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  • Java Process.waitFor() and IO streams

    - by lynks
    I have the following code; String[] cmd = { "bash", "-c", "~/path/to/script.sh" }; Process p = Runtime.getRuntime().exec(cmd); PipeThread a = new PipeThread(p.getInputStream(), System.out); PipeThread b = new PipeThread(p.getErrorStream(), System.err); p.waitFor(); a.die(); b.die(); The PipeThread class is quite simple so I will include it in full; public class PipeThread implements Runnable { private BufferedInputStream in; private BufferedOutputStream out; public Thread thread; private boolean die = false; public PipeThread(InputStream i, OutputStream o) { in = new BufferedInputStream(i); out = new BufferedOutputStream(o); thread = new Thread(this); thread.start(); } public void die() { die = true; } public void run() { try { byte[] b = new byte[1024]; while(!die) { int x = in.read(b, 0, 1024); if(x > 0) out.write(b, 0, x); else die(); out.flush(); } } catch(Exception e) { e.printStackTrace(); } try { in.close(); out.close(); } catch(Exception e) { } } } My problem is this; p.waitFor() blocks endlessly, even after the subprocess has terminated. If I do not create the pair of PipeThread instances, then p.waitFor() works perfectly. What is it about the piping of io streams that is causing p.waitFor() to continue blocking? I'm confused as I thought the IO streams would be passive, unable to keep a process alive, or to make Java think the process is still alive.

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  • Passing filtering functions to Where() in LINQ-to-SQL

    - by Daniel
    I'm trying to write a set of filtering functions that can be chained together to progressively filter a data set. What's tricky about this is that I want to be able to define the filters in a different context from that in which they'll be used. I've gotten as far as being able to pass a very basic function to the Where() clause in a LINQ statement: filters file: Func<item, bool> returnTrue = (i) => true; repository file: public IQueryable<item> getItems() { return DataContext.Items.Where(returnTrue); } This works. However, as soon as I try to use more complicated logic, the trouble begins: filters file: Func<item, bool> isAssignedToUser = (i) => i.assignedUserId == userId; repository file: public IQueryable<item> getItemsAssignedToUser(int userId) { return DataContext.Items.Where(isAssignedToUser); } This won't even build because userId isn't in the same scope as isAssignedToUser(). I've also tried declaring a function that takes the userId as a parameter: Func<item, int, bool> isAssignedToUser = (i, userId) => i.assignedUserId == userId; The problem with this is that it doesn't fit the function signature that Where() is expecting: Func<item, bool> There must be a way to do this, but I'm at a loss for how. I don't feel like I'm explaining this very well, but hopefully you get the gist. Thanks, Daniel

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  • Problem in filtering records using Dataview (C#3.0)

    - by Newbie
    I have a data table . The data table is basically getting populated from excel sheet. And there are many excel sheets. Henceforth, I have written a utility method for accomplishing the same. Now in some of the excel sheets, there are date columns and in some it is not(only text/string). My function is populating the values properly into the datatable from the excell sheet. But there are many blank rows in the excel sheets some are filled with NULL , some with " ". So I need to filter those records (which are NULL or " " ) first before further processing. What I am after is to use a dataview and apply the filter over there. DataView dv = dataTable.DefaultView; dv.RowFilter = ColumnName + " <> ''"; Well by using metedata (GetOleDbSchemaTable(OleDbSchemaGuid.Columns, restrection)) I was able to get the column names from the excel sheet , so getting the column names is not an issue. But the problem is as I said in some Excel sheet there are date fileds some are not. So the Filter condition of the Dataview needs to be proper. If I apply the above logic, and if it encounters a Datafield, it is throwing error Cannot perform '<' operation on System.DateTime and System.String. Could you people please help me out? I need to filter columns(not known at compile time + their data types) which can have NULL and " " I am using C#3.0 Thanks

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  • NPE annotation scenarios and static-analysis tools for Java

    - by alex2k8
    Here is a number of code snippets that can throw NullPointerException. 01: public void m1(@Nullable String text) { System.out.print(text.toLowerCase()); // <-- expect to be reported. } 02: private boolean _closed = false; public void m1(@Nullable String text) { if(_closed) return; System.out.print(text.toLowerCase()); // <-- expect to be reported. } 03: public void m1(@NotNull String text) { System.out.print(text.toLowerCase()); } public @Nullable String getText() { return "Some text"; } public void m2() { m1(getText()); // <-- expect to be reported. } Different people have access to different static-analysis tools. It would be nice to collect information, what tools are able to detect and report the issues, and what are failing. Also, if you have your own scenarious, please, publish them. Here my results FindBugs (1.3.9): 01: Parameter must be nonnull but is marked as nullable 02: NOT reported 03: NOT reported IntelliJ IDE 9.0.2 (Community edition): 01: Method invocation text.toLowerCase() may produce java.lang.NullPointerException 02: Method invocation text.toLowerCase() may produce java.lang.NullPointerException 03: Argument getText() might be null

