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  • import csv file/excel into sql database asp.net

    - by kiev
    Hi everyone! I am starting a project with asp.net visual studio 2008 / SQL 2000 (2005 in future) using c#. The tricky part for me is that the existing DB schema changes often and the import files columns will all have to me matched up with the existing db schema since they may not be one to one match on column names. (There is a lookup table that provides the tables schema with column names I will use) I am exploring different ways to approach this, and need some expert advice. Is there any existing controls or frameworks that I can leverage to do any of this? So far I explored FileUpload .NET control, as well as some 3rd party upload controls to accomplish the upload such as SlickUpload but the files uploaded should be < 500mb Next part is reading of my csv /excel and parsing it for display to the user so they can match it with our db schema. I saw CSVReader and others but for excel its more difficult since I will need to support different versions. Essentially The user performing this import will insert and/or update several tables from this import file. There are other more advance requirements like record matching but and preview of the import records, but I wish to get through understanding how to do this first. Update: I ended up using csvReader with LumenWorks.Framework for uploading the csv files.

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  • Null-free "maps": Is a callback solution slower than tryGet()?

    - by David Moles
    In comments to "How to implement List, Set, and Map in null free design?", Steven Sudit and I got into a discussion about using a callback, with handlers for "found" and "not found" situations, vs. a tryGet() method, taking an out parameter and returning a boolean indicating whether the out parameter had been populated. Steven maintained that the callback approach was more complex and almost certain to be slower; I maintained that the complexity was no greater and the performance at worst the same. But code speaks louder than words, so I thought I'd implement both and see what I got. The original question was fairly theoretical with regard to language ("And for argument sake, let's say this language don't even have null") -- I've used Java here because that's what I've got handy. Java doesn't have out parameters, but it doesn't have first-class functions either, so style-wise, it should suck equally for both approaches. (Digression: As far as complexity goes: I like the callback design because it inherently forces the user of the API to handle both cases, whereas the tryGet() design requires callers to perform their own boilerplate conditional check, which they could forget or get wrong. But having now implemented both, I can see why the tryGet() design looks simpler, at least in the short term.) First, the callback example: class CallbackMap<K, V> { private final Map<K, V> backingMap; public CallbackMap(Map<K, V> backingMap) { this.backingMap = backingMap; } void lookup(K key, Callback<K, V> handler) { V val = backingMap.get(key); if (val == null) { handler.handleMissing(key); } else { handler.handleFound(key, val); } } } interface Callback<K, V> { void handleFound(K key, V value); void handleMissing(K key); } class CallbackExample { private final Map<String, String> map; private final List<String> found; private final List<String> missing; private Callback<String, String> handler; public CallbackExample(Map<String, String> map) { this.map = map; found = new ArrayList<String>(map.size()); missing = new ArrayList<String>(map.size()); handler = new Callback<String, String>() { public void handleFound(String key, String value) { found.add(key + ": " + value); } public void handleMissing(String key) { missing.add(key); } }; } void test() { CallbackMap<String, String> cbMap = new CallbackMap<String, String>(map); for (int i = 0, count = map.size(); i < count; i++) { String key = "key" + i; cbMap.lookup(key, handler); } System.out.println(found.size() + " found"); System.out.println(missing.size() + " missing"); } } Now, the tryGet() example -- as best I understand the pattern (and I might well be wrong): class TryGetMap<K, V> { private final Map<K, V> backingMap; public TryGetMap(Map<K, V> backingMap) { this.backingMap = backingMap; } boolean tryGet(K key, OutParameter<V> valueParam) { V val = backingMap.get(key); if (val == null) { return false; } valueParam.value = val; return true; } } class OutParameter<V> { V value; } class TryGetExample { private final Map<String, String> map; private final List<String> found; private final List<String> missing; public TryGetExample(Map<String, String> map) { this.map = map; found = new ArrayList<String>(map.size()); missing = new ArrayList<String>(map.size()); } void test() { TryGetMap<String, String> tgMap = new TryGetMap<String, String>(map); for (int i = 0, count = map.size(); i < count; i++) { String key = "key" + i; OutParameter<String> out = new OutParameter<String>(); if (tgMap.tryGet(key, out)) { found.add(key + ": " + out.value); } else { missing.add(key); } } System.out.println(found.size() + " found"); System.out.println(missing.size() + " missing"); } } And finally, the performance test code: public static void main(String[] args) { int size = 200000; Map<String, String> map = new HashMap<String, String>(); for (int i = 0; i < size; i++) { String val = (i % 5 == 0) ? null : "value" + i; map.put("key" + i, val); } long totalCallback = 0; long totalTryGet = 0; int iterations = 20; for (int i = 0; i < iterations; i++) { { TryGetExample tryGet = new TryGetExample(map); long tryGetStart = System.currentTimeMillis(); tryGet.test(); totalTryGet += (System.currentTimeMillis() - tryGetStart); } System.gc(); { CallbackExample callback = new CallbackExample(map); long callbackStart = System.currentTimeMillis(); callback.test(); totalCallback += (System.currentTimeMillis() - callbackStart); } System.gc(); } System.out.println("Avg. callback: " + (totalCallback / iterations)); System.out.println("Avg. tryGet(): " + (totalTryGet / iterations)); } On my first attempt, I got 50% worse performance for callback than for tryGet(), which really surprised me. But, on a hunch, I added some garbage collection, and the performance penalty vanished. This fits with my instinct, which is that we're basically talking about taking the same number of method calls, conditional checks, etc. and rearranging them. But then, I wrote the code, so I might well have written a suboptimal or subconsicously penalized tryGet() implementation. Thoughts?

