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  • Could the Print document ive built in .net cause a UriFormatException?

    - by Smoka
    After adding Print Document, Dialog, and Button to my Forms app i now have UriFormatException and A first chance exception of type 'System.ComponentModel.Win32Exception' occurred in System.Drawing.dll Additional information: Access is denied Is there something wrong with the strings in my Document? Preview looks fine. but unhandled exception's when it tries to print.

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  • How to deferentiate between Programmer and JVM Exceptions

    - by Haxed
    As the title suggests, how can I tell a JVM thrown exception from a Programmatically(does this mean, thrown by a programmer or the program) thrown exception ? JVM Exceptions 1) ArrayIndexOutOfBoundsException 2) ClassCastException 3) NullPointerException Programmatically thrown 1) NumberFormatException 2) AssertionError Many Thanks

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  • System.Reflection.AmbiguousMatchException

    - by grid-wpf-architect
    Hi , I added Designer support for my control. I got the following exception when setting the property value like below. var colStyle = visibleColumn.Properties["PropertyName"].SetValue(Value); The same above code works fine for VS 2010 project but it shows the following exception for VS 2008 project InnerException: System.Reflection.AmbiguousMatchException Message="Ambiguous match found." Source="mscorlib"

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  • Why download popup window in browser not showing up when using JAX-RS v.s. standard servlet?

    - by masato-san
    When I try using standard servlet approach, in my browser the popup window shows up asking me whether to open .xls file or save it. I tried the exactly same code via JAX-RS and the browser popup won't show up somehow. Has anyone encounter this mystery? Standard servlet that works: package local.test.servlet; import java.io.IOException; import java.net.URL; import java.net.URLDecoder; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import local.test.jaxrs.ExcellaTestResource; import org.apache.poi.ss.usermodel.Workbook; import org.bbreak.excella.core.BookData; import org.bbreak.excella.core.exception.ExportException; import org.bbreak.excella.reports.exporter.ExcelExporter; import org.bbreak.excella.reports.exporter.ReportBookExporter; import org.bbreak.excella.reports.model.ConvertConfiguration; import org.bbreak.excella.reports.model.ReportBook; import org.bbreak.excella.reports.model.ReportSheet; import org.bbreak.excella.reports.processor.ReportProcessor; @WebServlet(name="ExcelServlet", urlPatterns={"/ExcelServlet"}) public class ExcelServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { //C:\Users\m-takayashiki\.netbeans\6.9\config\GF3\domain1 // ================== ?????? ======================= URL templateFileUrl = ExcellaTestResource.class.getResource("?????????.xls"); // /C:/Users/m-takayashiki/Documents/NetBeansProjects/KogaAlpha/build/web/WEB-INF/classes/local/test/jaxrs/?????????.xls System.out.println(templateFileUrl.getPath()); String templateFilePath = URLDecoder.decode(templateFileUrl.getPath(), "UTF-8"); String outputFileDir = "MasatoExcelHorizontalOutput"; ReportProcessor reportProcessor = new ReportProcessor(); ReportBook outputBook = new ReportBook(templateFilePath, outputFileDir, ExcelExporter.FORMAT_TYPE); ReportSheet outputSheet = new ReportSheet("??????"); outputBook.addReportSheet(outputSheet); // ======================================================== // --------------- ?????? ------------------------- reportProcessor.addReportBookExporter(new OutputStreamExporter(response)); System.out.println("wtf???"); reportProcessor.process(outputBook); System.out.println("done!!"); } catch(Exception e) { System.out.println(e); } } //end doGet() @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } }//end class class OutputStreamExporter extends ReportBookExporter { private HttpServletResponse response; public OutputStreamExporter(HttpServletResponse response) { this.response = response; } @Override public String getExtention() { return null; } @Override public String getFormatType() { return ExcelExporter.FORMAT_TYPE; } @Override public void output(Workbook book, BookData bookdata, ConvertConfiguration configuration) throws ExportException { System.out.println(book.getFirstVisibleTab()); System.out.println(book.getSheetName(0)); //TODO write to stream try { response.setContentType("application/vnd.ms-excel"); response.setHeader("Content-Disposition", "attachment; filename=masatoExample.xls"); book.write(response.getOutputStream()); response.getOutputStream().close(); System.out.println("booya!!"); } catch(Exception e) { System.out.println(e); } } }//end class JAX-RS way that won't display popup: package local.test.jaxrs; import java.net.URL; import java.net.URLDecoder; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.ws.rs.core.Context; import javax.ws.rs.core.UriInfo; import javax.ws.rs.Path; import javax.ws.rs.GET; import javax.ws.rs.Produces; import org.apache.poi.ss.usermodel.Workbook; import org.bbreak.excella.core.BookData; import org.bbreak.excella.core.exception.ExportException; import org.bbreak.excella.reports.exporter.ExcelExporter; import org.bbreak.excella.reports.exporter.ReportBookExporter; import org.bbreak.excella.reports.model.ConvertConfiguration; import org.bbreak.excella.reports.model.ReportBook; import org.bbreak.excella.reports.model.ReportSheet; import org.bbreak.excella.reports.processor.ReportProcessor; @Path("excellaTest") public class ExcellaTestResource { @Context private UriInfo context; @Context private HttpServletResponse response; @Context private HttpServletRequest request; public ExcellaTestResource() { } @Path("horizontalProcess") @GET //@Produces("application/vnd.ms-excel") @Produces("application/vnd.ms-excel") public void getProcessHorizontally() { try { //C:\Users\m-takayashiki\.netbeans\6.9\config\GF3\domain1 // ================== ?????? ======================= URL templateFileUrl = this.getClass().getResource("?????????.xls"); // /C:/Users/m-takayashiki/Documents/NetBeansProjects/KogaAlpha/build/web/WEB-INF/classes/local/test/jaxrs/?????????.xls System.out.println(templateFileUrl.getPath()); String templateFilePath = URLDecoder.decode(templateFileUrl.getPath(), "UTF-8"); String outputFileDir = "MasatoExcelHorizontalOutput"; ReportProcessor reportProcessor = new ReportProcessor(); ReportBook outputBook = new ReportBook(templateFilePath, outputFileDir, ExcelExporter.FORMAT_TYPE); ReportSheet outputSheet = new ReportSheet("??????"); outputBook.addReportSheet(outputSheet); // ======================================================== // --------------- ?????? ------------------------- reportProcessor.addReportBookExporter(new OutputStreamExporter(response)); System.out.println("wtf???"); reportProcessor.process(outputBook); System.out.println("done!!"); } catch(Exception e) { System.out.println(e); } //return response; return; } }//end class class OutputStreamExporter extends ReportBookExporter { private HttpServletResponse response; public OutputStreamExporter(HttpServletResponse response) { this.response = response; } @Override public String getExtention() { return null; } @Override public String getFormatType() { return ExcelExporter.FORMAT_TYPE; } @Override public void output(Workbook book, BookData bookdata, ConvertConfiguration configuration) throws ExportException { //TODO write to stream try { response.setContentType("application/vnd.ms-excel"); response.setHeader("Content-Disposition", "attachment; filename=masatoExample.xls"); book.write(response.getOutputStream()); response.getOutputStream().close(); System.out.println("booya!!"); } catch(Exception e) { System.out.println(e); } } }//end class

