Search Results

Search found 17407 results on 697 pages for 'static constructor'.

Page 390/697 | < Previous Page | 386 387 388 389 390 391 392 393 394 395 396 397  | Next Page >

  • Troubleshooting web timeouts with a Belkin router

    - by rexzilla
    I have a Belkin FSD7632-4 ADSL wifi router. Ever since I got it, I've faced this problem of websites timing out. For example, I go to flickr.com, and the images won't load because they come from farm1.static.flickr.com. Either I wait 10 minutes or so until the timed out sockets are closed and retry (with variable results) or I reboot the router. This happens irrespective of whether I use wired or wifi network. I'm in India, using Airtel Broadband, and if I use my ISP supplied Beetel 220BX ADSL router (which has no wifi and only one LAN port), everything works fine. I copied over the broadband settings from my old router: VPI/VCI values=1/32 Encapsulation=LLC MTU=1492 I have not enabled any firewall on the router. Is there anything else I can try? Or is it a defect with the router and should I take it back for a replacement? I bought it just 2 months ago.

    Read the article

  • Replace Whole Site by FTP

    - by Sam Machin
    Hi There, I've got a set of tools which periodically (about once a day) generate a complete set of static HTML pages for a site with associated folder structure etc. I then need to put those file onto the production server, my problem is that the server runs IIS(6 I think) and I only have regular FTP access. I need a way to automate the process of publishing the new site and it needs to a total replacement of the files each time its published, eg delete the whole folder & contents then put the new ones up. My source server is a ubuntu machine and I've got total control at that end, I have tried using CurlFTpFS but it seems to be too slow for what I'm trying to do and locks up. Rgds Sam

    Read the article

  • Implementing a modern web application with Web API on top of old services

    - by Gaui
    My company has many WCF services which may or may not be replaced in the near future. The old web application is written in WebForms and communicates straight with these services via SOAP and returns DataTables. Now I am designing a new modern web application in a modern style, an AngularJS client which communicates with an ASP.NET Web API via JSON. The Web API then communicates with the WCF services via SOAP. In the future I want to let the Web API handle all requests and go straight to the database, but because the business logic implemented in the WCF services is complicated it's going to take some time to rewrite and replace it. Now to the problem: I'm trying to make it easy in the near future to replace the WCF services with some other data storage, e.g. another endpoint, database or whatever. I also want to make it easy to unit test the business logic. That's why I have structured the Web API with a repository layer and a service layer. The repository layer has a straight communication with the data storage (WCF service, database, or whatever) and the service layer then uses the repository (Dependency Injection) to get the data. It doesn't care where it gets the data from. Later on I can be in control and structure the data returned from the data storage (DataTable to POCO) and be able to test the logic in the service layer with some mock repository (using Dependency Injection). Below is some code to explain where I'm going with this. But my question is, does this all make sense? Am I making this overly complicated and could this be simplified in any way possible? Does this simplicity make this too complicated to maintain? My main goal is to make it as easy as possible to switch to another data storage later on, e.g. an ORM and be able to test the logic in the service layer. And because the majority of the business logic is implemented in these WCF services (and they return DataTables), I want to be in control of the data and the structure returned to the client. Any advice is greatly appreciated. Update 20/08/14 I created a repository factory, so services would all share repositories. Now it's easy to mock a repository, add it to the factory and create a provider using that factory. Any advice is much appreciated. I want to know if I'm making things more complicated than they should be. So it looks like this: 1. Repository Factory public class RepositoryFactory { private Dictionary<Type, IServiceRepository> repositories; public RepositoryFactory() { this.repositories = new Dictionary<Type, IServiceRepository>(); } public void AddRepository<T>(IServiceRepository repo) where T : class { if (this.repositories.ContainsKey(typeof(T))) { this.repositories.Remove(typeof(T)); } this.repositories.Add(typeof(T), repo); } public dynamic GetRepository<T>() { if (this.repositories.ContainsKey(typeof(T))) { return this.repositories[typeof(T)]; } throw new RepositoryNotFoundException("No repository found for " + typeof(T).Name); } } I'm not very fond of dynamic but I don't know how to retrieve that repository otherwise. 2. Repository and service // Service repository interface // All repository interfaces extend this public interface IServiceRepository { } // Invoice repository interface // Makes it easy to mock the repository later on public interface IInvoiceServiceRepository : IServiceRepository { List<Invoice> GetInvoices(); } // Invoice repository // Connects to some data storage to retrieve invoices public class InvoiceServiceRepository : IInvoiceServiceRepository { public List<Invoice> GetInvoices() { // Get the invoices from somewhere // This could be a WCF, a database, or whatever using(InvoiceServiceClient proxy = new InvoiceServiceClient()) { return proxy.GetInvoices(); } } } // Invoice service // Service that handles talking to a real or a mock repository public class InvoiceService { // Repository factory RepositoryFactory repoFactory; // Default constructor // Default connects to the real repository public InvoiceService(RepositoryFactory repo) { repoFactory = repo; } // Service function that gets all invoices from some repository (mock or real) public List<Invoice> GetInvoices() { // Query the repository return repoFactory.GetRepository<IInvoiceServiceRepository>().GetInvoices(); } }