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  • Extending the .NET type system so the compiler enforces semantic meaning of primitive values in cert

    - by Drew Noakes
    I'm working with geometry a bit at the moment and am converting a lot between degrees and radians. Unfortunately, both of these are represented by double, so there's compile time warning/error if I try to pass a value in degrees where radians are expected. I believe F# has a compile-time solution for this (called units of measure.) I'd like to do something similar in C#. As another example, imagine a SQL library that accepts various query parameters as strings. It'd be good to have a way of enforcing that only clean strings were allowed to be passed in at runtime, and the only way to get a clean string was to pass through some SQL injection attack preventing logic. The obvious solution is to wrap the double/string/whatever in a new type to give it the type information the compiler needs. I'm curious if anyone has an alternative solution. If you do think wrapping is the only/best way, then please go into some of the downsides of the pattern (and any upsides I haven't mentioned too.) I'm especially concerned about the performance of abstracted primitive numeric types on my calculations at runtime.

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  • Web page database query optimization

    - by morpheous
    I am putting together a web page which is quite 'expensive' in terms of database hits. I don't want to start optimizing at this stage - though with me trying to hit a deadline, I may end up not optimizing at all. Currently the page requires 18 (that's right eighteen) hits to the db. I am already using joins, and some of the queries are UNIONed to minimize the trips to the db. My local dev machine can handle this (page is not slow) however, I feel if I release this into the wild, the number of queries will quickly overwhelm my database (MySQL). I could always use memcache or something similar, but I would much rather continue with my other dev work that needs to be completed before the deadline - at least retrieving the page works - its simply a matter of optimization now (if required). My question therefore is - is 18 db queries for a single page retrieval completely outrageous - (i.e. I should put everything on hold and optimize the hell of the retrieval logic), or shall I continue as normal, meet the deadline and release on schedule and see what happens? [Edit] Just to clarify, I have already done the 'obvious' things like using (single and composite) indexes for fields used in the queries. What I haven't yet done is to run a query analyzer to see if my indexes etc are optimal.

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  • Entity Framework in layered architecture

    - by Kamyar
    I am using a layered architecture with the Entity Framework. Here's What I came up with till now (All the projects Except UI are class library): Entities: The POCO Entities. Completely persistence ignorant. No Reference to other projects. Generated by Microsoft's ADO.Net POCO Entity Generator. DAL: The EDMX (Entity Model) file with the context class. (t4 generated). References: Entities BLL: Business Logic Layer. Will implement repository pattern on this layer. References: Entities, DAL. This is where the objectcontext gets populated: var ctx=new DAL.MyDBEntities(); UI: The presentation layer: ASP.NET website. References: Entities, BLL + a connection string entry to entities in the config file (question #2). Now my three questions: Is my layer discintion approach correct? In my UI, I access BLL as follows: var customerRep = new BLL.CustomerRepository(); var Customer = customerRep.GetByID(myCustomerID); The problem is that I have to define the entities connection string in my UI's web.config/app.config otherwise I get a runtime exception. IS defining the entities connectionstring in UI spoils the layers' distinction? Or is it accesptible in a muli layered architecture. Should I take any additional steps to perform chage tracking, lazy loading, etc (by etc I mean the features that Entity Framework covers in a conventional, 1 project, non POCO code generation)? Thanks and apologies for the lengthy question.

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  • Intermittent asp.net mvc exception: “A public action method ABC could not be found on controller XYZ

    - by Chris Schoon
    Hi, I'm getting an intermittent exception saying that asp.net mvc can’t find the action method. Here’s the exception: A public action method 'Fill' could not be found on controller 'Schoon.Form.Web.Controllers.ChrisController'. I think I have the routing set up correctly because this application works most of the time. Here is the controller’s action method. [ActionName("Fill")] [AcceptVerbs(HttpVerbs.Get | HttpVerbs.Post), UserIdFilter, DTOFilter] public ActionResult Fill(int userId, int subscriberId, DisplayMode? mode) { //… } The route: routes.MapRoute( "SchoonForm", "Form/Fill/{subscriberId}", new { controller = "ChrisController", action = "Fill" }, new { subscriberId = @"\d+" } ); And here is the stack: System.Web.HttpException: A public action method 'Fill' could not be found on controller 'Schoon.Form.Web.Controllers.ChrisController'. at System.Web.Mvc.Controller.HandleUnknownAction(String actionName) in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\Controller.cs:line 197 at System.Web.Mvc.Controller.ExecuteCore() in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\Controller.cs:line 164 at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\ControllerBase.cs:line 76 at System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\ControllerBase.cs:line 87 at System.Web.Mvc.MvcHandler.ProcessRequest(HttpContextBase httpContext) in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\MvcHandler.cs:line 80 at System.Web.Mvc.MvcHandler.ProcessRequest(HttpContext httpContext) in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\MvcHandler.cs:line 68 at System.Web.Mvc.MvcHandler.System.Web.IHttpHandler.ProcessRequest(HttpContext httpContext) in C:\dev\ThirdParty\MvcDev\src\SystemWebMvc\Mvc\MvcHandler.cs:line 104 at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) Here is an example of my filters they all work the same way: public class UserIdFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext filterContext) { const string Key = "userId"; if (filterContext.ActionParameters.ContainsKey(Key)) { filterContext.ActionParameters[Key] = // get the user id from session or cookie } base.OnActionExecuting(filterContext); } } Thanks, Chris

