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• How do I write a J2EE/EJB Singleton?

  - by Bears will eat you

  A day ago my application was one EAR, containing one WAR, one EJB JAR, and a couple of utility JAR files. I had a POJO singleton class in one of those utility files, it worked, and all was well with the world: EAR |--- WAR |--- EJB JAR |--- Util 1 JAR |--- Util 2 JAR |--- etc. Then I created a second WAR and found out (the hard way) that each WAR has its own ClassLoader, so each WAR sees a different singleton, and things break down from there. This is not so good. EAR |--- WAR 1 |--- WAR 2 |--- EJB JAR |--- Util 1 JAR |--- Util 2 JAR |--- etc. So, I'm looking for a way to create a Java singleton object that will work across WARs (across ClassLoaders?). The @Singleton EJB annotation seemed pretty promising until I found that JBoss 5.1 doesn't seem to support that annotation (which was added as part of EJB 3.1). Did I miss something - can I use @Singleton with JBoss 5.1? Upgrading to JBoss AS 6 is not an option right now. Alternately, I'd be just as happy to not have to use EJB to implement my singleton. What else can I do to solve this problem? Basically, I need a semi-application-wide* hook into a whole bunch of other objects, like various cached data, and app config info. As a last resort, I've already considered merging my two WARs into one, but that would be pretty hellish. *Meaning: available basically anywhere above a certain layer; for now, mostly in my WARs - the View and Controller (in a loose sense).

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• Orphan IBM JVM process

  - by Nicholas Key

  Hi people, I have this issue about orphan IBM JVM process being created in the process tree: For example: C:\Program Files\IBM\WebSphere\AppServer\bin>wsadmin -lang jython -f "C:\Hello.py" Hello.py has the simple implementation: import time i = 0 while (1): i = i + 1 print "Hello World " + str(i) time.sleep(3.0) My machine has such JVM information: C:\Program Files\WebSphere\java\bin>java -verbose:sizes -version -Xmca32K RAM class segment increment -Xmco128K ROM class segment increment -Xmns0K initial new space size -Xmnx0K maximum new space size -Xms4M initial memory size -Xmos4M initial old space size -Xmox1624995K maximum old space size -Xmx1624995K memory maximum -Xmr16K remembered set size -Xlp4K large page size available large page sizes: 4K 4M -Xmso256K operating system thread stack size -Xiss2K java thread stack initial size -Xssi16K java thread stack increment -Xss256K java thread stack maximum size java version "1.6.0" Java(TM) SE Runtime Environment (build pwi3260sr6ifix-20091015_01(SR6+152211+155930+156106)) IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Windows Server 2003 x86-32 jvmwi3260sr6-20091001_43491 (JIT enabled, AOT enabled) J9VM - 20091001_043491 JIT - r9_20090902_1330ifx1 GC - 20090817_AA) JCL - 20091006_01 While the program is running, I tried to kill it and subsequently I found an orphan IBM JVM process in the process tree. Is there a way to fix this issue? Why is there an orphan process in the first place? Is there something wrong with my code? I really don't believe that my simplistic code is wrongly implemented. Any suggestions?

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• Using Partitions for a large MySQL table

  - by user293594

  An update on my attempts to implement a 505,000,000-row table on MySQL on my MacBook Pro: Following the advice given, I have partitioned my table, tr: i UNSIGNED INT NOT NULL, j UNSIGNED INT NOT NULL, A FLOAT(12,8) NOT NULL, nu BIGINT NOT NULL, KEY (nu), key (A) with a range on nu. nu ought to be a real number, but because I only have 6-d.p. accuracy and the maximum value of nu is 30000. I multiplied it by 10^8 made it a BIGINT - I gather one can't use FLOAT or DOUBLE values to PARTITION a MySQL table. Anyway, I have 15 partitions (p0: nu<25,000,000,000, p1: nu<50,000,000,000, etc.). I was thinking that this should speed up a typical to SELECT: SELECT * FROM tr WHERE nu>95000000000 AND nu<100000000000 AND A.>1. to something of the order of the same query on a table consisting of only the data in the relevant partition (<30 secs). But it's taking 30mins+ to return rows for queries within a partition and double that if the query is for rows spanning two (contiguous) partitions. I realise I could just have 15 different tables, and query them separately, but is there a way to do this 'automatically' with partitions? Has anyone got any suggestions?