    Read the article

  • Net Screen manager setup

    - by Codezy
    I'm having an issue with our NSMExpress box. I'm trying to manage all our devices, range from ns5gt to ssg320m, and some of those devices have addresses assigned by dhcp from the ISP (like pppoe or dsl). The addresses are actually static but we have the register the MAC address in order to get this address. I can actually add the device in NSM except the IP that's on the untrust side isn't imported in as it's dynamic. Because of this I cannot change many options that pertian to the untrust interface as there is no IP. I've talked to JTAC on this and they didn't know if there was a way to do this or not but then they stated that Tim Hortons does this so I'm confused on how to get this working. Maybe i'm just missing something as I imagine that other people must be doing this as well. Any assistance is appreciated! Furthermore when I import a device this is the message I get: Warnings: Interface ethernet0/0 is a pppoe/dhcp/pppoa client and its ip is NOT IMPORTED because it may be dynamic.

    Read the article

  • help animating a player in Corona SDK

    - by andrew McCutchan
    Working on a game in the Corona SDK with Lua and I need help so the player animates on the line drawn. Right now he animates at the beggining and the end but not on the line. Here is the player code: function spawnPlayerObject(xPlayerSpawn,yPlayerSpawn,richTurn) --spawns Rich where we need him. -- riches sprite sheet and all his inital spirites. We need to adjust this so that animations 3-6 are the only ones that animate when moving horizontally local richPlayer = sprite.newSpriteSet(richSheet1,1,6) sprite.add(richPlayer, "rich", 1,6,500,1) rich = sprite.newSprite(richPlayer) rich.x = xPlayerSpawn rich.y = yPlayerSpawn rich:scale(_W*0.0009, _W*0.0009) -- scale is used to adjust the size of the object. richDir = richTurn rich.rotation = richDir rich:prepare("rich") rich:play() physics.addBody( rich, "static", { friction=1, radius = 15 } ) -- needs a better physics body for collision detection. end And here is the code for the line: function movePlayerOnLine(event) --for the original image replace all rich with player. if posCount ~= linePart then richDir = math.atan2(ractgangle_hit[posCount].y-rich.y,ractgangle_hit[posCount].x-rich.x)*180/math.pi playerSpeed = 5 rich.x = rich.x + math.cos(richDir*math.pi/180)*playerSpeed rich.y = rich.y + math.sin(richDir*math.pi/180)*playerSpeed if rich.x < ractgangle_hit[posCount].x+playerSpeed*10 and rich.x > ractgangle_hit[posCount].x-playerSpeed*10 then if rich.y < ractgangle_hit[posCount].y+playerSpeed*10 and rich.y > ractgangle_hit[posCount].y-playerSpeed*10 then posCount = posCount + 1 end end I don't think anything has changed recently but I have been getting an error when testing of "attempt to upvalue "rich" a nil value" on the second line, richDir = etc.

    Read the article

  • internal DNS server limiting the speed as 55kb/sec ?

    - by kartook
    Hi all , Thanks in advance to everyone . Here is my Question . 1 .We have LAN internal DNS server ( 192.168.205.200 ) 2. DNS server Running on my ADDITIONAL DOMAIN CONTROLLER 3. Tested with Nslookup IPADDRESS and hostname resolving without any error . 4 .DHCP server Running on 3750 Switch ( Checked with CISCO Confirmed the configuration ) .DNS name server pointed to 192.168.205.200 . ISSUE : 1.Host getting ipaddress and DNS from DHCP server .Maximum file transfer Bandwidth 55KB/sec . 2. Assigned Static DNS on Host as ISP DNSServer Address, host getting full bandwidth whihc is 1mb/sec Thanks Kartook

    Read the article

  • Idea of an algorithm to detect a website's navigation structure?

    - by Uwe Keim
    Currently I am in the process of developing an importer of any existing, arbitrary (static) HTML website into the upcoming release of our CMS. While the downloading the files is solved successfully, I'm pulling my hair off when it comes to detect a site structure (pages and subpages) purely from the HTML files, without the user specifying additional hints. Basically I want to get a tree like: + Root page 1 + Child page 1 + Child page 2 + Child child page1 + Child page 3 + Root page 2 + Child page 4 + Root page 3 + ... I.e. I want to be able to detect the menu structure from the links inside the pages. This has not to be 100% accurate, but at least I want to achieve more than just a flat list. I thought of looking at multiple pages to see similar areas and identify these as menu areas and parse the links there, but after all I'm not that satisfied with this idea. My question: Can you imagine any algorithm when it comes to detecting such a structure? Update 1: What I'm looking for is not a web spider, but an algorithm do create a logical tree of the relationship of the pages to be able to create pages and subpages inside my CMS when importing them. Update 2: As of Robert's suggestion I'll solve this by starting at the root page, and then simply parse links as you go and treat every link inside a page simply as a child page. Probably I'll recurse not in a deep-first manner but rather in a breadth-first manner to get a more balanced navigation structure.