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  • Multi-threaded Pooled Allocators

    - by Darren Engwirda
    I'm having some issues using pooled memory allocators for std::list objects in a multi-threaded application. The part of the code I'm concerned with runs each thread function in isolation (i.e. there is no communication or synchronization between threads) and therefore I'd like to setup separate memory pools for each thread, where each pool is not thread-safe (and hence fast). I've tried using a shared thread-safe singleton memory pool and found the performance to be poor, as expected. This is a heavily simplified version of the type of thing I'm trying to do. A lot has been included in a pseudo-code kind of way, sorry if it's confusing. /* The thread functor - one instance of MAKE_QUADTREE created for each thread */ class make_quadtree { private: /* A non-thread-safe memory pool for int linked list items, let's say that it's * something along the lines of BOOST::OBJECT_POOL */ pooled_allocator<int> item_pool; /* The problem! - a local class that would be constructed within each std::list as the * allocator but really just delegates to ITEM_POOL */ class local_alloc { public : //!! I understand that I can't access ITEM_POOL from within a nested class like //!! this, that's really my question - can I get something along these lines to //!! work?? pointer allocate (size_t n) { return ( item_pool.allocate(n) ); } }; public : make_quadtree (): item_pool() // only construct 1 instance of ITEM_POOL per // MAKE_QUADTREE object { /* The kind of data structures - vectors of linked lists * The idea is that all of the linked lists should share a local pooled allocator */ std::vector<std::list<int, local_alloc>> lists; /* The actual operations - too complicated to show, but in general: * * - The vector LISTS is grown as a quadtree is built, it's size is the number of * quadtree "boxes" * * - Each element of LISTS (each linked list) represents the ID's of items * contained within each quadtree box (say they're xy points), as the quadtree * is grown a lot of ID pop/push-ing between lists occurs, hence the memory pool * is important for performance */ } }; So really my problem is that I'd like to have one memory pool instance per thread functor instance, but within each thread functor share the pool between multiple std::list objects.

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  • How can two threads access a common array of buffers with minimal blocking ? (c#)

    - by Jelly Amma
    Hello, I'm working on an image processing application where I have two threads on top of my main thread: 1 - CameraThread that captures images from the webcam and writes them into a buffer 2 - ImageProcessingThread that takes the latest image from that buffer for filtering. The reason why this is multithreaded is because speed is critical and I need to have CameraThread to keep grabbing pictures and making the latest capture ready to pick up by ImageProcessingThread while it's still processing the previous image. My problem is about finding a fast and thread-safe way to access that common buffer and I've figured that, ideally, it should be a triple buffer (image[3]) so that if ImageProcessingThread is slow, then CameraThread can keep on writing on the two other images and vice versa. What sort of locking mechanism would be the most appropriate for this to be thread-safe ? I looked at the lock statement but it seems like it would make a thread block-waiting for another one to be finished and that would be against the point of triple buffering. Thanks in advance for any idea or advice. J.

