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  • Windows Service Webbrowser object invalid cast exception error

    - by Sam Youtsey
    Hi all, I'm having a bit of trouble with a Windows Service webbrowser object. It's attempting to load in values of username and password to a site but keeps failing and throwing the following error: System.InvalidCastException: Specified cast is not valid. at System.Windows.Forms.UnsafeNativeMethods.IHTMLDocument2.GetLocation() at System.Windows.Forms.WebBrowser.get_Document() at MyWindowsService.MyDataProcessor.login() The code that I'm using to make this call is: MyWebBrowser.Document.All["Login"].SetAttribute("Value", username); MyWebBrowser.Document.All["Password"].SetAttribute("Value", password); MyWebBrowser.Document.All["submit"].InvokeMember("Click"); Any ideas as to why it keeps failing? Thanks in advance for the help.

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  • java.sql.Exception ClosedConnection

    - by john
    I am getting the following error: java.sql.SQLException: Closed Connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208) at oracle.jdbc.driver.PhysicalConnection.getMetaData(PhysicalConnection.java:1508) at com.ibatis.sqlmap.engine.execution.SqlExecutor.moveToNextResultsSafely(SqlExecutor.java:348) at com.ibatis.sqlmap.engine.execution.SqlExecutor.handleMultipleResults(SqlExecutor.java:320) at com.ibatis.sqlmap.engine.execution.SqlExecutor.executeQueryProcedure(SqlExecutor.java:277) at com.ibatis.sqlmap.engine.mapping.statement.ProcedureStatement.sqlExecuteQuery(ProcedureStatement.java:34) at com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeQueryWithCallback(GeneralStatement.java:173) at com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeQueryForList(GeneralStatement.java:123) at com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:614) at com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:588) at com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.queryForList(SqlMapSessionImpl.java:118) at org.springframework.orm.ibatis.SqlMapClientTemplate$3.doInSqlMapClient(SqlMapClientTemplate.java:268) at org.springframework.orm.ibatis.SqlMapClientTemplate.execute(SqlMapClientTemplate.java:193) at org.springframework.orm.ibatis.SqlMapClientTemplate.executeWithListResult(SqlMapClientTemplate.java:219) at org.springframework.orm.ibatis.SqlMapClientTemplate.queryForList(SqlMapClientTemplate.java:266) at gov.hud.pih.eiv.web.authentication.AuthenticationUserDAO.isPihUserDAO(AuthenticationUserDAO.java:24) at gov.hud.pih.eiv.web.authorization.AuthorizationProxy.isAuthorized(AuthorizationProxy.java:125) at gov.hud.pih.eiv.web.authorization.AuthorizationFilter.doFilter(AuthorizationFilter.java:224) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246) at I am really stumped and can't figure out what could be causing this error. I am not able to reproduce the error on my machine but on production it is coming a lot of times. I am using iBatis in the whole application so there are no chances of my code not closing connections. We do have stored procedures that run for a long time before they return results (around 15 seconds). does anyone have any ideas on what could be causing this? I dont think raising the # of connections on the application server will fix this issue buecause if connections were running out then we'd see "Error on allocating connections"

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  • South migration error: NoMigrations exception for django.contrib.auth