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• suggestions for declarative GUI programming in Java

  - by Jason S

  I wonder if there are any suggestions for declarative GUI programming in Java. (I abhor visual-based GUI creator/editor software, but am getting a little tired of manually instantiating JPanels and Boxes and JLabels and JLists etc.) That's my overall question, but I have two specific questions for approaches I'm thinking of taking: JavaFX: is there an example somewhere of a realistic GUI display (e.g. not circles and rectangles, but listboxes and buttons and labels and the like) in JavaFX, which can interface with a Java sourcefile that accesses and updates various elements? Plain Old Swing with something to parse XUL-ish XML: has anyone invented a declarative syntax (like XUL) for XML for use with Java Swing? I suppose it wouldn't be hard to do, to create some code based on STaX which reads an XML file, instantiates a hierarchy of Swing elements, and makes the hierarchy accessible through some kind of object model. But I'd rather use something that's well-known and documented and tested than to try to invent such a thing myself. JGoodies Forms -- not exactly declarative, but kinda close & I've had good luck with JGoodies Binding. But their syntax for Form Layout seems kinda cryptic. edit: lots of great answers here! (& I added #3 above) I'd be especially grateful for hearing any experiences any of you have had with using one of these frameworks for real-world applications. p.s. I did try a few google searches ("java gui declarative"), just didn't quite know what to look for.

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• Why does this data YYYY-MM-DD regex fail in Java?

  - by ProfessionalAmateur

  Hello StackOverFlow, My first question and Im excited... I've lurked since go-live and love the site, however I apologize for any newbie errors, formatting, etc... I'm attempting to validate the format of a string field that contains a date in Java. We will receive the date in a string, I will validate its format before parsing it into a real Date object. The format being passed in is in the YYYY-MM-DD format. However I'm stuck on one of my tests, if I pass in "1999-12-33" the test will fail (as it should with a day number 33) with this incomplete pattern: ((19|20)\\d{2})-([1-9]|0[1-9]|1[0-2])-([12][0-9]|3[01]) However as soon as I add the characters in bold below it passes the test (but should not) ((19|20)\\d{2})-([1-9]|0[1-9]|1[0-2])-(0[1-9]|[1-9]|[12][0-9]|3[01]) *additional note, I know I can change the 0[1-9]|[1-9] into 0?[1-9] but I wanted to break everything down to its most simple format to try and find why this isn't working. Here is the scrap test I've put together to run through all the different date scenarios: import java.util.regex.Matcher; import java.util.regex.Pattern; public class scrapTest { public scrapTest() { } public static void main(String[] args) { scrapTest a = new scrapTest(); boolean flag = a.verfiyDateFormat("1999-12-33"); } private boolean verfiyDateFormat(String dateStr){ Pattern datePattern = Pattern.compile("((19|20)\\d{2})-([1-9]|0[1-9]|1[0-2])-(0[1-9]|[1-9]|[12][0-9]|3[01])"); Matcher dateMatcher = datePattern.matcher(dateStr); if(!dateMatcher.find()){ System.out.println("Invalid date format!!! -> " + dateStr); return false; } System.out.println("Valid date format."); return true; } } Ive been programming for ~10 years but extremely new to Java, so please feel free to explain anything as elementary as you see fit.

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• I've made something that might be useful to the community. Now what?

  - by Chris McCall

  If the specifics are important, I made a cruisecontrol.net publisher plugin that notifies a series of phone numbers via voice, announcing the current state of the build. It uses Twilio to do so. I'd like to avoid getting hung up on the specifics of what it is I've made, as I have this question a lot, with a number of little hobby one-offs. What's the state of the art as far as making my hobby output available to the world at large? There seem to be a lot of options for open-source project hosting, community features, and what role to take in all of this. It's a little bewildering. What I'm looking for is to put this out into the wild for free and basically take a hands-off approach from there. Is that realistic? Which project hosting service can I use for free to allow developers to at least download the code, report issues and collaborate with each other to improve the product? What snags have you run into that could make me regret this decision? I'm interested in war stories, advice and guidance on making this little product available to the community where it can be used.