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  • what practical proofs are there about the Turing completeness of neural nets? what nns can execute c

    - by Albert
    I'm interested in the computational power of neural nets. It is generally accepted that recurrent neural nets are Turing complete. Now I was searching for some papers which proofs this. What I found so far: Turing computability with neural nets, Hava T. Siegelmann and Eduardo D. Sontag, 1991 I think this is only interesting from a theoretical point of view because it needs to have the neuron activity of infinite exactness (to encode the state somehow as a rational number). S. Franklin and M. Garzon, Neural computability This needs an unbounded number of neurons and also doesn't really seem to be that much practical. (Note that another question of mine tries to point out this kind of problem between such theoretical results and the practice.) I'm searching mostly for some neural net which really can execute some code which I can also simulate and test in practice. Of course, in practice, they would have some kind of limited memory. Does anyone know something like this?

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  • Platform Framework and Middle-ware

    - by Walidix
    I really want to fix the meanings of this terms.This is what I know about them: Platform: is an environment that allows an application to run and it is usually composite by hardware and software e.g. your machine with your OS installed on it. However some software stack are also called as platform like Java Platform. Framework: is design-oriented. That is, it defines a skeleton of an application type. Also it saves time by offering, through an API, the common functionalities that a kind of applications must implement. Moreover a Framework include a software components that manage the application life-cycle. Middle-ware: is a software that offers services to an application in order to let it inter-operates with other applications or supports different platforms. Middle-ware can be a part of a framework. Is there something wrong or missing ?

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  • Is it a good idea to use MySQL and Neo4j together?

    - by Sanoj
    I will make an application with a lot of similar items (millions), and I would like to store them in a MySQL database, because I would like to do a lot of statistics and search on specific values for specific columns. But at the same time, I will store relations between all the items, that are related in many connected binary-tree-like structures (transitive closure), and relation databases are not good at that kind of structures, so I would like to store all relations in Neo4j which have good performance for this kind of data. My plan is to have all data except the relations in the MySQL database and all relations with item_id stored in the Neo4j database. When I want to lookup a tree, I first search the Neo4j for all the item_id:s in the tree, then I search the MySQL-database for all the specified items in a query that would look like: SELECT * FROM items WHERE item_id = 45 OR item_id = 345435 OR item_id = 343 OR item_id = 78 OR item_id = 4522 OR item_id = 676 OR item_id = 443 OR item_id = 4255 OR item_id = 4345 Is this a good idea, or am I very wrong? I haven't used graph-databases before. Are there any better approaches to my problem? How would the MySQL-query perform in this case?

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  • Strange client's address returned throug accept(..) function.