    - by danpalmer
    I have been using South on my project for a while, but I recently did a huge amount of development and changed development machine and I think something messed up in the process. The project works fine, but I can't apply migrations. Whenever I try to apply a migration I get the following traceback: danpalmer:pest Dan$ python manage.py migrate frontend Traceback (most recent call last): File "manage.py", line 11, in <module> execute_manager(settings) File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 362, in execute_manager utility.execute() File "/Library/Python/2.6/site-packages/django/core/management/__init__.py", line 303, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 195, in run_from_argv self.execute(*args, **options.__dict__) File "/Library/Python/2.6/site-packages/django/core/management/base.py", line 222, in execute output = self.handle(*args, **options) File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/management/commands/migrate.py", line 102, in handle delete_ghosts = delete_ghosts, File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/migration/__init__.py", line 182, in migrate_app applied = check_migration_histories(applied, delete_ghosts) File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/migration/__init__.py", line 85, in check_migration_histories m = h.get_migration() File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/models.py", line 34, in get_migration return self.get_migrations().migration(self.migration) File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/models.py", line 31, in get_migrations return Migrations(self.app_name) File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/migration/base.py", line 60, in __call__ self.instances[app_label] = super(MigrationsMetaclass, self).__call__(app_label_to_app_module(app_label), **kwds) File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/migration/base.py", line 88, in __init__ self.set_application(application, force_creation, verbose_creation) File "/Library/Python/2.6/site-packages/South-0.7-py2.6.egg/south/migration/base.py", line 159, in set_application raise exceptions.NoMigrations(application) south.exceptions.NoMigrations: Application '<module 'django.contrib.auth' from '/Library/Python/2.6/site-packages/django/contrib/auth/__init__.pyc'>' has no migrations. I am not that experienced with South and I haven't met this error before. The only helpful mention I can find online about this error is for pre-0.7 I think and I am on South 0.7. I ran 'easy_install -U South' just to make sure. Thanks for any help that you can provide. I really appreciate it.

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  • MSBuild Override Project Reference to resolve to Precompiled Assembly

    - by Ryu
    Situation I have about 400 csproj files using project references. About 3 of those a separate team wants to fork and incorporate into a standalone app. I branched the 3 projects of interest, and because the separate team uses a diff SVN repo I used svn externals to pull in these projects into the folder of the standalone app. Obviously since this team uses a different folder structure the project references no longer resolve. Attempted Solution I figured setting the msbuild properties ReferencePath and AdditionalLibPaths to point to a directory with all the precompiled dependencies would allow the project references a fallback point and resolve correctly. However that doesn't appear to be the case. Question Does anybody know a way to have a failed projectreference look up resolve to the precompiled dll? Perhaps point me to an automated tool to convert projectreferences to dll references? Or is there a better way to solve this problem? Thanks

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  • OutOfMemory exception when loading an image in .Net

    - by Ben
    Hi, Im loading an image from a SQL CE db and then trying to load that into a PictureBox. I am saving the image like this: if (ofd.ShowDialog() == DialogResult.OK) { picArtwork.ImageLocation = ofd.FileName; using (System.IO.FileStream fs = new System.IO.FileStream(ofd.FileName, System.IO.FileMode.Open)) { byte[] imageAsBytes = new byte[fs.Length]; fs.Read(imageAsBytes, 0, imageAsBytes.Length); thisItem.Artwork = imageAsBytes; fs.Close(); } } and then saving to the Db using LINQ To SQL. I load the image back like so: using (FileStream fs = new FileStream(@"C:\Temp\img.jpg", FileMode.CreateNew ,FileAccess.Write )) { byte[] img = (byte[])encoding.GetBytes(ThisFilm.Artwork.ToString()); fs.Write(img, 0, img.Length); } but am getting an OutOfMemoryException. I have read that this is a slight red herring and that there is probably something wrong with the filetype, but i cant figure what. Any ideas? Thanks picArtwork.Image = System.Drawing.Bitmap.FromFile(@"C:\Temp\img.jpg");

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  • What is weird about wrapping setjmp and longjmp?

    - by Max
    Hello. I am using setjmp and longjmp for the first time, and I ran across an issue that comes about when I wrap setjmp and longjmp. I boiled the code down to the following example: #include <stdio.h> #include <setjmp.h> jmp_buf jb; int mywrap_save() { int i = setjmp(jb); return i; } int mywrap_call() { longjmp(jb, 1); printf("this shouldn't appear\n"); } void example_wrap() { if (mywrap_save() == 0){ printf("wrap: try block\n"); mywrap_call(); } else { printf("wrap: catch block\n"); } } void example_non_wrap() { if (setjmp(jb) == 0){ printf("non_wrap: try block\n"); longjmp(jb, 1); } else { printf("non_wrap: catch block\n"); } } int main() { example_wrap(); example_non_wrap(); } Initially I thought example_wrap() and example_non_wrap() would behave the same. However, the result of running the program (GCC 4.4, Linux): wrap: try block non_wrap: try block non_wrap: catch block If I trace the program in gdb, I see that even though mywrap_save() returns 1, the else branch after returning is oddly ignored. Can anyone explain what is going on?