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• Rhino Mocks Partial Mock

  - by dotnet crazy kid

  I am trying to test the logic from some existing classes. It is not possible to re-factor the classes at present as they are very complex and in production. What I want to do is create a mock object and test a method that internally calls another method that is very hard to mock. So I want to just set a behaviour for the secondary method call. But when I setup the behaviour for the method, the code of the method is invoked and fails. Am I missing something or is this just not possible to test without re-factoring the class? I have tried all the different mock types (Strick,Stub,Dynamic,Partial ect.) but they all end up calling the method when I try to set up the behaviour. using System; using MbUnit.Framework; using Rhino.Mocks; namespace MMBusinessObjects.Tests { [TestFixture] public class PartialMockExampleFixture { [Test] public void Simple_Partial_Mock_Test() { const string param = "anything"; //setup mocks MockRepository mocks = new MockRepository(); var mockTestClass = mocks.StrictMock<TestClass>(); //record beahviour *** actualy call into the real method stub *** Expect.Call(mockTestClass.MethodToMock(param)).Return(true); //never get to here mocks.ReplayAll(); //this is what i want to test Assert.IsTrue(mockTestClass.MethodIWantToTest(param)); } public class TestClass { public bool MethodToMock(string param) { //some logic that is very hard to mock throw new NotImplementedException(); } public bool MethodIWantToTest(string param) { //this method calls the if( MethodToMock(param) ) { //some logic i want to test } return true; } } } }

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• java logging nightmare and log4j not behaving as expected with spring + tomcat6

  - by maverick

  I have a spring application that has configured log4j (via xml) and that runs on Tomcat6 that was working fine until we add a bunch of dependencies via Maven. At some point the whole application just started logging part of what it was supposed to be declared into the log4.xml "a small rant here" Why logging has to be that hard in java world? why suddenly an application that was just fine start behaving so weird and why it's so freaking hard to debug? I've been reading and trying to solve this issue for days but so far no luck, hopefully some expert here can give me some insights on this I've added log4j debug option to check whether log4j is taking reading the config file and its values and this is what part of it shows log4j: Level value for org.springframework.web is [debug]. log4j: org.springframework.web level set to DEBUG log4j: Retreiving an instance of org.apache.log4j.Logger. log4j: Setting [org.compass] additivity to [true]. log4j: Level value for org.compass is [debug]. log4j: org.compass level set to DEBUG As you can see debug is enabled for compass and spring.web but it only shows "INFO" level for both packages. My log4j config file has nothing out of extraordinary just a plain ConsoleAppender <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> <!-- Appenders --> <appender name="console" class="org.apache.log4j.ConsoleAppender"> <param name="Target" value="System.out" /> <layout class="org.apache.log4j.PatternLayout"> <param name="ConversionPattern" value="%-5p: %c - %m%n" /> </layout> </appender> What's the trick to make this work? What it's my misunderstanding here? Can someone point me in the right direction and explain how can I make this logging mess more bullet proof?

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• How can i add image in email body

  - by Kutbi

  final Intent i = new Intent(android.content.Intent.ACTION_SEND); i.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{ txt.getText().toString()}); i.putExtra(Intent.EXTRA_SUBJECT, "Merry Christmas"); i.setType("text/html"); Spanned html =Html.fromHtml("<html><body>h<b>ell</b>o<img src='http://www.pp.rhul.ac.uk/twiki/pub/TWiki/GnuPlotPlugin/RosenbrockFunctionSample.png'>world</body></html>", new ImageGetter() { InputStream s; public Drawable getDrawable(String url) { try { s = (InputStream) (new URL(url)).getContent(); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } Drawable d = Drawable.createFromStream(s, null); LogUtil.debug(this, "Got image: " + d.getClass() + ", " + d.getIntrinsicWidth() + "x" + d.getIntrinsicHeight()); d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); return d; }},null); i.putExtra(Intent.EXTRA_TEXT, html); startActivity(Intent.createChooser(i, "Send email"));*

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• Intercepting hyperlinks in an embedded Word document