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  • C# check if a COM (Serial) port is already open

    - by TK
    Is there an easy way of programmatically checking if a serial COM port is already open/being used? Normally I would use: try { // open port } catch (Exception ex) { // handle the exception } However, I would like to programatically check so I can attempt to use another COM port or some such.

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  • Hibernate Communications Link Failure in Restlet-Hibernate Based Java application powered by MySQL

    - by Vatsala
    Let me describe my question - I have a Java application - Hibernate as the DB interfacing layer over MySQL. I get the communications link failure error in my application. The occurence of this error is a very specific case. I get this error , When I leave mysql server unattended for more than approximately 6 hours (i.e. when there are no queries issued to MySQL for more than approximately 6 hours). I am pasting a top 'exception' level description below, and adding a pastebin link for a detailed stacktrace description. javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Cannot open connection - Caused by: org.hibernate.exception.JDBCConnectionException: Cannot open connection - Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure - The last packet successfully received from the server was 1,274,868,181,212 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. - Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure - The last packet successfully received from the server was 1,274,868,181,212 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. - Caused by: java.net.ConnectException: Connection refused: connect the link to the pastebin for further investigation - http://pastebin.com/4KujAmgD What I understand from these exception statements is that MySQL is refusing to take in any connections after a period of idle/nil activity. I have been reading up a bit about this via google search, and came to know that one of the possible ways to overcome this is to set values for c3p0 properties as c3p0 comes bundled with Hibernate. Specifically, I read from here http://www.mchange.com/projects/c3p0/index.html that setting two properties idleConnectionTestPeriod and preferredTestQuery will solve this for me. But these values dont seem to have had an effect. Is this the correct approach to fixing this? If not, what is the right way to get over this? The following are related Communications Link Failure questions at stackoverflow.com, but I've not found a satisfactory answer in their answers. http://stackoverflow.com/questions/2121829/java-db-communications-link-failure http://stackoverflow.com/questions/298988/how-to-handle-communication-link-failure Note 1 - i dont get this error when I am using my application continuosly. Note 2 - I use JPA with Hibernate and hence my hibernate.dialect,etc hibernate properties reside within the persistence.xml in the META-INF folder (does that prevent the c3p0 properties from working?)

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  • Find the closest palindrome number C#

    - by user294837
    Hi All, I am trying to create a console application that reads number from a file all underneath each other like so: 101 9 and then outputs into another file the closest palindrome number. So far what I have is not quite rightm i.e. I don't think I can put the class inside a method which is a bit more Java I was wandering if anyone could help at all? Thanks :) namespace PalidromeC { class Program { static public void Main(string[] args) { #region WriteAnswers try { StreamWriter sw = new StreamWriter("C://Temp/PalindromeAnswers.txt"); sw.WriteLine("Answers"); sw.Close(); }//try catch (Exception e) { Console.WriteLine("Exception: " + e.Message); }//catch #endregion #region ReadFile try { string numbers; StreamReader sr = new StreamReader("C://Temp/Palindrome.txt"); numbers = sr.ReadLine(); while (numbers != null) { Console.WriteLine(numbers); numbers = sr.ReadLine(); }//while sr.Close(); Console.ReadLine(); }//try catch (Exception e) { Console.WriteLine("Exception: " + e.Message); }//catch #endregion NearPalindromeFinder f = new NearPalindromeFinder(); int palindrome = f.findNearPalindrome(n); Console.WriteLine("Nearest Palindrome = " + palindrome); }//main public static void testFindNearestPalindrome(int n) { class NearPalindromeFinder { int findNearPalindrome(int start) { if (testPalindrome(start)) return start; else { int neg = start; int pos = start; for (int i = 0; i < start; i++) { if (testPalindrome(start-i)) { neg = start-i; break; }//if if (testPalindrome(start+i)) { pos = start+i; break; }//if }//for return (start == neg) ? pos : neg; }//else }//findNearPalindrome bool testPalindrome(int start) { if (start == 0 || start == 1) return true; String str = String.valueOf(start); String rev = new if (str.equals(rev)) return true; else return false; }//testPalindrome }//NearPalindromeFinder class }//testFindNearestPalindrome }//Program Class

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  • Django Generating RSS feed with description

    - by Issy
    Hey Guys, I am trying to generate a full rss feed, however when loading the feed in Mail, it just shows the title, with a read more link at the bottom. I have tried several different options. But none seem to work. I would like to generate the feed with a combination of several feeds in my modl. Here is the code i have tried: class LatestEvents(Feed): description_template = "events_description.html" def title(self): return "%s Events" % SITE.name def link(self): return '/events/' def items(self): events = list(Event.objects.all().order_by('-published_date')[:5]) return events author_name = 'Latest Events' def item_pubdate(self, item): return item.published_date And in my template which is stored in TEMPLATE_ROOT/feeds/ {{ obj.description|safe }} <h1>Event Location Details</h1> {{ obj.location|safe }} Even if i hard code the description it does not work.

