of that. What exactly is a prioritization or reservation mechanism and why would either of those be needed? Also, must early binding and namespaces go hand-in-hand? For some reason I can't wrap my head around the issues involved. Can anyone attempt a more fleshed out explanation? Also, why would namespaces impose runtime costs? In my mind I can't help but see little difference in concept between a namespace and a function using closures. For instance, Yahoo and Google both have YAHOO and google objects that "act like" namespaces in that they contain all of their public and private variables, functions, and objects within a single access point. So why, then, would a namespace be so significantly different in implementation? Maybe I just have a misconception as to what a namespace is exactly.

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• Data Modeling: Logical Modeling Exercise

  - by swisscheese

  In trying to learn the art of data storage I have been trying to take in as much solid information as possible. PerformanceDBA posted some really helpful tutorials/examples in the following posts among others: is my data normalized? and Relational table naming convention. I already asked a subset question of this model here. So to make sure I understood the concepts he presented and I have seen elsewhere I wanted to take things a step or two further and see if I am grasping the concepts. Hence the purpose of this post, which hopefully others can also learn from. Everything I present is conceptual to me and for learning rather than applying it in some production system. It would be cool to get some input from PerformanceDBA also since I used his models to get started, but I appreciate all input given from anyone. As I am new to databases and especially modeling I will be the first to admit that I may not always ask the right questions, explain my thoughts clearly, or use the right verbage due to lack of expertise on the subject. So please keep that in mind and feel free to steer me in the right direction if I head off track. If there is enough interest in this I would like to take this from the logical to physical phases to show the evolution of the process and share it here on Stack. I will keep this thread for the Logical Diagram though and start new one for the additional steps. For my understanding I will be building a MySQL DB in the end to run some tests and see if what I came up with actually works. Here is the list of things that I want to capture in this conceptual model. Edit for V1.2 The purpose of this is to list Bands, their members, and the Events that they will be appearing at, as well as offer music and other merchandise for sale Members will be able to match up with friends Members can write reviews on the Bands, their music, and their events. There can only be one review per member on a given item, although they can edit their reviews and history will be maintained. BandMembers will have the chance to write a single Comment on Reviews about the Band they are associated with. Collectively as a Band only one Comment is allowed per Review. Members can then rate all Reviews and Comments but only once per given instance Members can select their favorite Bands, music, Merchandise, and Events Bands, Songs, and Events will be categorized into the type of Genre that they are and then further subcategorized into a SubGenre if necessary. It is ok for a Band or Event to fall into more then one Genre/SubGenre combination. Event date, time, and location will be posted for a given band and members can show that they will be attending the Event. An Event can be comprised of more than one Band, and multiple Events can take place at a single location on the same day Every party will be tied to at least one address and address history shall be maintained. Each party could also be tied to more then one address at a time (i.e. billing, shipping, physical) There will be stored profiles for Bands, BandMembers, and general members. So there it is, maybe a bit involved but could be a great learning tool for many hopefully as the process evolves and input is given by the community. Any input? EDIT v1.1 In response to PerformanceDBA U.3) That means no merchandise other than Band merchandise in the database. Correct ? That was my original thought but you got me thinking. Maybe the site would want to sell its own merchandise or even other merchandise from the bands. Not sure a mod to make for