  - by Ryan

  Hello, I'm working on an app which uses embedded Word documents. We have a feature which allows them to insert a small clickable image into the doc - when the user clicks on it, we want the app to open another window based on some data specified by the user when the image was added. What the application does now is: When the image is inserted, the app creates a hyperlink for it and the data is used as the link destination The user ctrl+clicks on the image and the Word document the WindowSelectionChange event The app handles the WindowSelectionChange event and goes to open the specified window This approach worked fine with previous versions, when we had the 11.0 / Word 2003 interop dll's. We upgraded to 12.0/Word 2007 for the upcoming release, and in many cases the event is not firing when I click on the image - sometimes it does, sometimes it doesn't, and I'm descending into the cargo-cult world trying to figure out why - sometimes saving and re-opening the document works, sometimes killing the Word process and starting a new one fixes (or breaks) the feature. My guess is there's something going wrong with the WinSelChg event, but I'm not sure what. The usual process we have for applying the event handler is: try //remove the old one if any { ((Document)myAXFramerControl.ActiveDocument).Application.WindowSelectionChange -= new ApplicationEvents4_WindowSelectionChangeEventHandler(WSC_eventhandlerfunction); } catch{} ((Document)myAXFramerControl.ActiveDocument).Application.WindowSelectionChange += new ApplicationEvents4_WindowSelectionChangeEventHandler(WSC_eventhandlerfunction); Sometimes one or both of these will throw exceptions - usually a NullReferenceException when removing the handler. Adding the handler sometimes throws the "com object that has been separated from its underlying rcw cannot be used" exception, which I don't understand at all - my impression was that this only occurs when you, say, store a reference to the Word application or document and try to use it later. As it stands the WSC event handler is frequently never run; while I'm happy to fiddle with the app until it works once I can't really expect the same of the users who have been happily using this feature for a while now. Any ideas?

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• shielding #include within namespace { } block?

  - by Jeff

  Edit: I know that method 1 is essentially invalid and will probably use method 2, but I'm looking for the best hack or a better solution to mitigate rampant, mutable namespace proliferation. I have multiple class or method definitions in one namespace that have different dependencies, and would like to use the fewest namespace blocks or explicit scopings possible but while grouping #include directives with the definitions that require them as best as possible. I've never seen any indication that any preprocessor could be told to exclude namespace {} scoping from #include contents, but I'm here to ask if something similar to this is possible: (see bottom for explanation of why I want something dead simple) // NOTE: apple.h, etc., contents are *NOT* intended to be in namespace Foo! // would prefer something most this: namespace Foo { #include "apple.h" B *A::blah(B const *x) { /* ... */ } #include "banana.h" int B::whatever(C const &var) { /* ... */ } #include "blueberry.h" void B::something() { /* ... */ } } // namespace Foo ... // over this: #include "apple.h" #include "banana.h" #include "blueberry.h" namespace Foo { B *A::blah(B const *x) { /* ... */ } int B::whatever(C const &var) { /* ... */ } void B::something() { /* ... */ } } // namespace Foo ... // or over this: #include "apple.h" namespace Foo { B *A::blah(B const *x) { /* ... */ } } // namespace Foo #include "banana.h" namespace Foo { int B::whatever(C const &var) { /* ... */ } } // namespace Foo #include "blueberry.h" namespace Foo { void B::something() { /* ... */ } } // namespace Foo My real problem is that I have projects where a module may need to be branched but have coexisting components from the branches in the same program. I have classes like FooA, etc., that I've called Foo::A in the hopes being able to branch less painfully as Foo::v1_2::A, where some program may need both a Foo::A and a Foo::v1_2::A. I'd like "Foo" or "Foo::v1_2" to show up only really once per file, as a single namespace block, if possible. Moreover, I tend to prefer to locate blocks of #include directives immediately above the first definition in the file that requires them. What's my best choice, or alternatively, what should I be doing instead of hijacking the namespaces?

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• RSA_sign and RSACryptoProvider.VerifySignature