    Read the article

  • SQLServer 2008 FailOver and Load Balancing

    - by Jedi Master Spooky
    I have a project with a 2TB database ( 450.000.000 rows). I need to provide to the proyect a solution that gives FailOver and load Balacing, what do you recommend? We are going to use a NetApp Filer for the Data Files and for the File System of the Proyect. I read that SQl Clustering does not provide load balacing. If I cannnot have this feature and I have to go only to the FailOver what Server ( I presume that the key feature here is memory) would you recomend. We are adding 1.000.000 rows a day. Once the rows is inserted we are doing a lot of updates to that row for about 1 week then the row get static. Because of this I am thinking in some kind of history table or database or something like that. I am open to the Os servers implementation, I was thinking of a windows 2008 server with cluster but this depend of the database solution

    Read the article

  • Keeping multiple root directories in a single partition

    - by intuited
    I'm working out a partition scheme for a new install. I'd like to keep the root filesystem fairly small and static, so that I can use LVM snapshots to do backups without having to allocate a ton of space for the snapshot. However, I'd also like to keep the number of total partitions small. Even with LVM, there's inevitably some wasted space and it's still annoying and vaguely dangerous to allocate more. So there seem to be a couple of different options: Have the partition that will contain bulky, variable files, like /srv, /var, and /home, be the root partition, and arrange for the core system state — /etc, /usr, /lib, etc. — to live in a second partition. These files can (I think) be backed up using a different backup scheme, and I don't think LVM snapshots will be necessary for them. The opposite: putting the big variable directories on the second partition, and having the essential system directories live on the root FS. Either of these options require that certain directories be pointers of some variety to subdirectories of a second partition. I'm aware of two different ways to do this: symlinks and bind-mounts. Is one better than the other for this purpose? Is there another option? Do any of the various Ubuntu installation media/strategies support this style of partition layout?

    Read the article

  • iTunes Title Bar is Equal to the Location of the Library file?

    - by Urda
    I have never been able to get a clear answer on why the latest edition of iTunes does this. I have my entire iTunes library located in C:\itunes\ and the library data files inside C:\itunes\!library_info for backup purposes. However when version 9 of iTunes came out it went from having iTunes as the title, to !library_info. Anyway to get around this without moving my data files away? Annoying "feature" if that is what it is. Again Apple support and forums were of no help to me. Anyone have insight on this? System Info: Windows Vista x86 Ultimate, latest updates. iTunes Version 9.0.3.15 Screenshot: http://farm5.static.flickr.com/4072/4414557544_d0b25eb64c_o.jpg Flickr Page: http://www.flickr.com/photos/urda/4414557544/

    Read the article

  • Easy Deployment Split Tunnel VPN Connection

    - by Joey Harris
    I was wondering if anybody could offer some insight as to how I can mass deploy VPN connection settings that support split tunneling. It has to work on both Mac and Windows systems though if a script is used, it obviously can be 2 separate scripts for both platforms. I will be setting up a Windows server with a file server and Exchange server and to access the file server I will have the clients go through VPN because we will have sensitive data. I don't want the servers network to be bogged down with the clients normal internet traffic so I will be needing some way to setup split tunneling on the clients without them having to put in a few commands every time to setup the static routes. Ive looked at Cisco VPN client but I want to try and stick with windows RRAS and avoid buying a Cisco VPN endpoint. Im basically looking for a good VPN client that can support split tunneling and mass deployment.

    Read the article

  • Duck checker in Python: does one exist?

    - by elliot42
    Python uses duck-typing, rather than static type checking. But many of the same concerns ultimately apply: does an object have the desired methods and attributes? Do those attributes have valid, in-range values? Whether you're writing constraints in code, or writing test cases, or validating user input, or just debugging, inevitably somewhere you'll need to verify that an object is still in a proper state--that it still "looks like a duck" and "quacks like a duck." In statically typed languages you can simply declare "int x", and anytime you create or mutate x, it will always be a valid int. It seems feasible to decorate a Python object to ensure that it is valid under certain constraints, and that every time that object is mutated it is still valid under those constraints. Ideally there would be a simple declarative syntax to express "hasattr length and length is non-negative" (not in those words. Not unlike Rails validators, but less human-language and more programming-language). You could think of this as ad-hoc interface/type system, or you could think of it as an ever-present object-level unit test. Does such a library exist to declare and validate constraint/duck-checking on Python-objects? Is this an unreasonable tool to want? :) (Thanks!) Contrived example: rectangle = {'length': 5, 'width': 10} # We live in a fictional universe where multiplication is super expensive. # Therefore any time we multiply, we need to cache the results. def area(rect): if 'area' in rect: return rect['area'] rect['area'] = rect['length'] * rect['width'] return rect['area'] print area(rectangle) rectangle['length'] = 15 print area(rectangle) # compare expected vs. actual output! # imagine the same thing with object attributes rather than dictionary keys.

