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  • Transposing and Untransposing a String in java

    - by Will
    I have been working on two methods that will Transpose and Untranspose a String respectively. The solutions that I have come up with both work to the best of my knowledge. I just want to know if I could have solved these problems in a simpler way. My code seems like it is too long for the task that is being performed. The first method, transpose(), will take a String as a parameter and transpose it. If "bridge" is entered, the output will be "bergid". Likewise, with the unTranspose() method, if the user enters "bergid", the output will be "bridge". public void transpose( String s ) { String t = ""; int end = s.length() - 1; for ( int i = 0; i < s.length() / 2; i++ ) { t += Character.toString( s.charAt( i ) ) + Character.toString( s.charAt( end ) ); end--; } // Lenth of String is odd if ( s.length() % 2 == 1 ) { // add character in middle of String to the end of the new String t+= Character.toString( s.charAt( s.length() / 2 ) ); } System.out.println( t ); } public void unTranspose( String s ) { String t = ""; // Length of String is odd if ( s.length() % 2 == 1 ) { for ( int i = 0; i < s.length(); i+=2 ) { t+= Character.toString( s.charAt( i ) ); } for ( int i = s.length() - 2; i > 0; i -= 2 ) { t += Character.toString( s.charAt( i ) ); } System.out.println( t ); } // Length of String is even else if ( s.length() % 2 == 0 ) { for ( int i = 0; i < s.length() - 1; i+=2 ) { t+= Character.toString( s.charAt( i ) ); } for ( int i = s.length() - 1; i > 0; i -= 2 ) { t+= Character.toString( s.charAt( i ) ); } System.out.println( t ); } } My code looks horrible. I'm still not used to formatting my code correctly. Please bear with me. Thanks for your time

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  • Error using `loess.smooth` but not `loess` or `lowess`

    - by Sandy
    I need to smooth some simulated data, but occasionally run into problems when the simulated ordinates to be smoothed are mostly the same value. Here is a small reproducible example of the simplest case. > x <- 0:50 > y <- rep(0,51) > loess.smooth(x,y) Error in simpleLoess(y, x, w, span, degree, FALSE, FALSE, normalize = FALSE, : NA/NaN/Inf in foreign function call (arg 1) loess(y~x), lowess(x,y), and their analogue in MATLAB produce the expected results without error on this example. I am using loess.smooth here because I need the estimates evaluated at a set number of points. According to the documentation, I believe loess.smooth and loess are using the same estimation functions, but the former is an "auxiliary function" to handle the evaluation points. The error seems to come from a C function: > traceback() 3: .C(R_loess_raw, as.double(pseudovalues), as.double(x), as.double(weights), as.double(weights), as.integer(D), as.integer(N), as.double(span), as.integer(degree), as.integer(nonparametric), as.integer(order.drop.sqr), as.integer(sum.drop.sqr), as.double(span * cell), as.character(surf.stat), temp = double(N), parameter = integer(7), a = integer(max.kd), xi = double(max.kd), vert = double(2 * D), vval = double((D + 1) * max.kd), diagonal = double(N), trL = double(1), delta1 = double(1), delta2 = double(1), as.integer(0L)) 2: simpleLoess(y, x, w, span, degree, FALSE, FALSE, normalize = FALSE, "none", "interpolate", control$cell, iterations, control$trace.hat) 1: loess.smooth(x, y) loess also calls simpleLoess, but with what appears to be different arguments. Of course, if you vary enough of the y values to be nonzero, loess.smooth runs without error, but I need the program to run in even the most extreme case. Hopefully, someone can help me with one and/or all of the following: Understand why only loess.smooth, and not the other functions, produces this error and find a solution for this problem. Find a work-around using loess but still evaluating the estimate at a specified number of points that can differ from the vector x. For example, I might want to use only x <- seq(0,50,10) in the smoothing, but evaluate the estimate at x <- 0:50. As far as I know, using predict with a new data frame will not properly handle this situation, but please let me know if I am missing something there. Handle the error in a way that doesn't stop the program from moving onto the next simulated data set. Thanks in advance for any help on this problem.

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  • get_or_create generic relations in Django & python debugging in general

    - by rabidpebble
    I ran the code to create the generically related objects from this demo: http://www.djangoproject.com/documentation/models/generic_relations/ Everything is good intially: >>> bacon.tags.create(tag="fatty") <TaggedItem: fatty> >>> tag, newtag = bacon.tags.get_or_create(tag="fatty") >>> tag <TaggedItem: fatty> >>> newtag False But then the use case that I'm interested in for my app: >>> tag, newtag = bacon.tags.get_or_create(tag="wholesome") Traceback (most recent call last): File "<console>", line 1, in <module> File "/usr/local/lib/python2.6/dist-packages/django/db/models/manager.py", line 123, in get_or_create return self.get_query_set().get_or_create(**kwargs) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 343, in get_or_create raise e IntegrityError: app_taggeditem.content_type_id may not be NULL I tried a bunch of random things after looking at other code: >>> tag, newtag = bacon.tags.get_or_create(tag="wholesome", content_type=TaggedItem) ValueError: Cannot assign "<class 'generics.app.models.TaggedItem'>": "TaggedItem.content_type" must be a "ContentType" instance. or: >>> tag, newtag = bacon.tags.get_or_create(tag="wholesome", content_type=TaggedItem.content_type) InterfaceError: Error binding parameter 3 - probably unsupported type. etc. I'm sure somebody can give me the correct syntax, but the real problem here is that I have no idea what is going on. I have developed in strongly typed languages for over ten years (x86 assembly, C++ and C#) but am new to Python. I find it really difficult to follow what is going on in Python when things like this break. In the languages I mentioned previously it's fairly straightforward to figure things like this out -- check the method signature and check your parameters. Looking at the Django documentation for half an hour left me just as lost. Looking at the source for get_or_create(self, **kwargs) didn't help either since there is no method signature and the code appears very generic. A next step would be to debug the method and try to figure out what is happening, but this seems a bit extreme... I seem to be missing some fundamental operating principle here... what is it? How do I resolve issues like this on my own in the future?

