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  • Setting classpath and installing database via batch file

    - by Supereme
    Hi, I want my classpath to be set via a batch file. I'm working on Windows XP. I have two questions: My first question: I made a batch file in which I typed "set classpath = C:\WINDOWS\system32\;.;C:\jdk1.5.0\lib\tools.jar;C:\poi-3.6\poi-3.6-20091214.jar;C:\poi-3.6\poi-contrib-3.6-20091214.jar;C:\poi-3.6\poi-ooxml-3.6-20091214.jar;C:\poi-3.6\poi-ooxml-schemas-3.6-20091214.jar;C:\poi-3.6\poi-scratchpad-3.6-20091214.jar;E:\jdbc\postgresql-8.2-505.jdbc3.jar;C:\xmlbeans-2.5.0\lib\jsr173_1.0_api.jar;C:\xmlbeans-2.5.0\lib\resolver.jar;C:\xmlbeans-2.5.0\lib\xbean.jar;C:\xmlbeans-2.5.0\lib\xbean_xpath.jar;C:\xmlbeans-2.5.0\lib\xmlbeans-qname.jar;C:\xmlbeans-2.5.0\lib\xmlpublic.jar;C:\dom4j-1.6.1\dom4j-1.6.1.jar; exit" When I tried to run this file it ran but when I went into control panel systemadvancedenvironment variables and then selected classpath, it didn't show me the classpath I did set. What is the correct way to set the classpath via batch file? My second question: Is there any way by which we can install database via batch file say for eg: postgresql8.2? Thank you.

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  • OpenCV and iPhone

    - by gn-mithun
    Hello, I am writing an application to create a movie file from a bunch of images on an iPhone. I am using OpenCv. I downloaded openCv static libraries for arm(iPhones native instruction architecture) and the libraries were generated just fine. There were no problems linking to them libraries. As a first step, i was trying to create a .avi file using one image, to see if it works. But cvCreateVideoWriter always returns me a NULL value. I did some searchin and i believe its due to the codec not being present. I am trying this on the iPhone simulator. this is what i do... (void)viewDidLoad { [super viewDidLoad]; UIImage *anImage = [UIImage imageNamed:@"1.jpg"]; IplImage *img_color = [self CreateIplImageFromUIImage:anImage]; //The image gets created just fine CvVideoWriter *writer = cvCreateVideoWriter("out.avi",CV_FOURCC('P','I','M','1'), 25,cvSize(320,480),1); //writer is always null int result = cvWriteFrame(writer, img_color); NSLog(@"\n%d",result); //hence this is also 0 all the time cvReleaseVideoWriter(&writer); } I am not sure about the the second parameter. What sort of codec or what exactly it does... I am a n00B in this. Any suggestions?

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  • How do i write tasks? (parallel code)

    - by acidzombie24
    I am impressed with intel thread building blocks. I like how i should write task and not thread code and i like how it works under the hood with my limited understanding (task are in a pool, there wont be 100 threads on 4cores, a task is not guaranteed to run because it isnt on its own thread and may be far into the pool. But it may be run with another related task so you cant do bad things like typical thread unsafe code). I wanted to know more about writing task. I like the 'Task-based Multithreading - How to Program for 100 cores' video here http://www.gdcvault.com/sponsor.php?sponsor_id=1 (currently second last link. WARNING it isnt 'great'). My fav part was 'solving the maze is better done in parallel' which is around the 48min mark (you can click the link on the left side. That part is really all you need to watch if any). However i like to see more code examples and some API of how to write task. Does anyone have a good resource? I have no idea how a class or pieces of code may look after pushing it onto a pool or how weird code may look when you need to make a copy of everything and how much of everything is pushed onto a pool.

