Search Results

Search found 15777 results on 632 pages for 'desktop computers'.

Page 589/632 | < Previous Page | 585 586 587 588 589 590 591 592 593 594 595 596  | Next Page >

  • iPhone AVAudioPlayer failed to find codec

    - by Anthony
    Hello, I am writing an app that downloads a wav file from a server and needs to play that file. The files use the mulaw codec with 2:1 compression. These wav files are dynamically created by a seperate process so there is no way for me to preconvert the files to a different format or codec, I need to be able to play them as is. I am using an AVAudioPlayer instance initialized as follows: NSURL *audioURL = [[NSURL alloc] initWithString:@"http://xxx.../file.wav"]; NSData *audioData = [[NSData alloc] initWithContentsOfURL:audioURL]; AVAudioPlayer *audio = [[AVAudioPlayer alloc] initWithData:audioData error:nil]; [audio play]; However, when the play method executes, I get the following Console Output when executing on the Simulator: AudioQueue codec policy 1: failed to find a codec of the requested type I also tried saving the downloaded data to a local file and using a file URL, however that yeilds the same results. The downloaded file does play fine on both Mac and Windows based desktop media players. The SDK docs state that the mulaw codec is supported on the iPhone, so I am unsure why it is failing to find it. Any assistance would be greatly appreciated. Thanks.

    Read the article

  • Ultra-Portable Laptop or Tablet PC for Development and Sketching

    - by Nelson LaQuet
    I am a software developer that primarily writes in PHP, [X]HTML, CSS, Javascript, C# and C++. I use Eclipse for web development, Visual Studio 2008 for C++ and C# work, TortoiseSVN, Subversion server for local repositories, SQL Server Express, Apache and MYSQL. I also use Office 2007 for word processing and spreadsheets and use Vista Ultimate 64 as my primary operating system. The only other things I do on my laptop are watch movies, surf the internet and listen to music. I currently have a Acer Aspire 5100 (1.4 GHz AMD Turion X2, 2 GB of RAM and a 15.4" screen). This thing does not cut it in performance or portability, and in addition, my DVD drive failed. And before anybody posts about vista: I have had XP Professional 32 on it for the last two years, and recently upgraded to Vista 64. It is actually faster (with areo disabled) then XP; so it is not the OS that is causing the laptop to be slow. I usually sketch a lot, for explaining things, developing user interfaces and software architecture. Because of my requirements, I was thinking about a Lenovo X61 Tablet PC. It outperforms my current laptop, is significantly more portable, and... is a tablet. My question is: do any other software developers use this (or other tablets) for programming? Does it help to be able to sketch on the computer itself? And is it capable of being a good development machine? Will it handle the above software listed? If not, what is the best ultra-portable laptop that is good for programming? Or are ultra-portable laptops even good for programming? I could manage with my 15.4" screen, but am spoiled by my two 19" at my home desktop and my job's workstation.

    Read the article

  • How to publish internal data to the internet - as simple as possible

    - by mlarsen
    We have a .net 2-tier application where a desktop program is talking to a database. We support MS SQL Server 2000, 2005, 2008 and Oracle 9, 10 and 11. The application is sold, not as shrink-wrap, but pretty close. It is quite important for us that the installation and configuration is as easy as possible as installation instructions are usually supplied in written form to the customers internal IT-department. Our application is usually not seen as mission critical for the IT-department, so we need to keep their work down to a minimum. Now we are starting to get wishes for a web application build on top of the same data. The web application will be hosted by us and delivered as a SaaS application. Now the challenge is how to move data back and forth between the web application and the customers internal database. as I see it we have some requirements: We must be ready to handle the situation where the customers database is not accessible from the DMZ. I guess the easiest solution is that all communication is initiated from inside the customers lan. As little firewall configuration as possible. The best is if we can run without any special configuration as long as outgoing traffic from the customers lan are not blocked. If we need something changed in the firewall, we must be able to document that the change is secure. It doesn't have to be real time. Moving data in batches every ten minutes or so is OK. Data moves both ways, but not the same tables, so we don't have to support merges. It would be nice if we don't have to roll our own framework completely. Looking forward to hear your suggestions.