  - by Miky D

  I'm trying to get up to speed on how to get some code that uses OpenSSL for cryptography, to play nice with another program that I'm writing in C#, using the Microsoft cryptography providers available in .NET. More to the point, I'm trying to have the C# program verify an RSA message signature generated by the OpenSSL code. The code that generates the signature looks something like this: // Code in C, using the OpenSSL RSA implementation char msgToSign[] = "Hello World"; // the message to be signed char signature[RSA_size(rsa)]; // buffer that will hold signature int slen = 0; // will contain signature size // rsa is an OpenSSL RSA context, that's loaded with the public/private key pair memset(signature, 0, sizeof(signature)); RSA_sign(NID_sha1 , (unsigned char*)msgToSign , strlen(msgToSign) , signature , &slen , rsa); // now signature contains the message signature // and can be verified using the RSA_verify counterpart // .. I would like to verify the signature in C# In C#, I would do the following: import the other side's public key into an RSACryptoServiceProvider object receive the message and it's signature try to verify the signature I've got the first two parts working (I've verified that the public key is loading properly because I managed to send an RSA encrypted text from the C# code to the OpenSSL code in C and successfully have it decrypted) In order to verify the signature in C#, I've tried using the: VerifySignature method of the RSACryptoServiceProvider but that didn't work. And digging around the internet I was only able to find some vague information pointing out that .NET uses a different method for generating the signature than OpenSSL does. So, does anybody know how to accomplish this?

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• is there evidence that offshoring is causing developer salaries to go down? [closed]

  - by jcollum

  I realize this is a controversial and political topic. I'm trying to decide if offshoring is something that is effecting our industry in any substantial way or if it's just some bugaboo. I've read various posts on SO about it, but none addressed the idea of evidence for offshoring. Studies, papers, opinions of people who know about such things etc. I hear a lot about offshoring and its effect on our job market. However it all seems to be hearsay and conjecture. It does seem like some people are genuinely worried about it. This offshoring thing has been going on for quite some time, should be enough time for some real data to come out. If I had to pick a number I'd say it started during the dotcom boom -- a time when the need for developers far outweighed the local talent pool. We're now in a time when the talent pool is expensive and corporate wallets are tight, seems like an ideal time to find a good cheap developer in some other country. But is that actually happening? From reading some posts here on SO, I've concluded that offshoring is a really tough thing to do right. There are a lot of companies who think (or say) they can do it right, but some small percentage of them are actually able to pull it off. Is offshoring affecting the job market in any measurable way? Is offshoring measurable at all? Do we need to stop worrying about this?

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• How to change scope data in controller?

  - by Derooie

  I am a real newbie at angular. I created something now which will let me retrieve and add items via angular and get/put them in mongodb. I use express and mongoose in the app The question is, how can i modify the data before it reaches the DOM in the controller. In this example i have created a way to retrieve data, and i get it exactly as it is stored in mongodb. What i would like is that the field where i store 1 or 0 in the database, to be shown as text. So if mongo has a value 1 i get "the value in mongo is 1" and when the field has a value of 0 get "the value is zero". (just as an example, i like other texts, but it illustrate what i want) I post my controller, html and current output. Any help would be appreciated. Controller function getGuests($scope, $http) { $scope.formData = {}; $http.get('/api/guests') .success(function(data) { $scope.x = data; }) .error(function(data) { console.log('Error: ' + data); }); } HTML <div ng-controller="getGuests"> <div ng-repeat="guest in x"> {{ guest.voornaam }} {{ guest.aanwezig }} </div> </div> The current scope output, what i see in HTML. I like to change only the value of "aanwezig" in case the value of aanwezig is 0 or 1. firstname1 1 firstname2 0 Something else, but would be great to learn, is how i can do a specific mongodb query by the push of a button and get that result.

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• VSTO Word ContentControls, Y U No have Name property?

  - by System.Cats.Lol

  When you add a VSTO (not Word native) content control, you specify the name: controls.AddContentControl(wordRange, "foo", wdType); Where controls is the VSTO (extended) Document.Controls collection. You can later look up the control by name: ContentControl myContentControl = controls["foo"]; So why in the world is there no Name property for ContentControl? (or ContentControlBase, or any of the other derivatives). I'm implementing a wrapper class for the Document.Controls property that lets you add or iterate the content controls. When iterating the underlying Document.Controls, there's no way to look up the name of each control. (We need it to return an instance of our ContentControl wrapper). So currently I'm doing this in our ContentControls wrapper class: public IEnumerator<IContentControl> GetEnumerator() { System.Collections.IEnumerator en = this.wordControls.GetEnumerator(); while (en.MoveNext()) { // VSTO Document.Controls includes all managed controls, not just // VSTO ContentControls; return only those. if (en.Current is Microsoft.Office.Tools.Word.ContentControl) { // The control's name isn't stored with the control, only when it was added, // so use a placeholder name for the wrapper. yield return new ContentControl("Unknown", (Microsoft.Office.Tools.Word.ContentControl)en.Current); } } } I'd prefer to not have to resort to keeping a map of names-to-wrapper-objects in our ContentControls object. Can anyone tell me how to get the control's name (the name parameter that was passed to Controls.Add()?

