Search Results

Search found 6001 results on 241 pages for 'requires'.

Page 188/241 | < Previous Page | 184 185 186 187 188 189 190 191 192 193 194 195  | Next Page >

• 64-bit Alternative for Microsoft Jet

  - by David Robison

  Microsoft has chosen to not release a 64-bit version of Jet, their database driver for Access. Does anyone know of a good alternative? Here are the specific features that Jet supports that I need: Multiple users can connect to database over a network. Users can use Windows Explorer to copy the database while it is open without risking corruption. Access currently does this with enough reliability for what my customers need. Works well in C++ without requiring .Net. Alternatives I've considered that I do not think could work (though my understanding could be incorrect): SQLite: If multiple users connect to the database over a network, it will become corrupted. Firebird: Copying a database that is in use can corrupt the original database. SQL Server: Files in use are locked and cannot be copied. VistaDB: This appears to be .Net specific. Compile in 32-bit and use WOW64: There is another dependency that requires us to compile in 64-bit, even though we don't use any 64-bit functionality.

  Read the article

• How do I make a web interface for a socket server

  - by mgroat

  I've got a socket server running (it's something that's basically like a chat server). Users can telnet into it, but I'd like to make a web interface. This is the first time I've ever done something like this, so I'm not really sure where to start. A few thoughts I've had: Have some server-side Python (or PHP) on my webserver, which accesses the socket server. I think I know enough about sockets to have Python interact with the server, but how do I go about getting the website that the user sees to update in real time? Should I just have the website refresh few seconds? I would prefer to do things this way if I can figure out how. Write a Java applet that interacts with the socket server, and embed the applet in the website. I would have to re-learn a language that I haven't touched in years, but my main goal here is learning -- so that wouldn't be such a bad thing. The main problem I have with this is that it requires end users to have Java installed on their computers, which I'd rather not do. Is one of these two solutions the right way to go? Anybody know where I can find a good tutorial to get started? Edit: There's no real security concerns with exposing the server to the internet.

  Read the article

• How to ensure DB security for a Windows Forms application?

  - by Vilx-

  The basic setup is classic - you're creating a Windows Forms application that connects to a DB and does all kinds of enterprise-y stuff. Naturally, such an application will have many users with different access rights in the DB, and each with their own login name and password. So how do you implement this? One way is to create a DB login for every application user, but that's a pretty serious thing to do, which even requires admin rights on the DB server, etc. If the DB server hosts several applications, the admins are quite likely not to be happy with this. In the web world typically one creates his own "Users" table which contains all the necessary info, and uses one fixed DB login for all interaction. That is all nice for a web app, but a windows forms can't hide this master login information, negating security altogether. (It can try to hide, but all such attempts are easily broken with a bit of effort). So... is there some middle way? Perhaps logging in with a fixed login, and then elevating priviledges from a special stored procedure which checks the username and password?

  Read the article

• One big executable or many small DLL's?

  - by Patrick

  Over the years my application has grown from 1MB to 25MB and I expect it to grow further to 40, 50 MB. I don't use DLL's, but put everything in this one big executable. Having one big executable has certain advantages: Installing my application at the customer is really: copy and run. Upgrades can be easily zipped and sent to the customer There is no risk of having conflicting DLL's (where the customer has version X of the EXE, but version Y of the DLL) The big disadvantage of the big EXE is that linking times seem to grow exponentially. Additional problem is that a part of the code (let's say about 40%) is shared with another application. Again, the advantages are that: There is no risk on having a mix of incorrect DLL versions Every developer can make changes on the common code which speeds up developments. But again, this has a serious impact on compilation times (everyone compiles the common code again on his PC) and on linking times. The question http://stackoverflow.com/questions/2387908/grouping-dlls-for-use-in-executable mentions the possibility of mixing DLL's in one executable, but it looks like this still requires you to link all functions manually in your application (using LoadLibrary, GetProcAddress, ...). What is your opinion on executable sizes, the use of DLL's and the best 'balance' between easy deployment and easy/fast development?