    Read the article

  • My cocoa app won't capture key events

    - by Oscar
    Hi, i usually develop for iPhone. But now trying to make a pong game in Cocoa desktop application. Working out pretty well, but i can't find a way to capture key events. Here's my code: #import "PongAppDelegate.h" #define GameStateRunning 1 #define GameStatePause 2 #define BallSpeedX 10 #define BallSpeedY 15 @implementation PongAppDelegate @synthesize window, leftPaddle, rightPaddle, ball; - (void)applicationDidFinishLaunching:(NSNotification *)aNotification { gameState = GameStateRunning; ballVelocity = CGPointMake(BallSpeedX, BallSpeedY); [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(gameLoop) userInfo:nil repeats:YES]; } - (void)gameLoop { if(gameState == GameStateRunning) { [ball setFrameOrigin:CGPointMake(ball.frame.origin.x + ballVelocity.x, ball.frame.origin.y + ballVelocity.y)]; if(ball.frame.origin.x + 15 > window.frame.size.width || ball.frame.origin.x < 0) { ballVelocity.x =- ballVelocity.x; } if(ball.frame.origin.y + 35 > window.frame.size.height || ball.frame.origin.y < 0) { ballVelocity.y =- ballVelocity.y; } } } - (void)keyDown:(NSEvent *)theEvent { NSLog(@"habba"); // Arrow keys are associated with the numeric keypad if ([theEvent modifierFlags] & NSNumericPadKeyMask) { [window interpretKeyEvents:[NSArray arrayWithObject:theEvent]]; } else { [window keyDown:theEvent]; } } - (void)dealloc { [ball release]; [rightPaddle release]; [leftPaddle release]; [super dealloc]; } @end

    Read the article

  • How can we serialize a class that is not a custom class of our own?

    - by Doug
    I need to look at the properties of an object and I cannot instantiate this object in the proper state on my dev machine. I need my client to run some code on her machine, serialize the object in question to disk and then I can analyze the file. Here is the class I want to serialize. System.Security.AccessControl.RegistrySecurity Here is my code: Private Sub SerializeRegSecurity(ByVal regKey As RegistryKey) Try Dim regSecurity As System.Security.AccessControl.RegistrySecurity = regKey.GetAccessControl() Dim oXS As XmlSerializer = New XmlSerializer(GetType(System.Security.AccessControl.RegistrySecurity)) Dim oStmW As StreamWriter Dim regDebugFilePath As String = Path.Combine(My.Computer.FileSystem.SpecialDirectories.Desktop, "RegDebugFile.xml") 'Serialize object to XML and write it to XML file oStmW = New StreamWriter(regDebugFilePath) oXS.Serialize(oStmW, regSecurity) oStmW.Close() Catch ex As Exception Console.WriteLine(ex.ToString) End Try End Sub And here's what I end up with in my XML file: <?xml version="1.0" encoding="utf-8"?> Any ideas on how to accomplish what I am trying to do? How can we serialize a class that is not a custom class of our own? Thanks for ANY help. Even an alternate method.

    Read the article

  • g++ linker can't find const member function

    - by Max
    I have a Point class (with integer members x and y) that has a member function withinBounds that is declared like so: bool withinBounds(const Point&, const Point&) const; and defined like this: bool Point::withinBounds(const Point& TL, const Point& BR) const { if(x < TL.getX()) return false; if(x > BR.getX()) return false; if(y < TL.getY()) return false; if(y > BR.getY()) return false; // Success return true; } and then in another file, I call withinBounds like this: Point pos = currentPlayer->getPosition(); if(pos.withinBounds(topleft, bottomright)) { // code block } This compiles fine, but it fails to link. g++ gives me this error: /home/max/Desktop/Development/YARL/yarl/src/GameData.cpp:61: undefined reference to 'yarl::utility::Point::withinBounds(yarl::utility::Point const&, yarl::utility::Point const&)' When I make the function not const, it links fine. Anyone know the reason why? The linker error looks like it's looking for a non-const version of the function, but I don't know why it would.