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  • Working with extra fields in an Inline form - save_model, save_formset, can't make sense of the diff

    - by magicrebirth
    Suppose I am in the usual situation where there're extra fields in the many2many relationship: class Person(models.Model): name = models.CharField(max_length=128) class Group(models.Model): name = models.CharField(max_length=128) members = models.ManyToManyField(Person, through='Membership') class Membership(models.Model): person = models.ForeignKey(Person) group = models.ForeignKey(Group) date_joined = models.DateField() invite_reason = models.CharField(max_length=64) # other models which are unrelated to the ones above.. class Trip(models.Model): placeVisited = models.ForeignKey(Place) visitor = models.ForeignKey(Person) pleasuretrip = models.Boolean() class Place(models.Model): name = models.CharField(max_length=128) I want to add some extra fields in the Membership form that gets displayed through the Inline. These fields basically are a shortcut to the instantiation of another model (Trip). Trip can have its own admin views, but these shortcuts are needed because when my project partners are entering 'Membership' data in the system they happen to have also the 'Trip' information handy (and also because some of the info in Membership can just be copied over to Trip etc. etc.). So all I want to have is two extra fields in the Membership Inline - placeVisited and pleasuretrip - which together with the Person instance will let me instantiate the Trip model in the background... I found out I can easily add extra fields to the inline view by defining my own form. But once the data have been entered, how and when to reference to them in order to perform the save operations I need to do? class MyForm(forms.ModelForm): place = forms.ModelChoiceField(required=False, queryset=Place.objects.all(), label="place",) pleasuretrip = forms.BooleanField(required=False, label="...") class MembershipInline(admin.TabularInline): model = Membership form = MyForm def save_model(self, request, obj, form, change): place = form.place pleasuretrip = form.pleasuretrip person = form.person .... # now I can create Trip instances with those data .... obj.save() class GroupAdmin(admin.ModelAdmin): model = Group .... inlines = (MembershipInline,) This doesn't seem to work... I'm also a bit puzzled by the save_formset method... maybe is that the one I should be using? Many thanks in advance for the help!!!!

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  • How to avoid shell execution of a Process?

    - by adeel amin
    When I start a process like process = Runtime.getRuntime().exec("gnome-terminal");, it starts shell execution. I want to stop shell execution and want to redirect I/O from process, can anybody tell how I can do this? My code is: public void start_process() { try { process= Runtime.getRuntime().exec("gnome-terminal"); pw= new PrintWriter(process.getOutputStream(),true); br=new BufferedReader(new InputStreamReader(process.getInputStream())); err=new BufferedReader(new InputStreamReader(process.getErrorStream())); } catch (Exception ioe) { System.out.println("IO Exception-> " + ioe); } } public void execution_command() { if(check==2) { try { boolean flag=thread.isAlive(); if(flag==true) thread.stop(); Thread.sleep(30); thread = new MyReader(br,tbOutput,err,check); thread.start(); }catch(Exception ex){ JOptionPane.showMessageDialog(null, ex.getMessage()+"1"); } } else { try { Thread.sleep(30); thread = new MyReader(br,tbOutput,err,check); thread.start(); check=2; }catch(Exception ex){ JOptionPane.showMessageDialog(null, ex.getMessage()+"1"); } } } private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: command=tfCmd.getText().toString().trim(); pw.println(command); execution_command(); } When I enter some command in textfield and press execute button, nothing is displayed on my output textarea, how I can stop shell execution and redirect input and output?

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  • SQL - Multiple join conditions using OR?

    - by Brandi
    I have a query that is using multiple joins. The goal is to say "Out of table A, give me all the customer numbers in which you can match table A's EmailAddress with either email_to or email_from of table B. Ignore nulls, internal emails, etc.". It seems like it would be better to use an or condition in the join than multiple joins since it is the same table. When I try to use AND/OR it does not give the behaviour I expect... AND finishes in a reasonable time, but yields no results (I know that there are matches, so it must be some flaw in my logic) and OR never finishes (I have to kill it). Here is example code to illustrate the question: --my original query SELECT DISTINCT a.CustomerNo FROM A a WITH (NOLOCK) LEFT JOIN B e WITH (NOLOCK) ON a.EmailAddress = e.email_from RIGHT JOIN B f WITH (NOLOCK) ON a.EmailAddress = f.email_to WHERE a.EmailAddress NOT LIKE '%@mydomain.___' AND a.EmailAddress IS NOT NULL AND (e.email_from IS NOT NULL OR f.email_to IS NOT NULL) Here is what I tried, (I am attempting logical equivalence): SELECT DISTINCT a.CustomerNo FROM A a WITH (NOLOCK) LEFT JOIN B e WITH (NOLOCK) ON a.EmailAddress = e.email_from OR a.EmailAddress = e.email_to WHERE a.EmailAddress NOT LIKE '%@mydomain.___' AND a.EmailAddress IS NOT NULL AND (e.email_from IS NOT NULL OR e.email_to IS NOT NULL) So my question is two-fold: Why does having AND in the above query work in a few seconds and OR goes for minutes and never completes? What am I missing to make a logically equivalent statement that has only one join?