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  • Changing the message (or exception) in WPF ValidatesOnException binding

    - by Emad
    I have a WPF application using MVVM. I am using binding to a POCO object. The Textbox is bound to a property in the object like: <TextBox.Text> <Binding Path="CertainProperty" Mode="TwoWay" > <Binding.ValidationRules> <ExceptionValidationRule/> </Binding.ValidationRules> </Binding> </TextBox.Text> Now this property is a a int property and when the user tried to enter a non-numeric value, they get the "input string was not in a correct format". What I need to do is customize this message to a more user friendly one. How can I do that ?

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  • scripsharp reference web service / strongly type to results model

    - by user175528
    With scriptsharp (script#) is it possible to get strong typing when calling a service defined in my web app? The only way I can see is to: 1 - use linked / shared files to shadow copy my results classes / domain models across into my script# lib 2 - replicate my model across in the script# lib and use automapper to validate? 3 - use some .tt to code gen? also, even if I can do this, how do I get around the auto camel-casing script# does, when my service result (asmx) wont do this? (so my JSON response will comback as UserMessage, script# will have changed that to userMessage) basically, what I am looking to use script# to achieve is better compile time support against our domain model when calling and processing services in javascript, so something like this: Scriptlet public static class MyScriptlet { public static void Main() { MyService.Service1("hello", ProcessResponse);} public static void ProcessResponse(MyService.Service1ResponseData resp) { jQuery.Select('#Message').Text(resp.UserMessage); jQuery.Select('#Detail').Text(resp.UserDetail); } Service (in our web app) public class MyService { public class Service1ResponseData { public string UserMessage {get;set;} public string UserDetail {get;set;} } public Service1ResponseData Service1(string user) { return new Service1ResponseData() { UserMessage:"hi",UserDetail:"some text"}; } }

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  • Rendering a control generates security exception in .Net 4

    - by Jason Short
    I am having a problem with code that worked fine in .Net 2 giving this error under .Net 4. Build (web): Inheritance security rules violated while overriding member: 'Controls.RelatedPosts.RenderControl(System.Web.UI.HtmlTextWriter)'. Security accessibility of the overriding method must match the security accessibility of the method being overriden. This is in DotNetBlogEngine. There were several other security demands in the code that .Net 4 didn't seem to like. I followed some of the advice I found on blogs (and here) and got rid of all the other errors. But this one still eludes me. The Main blogengine core dll is not set for security demands anylonger and is compiled for .Net 4 as well. This error is in the website side attempting to use the dll. There are controls that call a RenderControl method taking an HtmlTextWriter. Apparently the text writer now has some soft of security attributes set on it. Each of the controls implements a custom interface ( public interface ICustomFilter ), there are no security permissions present or demands. The site is running full trust on my local dev machine.

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  • DataTableReader is invalid for current DataTable 'TempTable'

    - by Sk93
    Hi, I'm getting the following error whenever my code creates a DataTableReader from a valid DataTable Object: "DataTableReader is invalid for current DataTable 'TempTable'." The thing is, if I reboot my machine, it works fine for an undertimed amount of time, then dies with the above. The code that throws this error could have been working fine for hours and then: bang. you get this error. It's not limited to one line either; it's every single location that a DataTableReader is used. Also, this error does NOT occur on the production web server - ever. This is an example of one of the lines where it falls over: If I step over this line, I get this: However, if I do this in the immediate window: I get no problems. Same goes if I actually use that line in the code. This has been driving me nuts for the best part of a week, and I've failed to find anything on Google that could help (as I'm pretty positive this isn't a coding issue). Some technical info: DEV Box: Vista 32bit (with all current windows updates) Visual Studio 2008 v9.0.30729.1 SP dotNet Framework 3.5 SP1 SQL Server: Microsoft SQL Server 2005 Standard Edition- 9.00.4035.00 (X64) Windows 2003 64bit (with all current windows updates) Web Server: Windows 2003 64bit (with all current windows updates) any help, ideas, or advice would be greatly appreciated! Cheers, Ian