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  • Bring a subview to the top on mouseDown: AND keep receiving events (for dragging)

    - by d11wtq
    Ok, basically I have a view with a series of slightly overlapping subviews. When a subview is clicked, it moves to the top (among other things), by a really simple two-liner: -(void)mouseDown:(NSEvent *)theEvent { if (_selected) { // Don't do anything this subview is already in the foreground return; } NSView *superview = [self superview]; [self removeFromSuperview]; [superview addSubview:self position:NSWindowAbove relativeTo:nil]; } This works fine and seems to be the "normal" way to do this. The problem is that I'm now introducing some drag logic to the view, so I need to respond to -mouseDragged:. Unfortunately, since the view is removed from the view hierarchy and re-added in the process, I can have the view come to the foreground and be dragged in the same mouse action. It only drags if I leave go of the mouse and click on the view again, since the second click doesn't do any view hierarchy juggling. Is there anything I can do that will allow the view to move to the foreground like this, AND continue to receive the subsequent -mouseDragged: and -mouseUp: events that follow? I started along the lines of thinking of overriding -hitTest: in the superview and intercepting the mouseDown event in order to bring the view to the foreground before it actually receives the event. The problem here is, from within -hitTest:, how do I distinguish what type of event I'm actually performing the hit test for? I wouldn't want to move the subview to the foreground for other mouse events, such as mouseMoved etc.

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  • How to get notified about changes on SharePoint groups.

    - by Flo
    Hi, I'm actual looking for a way to get notified about any changes on a SharePoint group. First I though I would be able to this by attaching a event handler to some kind of group list. But unfortunately there are no such list representing SharePoint groups. My second attempt was to bind a event handler to the content type SharePointGroup but this didn't work either. So are there any other options to get notified about events on a SharePoint group? Bye, Flo EDIT: Thanks for the reply so far. I forgot to mention that I've already googled and read about the user information list. Sorry. First I found a forum entry where they post the relative URL to the user information list (_catalogs/users/simple.aspx). When I'm using this link to see the list,it only contains users and no groups. I don't know but perhaps this link does some filtering on the list. The other information I found about in several blog and forum posts was that a event handler attached to the user information list are not fired up on an events. I have to admit after reading that it doesn't work so many times and even on MSDN (http://msdn.microsoft.com/en-us/library/aa979520.aspx), I didn't try it on my own. The problem attaching the event handler to the content type wasn't the attaching thing, the handler simply didn't get fired when I for example changed a group name or deleted a user from the group. I don't have an idea why the handler doesn't get called I pretty sure I implemented the right methods and attached them to the right events. Any other suggestions how to get informed about changes on SharePoint groups?

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  • Python: slow read & write for millions of small files

    - by Jami
    I am building directory tree which has tons of subdirectories and files. The total directory count is somewhere along 256^32 subdirectories with 256 files in each end which are only a few bytes long. I did this so I would have fast access to these files (since i'm not searching and i'm just directly accessing then via a known file path) I have a python script that builds this filesystem and reads & writes those files. The problem is that when I reach more than 1Gb of total filesize, the read and write methods become extremely slow. Here's the function I have that reads the contents of a file (the file contains an integer string), adds a certain number to it, then writes it back to the original file. def addInFile(path, scoreToAdd): num = scoreToAdd try: shutil.copyfile(path, '/tmp/tmp.txt') fp = open('/tmp/tmp.txt', 'r') num += int(fp.readlines()[0]) fp.close() except: pass fp = open('/tmp/tmp.txt', 'w') fp.write(str(num)) fp.close() shutil.copyfile('/tmp/tmp.txt', path) I previously tried performing linux console commands but it was slower. I copy the file to a temporary file first then access/modify it then copy it back because i found this was faster than directly accessing the file. I think the cause of the slowdown is because there're tons of files. performing this function 1000 times sometimes reach 1 minute now, but before (when there were only a few files, 1000 calls was performed for only less than 1 second) How do you suggest I fix this?

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  • What is difference between my atoi() calls?

    - by Lucas
    I have a big number stored in a string and try to extract a single digit. But what are the differences between those calls? #include <iostream> #include <string> int main(){ std::string bigNumber = "93485720394857230"; char tmp = bigNumber.at(5); int digit = atoi(&tmp); int digit2 = atoi(&bigNumber.at(5)) int digit3 = atoi(&bigNumber.at(12)); std::cout << "digit: " << digit << std::endl; std::cout << "digit2: " << digit2 << std::endl; std::cout << "digit3: " << digit3 << std::endl; } This will produce the following output. digit: 7 digit2: 2147483647 digit3: 57230 The first one is the desired result. The second one seems to me to be a random number, which I cannot find in the string. The third one is the end of the string, but not just a single digit as I expected, but up from the 12th index to the end of the string. Can somebody explain the different outputs to me? EDIT: Would this be an acceptable solution? char tmp[2] = {bigNumber.at(5), '\0'}; int digit = atoi(tmp); std::cout << "digit: " << digit << std::endl;

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  • Why does Hibernate 2nd level cache only cache within a session?