    Read the article

  • The Java Specialist: An Interview with Java Champion Heinz Kabutz

    - by Janice J. Heiss
    Dr. Heinz Kabutz is well known for his Java Specialists’ Newsletter, initiated in November 2000, where he displays his acute grasp of the intricacies of the Java platform for an estimated 70,000 readers; for his work as a consultant; and for his workshops and trainings at his home on the Island of Crete where he has lived since 2006 -- where he is known to curl up on the beach with his laptop to hack away, in between dips in the Mediterranean. Kabutz was born of German parents and raised in Cape Town, South Africa, where he developed a love of programming in junior high school through his explorations on a ZX Spectrum computer. He received a B.S. from the University of Cape Town, and at 25, a Ph.D., both in computer science. He will be leading a two-hour hands-on lab session, HOL6500 – “Finding and Solving Java Deadlocks,” at this year’s JavaOne that will explore what causes deadlocks and how to solve them. Q: Tell us about your JavaOne plans.A: I am arriving on Sunday evening and have just one hands-on-lab to do on Monday morning. This is the first time that a non-Oracle team is doing a HOL at JavaOne under Oracle's stewardship and we are all a bit nervous about how it will turn out. Oracle has been immensely helpful in getting us set up. I have a great team helping me: Kirk Pepperdine, Dario Laverde, Benjamin Evans and Martijn Verburg from jClarity, Nathan Reynolds from Oracle, Henri Tremblay of OCTO Technology and Jeff Genender of Savoir Technologies. Monday will be hard work, but after that, I will hopefully get to network with fellow Java experts, attend interesting sessions and just enjoy San Francisco. Oh, and my kids have already given me a shopping list of things to get, like a GoPro Hero 2 dive housing for shooting those nice videos of Crete. (That's me at the beginning diving down.) Q: What sessions are you attending that we should know about?A: Sometimes the most unusual sessions are the best. I avoid the "big names". They often are spread too thin with all their sessions, which makes it difficult for them to deliver what I would consider deep content. I also avoid entertainers who might be good at presenting but who do not say that much.In 2010, I attended a session by Vladimir Yaroslavskiy where he talked about sorting. Although he struggled to speak English, what he had to say was spectacular. There was hardly anybody in the room, having not heard of Vladimir before. To me that was the highlight of 2010. Funnily enough, he was supposed to speak with Joshua Bloch, but if you remember, Google cancelled. If Bloch has been there, the room would have been packed to capacity.Q: Give us an update on the Java Specialists’ Newsletter.A: The Java Specialists' Newsletter continues being read by an elite audience around the world. The apostrophe in the name is significant.  It is a newsletter for Java specialists. When I started it twelve years ago, I was trying to find non-obvious things in Java to write about. Things that would be interesting to an advanced audience.As an April Fool's joke, I told my readers in Issue 44 that subscribing would remain free, but that they would have to pay US$5 to US$7 depending on their geographical location. I received quite a few angry emails from that one. I would have not earned that much from unsubscriptions. Most readers stay for a very long time.After Oracle bought Sun, the Java community held its breath for about two years whilst Oracle was figuring out what to do with Java. For a while, we were quite concerned that there was not much progress shown by Oracle. My newsletter still continued, but it was quite difficult finding new things to write about. We have probably about 70,000 readers, which is quite a small number for a Java publication. However, our readers are the top in the Java industry. So I don't mind having "only" 70000 readers, as long as they are the top 0.7%.Java concurrency is a very important topic that programmers think they should know about, but often neglect to fully understand. I continued writing about that and made some interesting discoveries. For example, in Issue 165, I showed how we can get thread starvation with the ReadWriteLock. This was a bug in Java 5, which was corrected in Java 6, but perhaps a bit too much. Whereas we could get starvation of writers in Java 5, in Java 6 we could now get starvation of readers. All of these interesting findings make their way into my courseware to help companies avoid these pitfalls.Another interesting discovery was how polymorphism works in the Server HotSpot compiler in Issue 157 and Issue 158. HotSpot can inline methods from interfaces that have only one implementation class in the JVM. When a new subclass is instantiated and called for the first time, the JVM will undo the previous optimization and re-optimize differently.Here is a little memory puzzle for your readers: public class JavaMemoryPuzzle {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzle jmp = new JavaMemoryPuzzle();    jmp.f();  }}When you run this you will always get an OutOfMemoryError, even though the local variable data is no longer visible outside of the code block.So here comes the puzzle, that I'd like you to ponder a bit. If you very politely ask the VM to release memory, then you don't get an OutOfMemoryError: public class JavaMemoryPuzzlePolite {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    for(int i=0; i<10; i++) {      System.out.println("Please be so kind and release memory");    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzlePolite jmp = new JavaMemoryPuzzlePolite();    jmp.f();    System.out.println("No OutOfMemoryError");  }}Why does this work? When I published this in my newsletter, I received over 400 emails from excited readers around the world, most of whom sent me the wrong explanation. After the 300th wrong answer, my replies became unfortunately a bit curt. Have a look at Issue 174 for a detailed explanation, but before you do, put on your thinking caps and try to figure it out yourself. Q: What do you think Java developers should know that they currently do not know?A: They should definitely get to know more about concurrency. It is a tough subject that most programmers try to avoid. Unfortunately we do come in contact with it. And when we do, we need to know how to protect ourselves and how to solve tricky system errors.Knowing your IDE is also useful. Most IDEs have a ton of shortcuts, which can make you a lot more productive in moving code around. Another thing that is useful is being able to read GC logs. Kirk Pepperdine has a great talk at JavaOne that I can recommend if you want to learn more. It's this: CON5405 – “Are Your Garbage Collection Logs Speaking to You?” Q: What are you looking forward to in Java 8?A: I'm quite excited about lambdas, though I must confess that I have not studied them in detail yet. Maurice Naftalin's Lambda FAQ is quite a good start to document what you can do with them. I'm looking forward to finding all the interesting bugs that we will now get due to lambdas obscuring what is really going on underneath, just like we had with generics.I am quite impressed with what the team at Oracle did with OpenJDK's performance. A lot of the benchmarks now run faster.Hopefully Java 8 will come with JSR 310, the Date and Time API. It still boggles my mind that such an important API has been left out in the cold for so long.What I am not looking forward to is losing perm space. Even though some systems run out of perm space, at least the problem is contained and they usually manage to work around it. In most cases, this is due to a memory leak in that region of memory. Once they bundle perm space with the old generation, I predict that memory leaks in perm space will be harder to find. More contracts for us, but also more pain for our customers. Originally published on blogs.oracle.com/javaone.