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  • .Except<T> is throwing an Exception

    - by Jason
    I have the following code: Public Shared Function GetAvailableManufacturers() As List(Of Manufacturer) 'first get all the live orders and extract their mfrs' Dim sos As List(Of OrderForm) = GetFormsByStatus(StockStatus.Building) Dim unavailableMfrs As New List(Of Manufacturer) For Each so As StockingOrder In sos unavailableMfrs.Add(so.Source) Next 'then remove all mfrs with an open SO from a list of all mfrs' Dim allMfrs As List(Of Manufacturer) = Manufacturer.GetManufacturers Return allMfrs.Except(unavailableMfrs) <----- error here End Function Explanation of what the above does: GetFormsByStatus() self-explanatory GetManufacturers() returns a list of all manufacturers in the database My idea to get available manufacturers was to get a list of all the manufacturers in my open forms, then get a list of all manufacturers and exclude all the manufacturers in the first list, illustrated like so (pseudo): List A: {1,2,3,4,5,6,7,8,9,10} List B: {5,7,10} Result: {1,2,3,4,6,8,9} I have set up my Manufacturer class according to this article so that it can be compared, but I'm still getting this error: Unable to cast object of type '<ExceptIterator>d__92'1[csCore.Manufacturer]' to type 'System.Collections.Generic.List'1[csCore.Manufacturer]'. I thought at first that because during testing GetFormsByStatus() returns 0 results maybe that was causing problems, but it doesn't make sense that Except() wouldn't work if the provided list had 0 items. Can anyone spot what I'm doing wrong? Thanks so much!

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  • [[UIDevice currentDevice] orientation] always null

    - by Toby Wilson
    As per the title. Calling [[UIDevice currentDevice] BeginGeneratingDeviceOrientationNotifications] has no effect. DidRotateToInterfaceOrientation etc events are working fine, but I need to be able to poll the device orientation arbitrarily. How can I fix/do this? The long story: I have a tab application with a navigation controller on each tab. The root view of tab number one is a graph that goes full screen when the orientation changes to landscape; however this needs to be checked whenever the view appears as the orientation change could have occurred elsewhere, so I was hoping to poll the orientation state whenever this view appears.

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  • Object Reference is required for non static field, method, or property

