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• VB app to web service

  - by brandon

  I know very little about web service but I assumed it would be the solution I was looking for. Basically I made an application in VB that I want to be ubiquitous for a lack of a better word. I need it to receive requests from multiple users and respond all at once. I was told "technically if you write a webservice you can provide as many results back to users as are connected." Maybe there is another solution for me that will give me the results I want. Here is an example of what I'm trying to do. Lets say I make an application in VB that does math. I now make a website. My website allows for a person to input 1 + 1 they click submit and my website then connects to my VB application running on my server listening for a request. It accepts the request from my website, and then it solves the math problem and returns the answer back to the website "1 + 1 = 2" That is only an example of the type of thing I need. My problem is that I can't have multiple people visiting my website all connecting to that same application running on my server so somehow I need the application to be where it can be accessed by multiple users. I was told a web service would be the answer but if there is another solution I'd like to know. If the only solution is a web service, then how can I manage to either convert the VB app to a web service? Can I have to convert the app to asp.net or some other language? Is there an easier option?

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• Getting the full-name of the current user, returns an empty string (C#/C++)

  - by Nir

  I try to get the full-name of the current log-in user (Fullname, not username). The following code C#, C++ works fine but on XP computers not connected to the Net, I get empty string as result if I run it ~20 minutes after login (It runs OK whithin the first ~20 minutes after login) A Win32 API (GetUserNameEx) is used rather that PrincipalContext since it PrincipalContext may takes up to 15 seconds when working offline. Any Help why am I getting an empty string as result though a user full name is specified??? - C# Code public static string CurrentUserFullName { get { const int EXTENDED_NAME_FORMAT_NAME_DISPLAY = 3; StringBuilder userName = new StringBuilder(256); uint length = (uint) userName.Capacity; string ret; if (GetUserNameEx(EXTENDED_NAME_FORMAT_NAME_DISPLAY, userName, ref length)) { ret = userName.ToString(); } else { int errorCode = Marshal.GetLastWin32Error(); throw new Win32Exception("GetUserNameEx Failed. Error code - " + errorCode); } return ret; } } [DllImport("Secur32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern bool GetUserNameEx(int nameFormat, StringBuilder lpNameBuffer, ref uint lpnSize); - Code in C++ #include "stdafx.h" #include <windows.h> #define SECURITY_WIN32 #include <Security.h> #pragma comment( lib, "Secur32.lib" ) int _tmain(int argc, _TCHAR* argv[]) { char szName[100]; ULONG nChars = sizeof( szName ); if ( GetUserNameEx( NameDisplay, szName, &nChars ) ) { printf( "Name: %s\n", szName); } else { printf( "Failed to GetUserNameEx\n" ); printf( "%d\n", GetLastError() ); } return 0; }

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• Where to place interactive objects in JavaScript?

  - by Chris

  I'm creating a web based application (i.e. JavaScript with jQuery and lots of SVG) where the user interacts with "objects" on the screen (think of DIVs that can be draged around, resized and connected by arraows - like a vector drawing programm or a graphical programming language). As each "object" contains individual information but is allways belonging to a "class" of elements it's obvious that this application should be programmed by using an OOP approach. But where do I store the "objects" best? Should I create a global structure ("registry") with all (JS native) objects and tell them "draw yourself on the DOM"? Or should I avoid such a structure and think of the (relevant) DOM nodes as my objects and attach the relevant data as .data() to them? The first approach is very MVC - but I guess the attachment of all the event handlers will be non trivial. The second approach will handle the events in a trivial way and it doesn't create a duplicate structure, but I guess the usual OO stuff (like methods) will be more complex. What do you recomend? I think the answer will be JavaScript and SVG specific as "usual" programming languages don't have such a highly organized output "canvas".