    Read the article

  • Linux: modpost does not build anything

    - by waffleman
    I am having problems getting any kernel modules to build on my machine. Whenever I build a module, modpost always says there are zero modules: MODPOST 0 modules To troubleshoot the problem, I wrote a test module (hello.c): #include <linux/module.h> /* Needed by all modules */ #include <linux/kernel.h> /* Needed for KERN_INFO */ #include <linux/init.h> /* Needed for the macros */ static int __init hello_start(void) { printk(KERN_INFO "Loading hello module...\n"); printk(KERN_INFO "Hello world\n"); return 0; } static void __exit hello_end(void) { printk(KERN_INFO "Goodbye Mr.\n"); } module_init(hello_start); module_exit(hello_end); Here is the Makefile for the module: obj-m = hello.o KVERSION = $(shell uname -r) all: make -C /lib/modules/$(KVERSION)/build M=$(shell pwd) modules clean: make -C /lib/modules/$(KVERSION)/build M=$(shell pwd) clean When I build it on my machine, I get the following output: make -C /lib/modules/2.6.32-27-generic/build M=/home/waffleman/tmp/mod-test modules make[1]: Entering directory `/usr/src/linux-headers-2.6.32-27-generic' CC [M] /home/waffleman/tmp/mod-test/hello.o Building modules, stage 2. MODPOST 0 modules make[1]: Leaving directory `/usr/src/linux-headers-2.6.32-27-generic' When I make the module on another machine, it is successful: make -C /lib/modules/2.6.24-27-generic/build M=/home/somedude/tmp/mod-test modules make[1]: Entering directory `/usr/src/linux-headers-2.6.24-27-generic' CC [M] /home/somedude/tmp/mod-test/hello.o Building modules, stage 2. MODPOST 1 modules CC /home/somedude/tmp/mod-test/hello.mod.o LD [M] /home/somedude/tmp/mod-test/hello.ko make[1]: Leaving directory `/usr/src/linux-headers-2.6.24-27-generic' I looked for any relevant documentation about modpost, but found little. Anyone know how modpost decides what to build? Is there an environment that I am possibly missing? BTW here is what I am running: uname -a Linux waffleman-desktop 2.6.32-27-generic #49-Ubuntu SMP Wed Dec 1 23:52:12 UTC 2010 i686 GNU/Linux

    Read the article

  • using a database and deploying the application

    - by evan
    I have a WPF application that stores a large amount of information in XML files and as the user uses the application they add more information to the XML files. It's basically using the XML files as a database. Since over the life of the program the XML files have gotten quite large, and I've been think about putting the data on a website, I've been looking into how to move all the information into an SQL database. I've used SQL databases with web applications (PHP, Ruby, and ASP.NET) but never with a Desktop application. Ideally I'd like to be able to keep all the information in one database file and distribute it along with the application without requiring the user to connect to a remote database (so they don't need an internet connection - though eventually it would be nice if could compare the local file's version with one online somewhere and update if necessary) and without making them install a local database server on their computer. Is this possible? I'd also like to use LINQ with any new database solution so switching to a database doesn't force to many changes (I read the XML with LINQ). I'm sure this question has been asked and that there are already some good tutorials on the subject but I just can't find them.

    Read the article

  • Creating Emulated iSCSI Target in a Lab/Testing Environment using Windows Server 2008 R2

    - by Brian McCleary
    We have a single server running Windows Server 2008 with Hyper-V installed running 5 virtual machines. I have purchased a second DELL R805 Server so that we can create a fail-over cluster to our current R805 that is currently in production. Right now, our R805 connects via iSCSI to a MD3000i iSCSI SAN. Before we try to roll out the second server and clustering to our production environment, I want to be able to test and "play with" the clustering features in our lab before rolling it out. The problem is that I don't want to spend a couple thousand dollars on another iSCSI SAN server just for testing. I already have two servers in my lab that are installed with Windows Server 2008 R2 64bit (one is the R805 and another spare desktop that was laying around) and with the Hyper-V roll enabled that should be ready to test with, but I don't have an iSCSI target to use as the Cluster Shared Volume. Is there anyway to install, either on a Hyper-V image or on a external spare computer that we have some sort of emulated iSCSI target? In our lab, we obviously don't need a real SAN, just something that we can test out how to setup the clustering properly outside of our production environment. Any advise is appreciated. FYI - I have read Jose Barret's blog on WUDSS at http://blogs.technet.com/josebda/archive/2008/01/07/installing-the-evaluation-version-of-wudss-2003-refresh-and-the-microsoft-iscsi-software-target-version-3-1-on-a-vm.aspx, but it seems awfully complex. I'm hoping for an easier solution.

    Read the article

  • Opening a pdf in .NET

    - by link664
    In the application we are working on we are trying to implement Help. We have a help pdf document and for the moment it has been deemed acceptable that when users click the help button it just opens the pdf. The application is a desktop app and the pdf file needs to be included in the install somehow and installed on the local machine. I essentially need two things: How would I add this pdf to the application so that it is available on the client machine after install? I can either put it in the resources of the project, or else I could put it in the Application Folder of the client setup installer. How would I open this pdf? I can either open this pdf by just launching the default pdf viewer for the file, or I can use the System.WinForms.WebBrowser tool to display it. However if I choose the second option, I am unsure of how to access the file stored in the resources or find it in the install folder. If you could please provide me with the code to do this (either in VB.Net or C#.Net) that would be great.