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  • Best Practice: Legitimate Cross-Site Scripting

    - by Ryan
    While cross-site scripting is generally regarded as negative, I've run into several situations where it's necessary. I was recently working within the confines of a very limiting content management system. I needed to include database code within the page, but the hosting server didn't have anything usable available. I set up a couple barebones scripts on my own server, originally thinking that I could use AJAX to import the contents of my scripts directly into the template of the CMS (thus retaining dynamic images, menu items, CSS, etc.). I was wrong. Due to the limitations of XMLHttpRequest objects, it's not possible to grab content from a different domain. So I thought "iFrame" - even though I'm not a fan of frames, I thought that I could create a frame that matched the width and height of the content, so that it would appear native. Again, I was blocked by cross-site scripting "protections." While I could indeed load a remote file into the iFrame, I couldn't execute JavaScript to modify its size on either the host page or inside the loaded page. In this particular scenario, I wasn't able to point a subdomain to my server. I also couldn't create a script on the CMS server that could proxy content from my server, so my last thought was to use a remote JavaScript. A remote JavaScript works. It breaks when the user has JavaScript disabled, which is a downside; but it works. The "problem" I was having with using a remote JavaScript was that I had to use the JS function document.write() to output any content. Any output that isn't JS causes script errors. In addition to using document.write() for every line, you also have to ensure that the content is escaped - or else you end up with more script errors. My solution was as follows: My script received a GET parameter ("page") and then looked for the file ({$page}.php), and read the contents into a variable. However, I had to use awkward buffering techniques in order to actually execute the included scripts (for things like database interaction) then strip the final content of all line break characters ("\n") followed by escaping all required characters. The end result is that my original script (which outputs JavaScript) accesses seemingly "standard" scripts on my server and converts their standard output to JavaScript for displaying within the CMS template. While this solution works, it seems like there may be a better way to accomplish the same thing. What is the best way to make cross-site scripting work specifically for the purpose of including content from a completely different domain?

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  • Issue with class template partial specialization

    - by DeadMG
    I've been trying to implement a function that needs partial template specializations and fallen back to the static struct technique, and I'm having a number of problems. template<typename T> struct PushImpl<const T&> { typedef T* result_type; typedef const T& argument_type; template<int StackSize> static result_type Push(IStack<StackSize>* sptr, argument_type ref) { // Code if the template is T& } }; template<typename T> struct PushImpl<const T*> { typedef T* result_type; typedef const T* argument_type; template<int StackSize> static result_type Push(IStack<StackSize>* sptr, argument_type ptr) { return PushImpl<const T&>::Push(sptr, *ptr); } }; template<typename T> struct PushImpl { typedef T* result_type; typedef const T& argument_type; template<int StackSize> static result_type Push(IStack<StackSize>* sptr, argument_type ref) { // Code if the template is neither T* nor T& } }; template<typename T> typename PushImpl<T>::result_type Push(typename PushImpl<T>::argument_type ref) { return PushImpl<T>::Push(this, ref); } First: The struct is nested inside another class (the one that offers Push as a member func), but it can't access the template parameter (StackSize), even though my other nested classes all could. I've worked around it, but it would be cleaner if they could just access StackSize like a normal class. Second: The compiler complains that it doesn't use or can't deduce T. Really? Thirdly: The compiler complains that it can't specialize a template in the current scope (class scope). I can't see what the problem is. Have I accidentally invoked some bad syntax?

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  • open layers LineString not working

    - by AlexS
    Sorry to bother you guys, but I'm stuck with his problem for half a day. I want to draw poly line in OpenLayers using LineString object, so I've copied the example from documentation. It runs ok but i can't see the line on the screen Code looks like this <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> var map; var lineLayer ; var points; var style; var polygonFeature function test() { lineLayer = new OpenLayers.Layer.Vector("Line Layer"); style = { strokeColor: '#0000ff', strokeOpacity: 1, strokeWidth: 10 }; map.addLayer(lineLayer); points = new Array(); points[0] =new OpenLayers.LonLat(-2.460181,27.333984 ).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());; points[1] = new OpenLayers.LonLat(-3.864255,-22.5 ).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());; var linear_ring = new OpenLayers.Geometry.LinearRing(points); polygonFeature = new OpenLayers.Feature.Vector( new OpenLayers.Geometry.Polygon([linear_ring]), null, style); lineLayer.addFeatures([polygonFeature]); alert("1"); } function initialize() { map = new OpenLayers.Map ("map_canvas", { controls:[ new OpenLayers.Control.Navigation(), new OpenLayers.Control.PanZoomBar(), new OpenLayers.Control.LayerSwitcher(), new OpenLayers.Control.Attribution()], maxExtent: new OpenLayers.Bounds(-20037508.34,-20037508.34,20037508.34,20037508.34), maxResolution: 156543.0399, numZoomLevels: 19, units: 'm', projection: new OpenLayers.Projection("EPSG:900913"), displayProjection: new OpenLayers.Projection("EPSG:4326") }); // Define the map layer // Here we use a predefined layer that will be kept up to date with URL changes layerMapnik = new OpenLayers.Layer.OSM.Mapnik("Mapnik"); map.addLayer(layerMapnik); var lonLat = new OpenLayers.LonLat(0, 0).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject()); map.zoomTo(3); map.setCenter(lonLat, 19); test(); } </head> <body onload="initialize()" > <div id="map_canvas" style="width: 828px; height: 698px"></div> I'm sure I'm missing some parameter in creation of map or something but I really can't figure which one.

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  • Can't make my WCF extension work

    - by Sergio Romero
    I have a WCF solution that consists of the following class libraries: Exercise.Services: Contains the implementation classes for the services. Exercise.ServiceProxy: Contains the classes that are instantiated in the client. Exercise.HttpHost: Contains the services (*.svc files). I'm calling the service from a console application and the "first version" works really well so I took the next step which is to create a custom ServiceHostFactory, ServiceHost, and InstanceProvider so I can use constructor injection in my services as it is explained in this article. These classes are implemented in yet another class library: 4. Exercise.StructureMapWcfExtension Now even though I've modified my service this: <%@ ServiceHost Language="C#" Debug="true" Factory="Exercise.StructureMapWcfExtension.StructureMapServiceHostFactory" Service="Exercise.Services.PurchaseOrderService" %> I always get the following exception: System.ServiceModel.CommunicationException Security negotiation failed because the remote party did not send back a reply in a timely manner. This may be because the underlying transport connection was aborted. It fails in this line of code: public class PurchaseOrderProxy : ClientBase<IPurchaseOrderService>, IPurchaseOrderService { public PurchaseOrderResponse CreatePurchaseOrder(PurchaseOrderRequest purchaseOrderRequest) { return base.Channel.CreatePurchaseOrder(purchaseOrderRequest); //Fails here } } But that is not all, I added a trace to the web.config file and this is the error that appears in the log file: System.InvalidOperationException The service type provided could not be loaded as a service because it does not have a default (parameter-less) constructor. To fix the problem, add a default constructor to the type, or pass an instance of the type to the host. So this means that my ServiceHostFactory is never being hit, I even set a breakpoint in both its constructor and its method and they never get hit. I've added a reference of the StructureMapWcfExtension library to all the other ones (even the console client), one by one to no avail. I also tried to use the option in the host's web.config file to configure the factory like so: <serviceHostingEnvironment> <serviceActivations> <add service="Exercise.Services.PurchaseOrderService" relativeAddress="PurchaseOrderService.svc" factory="Exercise.StructureMapWcfExtension.StructureMapServiceHostFactory"/> </serviceActivations> </serviceHostingEnvironment> That didn't work either. Please I need help in getting this to work so I can incorporate it to our project. Thank you. UPDATE: Here's the service host factory's code: namespace Exercise.StructureMapWcfExtension { public class StructureMapServiceHostFactory : ServiceHostFactory { private readonly Container Container; public StructureMapServiceHostFactory() { Container = new Container(); new ContainerConfigurer().Configure(Container); } protected override ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses) { return new StructureMapServiceHost(Container, serviceType, baseAddresses); } } public class ContainerConfigurer { public void Configure(Container container) { container.Configure(r => r.For<IPurchaseOrderFacade>().Use<PurchaseOrderFacade>()); } } }

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  • Saving a reference to a int.