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  • Code optimization - Unused methods

    - by Yochai Timmer
    How can I tell if a method will never be used ? I know that for dll files and libraries you can't really know if someone else (another project) will ever use the code. In general I assume that anything public might be used somewhere else. But what about private methods ? Is it safe to assume that if I don't see an explicit call to that method, it won't be used ? I assume that for private methods it's easier to decide. But is it safe to decide it ONLY for private methods ?

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  • jquery javascript module architecture on a website

    - by stephan
    I want to write a module on one html site - I will never leave the site I think about two possible concurrent basic approaches: We go into the module by use only a specific function (with specific params - everything which will happen, happen there - logic, exception handling etc) We go in by using one handler-fct, which manages some kind of action & a dataArray (depending on the action also fcts will be called - but not directly maybe for exception handling) So what you prefer?!

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  • ValidatorResources not found in application

    - by jojolapin
    I had been told to deploy a *.war file within tomcat and this application should be working fine. But for an unknown reason all I get is: System Exception: javax.servlet.jsp.JspException: ValidatorResources not found in application scope under key "org.apache.commons.validator.VALIDATOR_RESOURCES" I know that this application has been developed with STRUTS and I can obtain the source. But as I am not a specialist in this field, I come to ask for some help. Could you tell me what file could generate this exception please?

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  • Programmatically add an application to Windows Firewall

    - by RichieACC
    I have an application that is installed and updated via ClickOnce. The application downloads files via FTP, and therefore needs to be added as an exception to the windows firewall. Because of the way that ClickOnce works, the path to the EXE changes with every update, so the exception needs to change also. What would be the best way to have the changes made to the firewall so that it's invisible to the end user? (The application is written in C#)

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  • Unable to read data from the transport connection: the connection was closed

    - by webdreamer
    The exception is Remoting Exception - Authentication Failure. The detailed message says "Unable to read data from the transport connection: the connection was closed." I'm having trouble with creating two simple servers that can comunicate as remote objects in C#. ServerInfo is just a class I created that holds the IP and Port and can give back the address. It works fine, as I used it before, and I've debugged it. Also the server is starting just fine, no exception is thrown, and the channel is registered without problems. I'm using Forms to do the interfaces, and call some of the methods on the server, but didn't find any problems in passing the parameters from the FormsApplication to the server when debugging. All seems fine in that chapter. public ChordServerProgram() { RemotingServices.Marshal(this, "PADIBook"); nodeInt = 0; } public void startServer() { try { serverChannel = new TcpChannel(serverInfo.Port); ChannelServices.RegisterChannel(serverChannel, true); } catch (Exception e) { Console.WriteLine(e.ToString()); } } I run two instances of this program. Then startNode is called on one of the instances of the application. The port is fine, the address generated is fine as well. As you can see, I'm using the IP for localhost, since this server is just for testing purposes. public void startNode(String portStr) { IPAddress address = IPAddress.Parse("127.0.0.1"); Int32 port = Int32.Parse(portStr); serverInfo = new ServerInfo(address, port); startServer(); //node = new ChordNode(serverInfo,this); } Then, in the other istance, through the interface again, I call another startNode method, giving it a seed server to get information from. This is where it goes wrong. When it calls the method on the seedServer proxy it just got, a RemotingException is thrown, due to an authentication failure. (The parameter I'll want to get is the node, I'm just using the int to make sure the ChordNode class has nothing to do with this error.) public void startNode(String portStr, String seedStr) { IPAddress address = IPAddress.Parse("127.0.0.1"); Int32 port = Int32.Parse(portStr); serverInfo = new ServerInfo(address, port); IPAddress addressSeed = IPAddress.Parse("127.0.0.1"); Int32 portSeed = Int32.Parse(seedStr); ServerInfo seedInfo = new ServerInfo(addressSeed, portSeed); startServer(); ChordServerProgram seedServer = (ChordServerProgram)Activator.GetObject(typeof(ChordServerProgram), seedInfo.GetFullAddress()); // node = new ChordNode(serverInfo,this); int seedNode = seedServer.nodeInt; // node.chordJoin(seedNode.self); }

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  • Committed JDO writes do not apply on local GAE HRD, or possibly reused transaction