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• Waiting for data via select not working

  - by BSchlinker

  I'm currently working on a project which involves multiple clients connected to a server and waiting for data. I'm using select and monitoring the connection for incoming data. However, the client just continues to print nothing, acting as if select has discovered incoming data. Perhaps I'm attacking this wrong? For the first piece of data the server does send, it is displayed correctly. However, the server then disconnects and the client continues to spew blank lines. FD_ZERO(&readnet); FD_SET(sockfd, &readnet); while(1){ rv = select(socketdescrip, &readnet, NULL, NULL, &timeout); if (rv == -1) { perror("select"); // error occurred in select() } else if (rv == 0) { printf("Connection timeout! No data after 10 seconds.\n"); } else { // one or both of the descriptors have data if (FD_ISSET(sockfd, &readnet)) { numbytes = recv(sockfd, buf, sizeof buf, 0); printf("Data Received\n"); buf[numbytes] = '\0'; printf("client: received '%s'\n",buf); sleep(10); } } }

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• How do I set an og:type for the first time without losing likes?

  - by Travis

  When I first created my site, I neglected to add the Open Graph tags that Facebook recommends (http://developers.facebook.com/docs/opengraph/), and the site now has about 1200 Facebook likes through a fb:comments widget. http://graph.facebook.com/http://feedtheanimalssamples.com/ shows this: { "id": "http://feedtheanimalssamples.com/", "shares": 1204 } Recently, I've added added the following OG tags: <meta property="fb:app_id" content="59193243341" /> <meta property="og:title" content="Girl Talk - Feed The Animals Samples (old)" /> <meta property="og:image" content="http://feedtheanimalssamples.com/fta_small.png" /> <meta property="og:url" content="http://feedtheanimalssamples.com" /> But when I add the og:type tag: <meta property="og:type" content="website" /> and Lint the site, I lose all my likes. http://graph.facebook.com/http://feedtheanimalssamples.com/ starts showing this: { "id": "170545342993850", "name": "Girl Talk - Feed The Animals Samples", "picture": "http://profile.ak.fbcdn.net/hprofile-ak-snc4/188039_170545342993850_3277642_s.jpg", "link": "http://www.facebook.com/pages/Girl-Talk-Feed-The-Animals-Samples/170545342993850", "category": "Website", "website": "http://feedtheanimalssamples.com/", "description": "Interactively identifies the samples in the 2008 album 'Feed The Animals' by mashup artist Girl Talk.", "likes": 1 } (Note the "likes": 1.) So: How do I set the og:type without losing my likes? I'm trying to let my likers know that I've created a new and improved site. I'm following the instuctions at http://developers.facebook.com/blog/post/397 under "Publishing to Connected Users via Graph API", but using that API apparently requires specifying an og:type. Thanks!

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• UDP security and identifying incoming data.

  - by Charles

  I have been creating an application using UDP for transmitting and receiving information. The problem I am running into is security. Right now I am using the IP/socketid in determining what data belongs to whom. However, I have been reading about how people could simply spoof their IP, then just send data as a specific IP. So this seems to be the wrong way to do it (insecure). So how else am I suppose to identify what data belongs to what users? For instance you have 10 users connected, all have specific data. The server would need to match the user data to this data we received. The only way I can see to do this is to use some sort of client/server key system and encrypt the data. I am curious as to how other applications (or games, since that's what this application is) make sure their data is genuine. Also there is the fact that encryption takes much longer to process than unencrypted. Although I am not sure by how much it will affect performance. Any information would be appreciated. Thanks.