  Read the article

• Uncrackable anti-piracy protection/DRM even possible? [closed]

  - by some guy

  I hope that this is programming-related enough. You have probably heard about Ubisofts recent steps against piracy. (New DRM requires a constant connection to the Ubisoft server) Many people including me see this as intolerable because the only ones suffering from it at the end are the paying customers. Now to the actual question(s): Ubisoft justified this by calling this mechanism "Uncrackable, only playable by the paying customers". Is a so called uncrackable DRM even possible? You can reverse-engineer and modify everything, even if it takes long. Isn't Ubisoft already lying by calling something not crackable? I mean, hey - With the game you get all its content (textures, models, you know) and some anti-piracy mechanism hardcoded into it. How could that be "uncrackable"? You can just patch the unwanted mechanisms out ---- "Pirates" play the cracked game without problems and the paying customers are the idiots by having constant problems with the game and being unable to play it without a (working) internet connection. What are the points Ubisoft sees in this? If they are at least a bit intelligent and informed they know their anti-piracy protection won't last long. All they get is lower sales, angry customers and happy pirates and crackers.

  Read the article

• POST XML to server, receive PDF

  - by Shaggy Frog

  Similar to this question, we are developing a Web app where the client clicks a button to receive a PDF from the server. Right now we're using the .ajax() method with jQuery to POST the data the backend needs to generate the PDF (we're sending XML) when the button is pressed, and then the backend is generating the PDF entirely in-memory and sending it back as application/pdf in the HTTP response. One answer to that question requires the server-side save the PDF to disk so it can give back a URL for the client to GET. But I don't want the backend caching content at all. The other answer suggests the use of a jQuery plugin, but when you look at its code, it's actually generating a form element and then submitting the form. That method will not work for us since we are sending XML data in the body of the HTTP request. Is there a way to have the browser open up the PDF without caching the PDF server-side, and without requiring us to throw out our send-data-to-the-server-using-XML solution? (I'd like the browser to behave like it does when a form element is submitted -- a POST is made and then the browser looks at the Content-type header to determine what to do next, like load the PDF in the browser window, a la Safari)

  Read the article

• "You have already activated" message even when using bundle exec

  - by juanpastas

  I am installing gems in my Gemfile in shared path as Capistrano does by default, and when I run: bundle exec rake assets:precompile RAILS_ENV=production I get: You have already activated rake 0.9.2.2, but your Gemfile requires rake 10.0.4. Using bundle exec may solve this. See that: cat Gemfile.lock | grep rake returns: rake (>= 0.8.7) rake (10.0.4) This is my gem environment output: - RUBYGEMS VERSION: 1.8.24 - RUBY VERSION: 1.9.3 (2013-06-27 patchlevel 448) [x86_64-linux] - INSTALLATION DIRECTORY: /home/bitnami/my_app/shared/bundle/ruby/1.9.1/ - RUBY EXECUTABLE: /opt/bitnami/ruby/bin/ruby - EXECUTABLE DIRECTORY: /home/bitnami/my_app/shared/bundle/ruby/1.9.1/bin - RUBYGEMS PLATFORMS: - ruby - x86_64-linux - GEM PATHS: - /home/bitnami/my_app/shared/bundle/ruby/1.9.1/ - GEM CONFIGURATION: - :update_sources => true - :verbose => true - :benchmark => false - :backtrace => false - :bulk_threshold => 1000 - "gemhome" => "/home/bitnami/my_app/shared/bundle/ruby/1.9.1/" - "gempath" => ["/home/bitnami/my_app/shared/bundle/ruby/1.9.1/"] - REMOTE SOURCES: - http://rubygems.org/ Update which -a rake /opt/bitnami/rvm/bin/rake /opt/bitnami/ruby/bin/rake Update 2 I tried giving full path to rake, but same problem

  Read the article

• Eclipse 3.7 Classic Nightmare - ADT Installation

  - by Cal

  I've been trying to install the ADT for Eclipse Classic 3.7 to no avail. From what I've seen on searches, the general consensus seems to be to update the software, but alas I cannot do that, either. BELOW: An example of the error message received when trying to update Eclipse, or when attempting to install from a web location. Some sites could not be found. See the error log for more detail. Unable to read repository at http://download.eclipse.org/eclipse/updates/3.7/content.xml. Cannot assign requested address: JVM_Bind I followed the troubleshooting recommendations of Google/Android's developer section, and attempted to install ADT via archive. BELOW: The resulting error from attempting to install via archive. Cannot complete the install because one or more required items could not be found. Software being installed: Android Development Tools 11.0.0.v201105251008-128486 (com.android.ide.eclipse.adt.feature.group 11.0.0.v201105251008-128486) Missing requirement: Android Development Tools 11.0.0.v201105251008-128486 (com.android.ide.eclipse.adt.feature.group 11.0.0.v201105251008-128486) requires 'org.eclipse.gef 0.0.0' but it could not be found Now, from what I hear, the inability to update/install via Internet seems to be a proxy-related issue, however I don't believe that I'm under any such thing (I'm just using my computer connected to my home network for this). I'm using the most up-to-date versions of anything I can think of (ADT, Eclipse, SDK Tools etc). I'm using Windows 7 Ultimate 64bit, and am using the 64bit version of Eclipse Classic.