    - by JB
    using System; using System.IO; using System.Data; using System.Text; using System.Drawing; using System.Data.OleDb; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Drawing.Printing; using System.Collections.Generic; namespace Eagle_Eye_Class_Finder { public class GetSchedule { public GetSchedule() { IDnumber[] IDnumbers = new IDnumber[3]; IDnumbers[0] = new IDnumber() { Name = "Joshua Banks", ID = "900456317", year = "Senior", class1 = "TEET 4090", class2 = "TEET 3020", class3 = "TEET 3090", class4 = "TEET 4290" }; IDnumbers[1] = new IDnumber() { Name = "Sean Ward", ID = "900456318", year = "Junior", class1 = "ENGNR 4090", class2 = "ENGNR 3020", class3 = "ENGNR 3090", class4 = "ENGNR 4290" }; IDnumbers[2] = new IDnumber() { Name = "Terrell Johnson", ID = "900456319", year = "Sophomore", class1 = "BUS 4090", class2 = "BUS 3020", class3 = "BUS 3090", class4 = "BUS 4290" }; } public class IDnumber { public string Name { get; set; } public string ID { get; set; } public string year { get; set; } public string class1 { get; set; } public string class2 { get; set; } public string class3 { get; set; } public string class4 { get; set; } public static void ProcessNumber(IDnumber myNum) { StringBuilder myData = new StringBuilder(); myData.AppendLine(IDnumber.Name); myData.AppendLine(": "); myData.AppendLine(IDnumber.ID); myData.AppendLine(IDnumber.year); myData.AppendLine(IDnumber.class1); myData.AppendLine(IDnumber.class2); myData.AppendLine(IDnumber.class3); myData.AppendLine(IDnumber.class4); MessageBox.Show(myData); } public string GetDataFromNumber(string ID) { foreach (IDnumber idCandidateMatch in IDnumbers) { if (IDCandidateMatch.ID == ID) { StringBuilder myData = new StringBuilder(); myData.AppendLine(IDnumber.Name); myData.AppendLine(": "); myData.AppendLine(IDnumber.ID); myData.AppendLine(IDnumber.year); myData.AppendLine(IDnumber.class1); myData.AppendLine(IDnumber.class2); myData.AppendLine(IDnumber.class3); myData.AppendLine(IDnumber.class4); return myData; } } return ""; } } } }using System; using System.IO; using System.Data; using System.Text; using System.Drawing; using System.Data.OleDb; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Drawing.Printing; using System.Collections.Generic; namespace Eagle_Eye_Class_Finder { public class GetSchedule { public GetSchedule() { IDnumber[] IDnumbers = new IDnumber[3]; IDnumbers[0] = new IDnumber() { Name = "Joshua Banks", ID = "900456317", year = "Senior", class1 = "TEET 4090", class2 = "TEET 3020", class3 = "TEET 3090", class4 = "TEET 4290" }; IDnumbers[1] = new IDnumber() { Name = "Sean Ward", ID = "900456318", year = "Junior", class1 = "ENGNR 4090", class2 = "ENGNR 3020", class3 = "ENGNR 3090", class4 = "ENGNR 4290" }; IDnumbers[2] = new IDnumber() { Name = "Terrell Johnson", ID = "900456319", year = "Sophomore", class1 = "BUS 4090", class2 = "BUS 3020", class3 = "BUS 3090", class4 = "BUS 4290" }; } public class IDnumber { public string Name { get; set; } public string ID { get; set; } public string year { get; set; } public string class1 { get; set; } public string class2 { get; set; } public string class3 { get; set; } public string class4 { get; set; } public static void ProcessNumber(IDnumber myNum) { StringBuilder myData = new StringBuilder(); myData.AppendLine(IDnumber.Name); myData.AppendLine(": "); myData.AppendLine(IDnumber.ID); myData.AppendLine(IDnumber.year); myData.AppendLine(IDnumber.class1);// i get it for all of these myData.AppendLine(IDnumber.class2); myData.AppendLine(IDnumber.class3); myData.AppendLine(IDnumber.class4); MessageBox.Show(myData); } public string GetDataFromNumber(string ID) { foreach (IDnumber idCandidateMatch in IDnumbers) { if (IDCandidateMatch.ID == ID) { StringBuilder myData = new StringBuilder(); myData.AppendLine(IDnumber.Name); myData.AppendLine(": "); myData.AppendLine(IDnumber.ID); myData.AppendLine(IDnumber.year); myData.AppendLine(IDnumber.class1); myData.AppendLine(IDnumber.class2); myData.AppendLine(IDnumber.class3); myData.AppendLine(IDnumber.class4); return myData; } } return ""; } } } }

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  • External Reference to Richfaces modal

    - by John
    Hi, I need to get a <rich:modalPanel id="mod1" .../> component to load an external page on "show" action, defined as: <a4j:commandButton value="link" id="l1" reRender="mod1" oncomplete="Richfaces.showModalPanel('mod1')"> <f:setPropertyActionListener target="#{mybean.someParam}" value="#{myOtherbean.someOtherparam}" /> </a4j:commandButton> . My first try was with <rich:modalPanel id="mod1"> <ui:include src="#{mybean.generateURL()"/> </rich:modalPanel> but it just throws me a 404 page not found error, typing the generated URL directly into the address bar works perfectly fine. Does anyone know what's causing the problem , or what's the correct way to do this? The system is running on seam/richfaces. Thanks!