    - by Negai
    Hi everyone, I'm a socket programming newbie. Here's a snippet: struct sockaddr_storage client_addr; ... client_addr_size = sizeof(client_addr); client_socket = accept( server_socket, (struct sockaddr *)&client_addr, &client_addr_size ); ... result = inet_ntop( AF_INET, &((struct sockaddr_in *)&client_addr)->sin_addr, client_addr_str, sizeof(client_addr_str) ); Whenever the client connects the address I get is 0.0.0.0 regardless from the host. Can anybody explain, what I'm doing wrong? Thanks.

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  • How do I create Ntlm Type 1 and Type 3 messages in .Net

    - by brj011
    I need to create Type 1 message and Type 3 message for NTLM handshaking. Is there any .Net API for this? Essentially, the application is WPF based, but Socket is used in order to stream data from the server. Use of socket is a technical requirement, but the problem is when user needs to connect to the server using a proxy server. Further, if the proxy authorization is based on Ntlm, the client application needs to create Type 1 and Type 3 messages in order to handshake with the proxy server. My question is: Is there any API already available in .NET libraries that can be consumed in order to create these different types of NTLM messages? Any help or alternatives will be greatly appreciated. Thanks in advance.

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  • testing the controller in asp.net mvc

    - by csetzkorn
    Hi, I would like to test the validation of submitted DTO. This is the bare bone of a controller create action: [AcceptVerbs(HttpVerbs.Post)] public RedirectToRouteResult Create(SomeDTO SomeDTO) { SomeObject SomeObject = null; try { SomeObject = this.RepositoryService.getSomeObjectRepository().Create(SomeDTO, this.RepositoryService); } catch (BrokenRulesException ex) { ex.AddModelStateErrors(ModelState, "Model"); } catch (Exception e) { ModelState.AddModelError("Exception", e.Message); } TempData["ViewData"] = ViewData; TempData["SomeDTO "] = SomeDTO; return ModelState.IsValid ? RedirectToAction("SomeObjectDetail", new { Id = SomeObject.Id }) : RedirectToAction("Form"); } The mechanics , although not relevant, is as follows: I have a strongly typed view = form which submits a dto to this action which either returns the form or the details page of the created object. I would like to unit test whether the Model contains certain key/errorMessage combinations given some invalid dto. Did someone do similar stuff? Any pointers would be very much appreciated. Thanks. Best wishes, Christian

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  • For distributed applications, which to use, ASIO vs. MPI?

    - by Rhubarb
    I am a bit confused about this. If you're building a distributed application, which in some cases may perform parallel operations (although not necessarily mathematical), should you use ASIO or something like MPI? I take it MPI is a higher level than ASIO, but it's not clear where in the stack one would begin.

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  • error 734 the ppp link control protocal was terminated

    - by satheesh
    Hi, i want to connect my mobile internet to pc using bluetooth device. I installed blue soleil software in my pc. Steps: 1.I can able to pair my cellphone with pc bluetooth device. 2.I selected my device and select bluetooth dialup networking service. 3.It asks an alert "DUN connection with device?" in my mobile. 4.After Clicked "YES", connect bluetooth DUN connection window opens. 5.In that window there was a fields "User Name", "PassWord" which i leave empty and then in "Dial = 99**1#" and click Dial button. 6.After that it say "Registering your computer on the netwok.." and become fails. 7. The Error is as "error 734 the ppp link control protocal was terminated" The same procedure should be followed for Nokia 3110c it works fine.But in my samsung mobile c3053 it not connected also i am tryig with samsung corby pro BT3510 mobile . Is there any settings changes needed for samsung mobiles ? Can anyone help me ? Thanks in advance...........

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  • length of captured packets more than MTU

    - by kumar
    Hi, I m running iperf between two machines (linux) and I can observe the mtu of both the interfaces connected is 1500. I ran tcpdump to capture packets and I observed some packets have "length as 2962"....how come this is possible with mtu as only 1500? Please clarify. Thanks! Note: flags field is set as DF. and proto is TCP

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  • Can I Automap a tree hierarchy with Fluent NHibernate?