  Read the article

• Have I found a security problem in an API or do I just not understand SSL?

  - by jamieb

  I'm working on building a set of Python bindings around an XML-based API provided by a vendor. The vendor requires that all transactions be conducted over SSL. Using a Linux box, I created a key file and a CSR for my application. Using their self-service web portal, I then generate a certificate using that CSR. Both the key file and the certificate are used when making the SSL request to the API. I'm now working on designing exception classes to make error messages more verbose (and, hopefully, more useful to developers using my bindings). Part of my testing has included altering the key file: transpose a couple characters here, replace 4 or 5 with random characters there, etc. To my surprise, altering the key file had no effect! As long as I didn't change the total length of it, the API didn't complain about a bad key file. The only way I was able to throw an error was by swapping in a completely different key from another application. At that point, the API complained about the Common Name not matching. Is this normal behavior or has the vendor not properly implemented SSL?

  Read the article

• hadoop implementing a generic list writable

  - by Guruprasad Venkatesh

  I am working on building a map reduce pipeline of jobs(with one MR job's output feeding to another as input). The values being passed around are fairly complex, in that there are lists of different types and hash maps with values as lists. Hadoop api does not seem to have a ListWritable. Am trying to write a generic one, but it seems i can't instantiate a generic type in my readFields implementation, unless i pass in the class type itself: public class ListWritable<T extends Writable> implements Writable { private List<T> list; private Class<T> clazz; public ListWritable(Class<T> clazz) { this.clazz = clazz; list = new ArrayList<T>(); } @Override public void write(DataOutput out) throws IOException { out.writeInt(list.size()); for (T element : list) { element.write(out); } } @Override public void readFields(DataInput in) throws IOException{ int count = in.readInt(); this.list = new ArrayList<T>(); for (int i = 0; i < count; i++) { try { T obj = clazz.newInstance(); obj.readFields(in); list.add(obj); } catch (InstantiationException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } } } But hadoop requires all writables to have a no argument constructor to read the values back. Has anybody tried to do the same and solved this problem? TIA.

  Read the article

• Offline Mapping API

  - by Aaron M

  Are there any services available that allow me to manipulate maps in an offline setting? I am working on a project that requires me to take a map and based on features on the map, generate a game world. I have looked at a few of the API's for different providers: Google, ms, etc. The API's I looked seem to be strictly showing a user a map. I am looking for something that allows me to create a derivative of a map (the Gameworld), that will never be seen by the public, and is only used by the game engine. However one caveat is that I would like to be able to link the derivative created for use by the game engine, with something I can show the user. As an example. Think of a cross country racing sim. Users cannot control the vehicles directly in this game, they can only control the cars setup, driver, etc. I create a gameworld from a map. The gameworld data (driver position, etc) is overlayed onto a real map. A race might last several days. The only interaction users have with the real map is viewing their position on the map, and where they are in relation to the others. I don't want to violate the terms of the API here. I read Googles API TOS, and it seems to me that creating the gameworld would violdate their TOS. The features I really need are the following The ability to locate a specific place on the map by lat/long The ability/rights to grab those maps and save them as an image file temporarily for processing The ability/rights to store a gameworld that is based on the real map The ability to show a user a map with an overlay (this is optional. I can use googles API, or any other one that supports lat/long.)

  Read the article

• Can I use a static cache Helper method in a NET MVC controller?