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  • "no block given" errors with cache_money

    - by emh
    i've inherited a site that in production is generating dozens of "no block given" exceptions every 5 minutes. the top of the stack trace is: vendor/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:42:in `add' vendor/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:33:in `get' vendor/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:22:in `call' vendor/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:22:in `fetch' vendor/gems/nkallen-cache-money-0.2.5/lib/cash/accessor.rb:31:in `get' so it appears that the problem is in the cache money plugin. has anyone experienced something similar? i've cut and pasted the relevant code below -- anyone more familiar with blocks able to discern any obvious problems? 11 def fetch(keys, options = {}, &block) 12 case keys 13 when Array 14 keys = keys.collect { |key| cache_key(key) } 15 hits = repository.get_multi(keys) 16 if (missed_keys = keys - hits.keys).any? 17 missed_values = block.call(missed_keys) 18 hits.merge!(missed_keys.zip(Array(missed_values)).to_hash) 19 end 20 hits 21 else 22 repository.get(cache_key(keys), options[:raw]) || (block ? block.call : nil) 23 end 24 end 25 26 def get(keys, options = {}, &block) 27 case keys 28 when Array 29 fetch(keys, options, &block) 30 else 31 fetch(keys, options) do 32 if block_given? 33 add(keys, result = yield(keys), options) 34 result 35 end 36 end 37 end 38 end 39 40 def add(key, value, options = {}) 41 if repository.add(cache_key(key), value, options[:ttl] || 0, options[:raw]) == "NOT_STORED\r\n" 42 yield 43 end 44 end

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  • Compiler optimization of reference variables

    - by Phineas
    I often use references to simplify the appearance of code: vec3f& vertex = _vertices[index]; // Calculate the vertex position vertex[0] = startx + col * colWidth; vertex[1] = starty + row * rowWidth; vertex[2] = 0.0f; Will compilers recognize and optimize this so it is essentially the following? _vertices[index][0] = startx + col * colWidth; _vertices[index][1] = starty + row * rowWidth; _vertices[index][2] = 0.0f;

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  • Java Server Client Program I/O Exception

    - by AjayP
    I made this program: http://java.sun.com/docs/books/tutorial/networking/sockets/clientServer.html And it works perfectly if I put the server's hostname as 127.0.0.1 or my computers name (Ajay-PC). However these 2 methods are LAN or local only not internet. So I changed it to my internet ip. 70.128.xxx.xxx etc. But it didn't work. I checked: canyouseeme.org and it said 4444 was CLOSED. So I did a quick port forward. Portforward: Name: My Java Program Start Port: 4444 End Port: 4444 Server IP: 10.0.0.12 <-- (Yeah this is my Local IP I checked) then I tried canyouseeme.org AGAIN: and it said 4444 was OPEN I ran my server client program and it yet to work. So my problem is the client server program is not working on the internet just locally. So something is blocking it and I don't know what. Computer: Windows Vista x64 Norton AntiVirus 2010 Thanks! I'll give best answer or whatever to who ever answers the best ;) :)

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  • Should a Perl constructor return an undef or a "invalid" object?