    - by NakChak
    Is it possible to auto map a simple nested object structure? Something like this: public class Employee : Entity { public Employee() { this.Manages = new List<Employee>(); } public virtual string FirstName { get; set; } public virtual string LastName { get; set; } public virtual bool IsLineManager { get; set; } public virtual Employee Manager { get; set; } public virtual IList<Employee> Manages { get; set; } } It causes the following error at run time: Repeated column in mapping for collection: SharpKtulu.Core.Employee.Manages column: EmployeeFk Is it possible to automap this sort of structure, or do I have override the auto mapper for this sort of structure?

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  • c windows connect() fails. error 10049

    - by Joshua Moore
    The following two pieces of code compile, but I get a connect() failed error on the client side. (compiled with MinGW). Client Code: // thanks to cs.baylor.edu/~donahoo/practical/CSockets/code/TCPEchoClientWS.c #include <stdio.h> #include <winsock.h> #include <stdlib.h> #define RCVBUFSIZE 32 // size of receive buffer void DieWithError(char *errorMessage); int main(int argc, char* argv[]) { int sock; struct sockaddr_in echoServAddr; unsigned short echoServPort; char *servIP; char *echoString; char echoBuffer[RCVBUFSIZE]; int echoStringLen; int bytesRcvd, totalBytesRcvd; WSAData wsaData; if((argc < 3) || (argc > 4)){ fprintf(stderr, "Usage: %s <Sever IP> <Echo Word> [<Echo Port>]\n", argv[0]); exit(1); } if (argc==4) echoServPort = atoi(argv[3]); // use given port if any else echoServPort = 7; // echo is well-known port for echo service if(WSAStartup(MAKEWORD(2, 0), &wsaData) != 0){ // load winsock 2.0 dll fprintf(stderr, "WSAStartup() failed"); exit(1); } // create reliable, stream socket using tcp if((sock=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) DieWithError("socket() failed"); // construct the server address structure memset(&echoServAddr, 0, sizeof(echoServAddr)); echoServAddr.sin_family = AF_INET; echoServAddr.sin_addr.s_addr = inet_addr(servIP); // server IP address echoServAddr.sin_port = htons(echoServPort); // establish connection to the echo server if(connect(sock, (struct sockaddr*)&echoServAddr, sizeof(echoServAddr)) < 0) DieWithError("connect() failed"); echoStringLen = strlen(echoString); // determine input length // send the string, includeing the null terminator to the server if(send(sock, echoString, echoStringLen, 0)!= echoStringLen) DieWithError("send() sent a different number of bytes than expected"); totalBytesRcvd = 0; printf("Received: "); // setup to print the echoed string while(totalBytesRcvd < echoStringLen){ // receive up to the buffer size (minus 1 to leave space for a null terminator) bytes from the sender if(bytesRcvd = recv(sock, echoBuffer, RCVBUFSIZE-1, 0) <= 0) DieWithError("recv() failed or connection closed prematurely"); totalBytesRcvd += bytesRcvd; // keep tally of total bytes echoBuffer[bytesRcvd] = '\0'; printf("%s", echoBuffer); // print the echo buffer } printf("\n"); closesocket(sock); WSACleanup(); exit(0); } void DieWithError(char *errorMessage) { fprintf(stderr, "%s: %d\n", errorMessage, WSAGetLastError()); exit(1); } Server Code: // thanks cs.baylor.edu/~donahoo/practical/CSockets/code/TCPEchoServerWS.c #include <stdio.h> #include <winsock.h> #include <stdlib.h> #define MAXPENDING 5 // maximum outstanding connection requests #define RCVBUFSIZE 1000 void DieWithError(char *errorMessage); void HandleTCPClient(int clntSocket); // tcp client handling function int main(int argc, char **argv) { int serverSock; int clientSock; struct sockaddr_in echoServerAddr; struct sockaddr_in echoClientAddr; unsigned short echoServerPort; int clientLen; // length of client address data structure WSAData wsaData; if (argc!=2){ fprintf(stderr, "Usage: %s <Server Port>\n", argv[0]); exit(1); } echoServerPort = atoi(argv[1]); if(WSAStartup(MAKEWORD(2, 0), &wsaData)!=0){ fprintf(stderr, "WSAStartup() failed"); exit(1); } // create socket for incoming connections if((serverSock=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))<0) DieWithError("socket() failed"); // construct local address structure memset(&echoServerAddr, 0, sizeof(echoServerAddr)); echoServerAddr.sin_family = AF_INET; echoServerAddr.sin_addr.s_addr = htonl(INADDR_ANY); // any incoming interface echoServerAddr.sin_port = htons(echoServerPort); // local port // bind to the local address if(bind(serverSock, (struct sockaddr*)&echoServerAddr, sizeof(echoServerAddr) )<0) DieWithError("bind() failed"); // mark the socket so it will listen for incoming connections if(listen(serverSock, MAXPENDING)<0) DieWithError("listen() failed"); for (;;){ // run forever // set the size of the in-out parameter clientLen = sizeof(echoClientAddr); // wait for a client to connect if((clientSock = accept(serverSock, (struct sockaddr*)&echoClientAddr, &clientLen)) < 0) DieWithError("accept() failed"); // clientSock is connected to a client printf("Handling client %s\n", inet_ntoa(echoClientAddr.sin_addr)); HandleTCPClient(clientSock); } // NOT REACHED } void DieWithError(char *errorMessage) { fprintf(stderr, "%s: %d\n", errorMessage, WSAGetLastError()); exit(1); } void HandleTCPClient(int clientSocket) { char echoBuffer[RCVBUFSIZE]; // buffer for echostring int recvMsgSize; // size of received message // receive message from client if((recvMsgSize = recv(clientSocket, echoBuffer, RCVBUFSIZE, 0) <0)) DieWithError("recv() failed"); // send received string and receive again until end of transmission while(recvMsgSize > 0){ // echo message back to client if(send(clientSocket, echoBuffer, recvMsgSize, 0)!=recvMsgSize) DieWithError("send() failed"); // see if there's more data to receive if((recvMsgSize = recv(clientSocket, echoBuffer, RCVBUFSIZE, 0)) <0) DieWithError("recv() failed"); } closesocket(clientSocket); // close client socket } How can I fix this?