  - by Euston

  I realise there have been a few posts regarding where to add a cache check/update and the separation of concerns between the controller, the model and the caching code. There are two great examples that I have tried to work with but being new to MVC I wonder which one is the cleanest and suits the MVC methodology the best? I know you need to take into account DI and unit testing. Example 1 (Helper method with delegate) ...in controller var myObject = CacheDataHelper.Get(thisID, () => WebServiceServiceWrapper.GetMyObjectBythisID(thisID)); Example 2 (check for cache in model class) in controller var myObject = WebServiceServiceWrapper.GetMyObjectBythisID(thisID)); then in model class.............. if (!CacheDataHelper.Get(cachekey, out myObject)) { //do some repository processing // Add obect to cache CacheDataHelper.Add(myObject, cachekey); } Both use a static cache helper class but the first example uses a method signature with a delegate method passed in that has the name of the repository method being called. If the data is not in cache the method is called and the cache helper class handles the adding or updating to the current cache. In the second example the cache check is part of the repository method with an extra line to call the cache helper add method to update the current cache. Due to my lack of experience and knowledge I am not sure which one is best suited to MVC. I like the idea of calling the cache helper with the delegate method name in order to remove any cache code in the repository but I am not sure if using the static method in the controller is ideal? The second example deals with the above but now there is no separation between the caching check and the repository lookup. Perhaps that is not a problem as you know it requires caching anyway?

  Read the article

• C++ operator new, object versions, and the allocation sizes

  - by mizubasho

  Hi. I have a question about different versions of an object, their sizes, and allocation. The platform is Solaris 8 (and higher). Let's say we have programs A, B, and C that all link to a shared library D. Some class is defined in the library D, let's call it 'classD', and assume the size is 100 bytes. Now, we want to add a few members to classD for the next version of program A, without affecting existing binaries B or C. The new size will be, say, 120 bytes. We want program A to use the new definition of classD (120 bytes), while programs B and C continue to use the old definition of classD (100 bytes). A, B, and C all use the operator "new" to create instances of D. The question is, when does the operator "new" know the amount of memory to allocate? Compile time or run time? One thing I am afraid of is, programs B and C expect classD to be and alloate 100 bytes whereas the new shared library D requires 120 bytes for classD, and this inconsistency may cause memory corruption in programs B and C if I link them with the new library D. In other words, the area for extra 20 bytes that the new classD require may be allocated to some other variables by program B and C. Is this assumption correct? Thanks for your help.

  Read the article

• MySQL Ratings From Two Tables

  - by DirtyBirdNJ

  I am using MySQL and PHP to build a data layer for a flash game. Retrieving lists of levels is pretty easy, but I've hit a roadblock in trying to fetch the level's average rating along with it's pointer information. Here is an example data set: levels Table: level_id | level_name 1 | Some Level 2 | Second Level 3 | Third Level ratings Table: rating_id | level_id | rating_value 1 | 1 | 3 2 | 1 | 4 3 | 1 | 1 4 | 2 | 3 5 | 2 | 4 6 | 2 | 1 7 | 3 | 3 8 | 3 | 4 9 | 3 | 1 I know this requires a join, but I cannot figure out how to get the average rating value based on the level_id when I request a list of levels. This is what I'm trying to do: SELECT levels.level_id, AVG(ratings.level_rating WHERE levels.level_id = ratings.level_id) FROM levels I know my SQL is flawed there, but I can't figure out how to get this concept across. The only thing I can get to work is returning a single average from the entire ratings table, which is not very useful. Ideal Output from the above conceptually valid but syntactically awry query would be: level_id | level_rating 1| 3.34 2| 1.00 3| 4.54 My main issue is I can't figure out how to use the level_id of each response row before the query has been returned. It's like I want to use a placeholder... or an alias... I really don't know and it's very frustrating. The solution I have in place now is an EPIC band-aid and will only cause me problems long term... please help!

  Read the article

• ASP.NET inline code in a server control

  - by John

  Ok, we had a problem come up today at work. It is a strange one that I never would have even thought to try. <form id="form1" runat="server" method="post" action="Default.aspx?id=<%= ID %>" > Ok, it is very ugly and I wouldn't have ever tried it myself. It came up in some code that was written years ago but had been working up until this weekend after a bunch of updates were installed on a client's web server where the code is hosted. The actual result of this is the following html: <form name="form1" method="post" action="Default.aspx?id=&lt;%= ID %>" id="form1"> The url ends up like this: http://localhost:6735/Default.aspx?id=<%= ID %> Which as you can see, demonstrates that the "<" symbol is being encoded before ASP.NET actually processes the page. It seems strange to me as I thought that even though it is not pretty by any means, it should work. I'm confused. To make matters worse, the client insists that it is a bug in IE since it appears to work in Firefox. In fact, it is broken in Firefox as well, except for some reason Firefox treats it as a 0. Any ideas on why this happens and how to fix it easily? Everything I try to render within the server control ends up getting escaped. Edit Ok, I found a "fix" <form id="form1" runat="server" method="post" action='<%# String.Format("Default.aspx?id={0}", 5) %>' > But that requires me to call DataBind which is adding more of a hack to the original hack. Guess if nobody thinks of anything else I'll have to go with that.