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• Using proxy models

  - by smallB

  I've created Proxy model by subclassing QAbstractProxyModel and connected it as a model to my view. I also set up source model for this proxy model. Unfortunately something is wrong because I'm not getting anything displayed on my listView (it works perfectly when I have my model supplied as a model to view but when I supply this proxy model it just doesn't work). Here are some snippets from my code: #ifndef FILES_PROXY_MODEL_H #define FILES_PROXY_MODEL_H #include <QAbstractProxyModel> #include "File_List_Model.h" class File_Proxy_Model: public QAbstractProxyModel { public: explicit File_Proxy_Model(File_List_Model* source_model) { setSourceModel(source_model); } virtual QModelIndex mapFromSource(const QModelIndex & sourceIndex) const { return index(sourceIndex.row(),sourceIndex.column()); } virtual QModelIndex mapToSource(const QModelIndex & proxyIndex) const { return index(proxyIndex.row(),proxyIndex.column()); } virtual int columnCount(const QModelIndex & parent = QModelIndex()) const { return sourceModel()->columnCount(); } virtual int rowCount(const QModelIndex & parent = QModelIndex()) const { return sourceModel()->rowCount(); } virtual QModelIndex index(int row, int column, const QModelIndex & parent = QModelIndex()) const { return createIndex(row,column); } virtual QModelIndex parent(const QModelIndex & index) const { return QModelIndex(); } }; #endif // FILES_PROXY_MODEL_H //and this is a dialog class: Line_Counter::Line_Counter(QWidget *parent) : QDialog(parent), model_(new File_List_Model(this)), proxy_model_(new File_Proxy_Model(model_)), sel_model_(new QItemSelectionModel(proxy_model_,this)) { setupUi(this); setup_mvc_(); } void Line_Counter::setup_mvc_() { listView->setModel(proxy_model_); listView->setSelectionModel(sel_model_); }

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• how to get response from remote server

  - by ruhit

  I have made a desktop application in asp.net using c# that connecting with remote server.I am able to connect but how do i show that my login is successful or not. After that i want to retrieve data from the remote server..........so plz help me.I have written the below code..............is there any better way try { string strId = UserId_TextBox.Text; string strpasswrd = Password_TextBox.Text; ASCIIEncoding encoding = new ASCIIEncoding(); string postData = "UM_email=" + strId; postData += ("&UM_password=" + strpasswrd); byte[] data = encoding.GetBytes(postData); MessageBox.Show(postData); // Prepare web request... //HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("http://localhost/ruhit/basic_framework/index.php?menu=login=" + postData); HttpWebRequest myRequest =(HttpWebRequest)WebRequest.Create("http://www.facebook.com/login.php=" + postData); myRequest.Method = "POST"; myRequest.ContentType = "application/x-www-form-urlencoded"; myRequest.ContentLength = data.Length; Stream newStream = myRequest.GetRequestStream(); // Send the data. newStream.Write(data, 0, data.Length); MessageBox.Show("u r now connected"); HttpWebResponse response = (HttpWebResponse)myRequest.GetResponse(); // WebResponse response = myRequest.GetResponse(); StreamReader reader = new StreamReader(response.GetResponseStream()); string str = reader.ReadLine(); while (str != null) { str = reader.ReadLine(); MessageBox.Show(str); } reader.Close(); newStream.Close(); } catch { MessageBox.Show("error connecting"); }

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• Trying to edit an entity with data from dropdowns in MVC...

  - by user598352

  Hello! I'm having trouble getting my head around sending multiple models to a view in mvc. My problem is the following. Using EF4 I have a table with attributes organised by category. Couldn't post an image :-( [Have a table called attributes (AttributeTitle, AttributeName, CategoryID) connected to a table called Category (CategoryTitle).] What I want to do is be able to edit an attribute entity and have a dropdown of categories to choose from. I tried to make a custom viewmodel public class AttributeViewModel { public AttributeViewModel() { } public Attribute Attribute { get; set; } public IQueryable<Category> AllCategories { get; set; } } But it just ended up being a mess. <div class="editor-field"> <%: Html.DropDownList("Category", new SelectList((IEnumerable)Model.AllCategories, "CategoryID", "CategoryName")) %> </div> I was getting it back to the controller... [HttpPost] public ActionResult Edit(int AttributeID, FormCollection formcollection) { var _attribute = ProfileDB.GetAttribute(AttributeID); int _selcategory = Convert.ToInt32(formcollection["Category"]); _attribute.CategoryID = (int)_selcategory; try { UpdateModel(_attribute); (<---Error here) ProfileDB.SaveChanges(); return RedirectToAction("Index"); } catch (Exception e) { return View(_attribute); } } I've debugged the code and my _attribute looks correct and _attribute.CategoryID = (int)_selcategory updates the model, but then I get the error. Somewhere here I thought that there should be a cleaner way to do this, and that if I could only send two models to the view instead of having to make a custom viewmodel. To sum it up: I want to edit my attribute and have a dropdown of all of the available categories. Any help much appreciated!