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• Bilinear interpolation - DirectX vs. GDI+

  - by holtavolt

  I have a C# app for which I've written GDI+ code that uses Bitmap/TextureBrush rendering to present 2D images, which can have various image processing functions applied. This code is a new path in an application that mimics existing DX9 code, and they share a common library to perform all vector and matrix (e.g. ViewToWorld/WorldToView) operations. My test bed consists of DX9 output images that I compare against the output of the new GDI+ code. A simple test case that renders to a viewport that matches the Bitmap dimensions (i.e. no zoom or pan) does match pixel-perfect (no binary diff) - but as soon as the image is zoomed up (magnified), I get very minor differences in 5-10% of the pixels. The magnitude of the difference is 1 (occasionally 2)/256. I suspect this is due to interpolation differences. Question: For a DX9 ortho projection (and identity world space), with a camera perpendicular and centered on a textured quad, is it reasonable to expect DirectX.Direct3D.TextureFilter.Linear to generate identical output to a GDI+ TextureBrush filled rectangle/polygon when using the System.Drawing.Drawing2D.InterpolationMode.Bilinear setting? For this (magnification) case, the DX9 code is using this (MinFilter,MipFilter set similarly): Device.SetSamplerState(0, SamplerStageStates.MagFilter, (int)TextureFilter.Linear); and the GDI+ path is using: g.InterpolationMode = InterpolationMode.Bilinear; I thought that "Bilinear Interpolation" was a fairly specific filter definition, but then I noticed that there is another option in GDI+ for "HighQualityBilinear" (which I've tried, with no difference - which makes sense given the description of "added prefiltering for shrinking") Followup Question: Is it reasonable to expect pixel-perfect output matching between DirectX and GDI+ (assuming all external coordinates passed in are equal)? If not, why not? Finally, there are a number of other APIs I could be using (Direct2D, WPF, GDI, etc.) - and this question generally applies to comparing the output of "equivalent" bilinear interpolated output images across any two of these. Thanks!

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• CSS Design question, I've got myself completely turned around.

  - by Matt Dawdy

  Okay, I have a couple of other questions out there, but I think I'd better just ask from the beginning how you CSS experts would do this. Client's page is split into 2 rows -- header has some info, some aligned to left of page, some to right, some in the middle. This is currently done using a table. I'm fine with leaving this alone or changing it. My real question is that I need a page layout to handle the following: 2 columns - column on left is 200px, but can be "close" down to to 10px (not a slider, it's either 200 or 10 px). The column on the right needs to be as big as it needs to be -- which might be larger than the width of the page. When left column is "closed" then the right column slides over of course. Again, this right column might be 300px or it might be 4000 pixels (it's a reporting interface). Now, to add another wrinkle, SOME pages have 3 columns. The first 2 columns are each exactly 200px, and both can be "closed" down to 10 px each. But, the user may not close both columns, maybe just 1. Or none. Or both. The third column needs to act just like I described above, being able to be larger than the page width, and sliding over to take advantage of any of the "closed" left columns. Whew! I'm pretty confused as to how to go about this, as either I get it right but I can't scroll over to the right at all (overflow: hidden) and information is lost, or the right column jumps down below the left 2 columns and just looks plain stupid. My minimum browser requirements are IE8, FF3.5, Chrome and Safari (latest versions of all). Any and all pointers are gladly accepted.

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• Is there a significant mechanical difference between these faux simulations of default parameters?

  - by ccomet

  C#4.0 introduced a very fancy and useful thing by allowing default parameters in methods. But C#3.0 doesn't. So if I want to simulate "default parameters", I have to create two of that method, one with those arguments and one without those arguments. There are two ways I could do this. Version A - Call the other method public string CutBetween(string str, string left, string right, bool inclusive) { return str.CutAfter(left, inclusive).CutBefore(right, inclusive); } public string CutBetween(string str, string left, string right) { return CutBetween(str, left, right, false); } Version B - Copy the method body public string CutBetween(string str, string left, string right, bool inclusive) { return str.CutAfter(left, inclusive).CutBefore(right, inclusive); } public string CutBetween(string str, string left, string right) { return str.CutAfter(left, false).CutBefore(right, false); } Is there any real difference between these? This isn't a question about optimization or resource usage or anything (though part of it is my general goal of remaining consistent), I don't even think there is any significant effect in picking one method or the other, but I find it wiser to ask about these things than perchance faultily assume.