    - by Scott Chamberlain
    Here is a much simplified version of what I am trying to do static void Main(string[] args) { int test = 0; int test2 = 0; Test A = new Test(ref test); Test B = new Test(ref test); Test C = new Test(ref test2); A.write(); //Writes 1 should write 1 B.write(); //Writes 1 should write 2 C.write(); //Writes 1 should write 1 Console.ReadLine(); } class Test { int _a; public Test(ref int a) { _a = a; //I loose the reference here } public void write() { var b = System.Threading.Interlocked.Increment(ref _a); Console.WriteLine(b); } } In my real code I have a int that will be incremented by many threads however where the threads a called it will not be easy to pass it the parameter that points it at the int(In the real code this is happening inside a IEnumerator). So a requirement is the reference must be made in the constructor. Also not all threads will be pointing at the same single base int so I can not use a global static int either. I know I can just box the int inside a class and pass the class around but I wanted to know if that is the correct way of doing something like this? What I think could be the correct way: static void Main(string[] args) { Holder holder = new Holder(0); Holder holder2 = new Holder(0); Test A = new Test(holder); Test B = new Test(holder); Test C = new Test(holder2); A.write(); //Writes 1 should write 1 B.write(); //Writes 2 should write 2 C.write(); //Writes 1 should write 1 Console.ReadLine(); } class Holder { public Holder(int i) { num = i; } public int num; } class Test { Holder _holder; public Test(Holder holder) { _holder = holder; } public void write() { var b = System.Threading.Interlocked.Increment(ref _holder.num); Console.WriteLine(b); } } Is there a better way than this?

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  • How do you increase the number of processes in parallel with Powershell 3?

    - by Mark Shay
    I am trying to run 20 processes in parallel. I changed the session as below, but having no luck. I am getting only up to 5 parallel processes per session. $wo=New-PSWorkflowExecutionOption -MaxSessionsPerWorkflow 50 -MaxDisconnectedSessions 200 -MaxSessionsPerRemoteNode 50 -MaxActivityProcesses 50 Register-PSSessionConfiguration -Name ITWorkflows -SessionTypeOption $wo -Force Get-PSSessionConfiguration ITWorkflows | Format-List -Property * Is there a switch parameter to increase the number of processes? This is what I am running: Workflow MyWorkflow1 { Parallel { InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 2 and 2975416"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 2975417 and 5950831"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 5950832 and 8926246"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 8926247 and 11901661"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 11901662 and 14877076"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns"where OrderId between 14877077 and 17852491"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 17852492 and 20827906"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 20827907 and 23803321"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 23803322 and 26778736"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 26778737 and 29754151"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 29754152 and 32729566"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 32729567 and 35704981"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 35704982 and 38680396"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 38680397 and 432472144"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 432472145 and 435447559"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 435447560 and 438422974"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 864944289 and 867919703"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 867919704 and 870895118"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 870895119 and 1291465602"} InlineScript { import-module \\PS_Scripts\bulkins.ps1; BulkIns "where OrderId between 1291465603 and 1717986945"} }

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  • ArgumentNullException when accessing a FormView instance

    - by David
    Background: I have an ASP.NET page which has a numebr of user controls within it. There are 2 user controls which are of interest. I need to display either one of them or neither of them, depending on the record selected previously. In the user controls I need to set properties of some controls which are in a FormView. So in my user control code-behind I have a number of properties which look something like this: Private ReadOnly Property phSectionReports() As PlaceHolder Get Return fvConfirmationReport.FindControl("phSectionReports") End Get End Property The problem: I am having problems with this Property. Sometimes it is returning Nothing/Null and sometimes it is throwing a NullArgumentException with the message "Value cannot be null. Parameter name: container". The exception is coming from trying to reference the fvConfirmationReport variable. fvConfirmationReport is the ID of my FormView in the page itself. So I am really after things to look for and if any ideas what sort of conditions (e.g stage in page cycle, etc.) might lead to this? An example stack trace is included below. ASP.NET 3.5 SP1, VB.NET Thanks, StackTrace: at System.Web.UI.DataBinder.GetPropertyValue(Object container, String propName) at System.Web.UI.WebControls.GridView.CreateChildControls(IEnumerable dataSource, Boolean dataBinding) at System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding(IEnumerable data) at System.Web.UI.WebControls.GridView.PerformDataBinding(IEnumerable data) at System.Web.UI.WebControls.DataBoundControl.OnDataSourceViewSelectCallback(IEnumerable data) at System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) at System.Web.UI.WebControls.DataBoundControl.PerformSelect() at System.Web.UI.WebControls.BaseDataBoundControl.DataBind() at System.Web.UI.WebControls.GridView.DataBind() at System.Web.UI.Control.DataBindChildren() at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) ...snip... at System.Web.UI.Control.DataBind() at System.Web.UI.Control.DataBindChildren() at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) at System.Web.UI.WebControls.FormView.CreateChildControls(IEnumerable dataSource, Boolean dataBinding) at System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding(IEnumerable data) at System.Web.UI.WebControls.FormView.PerformDataBinding(IEnumerable data) at System.Web.UI.WebControls.DataBoundControl.OnDataSourceViewSelectCallback(IEnumerable data) at System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) at System.Web.UI.WebControls.DataBoundControl.PerformSelect() at System.Web.UI.WebControls.BaseDataBoundControl.DataBind() at System.Web.UI.WebControls.FormView.DataBind() at System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() at System.Web.UI.WebControls.FormView.EnsureDataBound() at System.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls() at System.Web.UI.Control.EnsureChildControls() at System.Web.UI.Control.FindControl(String id, Int32 pathOffset) at System.Web.UI.Control.FindControl(String id) at App_UserControls_xxx_ucConfirmationForm.get_phSectionReports() in ucConfirmationForm.ascx.vb:line 343 at App_UserControls_xxx_ucConfirmationForm.Page_Load(Object sender, EventArgs e) in ucConfirmationForm.ascx.vb:line 412 at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() ...snip... at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

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  • Unable to execute stored Procedure using Java and JDBC