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• Trouble tunneling my local Wordpress install to the mysql database on appfog

  - by alanmoo

  I've set up a wordpress install on appfog (using rackspace), and cloned the install to my local machine for development. I know the install works (using MAMP) because I created a local mysql database and changed wp-config.php to point to it. However, I want to develop without having to change wp-config.php every time I commit. After doing some research, it seems like the Appfog service Caldecott lets me tunnel into the mysql database on the server, using af tunnel. Unfortunately, I'm having issues with getting it working. Even if I change my MAMP mysql port to something like 8889, and tunnel mysql through port 3306, it looks like it's connected but I still get "Error establishing a database connection" when loading my localhost Wordpress. When I quit the mysql monitor (using ctrl+x, ctrl+c), I get a message stating "Error: 'mysql' execution failed; is it in your $PATH?'. Originally, no, it wasn't, but I've fixed my PATH variable on my local machine so that when I go to Terminal and just type mysql, it loads up. So I guess my question is 2 parts: 1.)Am I going with the right approach for Wordpress development on my local machine and 2.)If so, why is the tunnel not working?

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• Regularly update database without browser/user

  - by Chris M

  I currently have a MySQL database which I was hoping to use to store regularly updated data from a temperature sensor connected to the internet. I currently have a page that, when opened, will grab the current temperature and the current timestamp and add it as an entry to the database, but I was looking for a way to do that without me refreshing the page every 5 seconds. Detail: The data comes from an Arduino Ethernet, posted to an IP address. Currently, I'm using cURL to grab the data from the IP, add a timestamp and save it to the DB. Obviously only updates when the page is refreshed (it uses PHP). Here is a live feed of the data - http://wetdreams.org.uk/ChrisProject/UI/live_graph_two.html TL;DR - Basically I need a middle man to grab the data from the IP and post it to a MySQL Edit: Thanks for all the advice. There might be a little bit of confusion, I'm looking for a solution that (ideally) doesn't require a computer to be on at all (other than the Server containing Database). Since I'm looking to store data over long periods of time (weeks), I'd like to set it up and leave a script running on the server (or Arduino) that gets the temp and posts it to the Database. In my head I would like to have a page on the server that automatically (without any browser open, or any other prompting other than a timer) calls a PHP script. Hope that clears things up!

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• Javascript function with PHP throwing a "Illegally Formed XML Syntax" error

  - by Joe

  I'm trying to learn some javascript and i'm having trouble figuring out why my code is incorrect (i'm sure i'm doing something wrong lol), but anyways I am trying to create a login page so that when the form is submitted javascript will call a function that checks if the login is in a mysql database and then checks the validity of the password for the user if they exist. however I am getting an error (Illegally Formed XML Syntax) i cannot resolve. I'm really confused, mostly because netbeans is saying it is a xml syntax error and i'm not using xml. here is the code in question: function validateLogin(login){ login.addEventListener("input", function() { $value = login.value; if (<?php //connect to mysql mysql_connect(host, user, pass) or die(mysql_error()); echo("<script type='text/javascript'>"); echo("alert('MYSQL Connected.');"); echo("</script>"); //select db mysql_select_db() or die(mysql_error()); echo("<script type='text/javascript'>"); echo("alert('MYSQL Database Selected.');"); echo("</script>"); //query $result = mysql_query("SELECT * FROM logins") or die(mysql_error()); //check results against given login while($row = mysql_fetch_array($result)){ if($row[login] == $value){ echo("true"); exit(0); } } echo("false"); exit(0); ?>) { login.setCustomValidity("Invalid Login. Please Click 'Register' Below.") } else { login.setCustomValidity("") } }); } the code is in an external js file and the error throws on the last line. Also from reading i understand best practices is to not mix js and php so how would i got about separating them but maintaining the functionality i need? thanks!