    - by Synesso
    Using a named query in our application and with ehcache as the provider, it seems that the query results are tied to the session. Any attempt to access the value from the cache for a second time results in a LazyInitializationException We have set lazy=true for the following mapping because this object is also used by another part of the system which does not require the reference... and we want to keep it lean. <class name="domain.ReferenceAdPoint" table="ad_point" mutable="false" lazy="false"> <cache usage="read-only"/> <id name="code" type="long" column="ad_point_id"> <generator class="assigned" /> </id> <property name="name" column="ad_point_description" type="string"/> <set name="synonyms" table="ad_point_synonym" cascade="all-delete-orphan" lazy="true"> <cache usage="read-only"/> <key column="ad_point_id" /> <element type="string" column="synonym_description" /> </set> </class> <query name="find.adpoints.by.heading">from ReferenceAdPoint adpoint left outer join fetch adpoint.synonyms where adpoint.adPointField.headingCode = ?</query> Here's a snippet from our hibernate.cfg.xml <property name="hibernate.cache.provider_class">net.sf.ehcache.hibernate.SingletonEhCacheProvider</property> <property name="hibernate.cache.use_query_cache">true</property> It doesn't seem to make sense that the cache would be constrained to the session. Why are the cached queries not usable outside of the (relatively short-lived) sessions?

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  • Width of li with two floats different in IE, correct in FF

    - by Nathan Loding
    I've worked out most of the kinks with my "lava-lamp" effect that I'm trying to create. Basically I want two curly braces (both are images) to wrap a list-item, then follow over to the next list-item. I always build in FF, then make exceptions for IE. I can't figure out what exception I need to make! I'm using an absolutely positioned li that contains two div's. The first div is floated left, the second is floated right. The width of the li is set to the width of the li it supposed to be wrapping. Thus creating the effect of the braces on the left and right sides of the text. It works beautifully in Firefox, but IE has two issues: The bottoms of the images are cut off. Sometimes they reappear when the animation ends, sometimes they don't. I assume this has to do with height, but no matter what I set the height to, it fails! The width is completely wrong. Here's a live example of it: http://jsbin.com/odome/2 The left position in IE is always 5-7px more than in FF, but that's a small difference. I'm more concerned with the width and the bottoms of the images being trimmed. Thanks, as always, for the help!

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  • Is the Unicode prefix N still needed in SQL Compact Edition?

    - by Dave
    At least in previous versions of SQL Server, you had to prefix Unicode string constants with an "N" to make them be treated as Unicode. Thus, select foo from bar where fizz = N'buzz' (See "Server-Side Programming with Unicode" for SQL Server 2005 "from the horse's mouth" documentation.) We have an application that is using SQL Compact Edition and I am wondering if that is still necessary. From the testing I am doing, it appears to be unneeded. That is, the following SQL statements both behave identically in SQL CE, but the second one fails in SQL Server 2005: select foo from bar where foo=N'???' select foo from bar where foo='???' (I hope I'm not swearing in some language I don't know about...) I'm wondering if that is because all strings are treated as Unicode in SQL CE, or if perhaps the default code page is now Unicode-aware. If anyone has seen any official documentation, either yea or nay, I'd appreciate it. I know I could go the safe route and just add the "N"'s, but there's a lot of code that will need changed, and if I don't need to, I don't want to! Thanks for your help!

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  • Making a sqlite file stay existent between runs of the program

    - by Cocorico
    Hi! I'm having a problem with some sqlite code for an iPhone program in Xcode. I was opening my database like this: int result = sqlite3_open("stealtown.db", &database); Which is how they had it in a book I was looking at while I type the program. But then, that way of opening a database it only works when you run in simulator, not on device. So I finally figure out I need to do this: NSString *file = [[NSBundle mainBundle] pathForResource:@"stealtown" ofType:@"db"]; int result = sqlite3_open([file UTF8String], &database); And that works on device, EXCEPT one thing: Each time you launch the program, it starts as if you had never created the database, and when you stick an entry in the table, it's the ONLY entry in that table. When I used the first code on the simulator, I could open my program 6 times, each time adding 1 entry to a table, and at the end, I had 6 entries in that table. With the second code, I do exact same thing but each time there is only 1 entry in that table. Am I explaining this okay, I hope so, it's hard sometimes for me. Anyone maybe know why this would be?