    Read the article

  • Advantages/Disadvantages of AIR vs Flex/Web

    - by Lizzan
    Hi all, I'm tasked with writing an application for placing and connecting objects (sort of like a room planner where you can place furniture). I've made a demo using Flash Builder 4 and built it for AIR as a desktop app. Now the client wants the full app, but they and I am unsure whether to continue building it as an AIR app or transform it to a web application using Flex. I tried making a simple conversion of the AIR app to a web app, and most things worked but not all. The things that don't work seem to be simple bugs, though, not complete lack of capability. The capabilities that I'm going to need (except for the modelling) are: Printing of the finished image + a list of the furniture that has been placed A way to save and retrieve finished plans A way to export the list of furniture to Excel format Handling a whole slew of data about the different objects Only the printing has been implemented so far, and seems to work in the web app as well. What advantages/disadvantages are there with the two approaches? Are any of the capabilities I need much worse (or even impossible) to implement in either approach?

    Read the article

  • Adding an ADO.NET Entity Data Model throws build errors

    - by user3726262
    I am using Visual Studio 2013 express. I create a new project and then I add a database to that project. But, when I add an ADO.NET Entity Framework model to that project and then run the program, I get the following four build errors listed below. To try to remedy this myself, I added the namespaces 'System.Data.Entity' and 'System.Data.Entity.Design', but that didn't help. Also, I uninstalled and re-installed the Nuget package. I also uninstalled and re-installed Visual Studio 2013 Express for Windows Desktop. But these measures didn't help the situation either. Please note that I used to use the Entity Data model just fine. But it was around the time that I did a system restore on my computer, and when I updated VS 2013 with an update offered on the start page, and finally, when I signed up for MS Azure, that I started running into the problem described above. Now I would think that uninstalling and reinstalling Visual Studio 2013, and then installing the 'Nuget' Package would solve all problems. What am I missing here? The errors mentioned above are: Error 1 The type or namespace name 'Infrastructure' does not exist in the namespace 'System.Data.Entity' (are you missing an assembly reference?) C:\Users\John\documents\visual studio 2013\Projects\Riches\Riches\RichesModel.Context.cs 14 30 DataLayer Error 2 The type or namespace name 'DbContext' could not be found (are you missing a using directive or an assembly reference?) C:\Users\John\documents\visual studio 2013\Projects\Riches\Riches\RichesModel.Context.cs 16 52 DataLayer Error 3 The type or namespace name 'DbModelBuilder' could not be found (are you missing a using directive or an assembly reference?) C:\Users\John\documents\visual studio 2013\Projects\Riches\Riches\RichesModel.Context.cs 23 49 DataLayer Error 4 The type or namespace name 'DbSet' could not be found (are you missing a using directive or an assembly reference?) C:\Users\John\documents\visual studio 2013\Projects\Riches\Riches\RichesModel.Context.cs 28 16 DataLayer Thank you and I realize that my last attempt at this question was rather rough-draftish, John

    Read the article

  • JAVA - Download PDF file from Webserver

    - by Augusto Picciani
    I need to download a pdf file from a webserver to my pc and save it locally. I used Httpclient to connect to webserver and get the content body: HttpEntity entity=response.getEntity(); InputStream in=entity.getContent(); String stream = CharStreams.toString(new InputStreamReader(in)); int size=stream.length(); System.out.println("stringa html page LENGTH:"+stream.length()); System.out.println(stream); SaveToFile(stream); Then i save content in a file: //check CRLF (i don't know if i need to to this) String[] fix=stream.split("\r\n"); File file=new File("C:\\Users\\augusto\\Desktop\\progetti web\\test\\test2.pdf"); PrintWriter out = new PrintWriter(new FileWriter(file)); for (int i = 0; i < fix.length; i++) { out.print(fix[i]); out.print("\n"); } out.close(); I also tried to save a String content to file directly: OutputStream out=new FileOutputStream("pathPdfFile"); out.write(stream.getBytes()); out.close(); But the result is always the same: I can open pdf file but i can see white pages only. Does the mistake is around pdf stream and endstream charset encoding? Does pdf content between stream and endStream need to be manipulate in some others way?

    Read the article

  • What do we log and why do we log it?