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  • Avoiding mass propagation of properties and events for exposure to ViewModels.

    - by firoso
    I have an MVVM application I am developing that is to the point where I'm ready to start putting together a user interface (my client code is largely functional) I'm now running into the issue that I'm trying to get my application data to where I need it so that it can be consumed by the view model and then bound to the view. Unfortunately, it seems that I've either got a few structural oversights, or I'm just going to have to face the reality that I need to be propogating events and raising excessive amounts of errors to notify view models that thier properties have changed. Let me go into some examples of my issue: I have a class "Unit" contained in a class "Test", contained in a class "Session" contained in a class "TestManager" which is contained in "TestDataModel" which is utilized by "TestViewModel" which is databound to by my "TestView" .... WHOA. Now, consider that Unit (the bottom of the heiarchy) has a property called "Results" that is updated periodically, I want to expose that to my viewmodel and then databind it to my view, trouble is, the only way I can really think to do this is to perpetuate events WAY up a chain that say "I've been updated!" and then request the new value... This seems like an aweful way to do this. Alternatively, I could register a static event and raise it, and have the appropriate "Unit view model" grab the event and request the update. This SEEMS better... but... static events? Is that a taboo idea? Also, having an expression like: TestDataModel.TestManager.Session.Test.Unit.Results[i] Seems REALLY gross to have on a View Model. I know this all reeks of a bad design issue, but I can't figure out what I did wrong? Should I be using more singleton/container controlled lifetimes type objects? Register object instances with static helper containers? Obviously these are hard questions to answer without being intimate with the existing structure, but if you've run into situations like this, what did you do to refactor? Should I just live with this, add mass events, and propogate them?

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  • Best practice in Rails when editing scaffold made pages

    - by abegbg
    I have a best practice question. I have two classes, company and category. They have a many-to-many relationship. When clicking a category I shall go to a page showing all companies with the chosen category. Pretty straight forward. My question is: Should I list all the companies on the companies/index.html.erb after filtering the companies in the controller? or Should I list all the companies on the categories/show.html.erb page? or Should I do a completely new page, since it doesn't really fit into any of the two above? Do you generally make a new page when your goal doesn't fit the scaffold made pages or do you use them quite freely? I am working/learning alone with rails, so there are a lot of best practice questions popping up all the time. Cheers Carl

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  • Spring MVC: should service layer be returning operation specific DTO's ?