    Read the article

  • The Java Specialist: An Interview with Java Champion Heinz Kabutz

    - by Janice J. Heiss
    Dr. Heinz Kabutz is well known for his Java Specialists’ Newsletter, initiated in November 2000, where he displays his acute grasp of the intricacies of the Java platform for an estimated 70,000 readers; for his work as a consultant; and for his workshops and trainings at his home on the Island of Crete where he has lived since 2006 -- where he is known to curl up on the beach with his laptop to hack away, in between dips in the Mediterranean. Kabutz was born of German parents and raised in Cape Town, South Africa, where he developed a love of programming in junior high school through his explorations on a ZX Spectrum computer. He received a B.S. from the University of Cape Town, and at 25, a Ph.D., both in computer science. He will be leading a two-hour hands-on lab session, HOL6500 – “Finding and Solving Java Deadlocks,” at this year’s JavaOne that will explore what causes deadlocks and how to solve them. Q: Tell us about your JavaOne plans.A: I am arriving on Sunday evening and have just one hands-on-lab to do on Monday morning. This is the first time that a non-Oracle team is doing a HOL at JavaOne under Oracle's stewardship and we are all a bit nervous about how it will turn out. Oracle has been immensely helpful in getting us set up. I have a great team helping me: Kirk Pepperdine, Dario Laverde, Benjamin Evans and Martijn Verburg from jClarity, Nathan Reynolds from Oracle, Henri Tremblay of OCTO Technology and Jeff Genender of Savoir Technologies. Monday will be hard work, but after that, I will hopefully get to network with fellow Java experts, attend interesting sessions and just enjoy San Francisco. Oh, and my kids have already given me a shopping list of things to get, like a GoPro Hero 2 dive housing for shooting those nice videos of Crete. (That's me at the beginning diving down.) Q: What sessions are you attending that we should know about?A: Sometimes the most unusual sessions are the best. I avoid the "big names". They often are spread too thin with all their sessions, which makes it difficult for them to deliver what I would consider deep content. I also avoid entertainers who might be good at presenting but who do not say that much.In 2010, I attended a session by Vladimir Yaroslavskiy where he talked about sorting. Although he struggled to speak English, what he had to say was spectacular. There was hardly anybody in the room, having not heard of Vladimir before. To me that was the highlight of 2010. Funnily enough, he was supposed to speak with Joshua Bloch, but if you remember, Google cancelled. If Bloch has been there, the room would have been packed to capacity.Q: Give us an update on the Java Specialists’ Newsletter.A: The Java Specialists' Newsletter continues being read by an elite audience around the world. The apostrophe in the name is significant.  It is a newsletter for Java specialists. When I started it twelve years ago, I was trying to find non-obvious things in Java to write about. Things that would be interesting to an advanced audience.As an April Fool's joke, I told my readers in Issue 44 that subscribing would remain free, but that they would have to pay US$5 to US$7 depending on their geographical location. I received quite a few angry emails from that one. I would have not earned that much from unsubscriptions. Most readers stay for a very long time.After Oracle bought Sun, the Java community held its breath for about two years whilst Oracle was figuring out what to do with Java. For a while, we were quite concerned that there was not much progress shown by Oracle. My newsletter still continued, but it was quite difficult finding new things to write about. We have probably about 70,000 readers, which is quite a small number for a Java publication. However, our readers are the top in the Java industry. So I don't mind having "only" 70000 readers, as long as they are the top 0.7%.Java concurrency is a very important topic that programmers think they should know about, but often neglect to fully understand. I continued writing about that and made some interesting discoveries. For example, in Issue 165, I showed how we can get thread starvation with the ReadWriteLock. This was a bug in Java 5, which was corrected in Java 6, but perhaps a bit too much. Whereas we could get starvation of writers in Java 5, in Java 6 we could now get starvation of readers. All of these interesting findings make their way into my courseware to help companies avoid these pitfalls.Another interesting discovery was how polymorphism works in the Server HotSpot compiler in Issue 157 and Issue 158. HotSpot can inline methods from interfaces that have only one implementation class in the JVM. When a new subclass is instantiated and called for the first time, the JVM will undo the previous optimization and re-optimize differently.Here is a little memory puzzle for your readers: public class JavaMemoryPuzzle {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzle jmp = new JavaMemoryPuzzle();    jmp.f();  }}When you run this you will always get an OutOfMemoryError, even though the local variable data is no longer visible outside of the code block.So here comes the puzzle, that I'd like you to ponder a bit. If you very politely ask the VM to release memory, then you don't get an OutOfMemoryError: public class JavaMemoryPuzzlePolite {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    for(int i=0; i<10; i++) {      System.out.println("Please be so kind and release memory");    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzlePolite jmp = new JavaMemoryPuzzlePolite();    jmp.f();    System.out.println("No OutOfMemoryError");  }}Why does this work? When I published this in my newsletter, I received over 400 emails from excited readers around the world, most of whom sent me the wrong explanation. After the 300th wrong answer, my replies became unfortunately a bit curt. Have a look at Issue 174 for a detailed explanation, but before you do, put on your thinking caps and try to figure it out yourself. Q: What do you think Java developers should know that they currently do not know?A: They should definitely get to know more about concurrency. It is a tough subject that most programmers try to avoid. Unfortunately we do come in contact with it. And when we do, we need to know how to protect ourselves and how to solve tricky system errors.Knowing your IDE is also useful. Most IDEs have a ton of shortcuts, which can make you a lot more productive in moving code around. Another thing that is useful is being able to read GC logs. Kirk Pepperdine has a great talk at JavaOne that I can recommend if you want to learn more. It's this: CON5405 – “Are Your Garbage Collection Logs Speaking to You?” Q: What are you looking forward to in Java 8?A: I'm quite excited about lambdas, though I must confess that I have not studied them in detail yet. Maurice Naftalin's Lambda FAQ is quite a good start to document what you can do with them. I'm looking forward to finding all the interesting bugs that we will now get due to lambdas obscuring what is really going on underneath, just like we had with generics.I am quite impressed with what the team at Oracle did with OpenJDK's performance. A lot of the benchmarks now run faster.Hopefully Java 8 will come with JSR 310, the Date and Time API. It still boggles my mind that such an important API has been left out in the cold for so long.What I am not looking forward to is losing perm space. Even though some systems run out of perm space, at least the problem is contained and they usually manage to work around it. In most cases, this is due to a memory leak in that region of memory. Once they bundle perm space with the old generation, I predict that memory leaks in perm space will be harder to find. More contracts for us, but also more pain for our customers.