    - by Lucas
    This has been bugging me for quite some time. Reading various questions on SO, blogs and listening to colleagues, I keep hearing how important "logging" is. How various logging frameworks stack up against each other, and how there are so many to pick from it's (apparently) ridiculous. Now, I know what logging is. What I don't know is what is supposed to be logged and why. Sure, I can guess. Exceptions? Sounds like something one might want to log... but which exceptions? And is it only exceptions? And what do I do with the logged information? If it's an in-house app, then that could probably be put to good use, but if it's a commercial desktop application, how is the log of... whatever... helping anyone? I doubt regular users would be peeking inside. Is it then something you ask the users to provide on request? I'm deeply frustrated by my own ignorance in this. It's also surprising how little information there is about this. The info on the websites of the various logging frameworks is all written for an audience that already knows what it wants to log, and knows why it needs to do so. Same things goes for the various discussions on SO about logging, like for instance this highly voted up question on Logging best practices. For a question with so many votes, it's almost comical how there's next to nothing in there that would answer my what and why questions. So being finally fed up, I'm asking here: what do people log, and why do they log it?

    Read the article

  • Downloading a picture via urllib and python.

    - by Mike
    So I'm trying to make a Python script that downloads webcomics and puts them in a folder on my desktop. I've found a few similar programs on here that do something similar, but nothing quite like what I need. The one that I found most similar is right here (http://bytes.com/topic/python/answers/850927-problem-using-urllib-download-images). I tried using this code: >>> import urllib >>> image = urllib.URLopener() >>> image.retrieve("http://www.gunnerkrigg.com//comics/00000001.jpg","00000001.jpg") ('00000001.jpg', <httplib.HTTPMessage instance at 0x1457a80>) I then searched my computer for a file "00000001.jpg", but all I found was the cached picture of it. I'm not even sure it saved the file to my computer. Once I understand how to get the file downloaded, I think I know how to handle the rest. Essentially just use a for loop and split the string at the '00000000'.'jpg' and increment the '00000000' up to the largest number, which I would have to somehow determine. Any reccomendations on the best way to do this or how to download the file correctly? Thanks!

    Read the article

  • How to benchmark on multi-core processors

    - by Pascal Cuoq
    I am looking for ways to perform micro-benchmarks on multi-core processors. Context: At about the same time desktop processors introduced out-of-order execution that made performance hard to predict, they, perhaps not coincidentally, also introduced special instructions to get very precise timings. Example of these instructions are rdtsc on x86 and rftb on PowerPC. These instructions gave timings that were more precise than could ever be allowed by a system call, allowed programmers to micro-benchmark their hearts out, for better or for worse. On a yet more modern processor with several cores, some of which sleep some of the time, the counters are not synchronized between cores. We are told that rdtsc is no longer safe to use for benchmarking, but I must have been dozing off when we were explained the alternative solutions. Question: Some systems may save and restore the performance counter and provide an API call to read the proper sum. If you know what this call is for any operating system, please let us know in an answer. Some systems may allow to turn off cores, leaving only one running. I know Mac OS X Leopard does when the right Preference Pane is installed from the Developers Tools. Do you think that this make rdtsc safe to use again? More context: Please assume I know what I am doing when trying to do a micro-benchmark. If you are of the opinion that if an optimization's gains cannot be measured by timing the whole application, it's not worth optimizing, I agree with you, but I cannot time the whole application until the alternative data structure is finished, which will take a long time. In fact, if the micro-benchmark were not promising, I could decide to give up on the implementation now; I need figures to provide in a publication whose deadline I have no control over.

    Read the article

  • SharpDevelop WIX project: MSBuild Configurations

    - by chezy525
    Using SharpDevelop, I wrote a windows service with a WIX setup project to install/auto-start it. For testing purposes, I've done a number of things I don't want to do in the release version (i.e. add an uninstall shortcut to the desktop). So, my question really boils down to this; how do you handle build configurations within a WiX project? I think I've solved most of my problems after I found this question Passing build parameters to .wxs file to dynamicaly build wix installers. And thus far I've done the following: Added a property that checks the Configuration variable <Product> ... <Property Id="DEBUG">$(var.Configuration) == 'Debug'</Property> ... Separated all of the debug files into unique components and setup as a separate feature with a condition checking the DEBUG property. <Product> ... <Feature> ... <Feature Id="DebugFiles" Level="1"> <ComponentRef Id="UninstallShortcutComponent" /> <Condition Level="0">DEBUG</Condition> </Feature> ... Then, finally, pointing to the correct file based on the configuration, using the Configuration variable <Directory> ... <Component> <File Source="..\mainProject\bin\$(var.Configuration)\main.exe" /> </Component> ... So, now my question is simplified to how to handle files that may not exist under certain build configurations (like .pdb files). Using all of the above (including pointing the file source to the ...\bin\Release\*.pdb, which I know isn't expected to exist) I get a LGHT0103 compiler error, it can't find the file.