    - by eeeeaaii
    I'm using JDO 2.3 on app engine. I was using the Master/Slave datastore for local testing and recently switched over to using the HRD datastore for local testing, and parts of my app are breaking (which is to be expected). One part of the app that's breaking is where it sends a lot of writes quickly - that is because of the 1-second limit thing, it's failing with a concurrent modification exception. Okay, so that's also to be expected, so I have the browser retry the writes again later when they fail (maybe not the best hack but I'm just trying to get it working quickly). But a weird thing is happening. Some of the writes which should be succeeding (the ones that DON'T get the concurrent modification exception) are also failing, even though the commit phase completes and the request returns my success code. I can see from the log that the retried requests are working okay, but these other requests that seem to have committed on the first try are, I guess, never "applied." But from what I read about the Apply phase, writing again to that same entity should force the apply... but it doesn't. Code follows. Some things to note: I am attempting to use automatic JDO caching. So this is where JDO uses memcache under the covers. This doesn't actually work unless you wrap everything in a transaction. all the requests are doing is reading a string out of an entity, modifying part of the string, and saving that string back to the entity. If these requests weren't in transactions, you'd of course have the "dirty read" problem. But with transactions, isolation is supposed to be at the level of "serializable" so I don't see what's happening here. the entity being modified is a root entity (not in a group) I have cross-group transactions enabled Another weird thing is happening. If the concurrent modification thing happens, and I subsequently edit more than 5 more entities (this is the max for cross-group transactions), then nothing happens right away, but when I stop and restart the server I get "IllegalArgumentException: operating on too many entity groups in a single transaction". Could it be possible that the PMF is returning the same PersistenceManager every time, or the PM is reusing the same transaction every time? I don't see how I could possibly get the above error otherwise. The code inside the transaction just edits one root entity. I can't think of any other way that GAE would give me the "too many entity groups" error. The relevant code (this is a simplified version) PersistenceManager pm = PMF.getManager(); Transaction tx = pm.currentTransaction(); String responsetext = ""; try { tx.begin(); // I have extra calls to "makePersistent" because I found that relying // on pm.close didn't always write the objects to cache, maybe that // was only a DataNucleus 1.x issue though Key userkey = obtainUserKeyFromCookie(); User u = pm.getObjectById(User.class, userkey); pm.makePersistent(u); // to make sure it gets cached for next time Key mapkey = obtainMapKeyFromQueryString(); // this is NOT a java.util.Map, just FYI Map currentmap = pm.getObjectById(Map.class, mapkey); Text mapData = currentmap.getMapData(); // mapData is JSON stored in the entity Text newMapData = parseModifyAndReturn(mapData); // transform the map currentmap.setMapData(newMapData); // mutate the Map object pm.makePersistent(currentmap); // make sure to persist so there is a cache hit tx.commit(); responsetext = "OK"; } catch (JDOCanRetryException jdoe) { // log jdoe responsetext = "RETRY"; } catch (Exception e) { // log e responsetext = "ERROR"; } finally { if (tx.isActive()) { tx.rollback(); } pm.close(); } resp.getWriter().println(responsetext); EDIT: so I have verified that it fails after exactly 5 transactions. Here's what I do: I create a Foo (root entity), do a bunch of concurrent operations on that Foo, and some fail and get retried, and some commit but don't apply (as described above). Then, I start creating more Foos, and do a few operations on those new Foos. If I only create four Foos, stopping and restarting app engine does NOT give me the IllegalArgumentException. However if I create five Foos (which is the limit for cross-group transactions), then when I stop and restart app engine, I do get the exception. So it seems that somehow these new Foos I am creating are counting toward the limit of 5 max entities per transaction, even though they are supposed to be handled by separate transactions. It's as if a transaction is still open and is being reused by the servlet when it handles the new requests for the 2nd through 5th Foos. EDIT2: it looks like the IllegalArgument thing is independent of the other bug. In other words, it always happens when I create five Foos, even if I don't get the concurrent modification exception. I don't know if it's a symptom of the same problem or if it's unrelated. EDIT3: I found out what was causing the (unrelated) IllegalArgumentException, it was a dumb mistake on my part. But the other issue is still happening. EDIT4: added pseudocode for the datastore access EDIT5: I am pretty sure I know why this is happening, but I will still award the bounty to anyone who can confirm it. Basically, I think the problem is that transactions are not really implemented in the local version of the datastore. References: https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/gVMS1dFSpcU https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/deGasFdIO-M https://groups.google.com/forum/?hl=en&fromgroups=#!msg/google-appengine-java/4YuNb6TVD6I/gSttMmHYwo0J Because transactions are not implemented, rollback is essentially a no-op. Therefore, I get a dirty read when two transactions try to modify the record at the same time. In other words, A reads the data and B reads the data at the same time. A attempts to modify the data, and B attempts to modify a different part of the data. A writes to the datastore, then B writes, obliterating A's changes. Then B is "rolled back" by app engine, but since rollbacks are a no-op when running on the local datastore, B's changes stay, and A's do not. Meanwhile, since B is the thread that threw the exception, the client retries B, but does not retry A (since A was supposedly the transaction that succeeded).

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  • How does Sentry aggregate errors?