    - by jwmajors81
    I have been trying to execute a MS SQL Server stored procedure via JDBC today and have been unsuccessful thus far. The stored procedure has 1 input and 1 output parameter. With every combination I use when setting up the stored procedure call in code I get an error stating that the stored procedure couldn't be found. I have provided the stored procedure I'm executing below (NOTE: this is vendor code, so I cannot change it). set ANSI_NULLS ON set QUOTED_IDENTIFIER ON GO ALTER PROC [dbo].[spWCoTaskIdGen] @OutIdentifier int OUTPUT AS BEGIN DECLARE @HoldPolicyId int DECLARE @PolicyId char(14) IF NOT EXISTS ( SELECT * FROM UniqueIdentifierGen (UPDLOCK) ) INSERT INTO UniqueIdentifierGen VALUES (0) UPDATE UniqueIdentifierGen SET CurIdentifier = CurIdentifier + 1 SELECT @OutIdentifier = (SELECT CurIdentifier FROM UniqueIdentifierGen) END The code looks like: CallableStatement statement = connection .prepareCall("{call dbo.spWCoTaskIdGen(?)}"); statement.setInt(1, 0); ResultSet result = statement.executeQuery(); I get the following error: SEVERE: Could not find stored procedure 'dbo.spWCoTaskIdGen'. I have also tried CallableStatement statement = connection .prepareCall("{? = call dbo.spWCoTaskIdGen(?)}"); statement.registerOutParameter(1, java.sql.Types.INTEGER); statement.registerOutParameter(2, java.sql.Types.INTEGER); statement.executeQuery(); The above results in: SEVERE: Could not find stored procedure 'dbo.spWCoTaskIdGen'. I have also tried: CallableStatement statement = connection .prepareCall("{? = call spWCoTaskIdGen(?)}"); statement.registerOutParameter(1, java.sql.Types.INTEGER); statement.registerOutParameter(2, java.sql.Types.INTEGER); statement.executeQuery(); The code above resulted in the following error: Could not find stored procedure 'spWCoTaskIdGen'. Finally, I should also point out the following: I have used the MS SQL Server Management Studio tool and have been able to successfully run the stored procedure. The sql generated to execute the stored procedure is provided below: GO DECLARE @return_value int, @OutIdentifier int EXEC @return_value = [dbo].[spWCoTaskIdGen] @OutIdentifier = @OutIdentifier OUTPUT SELECT @OutIdentifier as N'@OutIdentifier ' SELECT 'Return Value' = @return_value GO The code being executed runs with the same user id that was used in point #1 above. In the code that creates the Connection object I log which database I'm connecting to and the code is connecting to the correct database. Any ideas? Thank you very much in advance.

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  • How can I use functools.partial on multiple methods on an object, and freeze parameters out of order

    - by Joseph Garvin
    I find functools.partial to be extremely useful, but I would like to be able to freeze arguments out of order (the argument you want to freeze is not always the first one) and I'd like to be able to apply it to several methods on a class at once, to make a proxy object that has the same methods as the underlying object except with some of its methods parameter being frozen (think of it as generalizing partial to apply to classes). I've managed to scrap together a version of functools.partial called 'bind' that lets me specify parameters out of order by passing them by keyword argument. That part works: >>> def foo(x, y): ... print x, y ... >>> bar = bind(foo, y=3) >>> bar(2) 2 3 But my proxy class does not work, and I'm not sure why: >>> class Foo(object): ... def bar(self, x, y): ... print x, y ... >>> a = Foo() >>> b = PureProxy(a, bar=bind(Foo.bar, y=3)) >>> b.bar(2) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: bar() takes exactly 3 arguments (2 given) I'm probably doing this all sorts of wrong because I'm just going by what I've pieced together from random documentation, blogs, and running dir() on all the pieces. Suggestions both on how to make this work and better ways to implement it would be appreciated ;) One detail I'm unsure about is how this should all interact with descriptors. Code follows. from types import MethodType class PureProxy(object): def __init__(self, underlying, **substitutions): self.underlying = underlying for name in substitutions: subst_attr = substitutions[name] if hasattr(subst_attr, "underlying"): setattr(self, name, MethodType(subst_attr, self, PureProxy)) def __getattribute__(self, name): return getattr(object.__getattribute__(self, "underlying"), name) def bind(f, *args, **kwargs): """ Lets you freeze arguments of a function be certain values. Unlike functools.partial, you can freeze arguments by name, which has the bonus of letting you freeze them out of order. args will be treated just like partial, but kwargs will properly take into account if you are specifying a regular argument by name. """ argspec = inspect.getargspec(f) argdict = copy(kwargs) if hasattr(f, "im_func"): f = f.im_func args_idx = 0 for arg in argspec.args: if args_idx >= len(args): break argdict[arg] = args[args_idx] args_idx += 1 num_plugged = args_idx def new_func(*inner_args, **inner_kwargs): args_idx = 0 for arg in argspec.args[num_plugged:]: if arg in argdict: continue if args_idx >= len(inner_args): # We can't raise an error here because some remaining arguments # may have been passed in by keyword. break argdict[arg] = inner_args[args_idx] args_idx += 1 f(**dict(argdict, **inner_kwargs)) new_func.underlying = f return new_func

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  • How to properly test Hibernate length restriction?

    - by Cesar
    I have a POJO mapped with Hibernate for persistence. In my mapping I specify the following: <class name="ExpertiseArea"> <id name="id" type="string"> <generator class="assigned" /> </id> <version name="version" column="VERSION" unsaved-value="null" /> <property name="name" type="string" unique="true" not-null="true" length="100" /> ... </class> And I want to test that if I set a name longer than 100 characters, the change won't be persisted. I have a DAO where I save the entity with the following code: public T makePersistent(T entity){ transaction = getSession().beginTransaction(); transaction.begin(); try{ getSession().saveOrUpdate(entity); transaction.commit(); }catch(HibernateException e){ logger.debug(e.getMessage()); transaction.rollback(); } return entity; } Actually the code above is from a GenericDAO which all my DAOs inherit from. Then I created the following test: public void testNameLengthMustBe100orLess(){ ExpertiseArea ea = new ExpertiseArea( "1234567890" + "1234567890" + "1234567890" + "1234567890" + "1234567890" + "1234567890" + "1234567890" + "1234567890" + "1234567890" + "1234567890"); assertTrue("Name should be 100 characters long", ea.getName().length() == 100); ead.makePersistent(ea); List<ExpertiseArea> result = ead.findAll(); assertEquals("Size must be 1", result.size(),1); ea.setName(ea.getName()+"1234567890"); ead.makePersistent(ea); ExpertiseArea retrieved = ead.findById(ea.getId(), false); assertTrue("Both objects should be equal", retrieved.equals(ea)); assertTrue("Name should be 100 characters long", (retrieved.getName().length() == 100)); } The object is persisted ok. Then I set a name longer than 100 characters and try to save the changes, which fails: 14:12:14,608 INFO StringType:162 - could not bind value '12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890' to parameter: 2; data exception: string data, right truncation 14:12:14,611 WARN JDBCExceptionReporter:100 - SQL Error: -3401, SQLState: 22001 14:12:14,611 ERROR JDBCExceptionReporter:101 - data exception: string data, right truncation 14:12:14,614 ERROR AbstractFlushingEventListener:324 - Could not synchronize database state with session org.hibernate.exception.DataException: could not update: [com.exp.model.ExpertiseArea#33BA7E09-3A79-4C9D-888B-4263314076AF] //Stack trace 14:12:14,615 DEBUG GenericDAO:87 - could not update: [com.exp.model.ExpertiseArea#33BA7E09-3A79-4C9D-888B-4263314076AF] 14:12:14,616 DEBUG JDBCTransaction:186 - rollback 14:12:14,616 DEBUG JDBCTransaction:197 - rolled back JDBC Connection That's expected behavior. However when I retrieve the persisted object to check if its name is still 100 characters long, the test fails. The way I see it, the retrieved object should have a name that is 100 characters long, given that the attempted update failed. The last assertion fails because the name is 110 characters long now, as if the ea instance was indeed updated. What am I doing wrong here?