    Read the article

  • What languages should a microISV use to write commercial software?

    - by Wal
    I've been writing software in Java for many years now, but it was always for internal applications that would be deployed to a server. I'd like to get into writing desktop applications now but I don't know where to start. I've written a few Java/Swing applications but again they were for internal use. My understanding is that Java and other semi-compiled and interpreted languages are too easy to reverse engineer, making them unsuitable for commercial software. I am aware that there are compilers for Java and some other interpreted language, but I've also heard that they are pricey and/or unreliable. Assuming I start a microISV and wish to develop and sell applications to a broad audience, what's my best bet? I would prefer something that can be written close to once, and compiled for different operating systems but I am not opposed to .NET and a Windows-only audience if other languages would compromise the experience (installation ease & user experience) in Windows. My only issue there is that I don't have a large starting budget and paying out the wazoo for the required development tools is not really in the cards.

    Read the article

  • How to restrict a content of string to less than 4MB and save that string in DB using C#

    - by Pranay B
    I'm working on a project where I need to get the Text data from pdf files and dump the whole text in a DB column. With the help of iTextsharp, I got the data and referred it String. But now I need to check whether the string exceeds the 4MB limit or not and if it is exceeding then accept the string data which is less than 4MB in size. This is my code: internal string ReadPdfFiles() { // variable to store file path string filePath = null; // open dialog box to select file OpenFileDialog file = new OpenFileDialog(); // dilog box title name file.Title = "Select Pdf File"; //files to be accepted by the user. file.Filter = "Pdf file (*.pdf)|*.pdf|All files (*.*)|*.*"; // set initial directory of computer system file.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop); // set restore directory file.RestoreDirectory = true; // execute if block when dialog result box click ok button if (file.ShowDialog() == DialogResult.OK) { // store selected file path filePath = file.FileName.ToString(); } //file path /// use a string array and pass all the pdf for searching //String filePath = @"D:\Pranay\Documentation\Working on SSAS.pdf"; try { //creating an instance of PdfReader class using (PdfReader reader = new PdfReader(filePath)) { //creating an instance of StringBuilder class StringBuilder text = new StringBuilder(); //use loop to specify how many pages to read. //I started from 5th page as Piyush told for (int i = 5; i <= reader.NumberOfPages; i++) { //Read the pdf text.Append(PdfTextExtractor.GetTextFromPage(reader, i)); }//end of for(i) int k = 4096000; //Test whether the string exceeds the 4MB if (text.Length < k) { //return the string text1 = text.ToString(); } //end of if } //end of using } //end try catch (Exception ex) { MessageBox.Show(ex.Message, "Please Do select a pdf file!!", MessageBoxButtons.OK, MessageBoxIcon.Warning); } //end of catch return text1; } //end of ReadPdfFiles() method Do help me!

    Read the article

  • JPA - Entity design problem

    - by Yatendra Goel
    I am developing a Java Desktop Application and using JPA for persistence. I have a problem mentioned below: I have two entities: Country City Country has the following attribute: CountryName (PK) City has the following attribute: CityName Now as there can be two cities with same name in two different countries, the primaryKey for City table in the datbase is a composite primary key composed of CityName and CountryName. Now my question is How to implement the primary key of the City as an Entity in Java @Entity public class Country implements Serializable { private String countryName; @Id public String getCountryName() { return this.countryName; } } @Entity public class City implements Serializable { private CityPK cityPK; private Country country; @EmbeddedId public CityPK getCityPK() { return this.cityPK; } } @Embeddable public class CityPK implements Serializable { public String cityName; public String countryName; } Now as we know that the relationship from Country to City is OneToMany and to show this relationship in the above code, I have added a country variable in City class. But then we have duplicate data(countryName) stored in two places in the City class: one in the country object and other in the cityPK object. But on the other hand, both are necessary: countryName in cityPK object is necessary because we implement composite primary keys in this way. countryName in country object is necessary because it is the standard way of showing relashionship between objects. How to get around this problem?