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  • How to get a Class literal from a generically specific Class

    - by h2g2java
    There are methods like these which require Class literals as argument. Collection<EmpInfo> emps = SomeSqlUtil.select( EmpInfo.class, "select * from emps"); or GWT.create(Razmataz.class); The problem presents itself when I need to supply generic specific classes like EmpInfo<String> Razmataz<Integer> The following would be wrong syntax Collection<EmpInfo<String>> emps = SomeSqlUtil.select( EmpInfo<String>.class, "select * from emps"); or GWT.create(Razmataz<Integer>.class); Because you cannot do syntax like Razmataz<Integer>.class So, how would I be able to squeeze a class literal out of EmpInfo<String> Razmataz<Integer> so that I could feed them as arguments to methods requiring Class literals? Further info Okay, I confess that I am asking this primarily for GWT. I have a pair of GWT RPC interface Razmataz. (FYI, GWT RPC interface has to be defined in server-client pairs). I plan to use the same interface pair for communicating whether it be String, Integer, Boolean, etc. GWT.create(Razmataz) for Razmataz<T> complains that, since I did not specify T, GWT compiler treated it as Object. Then GWT compiler would not accept Object class. It needs to be more specific than being an Object. So, it seems there is no way for me to tell GWT.create what T is because a Class literal is a runtime concept while generics is a compile time concept, Right?

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  • Designing DAOs around a JSON API for iPhone Development

    - by Bob Spryn
    So I've been trying to design a clean way of grabbing data for my models in iPhone land. All the data for my application is coming from JSON API's. So right now when a VC needs some models, it does the JSON call itself (asynch) and when it receives the data, it builds the models. It works, but I'm trying to think of a cleaner method whereby the DAO's retrieve the information for me and return the models, all in an async manner. My initial thought is build a protocol for my DAOs, such that the VC would instantiate a DAO and make itself the delegate. When you requested data [DAOinstance getAllUsers] the DAO would do all the network request stuff, and then when it had the data, it would call a method on its delegate (the VC) to pass the data. So I think that's a cool solution, but realized that if I needed to use the same DAO for different purposes in the same VC, my delegate method would have to branch logic depending on which DAO instance initiated the request. So my second thought was to be able to pass 'handler' selectors to the DAO object a la typical javascript patterns. So instead of an official protocol, I would say something like [DAOinstance getAllUsersWithSelector:"TheHandlerFunctionOnMyVC:"] Then when the DAO completed its network activities, it would call the passed selector on the VC, and pass the data back. So am I headed in the wrong direction entirely here? Seems like maybe an ok way to go. Any pointers or articles on designing this kind of data layer would be sweet. Thanks! Bob

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  • Windsor IHandlerSelector in RIA Services Visual Studio 2010 Beta2

    - by Savvas Sopiadis
    Hi everybody! I want to implement multi tenancy using Windsor and i don't know how to handle this situation: i succesfully used this technique in plain ASP.NET MVC projects and thought incorporating in a RIA Services project would be similar. So i used IHandlerSelector, registered some components and wrote an ASP.NET MVC view to verify it works in a plain ASP.NET MVC environment. And it did! Next step was to create a DomainService which got an IRepository injected in the constructor. This service is hosted in the ASP.NET MVC application. And it actually ... works:i can get data out of it to a Silverlight application. Sample snippet: public OrganizationDomainService(IRepository<Culture> cultureRepository) { this.cultureRepository = cultureRepository; } Last step is to see if it works multi-tenant-like: it does not! The weird thing is this: using some line of code and writing debug messages in a log file i verified that the correct handler is selected! BUT this handler seems not to be injected in the DomainService. I ALWAYS get the first handler (that's the logic in my SelectHandler) Can anybody verify this behavior? Is injection not working in RIA Services? Or am i missing something basic?? Development environment: Visual Studio 2010 Beta2 Thanks in advance

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  • javascript equivalent of ASP preInit event