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  • Problem with return 2 libc method

    - by jth
    Hi, I'am trying to understand the return2libc method. I'am using an ubuntu linux 9.10, 32 bit with ASLR disabled. In theory, it sounds quite easy, overwrite the saved eip with the address of system() (or whatever function you want), then put the address to which system() should return and after that, the parameter for system, the "/bin/bash"-string. But what happens is that my exploit keeps segfaulting the vulnerable program. I assume something with the system()-address went wrong. This is what I did so far: Determined the address of system(): (gdb) print system $1 = {<text variable, no debug info>} 0x167020 <system> (gdb) x/x system 0x167020 <system>: 0x890cec83 I used the subsequent x/x system because those 3 bytes returned by print system looks like an index in some sort of jumptable (PLT?), so I assume 0x890cec83 is the right address which is used to overwrite the saved eip. After that I determined the address of the /bin/bash string in memory, using a small C program which basically consists of this line: printf("Address of string /bin/bash: %p\n", getenv("SHELL")); Then I looked a little bit around in the memory and fount /bin/bash: (gdb) x/s 0xbffff6ca 0xbffff6ca: "/bin/bash" After I gathered this information, I filled the buffer: (gdb) b 9 Breakpoint 1 at 0x8048407: file victim.c, line 9. (gdb) r `perl -e 'print "A"x9 . "\x83\xec\x0c\x89FAKE\xca\f6\ff\bf";'` Breakpoint 1, main (argc=1111638594, argv=0xc360cca) at victim.c:10 10 return 0; (gdb) x/s 0xbffff6ca 0xbffff6ca: "/bin/bash" Stack frame looks like this: (gdb) i f Stack level 0, frame at 0xbffff440: eip = 0x8048407 in main (victim.c:10); saved eip 0x890cec83 source language c. Arglist at 0xbffff438, args: argc=1111638594, argv=0xc360cca Locals at 0xbffff438, Previous frame's sp is 0xbffff440 Saved registers: ebp at 0xbffff438, eip at 0xbffff43c This seems all right to me, saved eip was overwritten with the (hopefully) correct system()-address, return address for system was set to "FAKE" (shouldn't matter) and the address of /bin/bash also seems to be correct. When I'am continuing the execution, victim segfaults on some strange address and certainly not in 0x890cec83: (gdb) cont Continuing. Program received signal SIGSEGV, Segmentation fault. 0x0804840d in main (argc=Cannot access memory at address 0x41414149 ) at victim.c:11 11 } Has anyone an explanation or a hint what happens here and why the execution isn't redirected to 0x890cec83? Thanks in advance, any hint, and be it only vague, would be appreciated. I have no idea why this doesn't work.

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  • What are the benefits of using ORM over XML Serialization/Deserialization?

    - by Tequila Jinx
    I've been reading about NHibernate and Microsoft's Entity Framework to perform Object Relational Mapping against my data access layer. I'm interested in the benefits of having an established framework to perform ORM, but I'm curious as to the performance costs of using it against standard XML Serialization and Deserialization. Right now, I develop stored procedures in Oracle and SQL Server that use XML Types for either input or output parameters and return or shred XML depending on need. I use a custom database command object that uses generics to deserialize the XML results into a specified serializable class. By using a combination of generics, xml (de)serialization and Microsoft's DAAB, I've got a process that's fairly simple to develop against regardless of the data source. Moreover, since I exclusively use Stored Procedures to perform database operations, I'm mostly protected from changes in the data structure. Here's an over-simplified example of what I've been doing. static void main() { testXmlClass test = new test(1); test.Name = "Foo"; test.Save(); } // Example Serializable Class ------------------------------------------------ [XmlRootAttribute("test")] class testXmlClass() { [XmlElement(Name="id")] public int ID {set; get;} [XmlElement(Name="name")] public string Name {set; get;} //create an instance of the class loaded with data. public testXmlClass(int id) { GenericDBProvider db = new GenericDBProvider(); this = db.ExecuteSerializable("myGetByIDProcedure"); } //save the class to the database... public Save() { GenericDBProvider db = new GenericDBProvider(); db.AddInParameter("myInputParameter", DbType.XML, this); db.ExecuteSerializableNonQuery("mySaveProcedure"); } } // Database Handler ---------------------------------------------------------- class GenericDBProvider { public T ExecuteSerializable<T>(string commandText) where T : class { XmlSerializer xml = new XmlSerializer(typeof(T)); // connection and command code is assumed for the purposes of this example. // the final results basically just come down to... return xml.Deserialize(commandResults) as T; } public void ExecuteSerializableNonQuery(string commandText) { // once again, connection and command code is assumed... // basically, just execute the command along with the specified // parameters which have been serialized. } public void AddInParameter(string name, DbType type, object value) { StringWriter w = new StringWriter(); XmlSerializer x = new XmlSerializer(value.GetType()); //handle serialization for serializable classes. if (type == DbType.Xml && (value.GetType() != typeof(System.String))) { x.Serialize(w, value); w.Close(); // store serialized object in a DbParameterCollection accessible // to my other methods. } else { //handle all other parameter types } } } I'm starting a new project which will rely heavily on database operations. I'm very curious to know whether my current practices will be sustainable in a high-traffic situation and whether or not I should consider switching to NHibernate or Microsoft's Entity Framework to perform what essentially seems to boil down to the same thing I'm currently doing. I appreciate any advice you may have.