  Read the article

• Record the timestamps of slide changes during a live Powerpoint presentation?

  - by StackedCrooked

  I am planning to implement a lecture capture solution. One of the requirements is to record both the presenter and the slideshow. The presenter is recorded with a videocamera obviously, and the slideshow will probably be captured using a tool like Camtasia. Now during playback three components are visible: the presenter, the slides and a table of contents. Clicking a chapter title in the TOC causes the video to navigate to the corresponding section. This means that a mapping must be made between chapter titles and their timestamps in the video. Usually a change of topic is accompanied with a slide change in the Powerpoint presentation. So the timestamps could be deduced from the slidechanges. However, this requires me to detect slide changes during the live presentation. And I don't know how to do that. Anyone here knows how to do detect slide changes? Is there a Powerpoint API where I can connect event handlers or something like that? I'd greatly appreciate your help! Edit This issue is no longer relevant for my current work so this question will not be updated by me. However, you are still free to help others by posting your answers/insights here.

  Read the article

• Why does my .NET 4 application know .NET 4 is not installed

  - by Tergiver

  I developed an application that targeted .NET 4 the other day and XCOPY-installed it to a Windows XP machine. I had told the owner of the machine that they would need to install .NET Framework 4 to run my app and he told me he did (not a reliable source). When I ran the application I was presented with a message box that said this app requires .NET Framework 4, would I like to install it? Clicking the Yes button took me to the Microsoft web site and a few clicks later .NET 4 was installed, and the application successfully launched. Now I normally don't develop applications that target the latest version of .NET, I always target the lowest version I can (what features do I really need?). So this was my first .NET 4 app (and I only targeted 4 because it used a library that did). In the past, XCOPY-installing .NET applications to a machine that didn't have the correct version of .NET installed resulted in the application simply crashing on startup with no useful information presented to the user. Was it built into my app because I targeted .NET X? Was it something already installed on the target machine? I love the feature, I just want to know precisely how to leverage it in the future.

  Read the article

• Creating ODT and PDF files as end result

  - by Bill Zimmerman

  Hello, I've been working on an app to create various document formats for a while now, and I've had limited success. Ideally, I'd like to dynamically create a fairly simple ODT/PDF/DOC file. I've been focusing my efforts on ODT, because it is editable, and open enough that there are several tools which will convert it to any of the other formats I need. The problem is that the ODT XML files are NOT simple, and there aren't any good-quality API's I could find (especially in python). So far, I've had the most success creating a template ODT file, and then manipulating the DOM in python as needed. This is ok generally, but is quickly becoming inadequate and requires too much tweaking every single time I need to alter one of the templates. The requirements are: 1) Produce a simple document that will have lists, paragraphs, and the ability to draw simple graphics on the page (boxes, circles, etc...) 2) The ability to specify page size, and the different formats should generally print the exact same output when sent to a printer My questions: 1) Are there any other ways I can produce ODT/PDF/DOC files? 2) Would LaTeX be acceptable? I've never really used it, does anyone have experience converting LaTeX files into other formats? 3) Would it be possible to use HTML? There are a lot of converters online. Technically you can specify dimensions in mm/cm, etc..., but I am worried that the printed output will differ between browsers/converters.... Any other ideas?

  Read the article

• P0ST variables to web server?