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• Common lisp, CFFI, and instantiating c structs

  - by andrew

  Hi, I've been on google for about, oh, 3 hours looking for a solution to this "problem." I'm trying to figure out how to instantiate a C structure in lisp using CFFI. I have a struct in c: struct cpVect{cpFloat x,y;} Simple right? I have auto-generated CFFI bindings (swig, I think) to this struct: (cffi:defcstruct #.(chipmunk-lispify "cpVect" 'classname) (#.(chipmunk-lispify "x" 'slotname) :double) (#.(chipmunk-lispify "y" 'slotname) :double)) This generates a struct "VECT" with slots :X and :Y, which foreign-slot-names confirms (please note that I neither generated the bindings or programmed the C library (chipmunk physics), but the actual functions are being called from lisp just fine). I've searched far and wide, and maybe I've seen it 100 times and glossed over it, but I cannot figure out how to create a instance of cpVect in lisp to use in other functions. Note the function: cpShape *cpPolyShapeNew(cpBody *body, int numVerts, cpVect *verts, cpVect offset) Takes not only a cpVect, but also a pointer to a set of cpVects, which brings me to my second question: how do I create a pointer to a set of structs? I've been to http://common-lisp.net/project/cffi/manual/html_node/defcstruct.html and tried the code, but get "Error: Unbound variable: PTR" (I'm in Clozure CL), not to mention that looks to only return a pointer, not an instance. I'm new to lisp, been going pretty strong so far, but this is the first real problem I've hit that I can't figure out. Thanks!

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• Using SHFileOperation: What errors are occuring

  - by Sascha

  Hello I am using the function SHFileOperation() to send a file to the recycling bin. And I am getting 2 errors that I do not know what they mean because with this function the error codes are not GetLastError() values. Now when the function SHFileOperation() fails the return values are 0x57 (decimal 87) & 0x2 (decimal 2). Can you help me discover the definitions of these errors (expecially when you consider with this function, the errors are not part of the GetLastError() codes). Some important information: • I am using Windows 7 (& I know that MSDN says to use IFileOperation instead of SHFileOperation but I want to make my app backwards compatable which is why I am using SHFileOperation). If the error is occuring because I am using SHFileOperation on Windows 7 what solution could I use to make this work on all versions of windows from 2000 & up? • I have debugged extensively & as far as I know my SHFILEOPSTRUCT is correct (correct flags used, .pFrom is a double-null ended string). One thing I know for sure is that my path to the file is correct (leads to a real file & it correctly formatted). • About 2/5 times the SHFileOperation() works, meaning it sends the file to the recycle bin & does not returns an error BOOL result; SHFILEOPSTRUCT fileStruct; fileStruct.hwnd = hwnd; fileStruct.wFunc = FO_DELETE; fileStruct.pFrom = dest.c_str(); fileStruct.fFlags = FOF_FILESONLY; // FOF_ALLOWUNDO fileStruct.fAnyOperationsAborted = result; // Call operation(delete file) int success = SHFileOperation( &fileStruct ); // if delete was successful if ( success != 0 ) { printf( "%s \t %X %d \n", dest.c_str(), success, success ); cout << result << endl; MessageBox( hwnd, "Failed to delete file", "Error", MB_OK|MB_ICONERROR ); return; }

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• How can I access mainframe data with .Net applications and SQL Queries?

  - by orandov

  We have a large amount of data stored on an IBM mainframe using VSAM files. A lot of this data is dropped on the network every night in the form of text files to be processed and dumped into FoxPro and SQL Server databases. There are also many text files produced nightly by custom applications that get uploaded to the mainframe to keep everything in sync. Keeping the everything in sync is very tricky, to say the least. We are not getting rid of the mainframe any time soon and we would like to replace all the nightly batch processing with real time access to the mainframe data. We would like to be able to: Read data directly from the mainframe and produce reports based on it. Possibly using SQL queries. Read and Write data from custom .Net applications. We are not looking for a new platform to interface with the mainframe like Information Builders offers. We don't want to build application modules or reports with new "Business Intelligence" tools. We already know how to generate reports and write custom applications using SQL,.Net, Visual Studio, etc. All we are looking for is some sort of adapter to connect to our mainframe data. Any ideas are appreciated.