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  • How to handle large dataset with JPA (or at least with Hibernate)?

    - by Roman
    I need to make my web-app work with really huge datasets. At the moment I get either OutOfMemoryException or output which is being generated 1-2 minutes. Let's put it simple and suppose that we have 2 tables in DB: Worker and WorkLog with about 1000 rows in the first one and 10 000 000 rows in the second one. Latter table has several fields including 'workerId' and 'hoursWorked' fields among others. What we need is: count total hours worked by each user; list of work periods for each user. The most straightforward approach (IMO) for each task in plain SQL is: 1) select Worker.name, sum(hoursWorked) from Worker, WorkLog where Worker.id = WorkLog.workerId group by Worker.name; //results of this query should be transformed to Multimap<Worker, Long> 2) select Worker.name, WorkLog.start, WorkLog.hoursWorked from Worker, WorkLog where Worker.id = WorkLog.workerId; //results of this query should be transformed to Multimap<Worker, Period> //if it was JDBC then it would be vitally //to set resultSet.setFetchSize (someSmallNumber), ~100 So, I have two questions: how to implement each of my approaches with JPA (or at least with Hibernate); how would you handle this problem (with JPA or Hibernate of course)?

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  • Complex LINQ paging algorithm

    - by sharepointmonkey
    We have a list of projects that may or may not have a collection of subprojects. Our report needs to contain all the projects except those that are the parent project of a subproject. I need to page this into pages of, say, 25 rows. But if subprojects appear on that page then ALL the subprojects of that project must appear on the same page. So more than 25 items may appear if necessary. I've got as far as var pagedProjects = db.Projects.Where(x => !x.SubProjects.Any()).Skip( (pageNo -1) * pageSize).Take(pageSize); Obviously, this fails the second part of the requirements. As a further pain in the arse, I need to have a pager control on the report. So I'll need to be able to calculate the total number of pages. I could loop through the whole table of projects but the performance will suffer. Can anybody come up with a paged solution? EDIT - I should probably mention that SubProjects joins back onto Projects via a selfreferencing foreign key so the whole lot comes back as an IQueryable<Project>.

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  • DOS Batch file to echo a specific line number

    - by Lee
    So for the second part of my current dilemma, I have a list of folders in "c:\file_list.txt". I need to be able to extract them (well, echo them with some mods) based on the line number because this batch script is being called by an iterative macro process. I'm passing the line number as a parameter. @echo off setlocal enabledelayedexpansion set /a counter=0 set /a %%a = "" for /f "usebackq delims=" %%a in (c:\file_list.txt) do (if "!counter!"=="%1" goto :printme & set /a counter+=1) :printme echo %%a which gives me an output of "%a". Doh! So, I've tried echoing !a! (result: "ECHO is off."); I've tried echoing %a (result: a) I figured the easy thing to do would be to modify the "head.bat" code found here: http://stackoverflow.com/questions/130116/dos-batch-commands-to-read-first-line-from-text-file except rather than echoing every line - I'd just echo the last line found. Not as simple as one might think. I've noticed that my counter is staying at zero for some reason; I'm wondering if the "set /a counter+=1" is doing what I think it's doing.

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  • Upload two files at once

    - by Keyo
    I am trying to upload two files at once (two file fields) with codeigniters upload class. Despite having provided the field name codeigniter produces errors on the second field. I this a limitation of codeigniter, php or html or am I simply using the class incorectly? $this->upload->do_upload('video_file') $this->upload->do_upload('image_file') Produces this on the image field: The filetype you are attempting to upload is not allowed. Here are my two functions function upload_image() { $thumb_size = 94; $config['upload_path'] = './assets/uploads/images/'; $config['allowed_types'] = 'jpg|png|gif'; $config['max_size'] = '2048'; $config['file_name'] = 'video_' . rand(999999, 999999999); $this->load->library('upload', $config); if (!$this->upload->do_upload('image_file')) { $error = array('error' => $this->upload->display_errors()); return $error; } else { function upload_video() { $config['upload_path'] = './assets/uploads/videos/'; $config['allowed_types'] = 'flv'; $config['max_size'] = '0'; $config['file_name'] = 'video_' . rand(999999, 999999999); $this->load->library('upload', $config); if (!$this->upload->do_upload('video_file')) { $error = array('error' => $this->upload->display_errors()); return $error; } else {