    Read the article

  • how to multithread on a python server

    - by user3732790
    HELP please i have this code import socket from threading import * import time HOST = '' # Symbolic name meaning all available interfaces PORT = 8888 # Arbitrary non-privileged port s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print ('Socket created') s.bind((HOST, PORT)) print ('Socket bind complete') s.listen(10) print ('Socket now listening') def listen(conn): odata = "" end = 'end' while end == 'end': data = conn.recv(1024) if data != odata: odata = data print(data) if data == b'end': end = "" print("conection ended") conn.close() while True: time.sleep(1) conn, addr = s.accept() print ('Connected with ' + addr[0] + ':' + str(addr[1])) Thread.start_new_thread(listen,(conn)) and i would like it so that when ever a person comes onto the server it has its own thread. but i can't get it to work please someone help me. :_( here is the error code: Socket created Socket bind complete Socket now listening Connected with 127.0.0.1:61475 Traceback (most recent call last): File "C:\Users\Myles\Desktop\test recever - Copy.py", line 29, in <module> Thread.start_new_thread(listen,(conn)) AttributeError: type object 'Thread' has no attribute 'start_new_thread' i am on python version 3.4.0 and here is the users code: import socket #for sockets import time s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print('Socket Created') host = 'localhost' port = 8888 remote_ip = socket.gethostbyname( host ) print('Ip address of ' + host + ' is ' + remote_ip) #Connect to remote server s.connect((remote_ip , port)) print ('Socket Connected to ' + host + ' on ip ' + remote_ip) while True: message = input("> ") #Set the whole string s.send(message.encode('utf-8')) print ('Message send successfully') data = s.recv(1024) print(data) s.close

    Read the article

  • Serialize Forms into memory

    - by serhio
    Background: In a desktop MDI application we have a lot of forms. Task: Save the controls contents of closed forms(textbox texts, checkbox checks etc). Limitations: A saved form for (DB/Windows) user? For (DB/Windows) group of users? Both variants may be possible. Question: a) What is the best way? b) if I want do not use files, how to serialize the form into a MemoryStream and then recuperate it if the opening form was been once opened and serialized? StartingPoint: Implemented a form that implements ISerializable. Deserialize the form on opening, serialize onclosing: Public Sub GetObjectData(ByVal info As System.Runtime.Serialization.SerializationInfo, ByVal context As System.Runtime.Serialization.StreamingContext) Implements System.Runtime.Serialization.ISerializable.GetObjectData info.AddValue("tbxExportFolder", tbxExportFolder.Text, GetType(String)) info.AddValue("cbxCheckAliasUnicity", cbxCheckAliasUnicity.Checked, GetType(Boolean)) End Sub Public Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext) Me.New() Me.tbxExportFolder.Text = info.GetString("tbxExportFolder") Me.cbxCheckAliasUnicity.Checked = info.GetBoolean("cbxCheckAliasUnicity") End Sub Private Sub SerializeMe() Dim binFormatter As New Formatters.Binary.BinaryFormatter Dim fileStream As New FileStream(SerializedFilename, FileMode.Create) Try binFormatter.Serialize(fileStream, Me) Catch Throw Finally fileStream.Close() End Try End Sub Protected Overrides Sub OnClosing(ByVal e As System.ComponentModel.CancelEventArgs) SerializeMe() MyBase.OnClosing(e) End Sub

    Read the article

  • Failure remediation strategy for File I/O

    - by Brett
    I'm doing buffered IO into a file, both read and write. I'm using fopen(), fseeko(), standard ANSI C file I/O functions. In all cases, I'm writing to a standard local file on a disk. How often do these file I/O operations fail, and what should the strategy be for failures? I'm not exactly looking for stats, but I'm looking for a general purpose statement on how far I should go to handle error conditions. For instance, I think everyone recognizes that malloc() could and probably will fail someday on some user's machine and the developer should check for a NULL being returned, but there is no great remediation strategy since it probably means the system is out of memory. At least, this seems to be the approach taken with malloc() on desktop systems, embedded systems are different. Likewise, is it worth reattempting a file I/O operation, or should I just consider a failure to be basically unrecoverable, etc. I would appreciate some code samples demonstrating proper usage, or a library guide reference that indicates how this is to be handled. Any other data is, of course, welcome.

    Read the article

  • Why is a NullReferenceException thrown when a ToolStrip button is clicked twice with code in the `Click` event handler?