  - by OverTheRainbow

  Hello I've been trying several things from Google to POST data to a web server, but none of them work: I'm still stuck at how to convert the variables into the request, considering that the second variable is an SQL query so it has spaces. Does someone know the correct way to use a WebClient to POST data? I'd rather use WebClient because it requires less code than HttpWebRequest/HttpWebResponse. Here's what I tried so far: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim wc = New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim postData = String.Format("db={0}&query={1}", _ HttpUtility.UrlEncode("books.sqlite"), _ HttpUtility.UrlEncode("SELECT id,title FROM boooks")) 'Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", postData) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub Dim client = New WebClient() Dim nv As New Collection nv.Add("db", "books.sqlite") nv.Add("query", "SELECT id,title FROM books") Dim address As New Uri("http://localhost:9999/get") 'Dim bytRetData As Byte() = client.UploadValues(address, "POST", nv) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub 'Dim wc As New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query 'Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", bytArguments) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub End Sub Thank you.

  Read the article

• MSBuild / PowerShell: Copy SQL Server 2012 database to SQL Azure via BACPAC (for Continuous Integration)

  - by giveme5minutes

  I'm creating a continuous integration MSBuild script which copies a database in on-premise SQL Server 2012 to SQL Azure. Easy right? Methods After a fair bit of research I've come across the following methods: Use PowerShell to access the DAC library directly, then use the MSBuild PowerShell extension to wrap the script. This would require installing PowerShell 3 and working out how to make the MSBuild PowerShell extension work with it, as apparently MS moved the DAC API to a different namespace in the latest version of the library. PowerShell would give direct access to the API, but may require quite a bit of boilerplate. Use the sample DAC Framework Client Side Tools, which requires compiling them myself, as the downloads available from Codeplex only include the Hosted version. It would also require fixing them to use DAC 3.0 classes as they appear to currently use an earlier version of DAC. I could then call these tools from an <Exec Command="" /> in the MSBuild script. Less boilerplate and if I hit any bumps in the road I can just make changes to the source. Processes Using whichever method, the process could be either: Export from on-premise SQL Server 2012 to local BACPAC Upload BACPAC to blog storage Import BACPAC to SQL Azure via Hosted DAC Or: Export from on-premise SQL Server 2012 to local BACPAC Import BACPAC to SQL Azure via Client DAC Question All of the above seems to be quite a lot of effort for something that seems to be a standard feature... so before I start reinventing the wheel and documenting the results for all to see, is there something really obvious that I've missed here? Is there pre-written script that MS has released that I have not yet uncovered? There's an command in the GUI of SQL Server Management Studio 2012 that does EXACTLY what I'm trying to do (right click on local database, click "Tasks", click "Deploy Database to SQL Azure"). Surely if it's a few clicks in the GUI it must be a single command on the command line somewhere??

  Read the article

• c# multi inheritance

  - by user326839

  So ive got a base class which requires a Socket: class Sock { public Socket s; public Sock(Socket s) { this.s = s; } public virtual void Process(byte[] data) { } ... } then ive got another class. if a new socket gets accepted a new instance of this class will be created: class Game : Sock { public Random Random = new Random(); public Timerr Timers; public Test Test; public Game(Socket s) : base(s) { } public static void ReceiveNewSocket(object s) { Game Client = new Game((Socket)s); Client.Start(); } public override void Process(byte[] buf) { Timers = new Timerr(s); Test = new Test(s); Test.T(); } } in the Sock class ive got a virtual function that gets overwritten by the Game class.(Process function) in this function im calling a function from the Test Class(Test+ Timerr Class: class Test : Game { public Test(Socket s) : base(s) { } public void T() { Console.WriteLine(Random.Next(0, 10)); Timers.Start(); } } class Timerr : Game { public Timerr(Socket s) : base(s) { } public void Start() { Console.WriteLine("test"); } } ) So in the Process function im calling a function in Test. And in this function(T) i need to call a function from the Timerr Class.But the problem is its always NULL , although the constructor is called in Process. And e.g. the Random Class can be called, i guess its because its defined with the constructor.: public Random Random = new Random(); and thats why the other classes(without a constructor): public Timerr Timers; public Test Test; are always null in the inherited class Test.But its essentiel that i call other Methods of other classes in this function.How could i solve that?

  Read the article

• best practice to persist classes model

  - by Yaron Naveh

  My application contains a set of model classes. e.g. Person, Department... The user changes values for instances of these classes in the UI and the classes are persisted to my "project" file. Next time the user can open and edit the project. Next version of my product may change the model classes drastically. It will still need to open existing projects files (I will know how to handle missing data). How is it best to persist my model classes to the project file? The easiest way to persist classes is Data contract serialization. However it will fail on breaking changes (I expect to have such). How to handle this? use some other persistence, e.g. name-value collection or db which is more tolerance ship a "project converter" application to migrate old projects. This requires to either ship with both old and new models or to manipulate xml, which is best?