    Read the article

  • Stream.CopyTo() extension method

    - by DigiMortal
    In one of my applications I needed copy data from one stream to another. After playing with streams a little bit I wrote CopyTo() extension method to Stream class you can use to copy the contents of current stream to target stream. Here is my extension method. It is my working draft and it is possible that there must be some more checks before we can say this extension method is ready to be part of some API or class library. public static void CopyTo(this Stream fromStream, Stream toStream) {     if (fromStream == null)         throw new ArgumentNullException("fromStream");     if (toStream == null)         throw new ArgumentNullException("toStream");       var bytes = new byte[8092];     int dataRead;     while ((dataRead = fromStream.Read(bytes, 0, bytes.Length)) > 0)         toStream.Write(bytes, 0, dataRead); } And here is example how to use this extension method. using(var stream = response.GetResponseStream()) using(var ms = new MemoryStream()) {     stream.CopyTo(ms);       // Do something with copied data } I am using this code to copy data from HTTP response stream to memory stream because I have to use serializer that needs more than response stream is able to offer.

    Read the article

  • Routing traffic to another internal network

    - by Jason
    OK, so here is the scenario. I have 4 Locations connected with an MPLS. I have installed an ASA at the primary location which is 10.20.1.0. Traffic is fine internally and to the world, however... I can't route traffic over the MPLS to another network. It is being blocked by an implicit deny rule even though there is a rule to allow any to any less secure interface (it should be using the same interface in/out, right?). I have a static route for the network in and the ASA can ping it - Just not traffic on the internal network of the ASA. -Jason

    Read the article

  • ECMP Load Balancing in JUNOS

    - by SpacemanSpiff
    I'm trying to figure out how to use ECMP load balancing in JUNOS. I know this isn't the best way to load balance, but its quick and dirty and gets done what I need to. In ScreenOS this was pretty easy. Device: SRX220 JunOS: 10.3R2.11 Here's what I've got so far: routing-options { static { route 0.0.0.0/0 { next-hop [ 1.1.1.1 1.1.1.2 ]; metric 10; } } maximum-paths 2; Will that do it? Tom

    Read the article

  • Finding the normals of an oriented bounding box?