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  • HttpClient response handler always returns closed stream

    - by Alex Ciminian
    I'm new to Java development so please bear with me. Also, I hope I'm not the champion of tl;dr :). I'm using HttpClient to make requests over Http (duh!) and I'd gotten it to work for a simple servlet that receives an URL as a query string parameter. I realized that my code could use some refactoring, so I decided to make my own HttpResponseHandler, to clean up the code, make it reusable and improve exception handling. I currently have something like this: public class HttpResponseHandler implements ResponseHandler<InputStream>{ public InputStream handleResponse(HttpResponse response) throws ClientProtocolException, IOException { int statusCode = response.getStatusLine().getStatusCode(); InputStream in = null; if (statusCode != HttpStatus.SC_OK) { throw new HttpResponseException(statusCode, null); } else { HttpEntity entity = response.getEntity(); if (entity != null) { in = entity.getContent(); // This works // for (int i;(i = in.read()) >= 0;) System.out.print((char)i); } } return in; } } And in the method where I make the actual request: HttpClient httpclient = new DefaultHttpClient(); HttpGet httpget = new HttpGet(target); ResponseHandler<InputStream> httpResponseHandler = new HttpResponseHandler(); try { InputStream in = httpclient.execute(httpget, httpResponseHandler); // This doesn't work // for (int i;(i = in.read()) >= 0;) System.out.print((char)i); return in; } catch (HttpResponseException e) { throw new HttpResponseException(e.getStatusCode(), null); } The problem is that the input stream returned from the handler is closed. I don't have any idea why, but I've checked it with the prints in my code (and no, I haven't used them both at the same time :). While the first print works, the other one gives a closed stream error. I need InputStreams, because all my other methods expect an InputStream and not a String. Also, I want to be able to retrieve images (or maybe other types of files), not just text files. I can work around this pretty easily by giving up on the response handler (I have a working implementation that doesn't use it), but I'm pretty curious about the following: Why does it do what it does? How do I open the stream, if something closes it? What's the right way to do this, anyway :)? I've checked the docs and I couldn't find anything useful regarding this issue. To save you a bit of Googling, here's the Javadoc and here's the HttpClient tutorial (Section 1.1.8 - Response handlers). Thanks, Alex

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  • JDBC CommunicationsException with MySQL Database

    - by Dominik Siebel
    I'm having a little trouble with my MySQL- Connection- Pooling. This is the case: Different jobs are scheduled via Quartz. All jobs connect to different databases which works fine the whole day while the nightly scheduled jobs fail with a CommunicationsException... Quartz-Jobs: Job1 runs 0 0 6,10,14,18 * * ? Job2 runs 0 30 10,18 * * ? Job3 runs 0 0 5 * * ? As you can see the last job runs at 18 taking about 1 hour to run. The first job at 5am is the one that fails. I already tried all kinds of parameter-combinations in my resource config this is the one I am running right now: <!-- Database 1 (MySQL) --> <Resource auth="Container" driverClassName="com.mysql.jdbc.Driver" maxActive="100" maxIdle="30" maxWait="10000" removeAbandoned="true" removeAbandonedTimeout="60" logAbandoned="true" type="javax.sql.DataSource" name="jdbc/appDbProd" username="****" password="****" url="jdbc:mysql://127.0.0.1:3306/appDbProd?autoReconnect=true&amp;useUnicode=true&amp;characterEncoding=UTF-8" testWhileIdle="true" testOnBorrow="true" testOnReturn="true" validationQuery="SELECT 1" timeBetweenEvictionRunsMillis="1800000" /> <!-- Database 2 (MySQL) --> <Resource auth="Container" driverClassName="com.mysql.jdbc.Driver" maxActive="100" maxIdle="30" maxWait="10000" removeAbandoned="true" removeAbandonedTimeout="60" logAbandoned="true" type="javax.sql.DataSource" name="jdbc/prodDbCopy" username="****" password="****" url="jdbc:mysql://127.0.0.1:3306/prodDbCopy?autoReconnect=true&amp;useUnicode=true&amp;characterEncoding=UTF-8" testWhileIdle="true" testOnBorrow="true" testOnReturn="true" validationQuery="SELECT 1" timeBetweenEvictionRunsMillis="1800000" /> <!-- Database 3 (MSSQL)--> <Resource auth="Container" driverClassName="net.sourceforge.jtds.jdbc.Driver" maxActive="30" maxIdle="30" maxWait="100" removeAbandoned="true" removeAbandonedTimeout="60" logAbandoned="true" name="jdbc/catalogDb" username="****" password="****" type="javax.sql.DataSource" url="jdbc:jtds:sqlserver://127.0.0.1:1433;databaseName=catalog;useNdTLMv2=false" testWhileIdle="true" testOnBorrow="true" testOnReturn="true" validationQuery="SELECT 1" timeBetweenEvictionRunsMillis="1800000" /> For obvious reasons I changed IPs, Usernames and Passwords but they can be assumed to be correct, seeing that the application runs successfully the whole day. The most annoying thing is: The first job that runs first queries Database2 successfully but fails to query Database1 for some reason (CommunicationsException): Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 39,376,539 milliseconds ago. The last packet sent successfully to the server was 39,376,539 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem. Any ideas? Thanks!

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  • How to convert a 32bpp image to an indexed format?

    - by Ed Swangren
    So here are the details (I am using C# BTW): I receive a 32bpp image (JPEG compressed) from a server. At some point, I would like to use the Palette property of a bitmap to color over-saturated pixels (brightness 240) red. To do so, I need to get the image into an indexed format. I have tried converting the image to a GIF, but I get quality loss. I have tried creating a new bitmap in an index format by these methods: // causes a "Parameter not valid" error Bitmap indexed = new Bitmap(orig.Width, orig.Height, PixelFormat.Indexed) // no error, but the resulting image is black due to information loss I assume Bitmap indexed = new Bitmap(orig.Width, orig.Height, PixelFormat.Format8bppIndexed) I am at a loss now. The data in this image is changed constantly by the user, so I don't want to manually set pixels that have a brightness 240 if I can avoid it. If I can set the palette once when the image is created, my work is done. If I am going about this the wrong way to begin with please let me know. EDIT: Thanks guys, here is some more detail on what I am attempting to accomplish. We are scanning a tissue slide at high resolution (pathology application). I write the interface to the actual scanner. We use a line-scan camera. To test the line rate of the camera, the user scans a very small portion and looks at the image. The image is displayed next to a track bar. When the user moves the track bar (adjusting line rate), I change the overall intensity of the image in an attempt to model what it would look like at the new line rate. I do this using an ImageAttributes and ColorMatrix object currently. When the user adjusts the track bar, I adjust the matrix. This does not give me per pixel information, but the performance is very nice. I could use LockBits and some unsafe code here, but I would rather not rewrite it if possible. When the new image is created, I would like for all pixels with a brightness value of 240 to be colored red. I was thinking that defining a palette for the bitmap up front would be a clean way of doing this.