  Read the article

• What's a good Java-based Master-Slave communication mechanism?

  - by plecong

  I'm creating a Java application that requires master-slave communication between JVMs, possibly residing on the same physical machine. There will be a "master" server running inside a JEE application server (i.e. JBoss) that will have "slave" clients connect to it and dynamically register itself for communication (that is the master will not know the IP addresses/ports of the slaves so cannot be configured in advance). The master server acts as a controller that will dole work out to the slaves and the slaves will periodically respond with notifications, so there would be bi-directional communication. I was originally thinking of RPC-based systems where each side would be a server, but it could get complicated, so I'd prefer a mechanism where there's an open socket and they talk back and forth. I'm looking for a communication mechanism that would be low-latency where the messages would be mostly primitive types, so no serious serialization is necessary. Here's what I've looked at: RMI JMS: Built-in to Java, the "slave" clients would connect to the existing ConnectionFactory in the application server. JAX-WS/RS: Both master and slave would be servers exposing an RPC interface for bi-directional communication. JGroups/Hazelcast: Use shared distributed data structures to facilitate communication. Memcached/MongoDB: Use these as "queues" to facilitate communication, though the clients would have to poll so there would be some latency. Thrift: This does seem to keep a persistent connection, but not sure how to integrate/embed a Thrift server into JBoss WebSocket/Raw Socket: This would work, but require a lot more custom code than I'd like. Is there any technology I'm missing? Edit: Also looked at: JMX: Have the client connect to JBoss' JMX server and receive JMX notifications for bidirectional comms.

  Read the article

• va_arg with pointers

  - by Yktula

  I want to initialize a linked list with pointer arguments like so: /* * Initialize a linked list using variadic arguments * Returns the number of structures initialized */ int init_structures(struct structure *first, ...) { struct structure *s; unsigned int count = 0; va_list va; va_start(va, first); for (s = first; s != NULL; s = va_arg(va, (struct structure *))) { if ((s = malloc(sizeof(struct structure))) == NULL) { perror("malloc"); exit(EXIT_FAILURE); } count++; } va_end(va); return count; } The problem is that clang errors type name requires a specifier or qualifier at va_arg(va, (struct structure *)), and says that the type specifier defaults to int. It also notes instantiated form at (struct structure *) and struct structure *. This, what seems to be getting assigned to s is int (struct structure *). It compiles fine when parentheses are removed from (struct structure *), but the structures that are supposed to be initialized are inaccessible. Why is int assumed when parentheses are around the type argument passed to va_arg? How can I fix this?

  Read the article

• How to read data from file(.dat) in append mode

  - by govardhan

  We have an application which requires us to read data from a file (.dat) dynamically using deserialization. We are actually getting first object and it throws null pointer exception and "java.io.StreamCorruptedException:invalid type code:AC" when we are accessing other objects using a "for" loop. File file=null; FileOutputStream fos=null; BufferedOutputStream bos=null; ObjectOutputStream oos=null; try{ file=new File("account4.dat"); fos=new FileOutputStream(file,true); bos=new BufferedOutputStream(fos); oos=new ObjectOutputStream(bos); oos.writeObject(m); System.out.println("object serialized"); amlist=new MemberAccountList(); oos.close(); } catch(Exception ex){ ex.printStackTrace(); } Reading objects: try{ MemberAccount m1; file=new File("account4.dat");//add your code here fis=new FileInputStream(file); bis=new BufferedInputStream(fis); ois=new ObjectInputStream(bis); System.out.println(ois.readObject()); **while(ois.readObject()!=null){ m1=(MemberAccount)ois.readObject(); System.out.println(m1.toString()); }/*mList.addElement(m1);** // Here we have the issue throwing null pointer exception Enumeration elist=mList.elements(); while(elist.hasMoreElements()){ obj=elist.nextElement(); System.out.println(obj.toString()); }*/ } catch(ClassNotFoundException e){ } catch(EOFException e){ System.out.println("end"); } catch(Exception ex){ ex.printStackTrace(); }

  Read the article

< Previous Page | 184 185 186 187 188 189 190 191 192 193 194 195  | Next Page >