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• Extension methods for encapsulation and reusability

  - by tzaman

  In C++ programming, it's generally considered good practice to "prefer non-member non-friend functions" instead of instance methods. This has been recommended by Scott Meyers in this classic Dr. Dobbs article, and repeated by Herb Sutter and Andrei Alexandrescu in C++ Coding Standards (item 44); the general argument being that if a function can do its job solely by relying on the public interface exposed by the class, it actually increases encapsulation to have it be external. While this confuses the "packaging" of the class to some extent, the benefits are generally considered worth it. Now, ever since I've started programming in C#, I've had a feeling that here is the ultimate expression of the concept that they're trying to achieve with "non-member, non-friend functions that are part of a class interface". C# adds two crucial components to the mix - the first being interfaces, and the second extension methods: Interfaces allow a class to formally specify their public contract, the methods and properties that they're exposing to the world. Any other class can choose to implement the same interface and fulfill that same contract. Extension methods can be defined on an interface, providing any functionality that can be implemented via the interface to all implementers automatically. And best of all, because of the "instance syntax" sugar and IDE support, they can be called the same way as any other instance method, eliminating the cognitive overhead! So you get the encapsulation benefits of "non-member, non-friend" functions with the convenience of members. Seems like the best of both worlds to me; the .NET library itself providing a shining example in LINQ. However, everywhere I look I see people warning against extension method overuse; even the MSDN page itself states: In general, we recommend that you implement extension methods sparingly and only when you have to. So what's the verdict? Are extension methods the acme of encapsulation and code reuse, or am I just deluding myself?

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• Handle order dependence in loops

  - by Matt

  Hey all, I'm making a templating system where I instantiate each tag using a foreach loop. The issue is that some of the tags rely on each other so, I'm wondering how to get around that ordering from the looping. Here's an example: Class A { public $width; __construct() { $this->width = $B->width; // Undefined! Or atleast not set yet.. } } Class B { public $width; __construct() { $this->width = "500px"; } __tostring() { return "Hello World!"; } } Template.php $tags = array("A", "B"); foreach ($tags as $tag) { $TagObj[$tag] = new $tag(); } echo $TagObj['A']->width; // Nadamundo! EDIT: Ok just to clarify.. My main problem is that Class A relies on Class B, but class A is instantiated before class B, so therefore width has not yet been defined in class B. I am looking for a good way to make sure all the classes are loaded for everyone allowing the interdependencies to exist. For the future, please don't consider any syntax errors.. I just made up this example on the spot. Also assume that I have access to class B from class A after class B gets instantiated. I know this has applications elsewhere and I'm sure this has been solved before, if someone could enlighten me or point me in the right direction that'd be great! Thanks! Matt Mueler

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• Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

  - by ereOn

  Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

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• Caching Authentication Data

  - by PartlyCloudy

  Hi, I'm currently implementing a REST web service using CouchDB and RESTlet. The RESTlet layer is mainly for authentication and some minor filtering of the JSON data served by CouchDB: Clients <= HTTP = [ RESTlet <= HTTP = CouchDB ] I'm using CouchDB also to store user login data, because I don't want to add an additional database server for that purpose. Thus, each request to my service causes two CouchDB requests conducted by RESTlet (auth data + "real" request). In order to keep the service as efficent as possible, I want to reduce the number of requests, in this case redundant requests for login data. My idea now is to provide a cache (i.e.LRU-Cache via LinkedHashMap) within my RESTlet application that caches login data, because HTTP caching will probabily not be enough. But how do I invalidate the cache data, once a user changes the password, for instance. Thanks to REST, the application might run on several servers in parallel, and I don't want to create a central instance just to cache login data. Currently, I save requested auth data in the cache and try to auth new requests by using them. If a authentication fails or there is now entry available, I'll dispatch a GET request to my CouchDB storage in order to obtain the actual auth data. So in a worst case, users that have changed their data will perhaps still be able to login with their old credentials. How can I deal with that? Or what is a good strategy to keep the cache(s) up-to-date in general? Thanks in advance.

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