    - by Milo
    Here is my problem. I'm working on the physics for my 2D game. All objects are oriented bounding boxes (OBB) based on the separate axis theorem. In order to do collision resolution, I need to be able to get an object out out of the object it is penetrating. To do this I need to find the normal of the face(s) that the other OBB is touching. Example: The small red OBB is a car lets say, and the big OBB is a static building. I need to determine the unit vector that is the normal of the building edge(s) the car is penetrating to get the car out of there. Here are my questions: How do I determine which edges the car is penetrating. I know how to determine the normal of an edge, but how do I know if I need (-dy, dx) or (dy, -dx)? In the case I'm demonstrating the car is penetrating 2 edges, which edge(s) do I use to get it out? Answers or help with any or all of these is greatly appreciated. Thank you

    Read the article

  • Calculate the Intersection of Two Volumes

    - by igrad
    If you've ever played The Swapper, you'll have a good idea of what I'm asking about. I need to check for, and isolate, areas of a rectangle that may intersect with either a circle or another rectangle. These selected areas will receive special properties, and the areas will be non-static, since the intersecting shapes themselves will also be dynamic. My first thought was to use raycasting detection, though I've only seen that in use with circles, or even ellipses. I'm curious if there's a method of using raycasting with a more rectangular approach, or if there's a totally different method already in use to accomplish this task. I would like something more exact than checking in large chunks, and since I'm using SDL2 with a logical renderer size of 1920x1080, checking if each pixel is intersecting is out of the question, as it would slow things down past a playable speed. I already have a multi-shape collision function-template in place, and I could use that, though it only checks if sides or corners are intersecting; it does not compute the overlapping area, or even find the circle's secant line, though I can't imagine it would be overly complex to implement. TL;DR: I need to find and isolate areas of a rectangle that may intersect with a circle or another rectangle without checking every single pixel on-screen.

    Read the article

  • How to implement early exit / return in Haskell?

    - by Giorgio
    I am porting a Java application to Haskell. The main method of the Java application follows the pattern: public static void main(String [] args) { if (args.length == 0) { System.out.println("Invalid number of arguments."); System.exit(1); } SomeDataType d = getData(arg[0]); if (!dataOk(d)) { System.out.println("Could not read input data."); System.exit(1); } SomeDataType r = processData(d); if (!resultOk(r)) { System.out.println("Processing failed."); System.exit(1); } ... } So I have different steps and after each step I can either exit with an error code, or continue to the following step. My attempt at porting this to Haskell goes as follows: main :: IO () main = do a <- getArgs if ((length args) == 0) then do putStrLn "Invalid number of arguments." exitWith (ExitFailure 1) else do -- The rest of the main function goes here. With this solution, I will have lots of nested if-then-else (one for each exit point of the original Java code). Is there a more elegant / idiomatic way of implementing this pattern in Haskell? In general, what is a Haskell idiomatic way to implement an early exit / return as used in an imperative language like Java?

    Read the article

  • SharePoint 2010 Hosting :: Setting Default Column Values on a Folder Programmatically

    - by mbridge
    The reason I write this post today is because my initial searches on the Internet provided me with nothing on the topic.  I was hoping to find a reference to the SDK but I didn’t have any luck.  What I want to do is set a default column value on an existing folder so that new items in that folder automatically inherit that value.  It’s actually pretty easy to do once you know what the class is called in the API.  I did some digging and discovered that class is MetadataDefaults. It can be found in Microsoft.Office.DocumentManagement.dll.  Note: if you can’t find it in the GAC, this DLL is in the 14/CONFIG/BIN folder and not the 14/ISAPI folder.  Add a reference to this DLL in your project.  In my case, I am building a console application, but you might put this in an event receiver or workflow. In my example today, I have simple custom folder and document content types.  I have one shared site column called DocumentType.  I have a document library which each of these content types registered.  In my document library, I have a folder named Test and I want to set its default column values using code.  Here is what it looks like.  Start by getting a reference to the list in question.  This assumes you already have a SPWeb object.  In my case I have created it and it is called site. SPList customDocumentLibrary = site.Lists["CustomDocuments"]; You then pass the SPList object to the MetadataDefaults constructor. MetadataDefaults columnDefaults = new MetadataDefaults(customDocumentLibrary); Now I just need to get my SPFolder object in question and pass it to the meethod SetFieldDefault.  This takes a SPFolder object, a string with the name of the SPField to set the default on, and finally the value of the default (in my case “Memo”). SPFolder testFolder = customDocumentLibrary.RootFolder.SubFolders["Test"]; columnDefaults.SetFieldDefault(testFolder, "DocumentType", "Memo"); You can set multiple defaults here.  When you’re done, you will need to call .Update(). columnDefaults.Update(); Here is what it all looks like together. using (SPSite siteCollection = new SPSite("http://sp2010/sites/ECMSource")) {     using (SPWeb site = siteCollection.OpenWeb())     {         SPList customDocumentLibrary = site.Lists["CustomDocuments"];         MetadataDefaults columnDefaults = new MetadataDefaults(customDocumentLibrary);          SPFolder testFolder = customDocumentLibrary.RootFolder.SubFolders["Test"];         columnDefaults.SetFieldDefault(testFolder, "DocumentType", "Memo");         columnDefaults.Update();     } } You can verify that your property was set correctly on the Change Default Column Values page in your list This is something that I could see used a lot on an ItemEventReceiver attached to a folder to do metadata inheritance.  Whenever, the user changed the value of the folder’s property, you could have it update the default.  Your code might look something columnDefaults.SetFieldDefault(properties.ListItem.Folder, "MyField", properties.ListItem[" This is a great way to keep the child items updated any time the value a folder’s property changes.  I’m also wondering if this can be done via CAML.  I tried saving a site template, but after importing I got an error on the default values page.  I’ll keep looking and let you know what I find out.