that. Would it require an entire rework of the Catalog section or just the identifying relationship that exists with the Band? Attempted a mod to sell both complete albums or song. Either way they would both be in electronic format only available for download. That is why I listed an Album as being comprised of Songs rather then 2 separate entities. U.5) I understand what you bring up about the circular relation with Favorite. I would like to get to this “It is either one Entity with some form of differentiation (FavoriteType) which identifies its treatment” but how to is not clear to me. What am I missing here? u.6) “Business Rules This is probably the only area you are weak in.” Thanks for the honest response. I will readdress these but I hope to clear up some confusion in my head first with the responses I have posted back to you. Q.1) Yes I would like to have Accepted, Rejected, and Blocked. I am not sure what you are referring to as to how this would change the logical model? Q.2) A person does not have to be a User. They can exist only as a BandMember. Is that what you are asking? Minor Issue Zero, One, or More…Oops I admit I forgot to give this attention when building the model. I am submitting this version as is and will address in a future version. I need to read up more on Constraint Checking to make sure I am understanding things. M.4) Depends if you envision OrderPurchase in the future. Can you expand as to what you mean here? EDIT V1.2 In response to PerformanceDBA input... Lessons learned. I was mixing the concept of Identifying / Non-Identifying and Cardinality (i.e. Genre / SubGenre), and doing so inconsistently to make things worse. Associative Tables are not required in Logical Diagrams as their many-to-many relationships can be depicted and then expanded in the Physical Model. I was overlooking the Cardinality in a lot of the relationships The importance of reading through relationships using effective Verb Phrases to reassure I am modeling what I want to accomplish. U.2) In the concept of this model it is only required to track a Venue as a location for an Event. No further data needs to be collected. With that being said Events will take place on a given EventDate and will be hosted at a Venue. Venues will host multiple events and possibly multiple events on a given date. In my new model my thinking was that EventDate is already tied to Event . Therefore, Venue will not need a relationship with EventDate. The 5th and 6th bullets you have listed under U.2) leave me questioning my thinking though. Am I missing something here? U.3) Is it time to move the link between Item and Band up to Item and Party instead? With the current design I don't see a possibility to sell merchandise not tied to the band as you have brought up. U.5) I left as per your input rather than making it a discrete Supertype/Subtype Relationship as I don’t see a benefit of having that type of roll up. Additional Revisions AR.1) After going through the exercise for FavoriteItem, I feel that Item to Review requires a many-to-many relationship so that is indicated. Necessary? Ok here we go for v1.3 I took a few days on this version, going back and forth with my design. Once the logical process is complete, as I want to see if I am on the right track, I will go through in depth what I had learned and the troubles I faced as a beginner going through this process. The big point for this version was it took throwing in some Keys to help see what I was missing in the past. Going through the process of doing a matrix proved to be of great help also. Regardless of anything, if it wasn't for the input given by PerformanceDBA I would still be a lost soul wondering in the dark. Who knows my current design might reaffirm that I still am, but I have learned a lot so I am know I at least have a flashlight in my hand. At this point in time I admit that I am still confused about identifying and non-identifying relationships. In my model I had to use non-identifying relationships with non nulls just to join the relationships I wanted to model. In reading a lot on the subject there seems to be a lot of disagreement and indecisiveness on the subject so I did what I thought represented the right things in my model. When to force (identifying) and when to be free (non-identifying)? Anyone have inputs? EDIT V1.4 Ok took the V1.3 inputs and cleaned things up for this V1.4 Currently working on a V1.5 to include attributes.