    - by Pankaj Kumar
    Hi guys, searching for this has yielded no resuts.. i have a middle page that has an iframe and all the pages open in that iframe...i have to implement a chat system just like in Google and so to ensure that the chat windows did not close whwn the page would postback i am opening all pages in iframe.... this is a social networking site and user can have themes which have background images per theme now when i visit a friends profile the backgrounf image of the middle page should change... i have this code to find parent of iframe and change background image $(document).ready(function(){ var theme=document.getElementById("ctl00_decideFooterH").value; var t= parent.document.getElementsByTagName("body"); if(theme=='basicTheme'){ t[0].className="basic"; } else if(theme=='Tranquility') { t[0].className="Tranquility"; } else if(theme=='AbstractPink') { t[0].className="abstractPink"; } }); and this code is the master page that all child pages that would open in iframe would access..the trouble is that there is a lag between the theme application on server side(which happens at PreInit) and the background image change which is done by this document.ready that gets executed after the iframe has loaded.. so essentially i need a javascript function that would either execute parallel to PreInit or some other logic....so guys plz help its urgent

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  • Java Binary Tree. Priting InOrder traversal

    - by user69514
    I am having some problems printing an inOrder traversal of my binary tree. Even after inserting many items into the tree it's only printing 3 items. public class BinaryTree { private TreeNode root; private int size; public BinaryTree(){ this.size = 0; } public boolean insert(TreeNode node){ if( root == null) root = node; else{ TreeNode parent = null; TreeNode current = root; while( current != null){ if( node.getData().getValue().compareTo(current.getData().getValue()) <0){ parent = current; current = current.getLeft(); } else if( node.getData().getValue().compareTo(current.getData().getValue()) >0){ parent = current; current = current.getRight(); } else return false; if(node.getData().getValue().compareTo(parent.getData().getValue()) < 0) parent.setLeft(node); else parent.setRight(node); } } size++; return true; } /** * */ public void inOrder(){ inOrder(root); } private void inOrder(TreeNode root){ if( root.getLeft() !=null) this.inOrder(root.getLeft()); System.out.println(root.getData().getValue()); if( root.getRight() != null) this.inOrder(root.getRight()); } }

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  • simple image upload in aspnet mvc

    - by FosterZ
    hi,i'm building a simple school portal, i have stucked at uploading an image into my application, i.e a user should upload school image to my server, i have directory for images as ./Content/Images -- all uploading images should be uploaded to this directory. i have following code input type="file" id="SchoolImageUrl" name="SchoolImageUrl" class="required" using this m'getting a browse button, i have no idea how to upload that image to server and how would be my action controller ? i have following controller for creating school public ActionResult SchoolCreate(_ASI_School schoolToCreate, FormCollection collection) { if (!ModelState.IsValid) return View(); try { // TODO: Add insert logic here schoolToCreate.SchoolId = Guid.NewGuid().ToString(); schoolToCreate.UserId = new Guid(Request.Form["currentUser"]); schoolToCreate.SchoolAddedBy = User.Identity.Name; HttpPostedFileBase file = Request.Files["SchoolImageUrl"]; file.SaveAs(file.FileName); //schoolToCreate.SchoolImageUrl = Reuseable.ImageUpload(Request.Files["SchoolImageUrl"], Server.MapPath("../Content")); //schoolToCreate.SchoolImageUrl = Path.GetFullPath(Request.Files[0].FileName); schoolToCreate.SchoolImageUrl = collection["SchoolImageUrl"]; UpdateModel(schoolToCreate); _schoolRepository.CreateSchool(schoolToCreate); //_schoolRepository.SaveToDb(); return RedirectToAction("DepartmentCreate", "Department", new { userId = schoolToCreate.UserId, schoolId = schoolToCreate.SchoolId }); } catch { return View("CreationFailed"); } } here im geting object referece error

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  • copy rows before updating them to preserve archive in Postgres

    - by punkish
    I am experimenting with creating a table that keeps a version of every row. The idea is to be able to query for how the rows were at any point in time even if the query has JOINs. Consider a system where the primary resource is books, that is, books are queried for, and author info comes along for the ride CREATE TABLE authors ( author_id INTEGER NOT NULL, version INTEGER NOT NULL CHECK (version > 0), author_name TEXT, is_active BOOLEAN DEFAULT '1', modified_on TIMESTAMP DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (author_id, version) ) INSERT INTO authors (author_id, version, author_name) VALUES (1, 1, 'John'), (2, 1, 'Jack'), (3, 1, 'Ernest'); I would like to be able to update the above like so UPDATE authors SET author_name = 'Jack K' WHERE author_id = 1; and end up with 2, 1, Jack, t, 2012-03-29 21:35:00 2, 2, Jack K, t, 2012-03-29 21:37:40 which I can then query with SELECT author_name, modified_on FROM authors WHERE author_id = 2 AND modified_on < '2012-03-29 21:37:00' ORDER BY version DESC LIMIT 1; to get 2, 1, Jack, t, 2012-03-29 21:35:00 Something like the following doesn't really work CREATE OR REPLACE FUNCTION archive_authors() RETURNS TRIGGER AS $archive_author$ BEGIN IF (TG_OP = 'UPDATE') THEN -- The following fails because author_id,version PK already exists INSERT INTO authors (author_id, version, author_name) VALUES (OLD.author_id, OLD.version, OLD.author_name); UPDATE authors SET version = OLD.version + 1 WHERE author_id = OLD.author_id AND version = OLD.version; RETURN NEW; END IF; RETURN NULL; -- result is ignored since this is an AFTER trigger END; $archive_author$ LANGUAGE plpgsql; CREATE TRIGGER archive_author AFTER UPDATE OR DELETE ON authors FOR EACH ROW EXECUTE PROCEDURE archive_authors(); How can I achieve the above? Or, is there a better way to accomplish this? Ideally, I would prefer to not create a shadow table to store the archived rows.