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  • CascadingDropDown ViewState Problem

    - by Steven
    I have two Ajax CascadingDropDown extenders on my page. After a postback, the value of the first dropdown is set (presumably) triggering an event for the second dropdown to refresh. Question: How do I maintain both the contents (from queries) and selected value of both dropdowns after postback? C# answers also welcome. Default.aspx Active States<br /><asp:DropDownList ID="StatesDrop" runat="server" /><br /> Active Cities<br /><asp:DropDownList ID="CitiesDrop" runat="server" /><br /> <ajax:CascadingDropDown ID="StatesCasc" TargetControlID="StatesDrop" ServicePath="WebService1.asmx" ServiceMethod="GetActiveStates" Category="States" runat="server" PromptText="Select a State" PromptValue="?" /> <ajax:CascadingDropDown ID="CitiesCasc" TargetControlID="CitiesDrop" ServicePath="WebService1.asmx" ServiceMethod="GetActiveCities" Category="Cities" runat="server" ParentControlID="StatesDrop" PromptText="Select a City" PromptValue="?" /> WebService1.asmx.vb Imports System.Web.Services Imports System.Web.Services.Protocols Imports System.ComponentModel Imports System.Web.Script.Services Imports AjaxControlToolkit <System.Web.Script.Services.ScriptService()> _ <System.Web.Services.WebService(Namespace:="http://tempuri.org/")> _ <System.Web.Services.WebServiceBinding _ (ConformsTo:=WsiProfiles.BasicProfile1_1)> _ <ToolboxItem(False)> _ Public Class WebService1: Inherits System.Web.Services.WebService <WebMethod()> _ Public Function GetActiveStates (ByVal knownCategoryValues As String, _ ByVal category As String) As CascadingDropDownNameValue() Dim values As New List(Of CascadingDropDownNameValue)() 'Populate values with query' Return values.ToArray() End Function <WebMethod()> _ Public Function GetActiveCities (ByVal knownCategoryValues As String, _ ByVal category As String) As CascadingDropDownNameValue() Dim kv As StringDictionary = _ CascadingDropDown.ParseKnownCategoryValuesString(knownCategoryValues) Dim SelState As String = "" If kv.ContainsKey("State") Then SelState = kv("State") Dim values As New List(Of CascadingDropDownNameValue)() ' Populate values with query.' Return values.ToArray() End Function End Class

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  • Instantiating and starting a Scala Actor in a Map

    - by Bruce Ferguson
    I'm experimenting with a map of actors, and would like to know how to instantiate them and start them in one fell swoop... import scala.actors.Actor import scala.actors.Actor._ import scala.collection.mutable._ abstract class Message case class Update extends Message object Test { val groupings = "group1" :: "group2" :: "group3":: Nil val myActorMap = new HashMap[String,MyActor] def main(args : Array[String]) { groupings.foreach(group => myActorMap += (group -> new MyActor)) myActorMap("group2").start myActorMap("group2") ! Update } } class MyActor extends Actor { def act() { loop { react { case Update => println("Received Update") case _ => println("Ignoring event") } } } } The line: myActorMap("group2").start will grab the second instance, and let me start it, but I would like to be able to do something more like: groupings.foreach(group => myActorMap += (group -> (new MyActor).start)) but no matter how I wrap the new Actor, the compiler complains with something along the lines of: type mismatch; found : scala.actors.Actor required: com.myCompany.test.MyActor or various other complaints. I know it must be something simple to do with anonymous classes, but I can't see it right now. Any suggestions? Thanks in advance!!

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  • Overloading operator>> to a char buffer in C++ - can I tell the stream length?

    - by exscape
    I'm on a custom C++ crash course. I've known the basics for many years, but I'm currently trying to refresh my memory and learn more. To that end, as my second task (after writing a stack class based on linked lists), I'm writing my own string class. It's gone pretty smoothly until now; I want to overload operator that I can do stuff like cin my_string;. The problem is that I don't know how to read the istream properly (or perhaps the problem is that I don't know streams...). I tried a while (!stream.eof()) loop that .read()s 128 bytes at a time, but as one might expect, it stops only on EOF. I want it to read to a newline, like you get with cin to a std::string. My string class has an alloc(size_t new_size) function that (re)allocates memory, and an append(const char *) function that does that part, but I obviously need to know the amount of memory to allocate before I can write to the buffer. Any advice on how to implement this? I tried getting the istream length with seekg() and tellg(), to no avail (it returns -1), and as I said looping until EOF (doesn't stop reading at a newline) reading one chunk at a time.