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• How to detect a Socket disconnection?

  - by AngryHacker

  I've implemented a task using the async Sockets pattern in Silverlight 3. I started with Michael Schwarz's implementation and built on top of that. So basically, my Silverlight app establishes a persistent socket connection to a device and then data flows both ways as necessary between the device and the Silverlight app. One thing I am struggling with is how to detect disconnection. I could think of 2 approaches: Keep-Alive. I know this can be done at the Sockets level, but I am not sure how to do this in an async model. How would the Socket class let me know there has been a disconnection. Manual keep alive. Basically, I am having the Silverlight app send a dummy packet every 20 seconds or so. If it fails, I'd assume disconnection. However, incredibly, SocketAsyncEventArgs.SocketError always reports success, even if I simply unplug the device that the Silverlight app is connected to. I am not sure whether this is a bug or what or perhaps I need to upgrade to SL4. Any ideas, direction or implementation would be appreciated.

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• Modeling Buyers & Sellers in a Rails Ecommerce App

  - by MikeH

  I'm building a Rails app that has Etsy.com style functionality. In other words, it's like a mall. There are many buyers and many sellers. I'm torn about how to model the sellers. Key facts: There won't be many sellers. Perhaps less than 20 sellers in total. There will be many buyers. Hopefully many thousands :) I already have a standard user model in place with account creation and roles. I've created a 'role' of 'seller', which the admin will manually apply to the proper users. Since we'll have very few sellers, this is not an issue. I'm considering two approaches: (1) Create a 'store' model, which will contain all the relevant store information. Products would :belong_to :store, rather than belonging to the seller. The relationship between the user and store models would be: user :has_one store. My main problem with this is that I've always found has_one associations to be a little funky, and I usually try to avoid them. The app is fairly complex, and I'm worried about running into a cascade of problems connected to the has_one association as I get further along into development. (2) Simply include the relevant 'store' information as part of the user model. But in this case, the store-related db columns would only apply to a very small percentage of users since very few users will also be sellers. I'm not sure if this is a valid concern or not. It's very possible that I'm thinking about this incorrectly. I appreciate any thoughts. Thanks.

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• Cannot connect to MySQL server using JSP

  - by Dibya

  I just set foot on JSP. I started writing simple programs to display dates, system info. Then I tried to connect a MySQL database I have a free hosting account, but I am not able to connect to MySQL database. Here is my code: <%@ page import="java.sql.*" %> <%@ page import="java.io.*" %>  <html> <head> <title>Connection with mysql database</title> </head> <body> <h1>Connection status</h1> <% try { String connectionURL = "jdbc:mysql://mysql2.000webhost.com/a3932573_product"; Connection connection = null; Class.forName("com.mysql.jdbc.Driver").newInstance(); connection = DriverManager.getConnection(connectionURL, "a3932573_dibya", "******"); if(!connection.isClosed()) out.println("Successfully connected to " + "MySQL server using TCP/IP..."); connection.close(); }catch(Exception ex){ out.println("Unable to connect to database."); } %> </font> </body> </html> I am getting Message as Connection Status unable to connect to database. I have tested this connection using PHP using the same username, password and database name. Where am I making mistake?

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• How to iterate properly across a const set?