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• Is it possible to force the WCF test client to accept a self-signed certificate?

  - by Lawrence Johnston

  I have a WCF web service running in IIS 7 using a self-signed certificate (it's a proof of concept to make sure this is the route I want to go). It's required to use SSL. Is it possible to use the WCF Test Client to debug this service without needing a non-self-signed certificate? When I try I get this error: Error: Cannot obtain Metadata from https:///Service1.svc If this is a Windows (R) Communication Foundation service to which you have access, please check that you have enabled metadata publishing at the specified address. For help enabling metadata publishing, please refer to the MSDN documentation at http://go.microsoft.com/fwlink/?LinkId=65455.WS-Metadata Exchange Error URI: https:///Service1.svc Metadata contains a reference that cannot be resolved: 'https:///Service1.svc'. Could not establish trust relationship for the SSL/TLS secure channel with authority ''. The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. The remote certificate is invalid according to the validation procedure.HTTP GET Error URI: https:///Service1.svc There was an error downloading 'https:///Service1.svc'. The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. The remote certificate is invalid according to the validation procedure.

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• Using jquery validate with multiple fields of the same name

  - by Matt H

  I am trying to get jquery validate to work on multiple fields. Reason being I have dynamically generated fields added and they are simply a list of numbers. So I thought I'd put together a basic example and followed the concept from the accepted answer in the following link: http://stackoverflow.com/questions/931687/using-jquery-validate-plugin-to-validate-multiple-form-fields-with-identical-name However, it's not doing anything useful. Why is it not working? <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <script src="http://code.jquery.com/jquery-latest.js"></script> <script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/validate/lib/jquery.delegate.js"></script> <script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/validate/jquery.validate.js"></script> <script> $("#submit").click(function(){ $("field").each(function(){ $(this).rules("add", { required: true, email: true, messages: { required: "Specify a valid email" } }); }) }); $(document).ready(function(){ $("#myform").validate(); }); </script> </head> <body> <form id="myform"> <label for="field">Required, email: </label> <input class="left" id="field" name="field" /> <input class="left" id="field" name="field" /> <input class="left" id="field" name="field" /> <input class="left" id="field" name="field" /> <br/> <input type="submit" value="Validate!" id="submit" name="submit" /> </form> </body> </html>

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• A simple augmented reality application in C#

  - by Ian

  Hi All, I would like to start a personal project that will give me a lot of new concept to learn and understand. After some thought, I figured that an Augmented Reality related project will be the most beneficial for me because of the following reasons: I haven't tried interfacing a program with a live video/camera feed I haven't done any "image processing" project I haven't done any "graphics rendering" ever With that said, you can assume that I will totally suck at AR. So I'm here to ask for some advice regarding the best way to go through this. st milestone project that I am thinking of is to take a cheap webcam and read some Data Matrix using C#. nd milestone project will render some text-overlay on the feed when presented with a certain Data Matrix. rd milestone project will actually render some 3D shapes. I've searched all-around and found some nice yet advanced materials for AR: http://sites.google.com/site/augmentedrealitytestingsite/ http://soldeveloper.com/ http://www.mperfect.net/wpfAugReal/ So I came here to ask the following: Do you think my milestone is reasonable given my "deficiencies"? In order to start Milestone 1, can you give some materials that I can study? I prefer online materials. Thanks!

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• Hidden/Shown AsyncFileUpload Control Doesn't Fire Server-Side UploadedComplete Event

  - by Bob Mc

  I recently came across the AsyncFileUpload control in the latest (3.0.40412) release of the ASP.Net Ajax Control Toolkit. There appears to be an issue when using it in a hidden control that is later revealed, such as a <div> tag with visible=false. Example: Page code - <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="act" %> . . . <act:ToolkitScriptManager runat="server" ID="ScriptManager1" /> <asp:UpdatePanel runat="server" ID="upnlFileUpload"> <ContentTemplate> <asp:Button runat="server" ID="btnShowUpload" Text="Show Upload" /> <div runat="server" id="divUpload" visible="false"> <act:AsyncFileUpload runat="server" id="ctlFileUpload" /> </div> </ContentTemplate> </asp:UpdatePanel> Server-side Code - Protected Sub ctlFileUpload_UploadedComplete(ByVal sender As Object, ByVal e As AjaxControlToolkit.AsyncFileUploadEventArgs) Handles ctlFileUpload.UploadedComplete End Sub Protected Sub btnShowUpload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnShowUpload.Click divUpload.Visible = True End Sub I have a breakpoint on the UploadedComplete event but it never fires. However, if you take the AsyncFileUpload control out of the <div>, making it visible at initial page render, the control works as expected. So, is this a bug within the AsynchUploadControl, or am I not grasping a fundamental concept (which happens regularly)?

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• Confusion about Kerberos, delegation and SPNs.

  - by Vilx-

  I'm trying to write a proof-of-concept application that performs Kerberos delegation. I've written all the code, and it seems to working (I'm authenticating fine), but the resulting security context doesn't have the ISC_REQ_DELEGATE flag set. So I'm thinking that maybe one of the endpoints (client or server) is forbidden to delegate. However I'm not authenticating against an SPN. Just one domain user against another domain user. As the SPN for InitializeSecurityContext() I'm passing "[email protected]" (which is the user account under which the server application is running). As I understand, domain users have delegation enabled by default. Anyway, I asked the admin to check, and the "account is sensitive and cannot be delegated" checkbox is off. I know that if my server was running as a NETWORK SERVICE and I used an SPN to connect to it, then I'd need the computer account in AD to have the "Trust computer for delegation" checkbox checked (off by default), but... this is not the case, right? Or is it? Also - when the checkbox in the computer account is set, do the changes take place immediately, or must I reboot the server PC or wait for a while?

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