    - by Hugo Rodger-Brown
    I am using Sentry (in a django project), and I'd like to know how I can get the errors to aggregate properly. I am logging certain user actions as errors, so there is no underlying system exception, and am using the culprit attribute to set a friendly error name. The message is templated, and contains a common message ("User 'x' was unable to perform action because 'y'"), but is never exactly the same (different users, different conditions). Sentry clearly uses some set of attributes under the hood to determine whether to aggregate errors as the same exception, but despite having looked through the code, I can't work out how. Can anyone short-cut my having to dig further into the code and tell me what properties I need to set in order to manage aggregation as I would like? [UPDATE 1: event grouping] This line appears in sentry.models.Group: class Group(MessageBase): """ Aggregated message which summarizes a set of Events. """ ... class Meta: unique_together = (('project', 'logger', 'culprit', 'checksum'),) ... Which makes sense - project, logger and culprit I am setting at the moment - the problem is checksum. I will investigate further, however 'checksum' suggests that binary equivalence, which is never going to work - it must be possible to group instances of the same exception, with differenct attributes? [UPDATE 2: event checksums] The event checksum comes from the sentry.manager.get_checksum_from_event method: def get_checksum_from_event(event): for interface in event.interfaces.itervalues(): result = interface.get_hash() if result: hash = hashlib.md5() for r in result: hash.update(to_string(r)) return hash.hexdigest() return hashlib.md5(to_string(event.message)).hexdigest() Next stop - where do the event interfaces come from? [UPDATE 3: event interfaces] I have worked out that interfaces refer to the standard mechanism for describing data passed into sentry events, and that I am using the standard sentry.interfaces.Message and sentry.interfaces.User interfaces. Both of these will contain different data depending on the exception instance - and so a checksum will never match. Is there any way that I can exclude these from the checksum calculation? (Or at least the User interface value, as that has to be different - the Message interface value I could standardise.) [UPDATE 4: solution] Here are the two get_hash functions for the Message and User interfaces respectively: # sentry.interfaces.Message def get_hash(self): return [self.message] # sentry.interfaces.User def get_hash(self): return [] Looking at these two, only the Message.get_hash interface will return a value that is picked up by the get_checksum_for_event method, and so this is the one that will be returned (hashed etc.) The net effect of this is that the the checksum is evaluated on the message alone - which in theory means that I can standardise the message and keep the user definition unique. I've answered my own question here, but hopefully my investigation is of use to others having the same problem. (As an aside, I've also submitted a pull request against the Sentry documentation as part of this ;-)) (Note to anyone using / extending Sentry with custom interfaces - if you want to avoid your interface being use to group exceptions, return an empty list.)

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  • When are global variables acceptable?

    - by dsimcha
    Everyone here seems to hate global variables, but I see at least one very reasonable use for them: They are great for holding program parameters that are determined at program initialization and not modified afterwords. Do you agree that this is an exception to the "globals are evil" rule? Is there any other exception that you can think of, besides in quick and dirty throwaway code where basically anything goes? If not, why are globals so fundamentally evil that you do not believe that there are any exceptons?

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  • Android App Crashes On Second Run