  - by Jared

  I'm working on a program that's supposed to represent a graph. My issue is in my printAdjacencyList function. Basically, I have a Graph ADT that has a member variable "nodes", which is a map of the nodes of that graph. Each Node has a set of Edge* to the edges it is connected to. I'm trying to iterate across each node in the graph and each edge of a node. void MyGraph::printAdjacencyList() { std::map<std::string, MyNode*>::iterator mit; std::set<MyEdge*>::iterator sit; for (mit = nodes.begin(); mit != nodes.end(); mit++ ) { std::cout << mit->first << ": {"; const std::set<MyEdge*> edges = mit->second->getEdges(); for (sit = edges.begin(); sit != edges.end(); sit++) { std::pair<MyNode*, MyNode*> edgeNodes = *sit->getEndpoints(); } } std::cout << " }" << std::endl; } getEdges is declared as: const std::set<MyEdge*>& getEdges() { return edges; }; and get Endpoints is declared as: const std::pair<MyNode*, MyNode*>& getEndpoints() { return nodes; }; The compiler error I'm getting is: MyGraph.cpp:63: error: request for member `getEndpoints' in `*(&sit)->std::_Rb_tree_const_iterator<_Tp>::operator-> [with _Tp = MyEdge*]()', which is of non-class type `MyEdge* const' MyGraph.cpp:63: warning: unused variable 'edgeNodes' I have figured out that this probably means I'm misusing const somewhere, but I can't figure out where for the life of me. Any information would be appreciated. Thanks!

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• java.lang.ClassNotFoundException: com.mysql.jdbc.Driver When run jar file

  - by user1024858

  Hi all, Connection conn = null; String url = "jdbc:mysql://localhost:3306/"; String dbName = "test"; String driver = "com.mysql.jdbc.Driver"; String userName = "root"; String password = "admin"; try { Class.forName(driver).newInstance(); conn = DriverManager.getConnection(url+dbName,userName,password); System.out.println("Connected to the database"); conn.close(); System.out.println("Disconnected from database"); } catch (Exception e) { e.printStackTrace();} I run in eclipse it's ok, but i built to jar file and run on command line java -jar Test.jar i get this error: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at java.net.URLClassLoader$1.run(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Unknown Source) Please help me how to fix it. Thanks!!!

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• What is the best way of doing this? (WCF 4)

  - by Jason Porter

  I have a multith-threaded, continusly running application that connects with multiple devices via TCP/IP sockets and exposes a set of WCF API's for controlling, monitoring and reporting on these devices. I would like to host this on IIS for the ususal reasons of not having to worry about re-starting the app in case of errors. So the issue I have is the main application running in parallel with the WCF Servies. To accomplish this I use the static AppInitialize class to start a thread which has the main applicaiton loop. The WCF services mostly report or control the shared objects with this thread. There are two problems that I see with this approach. One is that if the thread dies, IIS has no clue to re-start it so I have to play some tricks with some WCF calls. The other is that the backrgound thread deals with potentially thousands of devices that are connected permanently (typically a thread per socket connection). So I am not sure if IIS is buying me anything in this case. Another approach that I am thinking is to use WF for the main application that deals with the sockets and host both the WF and my WCF services in IIS using AppFabric. Since I have not use WF or AppFabric I am reaching out to see if this would be good approach or there are better alternative.

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• Android - save/restore state of custom class

  - by user1209216

  I have some class for ssh support - it uses jsch internally. I use this class on main activity, this way: public class MainActivity extends Activity { SshSupport ssh = new SshSupport(); ..... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //Handle events for ssh ssh.eventHandler = new ISshEvents() { @Override public void SshCommandExecuted(SshCommandsEnum commandType, String result) { } //other overrides here } //Ssh operations on gui item click @Override public void onItemClick(AdapterView<?> arg0, View v, int position, long arg3) { if (ssh.IsConnected() == false) { try { ssh.ConnectAsync(/*parameters*/); } catch (Exception e) { e.printStackTrace(); } } try { ssh.ExecuteCommandAsync(SshCommandsEnum.values()[position]); } catch (Exception e) { e.printStackTrace(); } } }); } It works very well. My application connects to ssh, performs all needed operation in background thread and results are reported to gui, via events as shown above. But nothing works after user change device orientation. It's clear for me - activity is re-created and all state is lost. Unfortunately, my SshSupport class object is lost as well. It's pretty easy to store gui state for dynamically changed/added objects (using put/get serializable etc methods). But I have no idea how to prevent my ssh object, ssh connected session being lost. Since my class is not serializable, I can't save it to bundle. Also, even if I make my SshSupport class serializable, jsch objects it uses still are not serializable. So what is the best way to solve this?