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  • MalformedURLException with file URI

    - by Paul Reiners
    While executing the following code: doc = builder.parse(file); where doc is an instance of org.w3c.dom.Document and builder is an instance of javax.xml.parsers.DocumentBuilder, I'm getting the following exception: Exception in thread "main" java.net.MalformedURLException: unknown protocol: c at java.net.URL.<init>(Unknown Source) at java.net.URL.<init>(Unknown Source) at java.net.URL.<init>(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source) at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source) at javax.xml.parsers.DocumentBuilder.parse(Unknown Source) at com.acme.ItemToThetaValues.createFiles(ItemToThetaValues.java:47) It's choking on this line of the file: <!DOCTYPE questestinterop SYSTEM "C:\Program Files\Acme\parsers\acme_full.dtd"> I am not getting this error on my machine, while a user is getting it on his machine. We are both using version 6 of the Sun JRE. This error also occurs when he's uses double backslashes in the path instead of single backslashes and when he uses forward slashes instead of backslashes. First of all, is the XML correct? Is the path expressed correctly? Second of all, why is this error occurring on one computer but not on another?

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  • Volatile fields in C#

    - by Danny Chen
    From the specification 10.5.3 Volatile fields: The type of a volatile field must be one of the following: A reference-type. The type byte, sbyte, short, ushort, int, uint, char, float, bool, System.IntPtr, or System.UIntPtr. An enum-type having an enum base type of byte, sbyte, short, ushort, int, or uint. First I want to confirm my understanding is correct: I guess the above types can be volatile because they are stored as a 4-bytes unit in memory(for reference types because of its address), which guarantees the read/write operation is atomic. A double/long/etc type can't be volatile because they are not atomic reading/writing since they are more than 4 bytes in memory. Is my understanding correct? And the second, if the first guess is correct, why a user defined struct with only one int field in it(or something similar, 4 bytes is ok) can't be volatile? Theoretically it's atomic right? Or it's not allowed simply because that all user defined structs(which is possibly more than 4 bytes) are not allowed to volatile by design?

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  • How do JVM's implicit memory barriers behave when chaining constructors

    - by Joonas Pulakka
    Referring to my earlier question on incompletely constructed objects, I have a second question. As Jon Skeet pointed out, there's an implicit memory barrier in the end of a constructor that makes sure that final fields are visible to all threads. But what if a constructor calls another constructor; is there such a memory barrier in the end of each of them, or only in one being called from outside? That is, when the "wrong" solution is: public class ThisEscape { public ThisEscape(EventSource source) { source.registerListener( new EventListener() { public void onEvent(Event e) { doSomething(e); } }); } } And the correct one would be a factory method version: public class SafeListener { private final EventListener listener; private SafeListener() { listener = new EventListener() { public void onEvent(Event e) { doSomething(e); } } } public static SafeListener newInstance(EventSource source) { SafeListener safe = new SafeListener(); source.registerListener(safe.listener); return safe; } } Would the following work too, or not? public class MyListener { private final EventListener Listener; private MyListener() { listener = new EventListener() { public void onEvent(Event e) { doSomething(e); } } } public MyListener(EventSource source) { this(); source.register(listener); } }

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  • Sql Exception: Error converting data type numeric to numeric

    - by Lucifer
    Hello We have a very strange issue with a database that has been moved from staging to production. The first time the database was moved it was by detaching, copying and reattaching, the second time we tried restoring from a backup of the staging. Both SQL Servers are the same version of MS SQL 2008, running on 64 bit hardware. The code accessing the database is the same build, built using the .net 2.0 framework. Here is the error message and some of the stack trace: Exception Details: System.Data.SqlClient.SqlException: Error converting data type numeric to numeric. Stack Trace: [SqlException (0x80131904): Error converting data type numeric to numeric.] System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1953274 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4849707 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2392 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +204 System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +954 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +162 System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +175 System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +137 Version Information: Microsoft .NET Framework Version:2.0.50727.4200; ASP.NET Version:2.0.50727.4016

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  • Using recursion to to trim a binary tree based on a given min and max value