    - by user1091286
    My app runs fine on first run. On the Menu I added two choices options and quit. options which set up a new intent who goes to a PreferenceActivity and quit which simply call: "android.os.Process.killProcess(android.os.Process.myPid());" On the second time I run my app (after I quit from inside the emulator) it crashes.. Ideas? the menu is called by the foolowing code: @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu , menu); return true; } - @Override public boolean onOptionsItemSelected(MenuItem item) { // Set up a new intent between the updater service and the main screen Intent options = new Intent(this, OptionsScreenActivity.class); // Switch case on the options switch (item.getItemId()) { case R.id.options: startActivity(options); return true; case R.id.quit: android.os.Process.killProcess(android.os.Process.myPid()); return true; default: return false; } Code for SeekBarPreference: package com.testapp.logic; import com.testapp.R; import android.content.Context; import android.content.res.TypedArray; import android.preference.Preference; import android.util.AttributeSet; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.widget.RelativeLayout; import android.widget.SeekBar; import android.widget.SeekBar.OnSeekBarChangeListener; import android.widget.TextView; public class SeekBarPreference extends Preference implements OnSeekBarChangeListener { private final String TAG = getClass().getName(); private static final String ANDROIDNS="http://schemas.android.com/apk/res/android"; private static final String PREFS="com.testapp.logic"; private static final int DEFAULT_VALUE = 5; private int mMaxValue = 100; private int mMinValue = 1; private int mInterval = 1; private int mCurrentValue; private String mUnitsLeft = ""; private String mUnitsRight = ""; private SeekBar mSeekBar; private TextView mStatusText; public SeekBarPreference(Context context, AttributeSet attrs) { super(context, attrs); initPreference(context, attrs); } public SeekBarPreference(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); initPreference(context, attrs); } private void initPreference(Context context, AttributeSet attrs) { setValuesFromXml(attrs); mSeekBar = new SeekBar(context, attrs); mSeekBar.setMax(mMaxValue - mMinValue); mSeekBar.setOnSeekBarChangeListener(this); } private void setValuesFromXml(AttributeSet attrs) { mMaxValue = attrs.getAttributeIntValue(ANDROIDNS, "max", 100); mMinValue = attrs.getAttributeIntValue(PREFS, "min", 0); mUnitsLeft = getAttributeStringValue(attrs, PREFS, "unitsLeft", ""); String units = getAttributeStringValue(attrs, PREFS, "units", ""); mUnitsRight = getAttributeStringValue(attrs, PREFS, "unitsRight", units); try { String newInterval = attrs.getAttributeValue(PREFS, "interval"); if(newInterval != null) mInterval = Integer.parseInt(newInterval); } catch(Exception e) { Log.e(TAG, "Invalid interval value", e); } } private String getAttributeStringValue(AttributeSet attrs, String namespace, String name, String defaultValue) { String value = attrs.getAttributeValue(namespace, name); if(value == null) value = defaultValue; return value; } @Override protected View onCreateView(ViewGroup parent){ RelativeLayout layout = null; try { LayoutInflater mInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); layout = (RelativeLayout)mInflater.inflate(R.layout.seek_bar_preference, parent, false); } catch(Exception e) { Log.e(TAG, "Error creating seek bar preference", e); } return layout; } @Override public void onBindView(View view) { super.onBindView(view); try { // move our seekbar to the new view we've been given ViewParent oldContainer = mSeekBar.getParent(); ViewGroup newContainer = (ViewGroup) view.findViewById(R.id.seekBarPrefBarContainer); if (oldContainer != newContainer) { // remove the seekbar from the old view if (oldContainer != null) { ((ViewGroup) oldContainer).removeView(mSeekBar); } // remove the existing seekbar (there may not be one) and add ours newContainer.removeAllViews(); newContainer.addView(mSeekBar, ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); } } catch(Exception ex) { Log.e(TAG, "Error binding view: " + ex.toString()); } updateView(view); } /** * Update a SeekBarPreference view with our current state * @param view */ protected void updateView(View view) { try { RelativeLayout layout = (RelativeLayout)view; mStatusText = (TextView)layout.findViewById(R.id.seekBarPrefValue); mStatusText.setText(String.valueOf(mCurrentValue)); mStatusText.setMinimumWidth(30); mSeekBar.setProgress(mCurrentValue - mMinValue); TextView unitsRight = (TextView)layout.findViewById(R.id.seekBarPrefUnitsRight); unitsRight.setText(mUnitsRight); TextView unitsLeft = (TextView)layout.findViewById(R.id.seekBarPrefUnitsLeft); unitsLeft.setText(mUnitsLeft); } catch(Exception e) { Log.e(TAG, "Error updating seek bar preference", e); } } public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { int newValue = progress + mMinValue; if(newValue > mMaxValue) newValue = mMaxValue; else if(newValue < mMinValue) newValue = mMinValue; else if(mInterval != 1 && newValue % mInterval != 0) newValue = Math.round(((float)newValue)/mInterval)*mInterval; // change rejected, revert to the previous value if(!callChangeListener(newValue)){ seekBar.setProgress(mCurrentValue - mMinValue); return; } // change accepted, store it mCurrentValue = newValue; mStatusText.setText(String.valueOf(newValue)); persistInt(newValue); } public void onStartTrackingTouch(SeekBar seekBar) {} public void onStopTrackingTouch(SeekBar seekBar) { notifyChanged(); } @Override protected Object onGetDefaultValue(TypedArray ta, int index){ int defaultValue = ta.getInt(index, DEFAULT_VALUE); return defaultValue; } @Override protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { if(restoreValue) { mCurrentValue = getPersistedInt(mCurrentValue); } else { int temp = 0; try { temp = (Integer)defaultValue; } catch(Exception ex) { Log.e(TAG, "Invalid default value: " + defaultValue.toString()); } persistInt(temp); mCurrentValue = temp; } } } Logcat: E/AndroidRuntime( 4525): FATAL EXCEPTION: main E/AndroidRuntime( 4525): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.ui.testapp/com.logic.testapp.SeekBarPreferen ce}: java.lang.InstantiationException: can't instantiate class com.logic.testapp.SeekBarPreference; no empty constructor E/AndroidRuntime( 4525): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1879) E/AndroidRuntime( 4525): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980) E/AndroidRuntime( 4525): at android.app.ActivityThread.access$600(ActivityThread.java:122) E/AndroidRuntime( 4525): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146) E/AndroidRuntime( 4525): at android.os.Handler.dispatchMessage(Handler.java:99) E/AndroidRuntime( 4525): at android.os.Looper.loop(Looper.java:137) E/AndroidRuntime( 4525): at android.app.ActivityThread.main(ActivityThread.java:4340) E/AndroidRuntime( 4525): at java.lang.reflect.Method.invokeNative(Native Method) E/AndroidRuntime( 4525): at java.lang.reflect.Method.invoke(Method.java:511) E/AndroidRuntime( 4525): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) E/AndroidRuntime( 4525): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) E/AndroidRuntime( 4525): at dalvik.system.NativeStart.main(Native Method) E/AndroidRuntime( 4525): Caused by: java.lang.InstantiationException: can't instantiate class com.logic.testapp.SeekBarPreference; no empty construc tor E/AndroidRuntime( 4525): at java.lang.Class.newInstanceImpl(Native Method) E/AndroidRuntime( 4525): at java.lang.Class.newInstance(Class.java:1319) E/AndroidRuntime( 4525): at android.app.Instrumentation.newActivity(Instrumentation.java:1023) E/AndroidRuntime( 4525): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1870) E/AndroidRuntime( 4525): ... 11 more W/ActivityManager( 84): Force finishing activity com.ui.testapp/com.logic.testapp.SeekBarPreference W/ActivityManager( 84): Force finishing activity com.ui.testapp/.MainScreen I/WindowManager( 84): createSurface Window{41a90320 paused=false}: DRAW NOW PENDING W/ActivityManager( 84): Activity pause timeout for ActivityRecord{4104a848 com.ui.testapp/com.logic.testapp.SeekBarPreference} W/NetworkManagementSocketTagger( 84): setKernelCountSet(10021, 1) failed with errno -2 I/WindowManager( 84): createSurface Window{412bcc10 com.android.launcher/com.android.launcher2.Launcher paused=false}: DRAW NOW PENDING W/NetworkManagementSocketTagger( 84): setKernelCountSet(10045, 0) failed with errno -2 I/Process ( 4525): Sending signal. PID: 4525 SIG: 9 I/ActivityManager( 84): Process com.ui.testapp (pid 4525) has died. I/WindowManager( 84): WIN DEATH: Window{41a6c9c0 com.ui.testapp/com.ui.testapp.MainScreen paused=true}