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• Flash browser game - HTTP + PHP vs Socket + Something else

  - by Maurycy Zarzycki

  I am developing a non-real time browser RPG game (think Kingdom of Loathing) which would be played from within a Flash app. At first I just wanted to make the communication with server using simply URLLoader to tell PHP what I am doing, and using $_SESSION to store data needed in-between request. I wonder if it wouldn't be better to base it on a socket connection, an app residing on a server written in Java or Python. The problem is I have never ever written such an app so I have no idea how much I'd have to "shift" my thoughts from simple responding do request (like PHP) to continuously working application. I won't hide I am also concerned about the memory and CPU usage of such Server app, when for example there would be hundreds of users connected. I've done some research. I have tried to do some research, but thanks to my nil knowledge on the sockets subject I haven't found anything helpful. So, considering the fact I don't need real time data exchange, will it be wise to develop the server side part as socket server, not in plain ol' PHP?

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• How to identify multiple identical pairs in two vectors

  - by Sacha Epskamp

  In my graph-package (as in graph theory, nodes connected by edges) I have a vector indicating for each edge the node of origin from, a vector indicating for each edge the node of destination to and a vector indicating the curve of each edge curve. By default I want edges to have a curve of 0 if there is only one edge between two nodes and curve of 0.2 if there are two edges between two nodes. The code that I use now is a for-loop, and it is kinda slow: curve <- rep(0,5) from<-c(1,2,3,3,2) to<-c(2,3,4,2,1) for (i in 1:length(from)) { if (any(from==to[i] & to==from[i])) { curve[i]=0.2 } } So basically I look for each edge (one index in from and one in to) if there is any other pair in from and to that use the same nodes (numbers). What I am looking for are two things: A way to identify if there is any pair of nodes that have two edges between them (so I can omit the loop if not) A way to speed up this loop # EDIT: To make this abit clearer, another example: from <- c(4L, 6L, 7L, 8L, 1L, 9L, 5L, 1L, 2L, 1L, 10L, 2L, 6L, 7L, 10L, 4L, 9L) to <- c(1L, 1L, 1L, 2L, 3L, 3L, 4L, 5L, 6L, 7L, 7L, 8L, 8L, 8L, 8L, 10L, 10L) cbind(from,to) from to [1,] 4 1 [2,] 6 1 [3,] 7 1 [4,] 8 2 [5,] 1 3 [6,] 9 3 [7,] 5 4 [8,] 1 5 [9,] 2 6 [10,] 1 7 [11,] 10 7 [12,] 2 8 [13,] 6 8 [14,] 7 8 [15,] 10 8 [16,] 4 10 [17,] 9 10 In these two vectors, pair 3 is identical to pair 10 (both 1 and 7 in different orders) and pairs 4 and 12 are identical (both 2 and 8). So I would want curve to become: [1,] 0.0 [2,] 0.0 [3,] 0.2 [4,] 0.2 [5,] 0.0 [6,] 0.0 [7,] 0.0 [8,] 0.0 [9,] 0.0 [10,] 0.2 [11,] 0.0 [12,] 0.2 [13,] 0.0 [14,] 0.0 [15,] 0.0 [16,] 0.0 [17,] 0.0 (as I vector, I transposed twice to get row numbers).