    - by arrages
    In my Spring MVC application I am using DTO in the presentation layer in order to encapsulate the domain model in the service layer. The DTO's are being used as the spring form backing objects. hence my services look something like this: userService.storeUser(NewUserRequestDTO req); The service layer will translate DTO - Domain object and do the rest of the work. Now my problem is that when I want to retrieve a DTO from the service to perform say an Update or Display I can't seem to find a better way to do it then to have multiple methods for the lookup that return different DTO's like... EditUserRequestDTO userService.loadUserForEdit(int id); DisplayUserDTO userService.loadUserForDisplay(int id); but something does not feel right about this approach. The reason do have separate DTO's is that DisplayUserDTO is strongly typed to be read only and also there are many properties of user that are entities from a lookup table in the db (like city and state) so the DisplayUserDTO would have the string description of the properties while the EditUserRequestDTO will have the id's that will back the select drop down lists in the forms. What do you think? thanks

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  • Does Mobile phone have Server : Port Scheme ?

    - by MilkBottle
    Hi I hope I can get all the help i can get here. I am new to mobile phone programming. I find networking very interesting and I have this question: Does Mobile phone like WinMo or other phone have Server:Port scheme and what are the ports ? To show what I mean, I use PC to demonstarte, there are many ports ( restricted and established ). The below is the Server : Port scheme Server : port example WebServer 80 So, to use a TCPListener on PC , I can use any port as long as there are not restricted and establsihed) to listen incoming TcpClient . 2) How do I use a TCPListener and Which portNo I need to use to listen incoming TcpClient from the other end in Net Compact Framework? Thanks

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  • Dynamically find other hosts in a LAN in Java

    - by Federico Cristina
    A while ago I developed a little LAN chat app. in Java which allows chatting with other hosts, send images, etc. Although it was created just for fun, now it's being used where I work. Currently, there is no "chat server" on the app. where each client registers, updates it's status, etc. (I liked the idea of symmetric design and not depending on a server running on some other machine). Instead, each host is a client/server which has a hosts.properties file with the hostname of the other hosts, and - for instance - broadcasts to each one of them when sending a massive message/image/whatever. In the beginning there were just a couple of hosts, so this hosts.properties file wasn't an issue. But as the amount of users increased, the need of updating that file was a bit daunting. So now I've decided to get rid of it, and each time the app. starts, dynammically find the other active hosts. However, I cannot find the correct way of implement this. I've tried starting different threads, each one of them searching for other hosts in a known range of IP addresses. Something like this (simplified for the sake of readability): /** HostsLocator */ public static void searchForHosts(boolean waitToEnd) { for (int i=0; i < MAX_IP; i+= MAX_IP / threads) { HostsLocator detector = new HostsLocator(i, i+(MAX_IP / threads - 1)); // range: from - to new Thread(detector).start(); } } public void run() { for (int i=from; i<=to; i++) findHosts( maskAddress + Integer.toString(i) ); } public static boolean findHosts(String IP) { InetAddress address = InetAddress.getByName(IP); if ( address.isReachable(CONNECTION_TIME_OUT) ) // host found! } However: With a single thread and a low value in CONNECTION_TIME_OUT (500ms) I get wrong Host Not Found status for for hosts actually active. With a high value in CONNECTION_TIME_OUT (5000ms) and only one single thread takes forever to end With several threads I've also found problems similar like the first one, due to collisions. So... I guess there's a better way of solving this problem but I couldn't find it. Any advice? Thanks!

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  • What is a 'better' approach to query/save from server: DTO or Wcf Data Services?

    - by bonefisher
    From my perspective, the Data Services and their query approach is useful when querying simple object graphs from your server-side domain model. But when you want to query complex dependencies I couldn't create anything good out of it. The classic DTO approach is fine-grained and can handle everything, but the downside is that you have to create Dto classes for every type of server-request which is time consuming and you have to synchronize the Dto type with your domain entity/business logic.

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