    - by Patrick
    I created a clean WindowsFormsApplication solution, added a ToolStrip to the main form, and placed one button on it. I've added also an OpenFileDialog, so that the Click event of the ToolStripButton looks like the following: private void toolStripButton1_Click(object sender, EventArgs e) { openFileDialog1.ShowDialog(); } I didn't change any other properties or events. The funny thing is that when I double-click the ToolStripButton (the second click must be quite fast, before the dialog opens), then cancel both dialogs (or choose a file, it doesn't really matter) and then click in the client area of main form, a NullReferenceException crashes the application (error details attached at the end of the post). Please note that the Click event is implemented while DoubleClick is not. What's even more strange that when the OpenFileDialog is replaced by any user-implemented form, the ToolStripButton blocks from being clicked twice. I'm using VS2008 with .NET3.5. I didn't change many options in VS (only fontsize, workspace folder and line numbering). Does anyone know how to solve this? It is 100% replicable on my machine, is it on others too? One solution that I can think of is disabling the button before calling OpenFileDialog.ShowDialog() and then enabling the button back (but it's not nice). Any other ideas? And now the promised error details: System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object." Source="System.Windows.Forms" StackTrace: at System.Windows.Forms.NativeWindow.WindowClass.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.PeekMessage(MSG& msg, HandleRef hwnd, Int32 msgMin, Int32 msgMax, Int32 remove) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(Form mainForm) at WindowsFormsApplication1.Program.Main() w C:\Users\Marchewek\Desktop\Workspaces\VisualStudio\WindowsFormsApplication1\Program.cs:line 20 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException:

    Read the article

  • Python 3.3 Webserver restarting problems

    - by IPDGino
    I have made a simple webserver in python, and had some problems with it before as described here: Python (3.3) Webserver script with an interesting error In that question, the answer was to use a While True: loop so that any crashes or errors would be resolved instantly, because it would just start itself again. I've used this for a while, and still want to make the server restart itself every few minutes, but on Linux for some reason it won't work for me. On windows the code below works fine, but on linux it keeps saying Handler class up here ... ... class Server: def __init__(self): self.server_class = HTTPServer self.server_adress = ('MY IP GOES HERE, or localhost', 8080) global httpd httpd = self.server_class(self.server_adress, Handler) self.main() def main(self): if count > 1: global SERVER_UP_SINCE HOUR_CHECK = int(((count - 1) * RESTART_INTERVAL) / 60) SERVER_UPTIME = str(HOUR_CHECK) + " MINUTES" if HOUR_CHECK > 60: minutes = int(HOUR_CHECK % 60) hours = int(HOUR_CHECK // 60) SERVER_UPTIME = ("%s HOURS, %s MINUTES" % (str(hours), str(minutes))) SERVING_ON_ADDR = self.server_adress SERVER_UP_SINCE = str(SERVER_UP_SINCE) SERVER_RESTART_NUMBER = count - 1 print(""" SERVER INFO ------------------------------------- SERVER_UPTIME: %s SERVER_UP_SINCE: %s TOTAL_FILES_SERVED: %d SERVING_ON_ADDR: %s SERVER_RESTART_NUMBER: %s \n\nSERVER HAS RESTARTED """ % (SERVER_UPTIME, SERVER_UP_SINCE, TOTAL_FILES, SERVING_ON_ADDR, SERVER_RESTART_NUMBER)) else: print("SERVER_BOOT=1\nSERVER_ONLINE=TRUE\nRESTART_LOOP=TRUE\nSERVING_ON_ADDR:%s" % str(self.server_adress)) while True: try: httpd.serve_forever() except KeyboardInterrupt: print("Shutting down...") break httpd.shutdown() httpd.socket.close() raise(SystemExit) return def server_restart(): """If you want the restart timer to be longer, replace the number after the RESTART_INTERVAL variable""" global RESTART_INTERVAL RESTART_INTERVAL = 10 threading.Timer(RESTART_INTERVAL, server_restart).start() global count count = count + 1 instance = Server() if __name__ == "__main__": global SERVER_UP_SINCE SERVER_UP_SINCE = strftime("%d-%m-%Y %H:%M:%S", gmtime()) server_restart() Basically, I make a thread to restart it every 10 seconds (For testing purposes) and start the server. After ten seconds it will say File "/home/username/Desktop/Webserver/server.py", line 199, in __init__ httpd = self.server_class(self.server_adress, Handler) File "/usr/lib/python3.3/socketserver.py", line 430, in __init__ self.server_bind() File "/usr/lib/python3.3/http/server.py", line 135, in server_bind socketserver.TCPServer.server_bind(self) File "/usr/lib/python3.3/socketserver.py", line 441, in server_bind self.socket.bind(self.server_address) OSError: [Errno 98] Address already in use As you can see in the except KeyboardInterruption line, I tried everything to make the server stop, and the program stop, but it will NOT stop. But the thing I really want to know is how to make this server able to restart, without giving some wonky errors.

    Read the article

< Previous Page | 585 586 587 588 589 590 591 592 593 594 595 596  | Next Page >