    - by Justin
    As the title says, I have to trim a binary tree based on a given min and max value. Each node stores a value, and a left/right node. I may define private helper methods to solve this problem, but otherwise I may not call any other methods of the class nor create any data structures such as arrays, lists, etc. An example would look like this: overallRoot _____[50]____________________ / \ __________[38] _______________[90] / \ / _[14] [42] [54]_____ / \ \ [8] [20] [72] \ / \ [26] [61] [83] trim(52, 65); should return: overallRoot [54] \ [61] My attempted solution has three methods: public void trim(int min, int max) { rootFinder(overallRoot, min, max); } First recursive method finds the new root perfectly. private void rootFinder(IntTreeNode node, int min, int max) { if (node == null) return; if (overallRoot.data < min) { node = overallRoot = node.right; rootFinder(node, min, max); } else if (overallRoot.data > max) { node = overallRoot = node.left; rootFinder(node, min, max); } else cutter(overallRoot, min, max); } This second method should eliminate any further nodes not within the min/max, but it doesn't work as I would hope. private void cutter(IntTreeNode node, int min, int max) { if (node == null) return; if (node.data <= min) { node.left = null; } if (node.data >= max) { node.right = null; } if (node.data < min) { node = node.right; } if (node.data > max) { node = node.left; } cutter(node.left, min, max); cutter(node.right, min, max); } This returns: overallRoot [54]_____ \ [72] / [61] Any help is appreciated. Feel free to ask for further explanation as needed.

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  • Android: changing drawable states of option menu items seems to have side-effects

    - by pjv
    In my onCreateOptionsMenu() I have basically the following: public boolean onCreateOptionsMenu(Menu menu) { menu.add(Menu.NONE, MENU_ITEM_INSERT, Menu.NONE, R.string.item_menu_insert).setShortcut('3', 'a').setIcon(android.R.drawable.ic_menu_add); PackageManager pm = getPackageManager(); if(pm.hasSystemFeature(PackageManager.FEATURE_CAMERA) && pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_AUTOFOCUS)){ menu.add(Menu.NONE, MENU_ITEM_SCAN_ADD, Menu.NONE, ((Collectionista.DEBUG)?"DEBUG Scan and add item":getString(R.string.item_menu_scan_add))).setShortcut('4', 'a').setIcon(android.R.drawable.ic_menu_add); } ... } And in onPrepareOptionsMenu among others the following: final boolean scanAvailable = ScanIntent.isInstalled(this); final MusicCDItemScanAddTask task = new MusicCDItemScanAddTask(this); menu.findItem(MENU_ITEM_SCAN_ADD).setEnabled(scanAvailable && (tasks == null || !existsTask(task))); As you see, two options items have the same drawable set (android.R.drawable.ic_menu_add). Now, if in onPrepareOptionsMenu the second menu item gets disabled, its label and icon become gray, but also the icon of the first menu item becomes gray, while the label of that fist menu item stays black and it remains clickable. What is causing this crosstalk between the two icons/drawables? Shouldn't the system handle things like mutate() in this case? I've included a screenshot:

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  • Python and Unicode: How everything should be Unicode

    - by A A
    Forgive if this a long a question: I have been programming in Python for around six months. Self taught, starting with the Python tutorial and then SO and then just using Google for stuff. Here is the sad part: No one told me all strings should be Unicode. No, I am not lying or making this up, but where does the tutorial mention it? And most examples also I see just make use of byte strings, instead of Unicode strings. I was just browsing and came across this question on SO, which says how every string in Python should be a Unicode string. This pretty much made me cry! I read that every string in Python 3.0 is Unicode by default, so my questions are for 2.x: Should I do a: print u'Some text' or just print 'Text' ? Everything should be Unicode, does this mean, like say I have a tuple: t = ('First', 'Second'), it should be t = (u'First', u'Second')? I read that I can do a from __future__ import unicode_literals and then every string will be a Unicode string, but should I do this inside a container also? When reading/ writing to a file, I should use the codecs module. Right? Or should I just use the standard way or reading/ writing and encode or decode where required? If I get the string from say raw_input(), should I convert that to Unicode also? What is the common approach to handling all of the above issues in 2.x? The from __future__ import unicode_literals statement? Sorry for being a such a noob, but this changes what I have been doing for a long time and so clearly I am confused.

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