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  • Cannot access Class methods from previous windows form - C#

    - by George
    I am writing an app, still, where I need to test some devices every minute for 30 minutes. It made sense to use a timer set to kick off every 60 secs and do whats required in the event handler. However, I need the app to wait for the 30 mins until I have finished with the timer since the following code alters the state of the devices I am trying to monitor. I obviously don't want to use any form of loop to do this. I thought of using another windows form, since I also display the progress, which will simply kick off the timer and wait until its complete. The problem I am having with this is that I use a device Class and cant seem to get access to the methods in the device class from the 2nd (3rd actually - see below) windows form. I have an initial windows form where I get input from the user, then call the 2nd windows form where it work out which tests need to be done and which device classes need to be used, and then I want to call the 3rd windows form to handle the timer. I will have up to 6-7 device classes and so wanted to only instantiate them when actually requiring them, from the 2nd form. Should I have put this logic into the 1st windows form (program class ??) ? Would I not still have the problem of not being able to access device class methods from there too ? Anyway, perhaps someone knows of a better way to do the checks every minute without the rest of the code executing (and changing the status of the devices) or how I should be accessing the methods in the app ?? Well that's the problem, I cant get that part of it to work correctly. Here is the definition for the calling form including the device class - namespace NdtStart { public partial class fclsNDTCalib : Form { NDTClass NDT = new NDTClass(); public fclsNDTCalib() (new fclsNDTTicker(NDT)).ShowDialog(); Here is the class def for the called form - namespace NdtStart { public partial class fclsNDTTicker : Form { public fclsNDTTicker() I tried lots but couldn't get the arguments to work.

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  • Trying to use HttpWebRequest to load a page in a file.

    - by Malcolm
    Hi, I have a ASP.NET MVC app that works fine in the browser. I am using the following code to be able to write the html of a retrieved page to a file. (This is to use in a PDF conversion component) But this code errors out continually but not in the browser. I get timeout errors sometimes asn 500 errors. Public Function GetPage(ByVal url As String, ByVal filename As String) As Boolean Dim request As HttpWebRequest Dim username As String Dim password As String Dim docid As String Dim poststring As String Dim bytedata() As Byte Dim requestStream As Stream Try username = "pdfuser" password = "pdfuser" docid = "docid=inv12154" poststring = String.Format("username={0}&password={1}&{2}", username, password, docid) bytedata = Encoding.UTF8.GetBytes(poststring) request = WebRequest.Create(url) request.Method = "Post" request.ContentLength = bytedata.Length request.ContentType = "application/x-www-form-urlencoded" requestStream = request.GetRequestStream() requestStream.Write(bytedata, 0, bytedata.Length) requestStream.Close() request.Timeout = 60000 Dim response As HttpWebResponse Dim responseStream As Stream Dim reader As StreamReader Dim sb As New StringBuilder() Dim line As String = String.Empty response = request.GetResponse() responseStream = response.GetResponseStream() reader = New StreamReader(responseStream, System.Text.Encoding.ASCII) line = reader.ReadLine() While (Not line Is Nothing) sb.Append(line) line = reader.ReadLine() End While File.WriteAllText(filename, sb.ToString()) Catch ex As Exception MsgBox(ex.Message) End Try Return True End Function

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  • Java - If statement with String comparison fails

    - by Andrea
    I really don't know why the if statement below is not executing: if (s == "/quit") { System.out.println("quitted"); } Below is the whole class. It is probably a really stupid logic problem but I have been pulling my hair out over here not being able to figure this out. Thanks for looking :) class TextParser extends Thread { public void run() { while (true) { for(int i = 0; i < connectionList.size(); i++) { try { System.out.println("reading " + i); Connection c = connectionList.elementAt(i); Thread.sleep(200); System.out.println("reading " + i); String s = ""; if (c.in.ready() == true) { s = c.in.readLine(); //System.out.println(i + "> "+ s); if (s == "/quit") { System.out.println("quitted"); } if(! s.equals("")) { for(int j = 0; j < connectionList.size(); j++) { Connection c2 = connectionList.elementAt(j); c2.out.println(s); } } } } catch(Exception e){ System.out.println("reading error"); } } } } }

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  • ADO.NET Multiple simultaneous reads from an open database.