    Read the article

  • How to benchmark apache/nginx setup

    - by Saif Bechan
    I am planning to setup nginx as reverse proxy. I will have apache to deliver my dynamic content, and nginx will deliver the static content. My configuration i have now is just Apache with fastCGI. This gives me no configuration problems and runs great. After I have set up nginx I want to run some benchmarks to see if I really got some performance increases, else i will switch back. Does anyone know how I can benchmark this type of setup? Or maybe someone did this already and have some canned results, I will be glad to hear them.

    Read the article

  • How do I apply different probability factors in an algorithm for a cricket simulation game?

    - by Komal Sharma
    I am trying to write the algorithm for a cricket simulation game which generates runs on each ball between 0 to 6. The run rate or runs generated changes when these factors come into play like skill of the batsman, skill of the bowler, target to be chased. Wickets left. If the batsman is skilled more runs will be generated. There will be a mode of play of the batsman aggressive, normal, defensive. If he plays aggressive chances of getting out will be more. If the chasing target is more the run rate should be more. If the overs are final the run rate should be more. I am using java random number function for this. The code so far I've written is public class Cricket { public static void main(String args[]) { int totalRuns=0; //i is the balls bowled for (int i = 1; i <= 60 ; i++) { int RunsPerBall = (int)(Math.random()*6); //System.out.println(Random); totalRuns=totalRuns+RunsPerBall; } System.out.println(totalRuns); } } Can somebody help me how to apply the factors in the code. I believe probability will be used with this. I am not clear how to apply the probability of the factors stated above in the code.

    Read the article

  • Site in subdomain (MaraDNS + Nginx)

    - by Grzegorz
    Welcome, Actually I'm doing some experiments on my VPS with Ubuntu. I've installed MaraDNS with Nginx. At this moment I've correctly launch static site which is available from Internet (maindomain.com). In next step I want to add new site which will be available in subdomain, for example dev.maindomain.com. I've tried to db.maindomain.com file (used by MaraDNS): maindomain.com. xxx.xxx.xxx.xxx www.maindomain.com. CNAME maindomain.com. dev.maindomain.com. xxx.xxx.xxx.xxx Where xxx.xxx.xxx.xxx is VPS IP address. In nginx.conf I have: server { listen 80; server_name maindomain.com; access_log /var/log/nginx/maindomain.com.log location / { root /var/www/maindomain.com; index index.html; } } server { listen 80; server_name dev.maindomain.com; access_log /var/log/nginx/dev.maindomain.com.log location / { root /var/www/dev.maindomain.com; index index.html; } } With this configuration maindomain.com works properly, but dev.maindomain.com isn't available. When I try: ping dev.maindomain.com then I get my xxx.xxx.xxx.xxx IP. Do you have any suggestions how can I resolve this problem?

    Read the article

  • How can we protect the namespace of an object in Javascript?

    - by Eduard Florinescu
    Continuing from my previous question: Javascript simple code to understand prototype-based OOP basics Let's say we run into console this two separate objects(even if they are called child and parent there is no inheritance between them): var parent = { name: "parent", print: function(){ console.log("Hello, "+this.name); } }; var child = { name: "child", print: function(){ console.log("Hi, "+this.name); } }; parent.print() // This will print: Hello, parent child.print() // This will print: Hi, child temp =parent; parent = child; child = temp; parent.print() // This will now print: Hi, child child.print() // This will now print: Hello, parent Now suppose that parent is a library, as a HTML5 application in a browser this cannot do much harm because is practically running sandboxed, but now with the advent of the ChromeOS, FirefoxOS and other [Browser] OS they will also be linked to a native API, that would be a head out of the „sandbox”. Now if someone changes the namespace it would be harder for a code reviewer (either automated or not ) to spot an incorrect use if the namespaces changes. My question would be: Are there many ways in which the above situation can be done and what can be done to protect this namespaces? (Either in the javascript itself or by some static code analysis tool)

    Read the article

< Previous Page | 386 387 388 389 390 391 392 393 394 395 396 397  | Next Page >