    - by DVK
    Question: What is considered to be "Best practice" - and why - of handling errors in a constructor?. "Best Practice" can be a quote from Schwartz, or 50% of CPAN modules use it, etc...; but I'm happy with well reasoned opinion from anyone even if it explains why the common best practice is not really the best approach. As far as my own view of the topic (informed by software development in Perl for many years), I have seen three main approaches to error handling in a perl module (listed from best to worst in my opinion): Construct an object, set an invalid flag (usually "is_valid" method). Often coupled with setting error message via your class's error handling. Pros: Allows for standard (compared to other method calls) error handling as it allows to use $obj->errors() type calls after a bad constructor just like after any other method call. Allows for additional info to be passed (e.g. 1 error, warnings, etc...) Allows for lightweight "redo"/"fixme" functionality, In other words, if the object that is constructed is very heavy, with many complex attributes that are 100% always OK, and the only reason it is not valid is because someone entered an incorrect date, you can simply do "$obj->setDate()" instead of the overhead of re-executing entire constructor again. This pattern is not always needed, but can be enormously useful in the right design. Cons: None that I'm aware of. Return "undef". Cons: Can not achieve any of the Pros of the first solution (per-object error messages outside of global variables and lightweight "fixme" capability for heavy objects). Die inside the constructor. Outside of some very narrow edge cases, I personally consider this an awful choice for too many reasons to list on the margins of this question. UPDATE: Just to be clear, I consider the (otherwise very worthy and a great design) solution of having very simple constructor that can't fail at all and a heavy initializer method where all the error checking occurs to be merely a subset of either case #1 (if initializer sets error flags) or case #3 (if initializer dies) for the purposes of this question. Obviously, choosing such a design, you automatically reject option #2.

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  • Why is C++0x's `noexcept` checked dynamically?

    - by rlbond
    I am curious about the rationale behind noexcept in the C++0x FCD. throw(X) was depreciated, but noexcept seems to do the same thing. Is there a reason that noexcept isn't checked at compile time? It seems that it would be better if these functions were checked statically that they only called throwing functions within a try block.

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  • How to avoid an HttpException due to timeout

    - by Dan
    I'm working on a website powered by .NET asp/C# code. The clients require that sessions have a 25 minute timeout. However, sometimes the site is used, and a user stays connected for long periods of time (longer than 25 mins). Session_End is triggered: protected void Session_End(Object sender, EventArgs e) { Hashtable trackingInformaiton = (Hashtable)Application["trackingInformation"]; trackingInformaiton.Remove(Session["trackingID"]); } The user returns some time later, but when they interact with the website, they get an error, and we get this email notification: User: Unauthenticated User Error: System.Web.HttpException Description: Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request... The telling part of the stack trace is System.Web.UI.Control.AddedControl. Apparently, the server has thrown away the session data, and is sending new data, but the client is trying to deal with old data. Hence the error that "the control tree into which viewstate is being loaded [doesn't] match the control tree that was used to save the viewstate during the prevoius request." So here's the question. How can I force instruct the user's browser to redirect to a "you're logged out" screen when the connection times out? (Is it something I should add to the Session_End method?)

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  • good documentation about "avoid catching throwable", in context of weblogic server

    - by Marcel
    hi all, i am currently refactoring an existing codebase (EJBs...) to rip out all blocks where a Throwable is catched inside of the EJB. try { ... do some business logic } catch(Throwable t){ ... log and swallow ... :-( } i want/need to convince the people around me with proper documentation that "catching throwable" is a no-go for an EJB (we have lots of discussions around this :-(( ). weblogic will handle all the "Error" conditions and maybe invalidate EJBs and put fresh(working) EJBs into the pool. catching Throwable would undermine all these security nets provided by weblogic. and catching throwable is bad practice anyway (but people here are reluctant and use the "throwable" hammer everywhere). is anyone able to point me to some online docs where this behaviour is explained (for weblogic or jboss or...). i searched via google and had a look at the weblogic docs but wasn't able to find anything, just generic java doc. any help highly appreciated cheers marcel

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  • Exception Specification

    - by atch
    Hi, guys I know that this feature will be depracated in c++0x, but for me as a total novice it seems like a good idea to have it. Could anyone explain to me why isn't a good idea? Thanks in advance. P.S. I know I've said it but I'll say it again: formating in this forum really pisses me off. Why can't I have ENTER as end of line but instead of I have to press space twice?

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