    - by Deverill
    Answer not needed - my logic was wrong and this question is invalid. Charles helped me see where I went off-tracks. Thanks I have a utility that moves data from one source to another. In the process of writing the record I check to see if it exists and do an update/insert as necessary. The difficulty I have is that as I'm writing the main record info there is a 2nd table for "custom data" that I have to check to see if it exists and do an update/insert for that as well. Example: I may be loading a pencil sharpener that may or may not exist. While I'm writing it into destination it has characteristics such as style, color, etc. and each of them may or may not exist. As written I seem to need to have 2 DataReaders open, one for the sharpener and one to check for and update color. I am new to ADO.NET, but not to programming and it's more complicated than I listed but for sanity's sake I didn't put all the details. My question is: What am I missing? You can't have 2 readers open at the same time on a connection, yet I can't close the first if I'm stepping through all products. It seems inefficient to have 2 connections, readers, etc. for this. Is there a feature of ADO.NET DBs that I'm missing? How would you do it? Thanks!

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  • Java Code for calculating Leap Year, is this code correct ?

    - by Ibn Saeed
    Hello I am following "The Art and Science of Java" book and it shows how to calculate a leap year. The book uses ACM Java Task Force's library. Here is the code the books uses: import acm.program.*; public class LeapYear extends ConsoleProgram { public void run() { println("This program calculates leap year."); int year = readInt("Enter the year: "); boolean isLeapYear = ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0)); if (isLeapYear) { println(year + " is a leap year."); } else println(year + " is not a leap year."); } } Now, this is how I calculated the leap year. import acm.program.*; public class LeapYear extends ConsoleProgram { public void run() { println("This program calculates leap year."); int year = readInt("Enter the year: "); if ((year % 4 == 0) && year % 100 != 0) { println(year + " is a leap year."); } else if ((year % 4 == 0) && (year % 100 == 0) && (year % 400 == 0)) { println(year + " is a leap year."); } else { println(year + " is not a leap year."); } } } Is there anything wrong with my code or should i use the one provided by the book ? EDIT :: Both of the above code works fine, What i want to ask is which code is the best way to calculate the leap year.

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  • Gui problem after rewriting to MVC