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  • Checking a set of listbox items against a text box vb.net

    - by Shane Fagan
    Hi all I have this code to check if an item from a textbox is in a listbox and its giving me the error at the bottom. Any ideas what im doing wrong? I copied it from another part of my project and it was working for that part so I cant see whats wrong. If LocationsSearchTextBox.Text <> "" And LocationListBox.Items.Count > 0 Then tempInt = 0 While (tempInt < ClientListBox.Items.Count) If LocationListBox.Items(tempInt).ToString.Contains(LocationsSearchTextBox.Text) = False Then LocationListBox.Items.RemoveAt(tempInt) End If tempInt += 1 End While End If System.ArgumentOutOfRangeException was unhandled Message="InvalidArgument=Value of '2' is not valid for 'index'. Parameter name: index" ParamName="index" Source="System.Windows.Forms" StackTrace: at System.Windows.Forms.ListBox.ObjectCollection.get_Item(Int32 index) at AuctioneerProject.Viewing.LocationsSearchTextBox_KeyPress(Object sender, KeyPressEventArgs e) in C:\Users\admin\Desktop\Auctioneers\AuctioneerProject\AuctioneerProject\Viewing.vb:line 301 at System.Windows.Forms.Control.OnKeyPress(KeyPressEventArgs e) at System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m) at System.Windows.Forms.Control.ProcessKeyMessage(Message& m) at System.Windows.Forms.Control.WmKeyChar(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.TextBoxBase.WndProc(Message& m) at System.Windows.Forms.TextBox.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine) at AuctioneerProject.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException:

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  • Under what circumstances is an SqlConnection automatically enlisted in an ambient TransactionScope T

    - by Triynko
    What does it mean for an SqlConnection to be "enlisted" in a transaction? Does it simply mean that commands I execute on the connection will participate in the transaction? If so, under what circumstances is an SqlConnection automatically enlisted in an ambient TransactionScope Transaction? See questions in code comments. My guess to each question's answer follows each question in parenthesis. Scenario 1: Opening connections INSIDE a transaction scope using (TransactionScope scope = new TransactionScope()) using (SqlConnection conn = ConnectToDB()) { // Q1: Is connection automatically enlisted in transaction? (Yes?) // // Q2: If I open (and run commands on) a second connection now, // with an identical connection string, // what, if any, is the relationship of this second connection to the first? // // Q3: Will this second connection's automatic enlistment // in the current transaction scope cause the transaction to be // escalated to a distributed transaction? (Yes?) } Scenario 2: Using connections INSIDE a transaction scope that were opened OUTSIDE of it //Assume no ambient transaction active now SqlConnection new_or_existing_connection = ConnectToDB(); //or passed in as method parameter using (TransactionScope scope = new TransactionScope()) { // Connection was opened before transaction scope was created // Q4: If I start executing commands on the connection now, // will it automatically become enlisted in the current transaction scope? (No?) // // Q5: If not enlisted, will commands I execute on the connection now // participate in the ambient transaction? (No?) // // Q6: If commands on this connection are // not participating in the current transaction, will they be committed // even if rollback the current transaction scope? (Yes?) // // If my thoughts are correct, all of the above is disturbing, // because it would look like I'm executing commands // in a transaction scope, when in fact I'm not at all, // until I do the following... // // Now enlisting existing connection in current transaction conn.EnlistTransaction( Transaction.Current ); // // Q7: Does the above method explicitly enlist the pre-existing connection // in the current ambient transaction, so that commands I // execute on the connection now participate in the // ambient transaction? (Yes?) // // Q8: If the existing connection was already enlisted in a transaction // when I called the above method, what would happen? Might an error be thrown? (Probably?) // // Q9: If the existing connection was already enlisted in a transaction // and I did NOT call the above method to enlist it, would any commands // I execute on it participate in it's existing transaction rather than // the current transaction scope. (Yes?) }

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  • Opinion on "loop invariants", and are these frequently used in the industry?

    - by Michael Aaron Safyan
    I was thinking back to my freshman year at college (five years ago) when I took an exam to place-out of intro-level computer science. There was a question about loop invariants, and I was wondering if loop invariants are really necessary in this case or if the question was simply a bad example... the question was to write an iterative definition for a factorial function, and then to prove that the function was correct. The code that I provided for the factorial function was as follows: public static int factorial(int x) { if ( x < 0 ){ throw new IllegalArgumentException("Parameter must be = 0"); }else if ( x == 0 ){ return 1; }else{ int result = 1; for ( int i = 1; i <= x; i++ ){ result*=i; } return result; } } My own proof of correctness was a proof by cases, and in each I asserted that it was correct by definition (x! is undefined for negative values, 0! is 1, and x! is 1*2*3...*x for a positive value of x). The professor wanted me to prove the loop using a loop invariant; however, my argument was that it was correct "by definition", because the definition of "x!" for a positive integer x is "the product of the integers from 1... x", and the for-loop in the else clause is simply a literal translation of this definition. Is a loop invariant really needed as a proof of correctness in this case? How complicated must a loop be before a loop invariant (and proper initialization and termination conditions) become necessary for a proof of correctness? Additionally, I was wondering... how often are such formal proofs used in the industry? I have found that about half of my courses are very theoretical and proof-heavy and about half are very implementation and coding-heavy, without any formal or theoretical material. How much do these overlap in practice? If you do use proofs in the industry, when do you apply them (always, only if it's complicated, rarely, never)?

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  • Using Complex datatype with python SUDS client

    - by sachin
    hi, I am trying to call webservice from python client using SUDS. When I call a function with a complex data type as input parameter, it is not passed correctly, but complex data type is getting returned correctly froma webservice call. Webservice Type: Soap Binding 1.1 Document/Literal Webserver: Weblogic 10.3 Python Version: 2.6.5, SUDS version: 0.3.9 here is the code I am using: Python Client: from suds.client import Client url = 'http://192.168.1.3:7001/WebServiceSecurityOWSM-simple_ws-context-root/SimpleServicePort?WSDL' client = Client(url) print client #simple function with no operation on input... result = client.service.sopHello() print result result = client.service.add10(10) print result params = client.factory.create('paramBean') print params params.intval = 10 params.longval = 20 params.strval = 'string value' #print "params" print params try: result = client.service.printParamBean(params) print result except WebFault, e: print e try: result = client.service.modifyParamBean(params) print result except WebFault, e: print e print params webservice java class: package simple_ws; import javax.jws.Oneway; import javax.jws.WebMethod; import javax.jws.WebService; import javax.jws.soap.SOAPBinding; public class SimpleService { public SimpleService() { } public void sopHello(int i) { System.out.println("sopHello: hello"); } public int add10(int i) { System.out.println("add10:"); return 10+i; } public void printParamBean(ParamBean pb) { System.out.println(pb); } public ParamBean modifyParamBean(ParamBean pb) { System.out.println(pb); pb.setIntval(pb.getIntval()+10); pb.setStrval(pb.getStrval()+"blah blah"); pb.setLongval(pb.getLongval()+200); return pb; } } and the bean Class: package simple_ws; public class ParamBean { int intval; String strval; long longval; public void setIntval(int intval) { this.intval = intval; } public int getIntval() { return intval; } public void setStrval(String strval) { this.strval = strval; } public String getStrval() { return strval; } public void setLongval(long longval) { this.longval = longval; } public long getLongval() { return longval; } public String toString() { String stri = "\nInt val:" +intval; String strstr = "\nstrval val:" +strval; String strl = "\nlong val:" +longval; return stri+strstr+strl; } } so, as issue is like this: on call: client.service.printParamBean(params) in python client, output on server side is: Int val:0 strval val:null long val:0 but on call: client.service.modifyParamBean(params) Client output is: (reply){ intval = 10 longval = 200 strval = "nullblah blah" } What am i doing wrong here??