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  • DateTimeZone error: Unknown or bad timezone

    - by Falya
    I am trying to run this script: <?php $d = new DateTime('now', new DateTimeZone('Asia/Kolkata')); $time = $d->format('H:i'); echo $time; ?> but I got this error: Fatal error: Uncaught exception 'Exception' with message 'DateTimeZone::__construct() [<a href='function.DateTimeZone---construct'>function.DateTimeZone---construct</a>]: Unknown or bad timezone (Asia/Kolkata) Though it works well for Asia/Dacca for example. What could be the problem and how to fix it?

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  • Should I start to use CSS 3 & HTML 5?

    - by LeonixSolutions
    I fear this may sound subjective, sorry. I am wondering how "safe" it is to use CSS3 & HTML5 in a commercial app. I really want the power that they give, but am obviously wary that they are not completely standardized. If it helps any I can probably enforce the use of Chrome as the browser; I can likely offer FireFox as an alternative. I personally do not want to let the user choose their own browser and can probably enforce my choice in a corporate environment which is already heavily biased towards Google. I suppose that if I can enforce a Chrome only policy & carefully test before release then my only worry is that some "behaviour" may change in future. Would you risk it, or would play safe (or go with an alternative, such as a Java app, forgetting the browser)?

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  • VC++2008 Debugger doesn't find library sources

    - by Stefan Monov
    An exception got thrown from a lib I use in my project. As I looked at the callstack, I clicked at the lib function that threw the exception. An "Open File" dialog popped up, prompting me to tell it where the lib source is located. Now clearly something is wrong. This should happen automatically somehow. How do I tell VS where to look for all files from that lib?

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  • Parameter passed by const reference returned by const reference.

    - by Alien01
    Hello, I was reading C++ Faq Second Edition , faq number 32.08 . FAQ says that parameter passed by const reference and returned by const reference can cause dangling reference. But it is ok if parameter is passed by reference and returned by reference. I got it that it is unsafe in case of const reference but how is it safe in case when parameter is non const reference. Last line of FAQ says "Note that if a function accepts a parameter by non-const reference (for example, f(string& s)), returning a copy of this reference parameter is safe because a temporary cannot be passed by non-const reference." Need some insight on this!!

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  • Why does this script work in the current directory but fail when placed in the path?

    - by kiloseven
    I wish to replace my failing memory with a very small shell script. #!/bin/sh if ! [ –a $1.sav ]; then mv $1 $1.sav cp $1.sav $1 fi nano $1 is intended to save the original version of a script. If the original has been preserved before, it skips the move-and-copy-back (and I use move-and-copy-back to preserve the original timestamp). This works as intended if, after I make it executable with chmod I launch it from within the directory where I am editing, e.g. with ./safe.sh filename However, when I move it into /usr/bin and then I try to run it in a different directory (without the leading ./) it fails with: *-bash: /usr/bin/safe.sh: /bin/sh: bad interpreter: Text file busy* My question is, when I move this script into the path (verified by echo $PATH) why does it then fail? D'oh? Inquiring minds want to know how to make this work.

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