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• C# Linq to SQL connection string (newbie)

  - by Chris'o

  i am a new linq to sql learner and this is my very first attempt to create a data viewer program. The idea is simple, i'd like to create a software that is able to view content of a table in a database. That's it. I got an early problem here already and i have seen many tutes and articles online but I still cant fix the bug. Here is my code: static void Main(string[] args) { string cs = "Data Source=localhost;Initial Catalog=somedb;Integrated Security=SSPI;"; var db = new DataClasses1DataContext(cs); db.Connection.Open(); foreach (var b in db.Mapping.GetTables()) Console.WriteLine(b.TableName); Console.ReadKey(true); } When I tried to check db.connection.equals(null); it returns false, so i thought i have connected successfully to the database since there is no error at all. But the code above doesn't print anything out to the screen. I kind of lost and don't know what's going on here. Does anyone know what is going wrong here?

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• passing reference of class to another class android error

  - by prolink007

  I recently asked the precursor to this question and had a great reply. However, when i was working this into my android application i am getting an unexpected error and was wondering if everyone could take a look at my code and help me see what i am doing wrong. Link to the initial question: passing reference of class to another class My ERROR: "The constructor ConnectDevice(new View.OnClickListener(){}) is undefined" The above is an error detected by eclipse. Thanks in advance! Below are My code snippets: public class SmartApp extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.intro); final Button connectDeviceButton = (Button) findViewById(R.id.connectDeviceButton); connectDeviceButton.setOnClickListener( new View.OnClickListener() { @Override public void onClick(View v) { Thread cThread = new Thread(new ConnectDevice(this)); cThread.start(); } }); } } public class ConnectDevice implements Runnable { private boolean connected; private SmartApp smartAppRef; private ObjectInputStream ois; public ConnectDevice(SmartApp smartAppRef) { this.smartAppRef = smartAppRef; } }

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• New to JEE; architecture suggestions for a service/daemon?

  - by Kate

  I am brand new to the JEE world. As an exercise to try and familiarize myself with JEE, I'm trying to create a tiered web-app, but I'm getting a little stuck on what the best way is to spin up a service in the background that does work. Parameters of the service: It must open and hold a socket connection and receive information from the connected server. There is a 1-to-1 correlation between a user and a new socket connection. So the idea is the user presses a button on the web-page, and somewhere on the server a socket connection is opened. For the remainder of the users session (or until the user presses some sort of disconnect button) the socket remains open and pushes received information to some sort of centralized store that servlets can query and return to the user via AJAX. Is there a JEE type way to handle this situation? Naturally what I would think to do is to just write a Java application that listens on a port that the servlets can connect to and spawns new threads that open these sockets, but that seems very ad-hoc to me. (PS: I am also new to Stack Overflow, so forgive me if it takes me some time to figure the site out!)

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• Can't open COM1 from application launched at startup

  - by n0rd

  I'm using WinLIRC with IR receiver connected to serial port COM1 on Windows 7 x64. WinLIRC is added to Startup folder (Start-All applications-Startup) so it starts every time I log in. Very often (but not all the time) I see initialization error messages from WinLIRC, which continue for some time (couple of minutes) if I retry initialization, and after some retries it initializes correctly and works fine. If I remove it from Startup and start manually at any other moment it starts without errors. I've downloaded WinLIRC sources and added MessageBox calls here and there so I can see what happens during initialization and found out that CreateFile call fails: if((hPort=CreateFile( settings.port,GENERIC_READ | GENERIC_WRITE, 0,0,OPEN_EXISTING,FILE_FLAG_OVERLAPPED,0))==INVALID_HANDLE_VALUE) { char buffer[256]; sprintf_s(buffer, "CreateFile(%s) failed with %d", settings.port, GetLastError()); MessageBox(NULL, buffer, "debug", MB_OK); hPort=NULL; return false; } I see message box saying "CreateFile(COM1) failed with 5", and 5 is an error code for "Access denied" error according to this link. So the question is why opening COM-port can fail with such error right after booting Windows and proceed normally few seconds or minutes later?

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