    - by trevor_nise
    I'm practicing MVC style programming. I have a Mastermind game in a single file, working with no problems (maybe apart of the fact that "Check" button is invisible at start). http://paste.pocoo.org/show/226726/ But when I've rewritten it to model, view, controller files - when I click on empty Pin (that should be updated, and repainted with new color) - noting happens. Can anybody see any problems here ? I've tried placing repaint() in different places, but it simply does not work at all :/ Main : public class Main { public static void main(String[] args){ Model model = new Model(); View view = new View("Mastermind", 400, 590, model); Controller controller = new Controller(model, view); view.setVisible(true); } } Model : import java.util.Random; public class Model{ static final int LINE = 5, SCORE = 10, OPTIONS = 20; Pin pins[][] = new Pin[21][LINE]; int combination[] = new int[LINE]; int curPin = 0; int turn = 1; Random generator = new Random(); int repaintPin; boolean pinsRepaint=false; int pinsToRepaint; boolean isUpdate = true, isPlaying = true, isRowFull = false; static final int HIT_X[] = {270,290,310,290,310}, HIT_Y[] = {506,496,496,516,516}; public Model(){ for ( int i=0; i < SCORE; i++ ){ for ( int j = 0; j < LINE; j++ ){ pins[i][j] = new Pin(20,0); pins[i][j].setPosition(j*50+30,510-i*50); pins[i+SCORE][j] = new Pin(8,0); pins[i+SCORE][j].setPosition(HIT_X[j],HIT_Y[j]-i*50); } } for ( int i=0; i < LINE; i++ ){ pins[OPTIONS][i] = new Pin( 20, i+2 ); pins[OPTIONS][i].setPosition( 370,i * 50 + 56); } } void fillHole(int color) { pins[turn-1][curPin].setColor(color+1); pinsRepaint = true; pinsToRepaint = turn; curPin = (curPin+1) % LINE; if (curPin == 0){ isRowFull = true; } pinsRepaint = false; pinsToRepaint = 0; } void check() { int junkPins[] = new int[LINE], junkCode[] = new int[LINE]; int pinCount = 0, pico = 0; for ( int i = 0; i < LINE; i++ ) { junkPins[i] = pins[turn-1][i].getColor(); junkCode[i] = combination[i]; } for ( int i = 0; i < LINE; i++ ){ if (junkPins[i]==junkCode[i]) { pins[turn+SCORE][pinCount].setColor(1); pinCount++; pico++; junkPins[i] = 98; junkCode[i] = 99; } } for ( int i = 0; i < LINE; i++ ){ for ( int j = 0; j < LINE; j++ ) if (junkPins[i]==junkCode[j]) { pins[turn+SCORE][pinCount].setColor(2); pinCount++; junkPins[i] = 98; junkCode[j] = 99; j = LINE; } } pinsRepaint = true; pinsToRepaint = turn + SCORE; pinsRepaint = false; pinsToRepaint=0; if ( pico == LINE ){ isPlaying = false; } else if ( turn >= 10 ){ isPlaying = false; } else{ curPin = 0; isRowFull = false; turn++; } } void combination() { for ( int i = 0; i < LINE; i++ ){ combination[i] = generator.nextInt(6) + 1; } } } class Pin{ private int color, X, Y, radius; public Pin(){ X = 0; Y = 0; radius = 0; color = 0; } public Pin( int r,int c ){ X = 0; Y = 0; radius = r; color = c; } public int getX(){ return X; } public int getY(){ return Y; } public int getRadius(){ return radius; } public void setRadius(int r){ radius = r; } public void setPosition( int x,int y ){ this.X = x ; this.Y = y ; } public void setColor( int c ){ color = c; } public int getColor() { return color; } } View: import java.awt.*; import javax.swing.*; public class View extends Frame{ Model model; JButton checkAnswer; private JPanel button; private static final Color COLORS[] = {Color.black, Color.white, Color.red, Color.yellow, Color.green, Color.blue, new Color(7, 254, 250)}; public View(String name, int w, int h, Model m){ model = m; setTitle( name ); setSize( w,h ); setResizable( false ); this.setLayout(new BorderLayout()); button = new JPanel(); button.setSize( new Dimension(400, 100)); button.setVisible(true); checkAnswer = new JButton("Check"); checkAnswer.setSize( new Dimension(200, 30)); button.add( checkAnswer ); this.add( button, BorderLayout.SOUTH); button.setVisible(true); } @Override public void paint( Graphics g ) { g.setColor( new Color(238, 238, 238)); g.fillRect( 0,0,400,590); for ( int i=0; i < model.pins.length; i++ ) { paintPins(model.pins[i][0],g); paintPins(model.pins[i][1],g); paintPins(model.pins[i][2],g); paintPins(model.pins[i][3],g); paintPins(model.pins[i][4],g); } } @Override public void update( Graphics g ) { if ( model.isUpdate ) { paint(g); } else { model.isUpdate = true; paintPins(model.pins[model.repaintPin-1][0],g); paintPins(model.pins[model.repaintPin-1][1],g); paintPins(model.pins[model.repaintPin-1][2],g); paintPins(model.pins[model.repaintPin-1][3],g); paintPins(model.pins[model.repaintPin-1][4],g); } } void repaintPins( int pin ) { model.repaintPin = pin; model.isUpdate = false; repaint(); } public void paintPins(Pin p, Graphics g ){ int X = p.getX(); int Y = p.getY(); int color = p.getColor(); int radius = p.getRadius(); int x = X-radius; int y = Y-radius; if (color > 0){ g.setColor( COLORS[color]); g.fillOval( x,y,2*radius,2*radius ); } else{ g.setColor( new Color(238, 238, 238) ); g.drawOval( x,y,2*radius-1,2*radius-1 ); } g.setColor( Color.black ); g.drawOval( x,y,2*radius,2*radius ); } } Controller: import java.awt.*; import java.awt.event.*; public class Controller implements MouseListener, ActionListener { private Model model; private View view; public Controller(Model m, View v){ model = m; view = v; view.addWindowListener( new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } }); view.addMouseListener(this); view.checkAnswer.addActionListener(this); model.combination(); } public void actionPerformed( ActionEvent e ) { if(e.getSource() == view.checkAnswer){ if(model.isRowFull){ model.check(); } } } public void mousePressed(MouseEvent e) { Point mouse = new Point(); mouse = e.getPoint(); if (model.isPlaying){ if (mouse.x > 350) { int button = 1 + (int)((mouse.y - 32) / 50); if ((button >= 1) && (button <= 5)){ model.fillHole(button); if(model.pinsRepaint){ view.repaintPins( model.pinsToRepaint ); } } } } } public void mouseClicked(MouseEvent e) {} public void mouseReleased(MouseEvent e){} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} }

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  • Rotate MapView in Android

    - by Matthew B.
    I am writing an Android app where one of the features is that the map will rotate according to the compass (i.e. if the phone is pointing east, the map will be oriented so that the east side of the map is on top). Previous answers that I have found suggested over writing the onDraw() method in mapView, however, the api changed the method to final so it cannot be overwritten. As a result I have tried to overwrite the dispatchDraw() method like so: Note: -compass is a boolean that if true, rotate the view -bearing is a float variable that has the degrees that the view should rotate protected void dispatchDraw(Canvas canvas) { canvas.save(); if (compass) { final float w = this.getWidth(); final float h = this.getHeight(); final float scaleFactor = (float)(Math.sqrt(h * h + w * w) / Math.min(w, h)); final float centerX = w / 2.0f; final float centerY = h / 2.0f; canvas.rotate(bearing, centerX, centerY); canvas.scale(scaleFactor, scaleFactor, centerX, centerY); } super.dispatchDraw(canvas); canvas.restore(); }

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