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  • G++, compiler warnings, c++ templates

    - by Ian
    During the compilatiion of the C++ program those warnings appeared: c:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bc:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:2317: instantiated from `void std::partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Object<double>**, std::vector<Object<double>*, std::allocator<Object<double>*> > >, _Compare = sortObjects<double>]' c:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:2506: instantiated from `void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Object<double>**, std::vector<Object<double>*, std::allocator<Object<double>*> > >, _Size = int, _Compare = sortObjects<double>]' c:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:2589: instantiated from `void std::sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Object<double>**, std::vector<Object<double>*, std::allocator<Object<double>*> > >, _Compare = sortObjects<double>]' io/../structures/objects/../../algorithm/analysis/../../structures/list/ObjectsList.hpp:141: instantiated from `void ObjectsList <T>::sortObjects(unsigned int, T, T, T, T, unsigned int) [with T = double]' I do not why, because all objects have only template parameter T, their local variables are also T. The only place, where I am using double is main. There are objects of type double creating and adding into the ObjectsList... Object <double> o1; ObjectsList <double> olist; olist.push_back(o1); .... T xmin = ..., ymin = ..., xmax = ..., ymax = ...; unsigned int n = ...; olist.sortAllObjects(xmin, ymin, xmax, ymax, n); and comparator template <class T> class sortObjects { private: unsigned int n; T xmin, ymin, xmax, ymax; public: sortObjects ( const T xmin_, const T ymin_, const T xmax_, const T ymax_, const int n_ ) : xmin ( xmin_ ), ymin ( ymin_ ), xmax ( xmax_ ), ymax ( ymax_ ), n ( n_ ) {} bool operator() ( const Object <T> *o1, const Object <T> *o2 ) const { T dmax = (std::max) ( xmax - xmin, ymax - ymin ); T x_max = ( xmax - xmin ) / dmax; T y_max = ( ymax - ymin ) / dmax; ... return ....; } representing ObjectsList method: template <class T> void ObjectsList <T> ::sortAllObjects ( const T xmin, const T ymin, const T xmax, const T ymax, const unsigned int n ) { std::sort ( objects.begin(), objects.end(), sortObjects <T> ( xmin, ymin, xmax, ymax, n ) ); }

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  • How to combine designable components with dependency injection

    - by Wim Coenen
    When creating a designable .NET component, you are required to provide a default constructor. From the IComponent documentation: To be a component, a class must implement the IComponent interface and provide a basic constructor that requires no parameters or a single parameter of type IContainer. This makes it impossible to do dependency injection via constructor arguments. (Extra constructors could be provided, but the designer would ignore them.) Some alternatives we're considering: Service Locator Don't use dependency injection, instead use the service locator pattern to acquire dependencies. This seems to be what IComponent.Site.GetService is for. I guess we could create a reusable ISite implementation (ConfigurableServiceLocator?) which can be configured with the necessary dependencies. But how does this work in a designer context? Dependency Injection via properties Inject dependencies via properties. Provide default instances if they are necessary to show the component in a designer. Document which properties need to be injected. Inject dependencies with an Initialize method This is much like injection via properties but it keeps the list of dependencies that need to be injected in one place. This way the list of required dependencies is documented implicitly, and the compiler will assists you with errors when the list changes. Any idea what the best practice is here? How do you do it? edit: I have removed "(e.g. a WinForms UserControl)" since I intended the question to be about components in general. Components are all about inversion of control (see section 8.3.1 of the UMLv2 specification) so I don't think that "you shouldn't inject any services" is a good answer. edit 2: It took some playing with WPF and the MVVM pattern to finally "get" Mark's answer. I see now that visual controls are indeed a special case. As for using non-visual components on designer surfaces, I think the .NET component model is fundamentally incompatible with dependency injection. It appears to be designed around the service locator pattern instead. Maybe this will start to change with the infrastructure that was added in .NET 4.0 in the System.ComponentModel.Composition namespace.

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  • live search with Jquery

    - by user272899
    Hello! I am trying to implement a live search on my site. I am using a script somebody has already created. http://www.reynoldsftw.com/2009/03/live-mysql-database-search-with-jquery/ I have got the Jquery, css, html working correctly but am having troubles with the php. I need to change it to contain my database information but everytime I do I recieve an error: Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\wamp\www\search.php on line 33 These are the details of my database: database name: development table name: links Columns: id, sitename, siteurl, description, category This is the php script <?php $dbhost = "localhost"; $dbuser = "root"; $dbpass = "password"; $dbname = "links"; $conn = mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql'); mysql_select_db($dbname); if(isset($_GET['query'])) { $query = $_GET['query']; } else { $query = ""; } if(isset($_GET['type'])) { $type = $_GET['type']; } else { $query = "count"; } if($type == "count") { $sql = mysql_query("SELECT count(url_id) FROM urls WHERE MATCH(url_url, url_title, url_desc) AGAINST('$query' IN BOOLEAN MODE)"); $total = mysql_fetch_array($sql); $num = $total[0]; echo $num; } if($type == "results") { $sql = mysql_query("SELECT url_url, url_title, url_desc FROM urls WHERE MATCH(url_url, url_title, url_desc) AGAINST('$query' IN BOOLEAN MODE)"); while($array = mysql_fetch_array($sql)) { $url_url = $array['url_url']; $url_title = $array['url_title']; $url_desc = $array['url_desc']; echo "<div class=\"url-holder\"><a href=\"" . $url_url . "\" class=\"url-title\" target=\"_blank\">" . $url_title . "</a> <div class=\"url-desc\">" . $url_desc . "</div></div>"; } } mysql_close($conn); ?> Can anybody help me input this database info correctly? I have tried many times but keep getting an error. Thanks in advance.

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