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  • windows shell scripting through java

    - by GAURAV JAISWAL
    i am designing a desktop application like nero for removable media storage that also includes features of copyfast. i want to add an option of my own choice in the windows explorer right click menu. how can i do that? am i proceeding in the right direction?

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  • Dozer deep mapping not working

    - by user363900
    I am trying to use dozer to map between classes. I have a source class that looks like this: public class initRequest{ protected String id; protected String[] details } I have a destination class that looks like this: public class initResponse{ protected String id; protected DetailsObject detObj; } public class DetailsObject{ protected List<String> details; } So essentially i want the string in the details array to be populated into the List in the Details object. I have tried a mapping like this: <mapping wildcard="true" > <class-a>com.starwood.valhalla.sgpms.dto.InitiateSynchronizationDTO</class-a> <class-b>com.starwood.valhalla.psi.sgpms.dto.InitiateSynchronizationDTO</class-b> <field> <a is-accessible="true">reservations</a> <b is-accessible="true">reservations.confirmationNum</b> </field> </mapping> But I get this error: Exception in thread "main" net.sf.dozer.util.mapping.MappingException: java.lang.NoSuchFieldException: reservations.confirmationNum at net.sf.dozer.util.mapping.util.MappingUtils.throwMappingException(MappingUtils.java:91) at net.sf.dozer.util.mapping.propertydescriptor.FieldPropertyDescriptor.<init>(FieldPropertyDescriptor.java:43) at net.sf.dozer.util.mapping.propertydescriptor.PropertyDescriptorFactory.getPropertyDescriptor(PropertyDescriptorFactory.java:53) at net.sf.dozer.util.mapping.fieldmap.FieldMap.getDestPropertyDescriptor(FieldMap.java:370) at net.sf.dozer.util.mapping.fieldmap.FieldMap.getDestFieldType(FieldMap.java:103) at net.sf.dozer.util.mapping.util.MappingsParser.processMappings(MappingsParser.java:95) at net.sf.dozer.util.mapping.util.CustomMappingsLoader.load(CustomMappingsLoader.java:77) at net.sf.dozer.util.mapping.DozerBeanMapper.loadCustomMappings(DozerBeanMapper.java:149) at net.sf.dozer.util.mapping.DozerBeanMapper.getMappingProcessor(DozerBeanMapper.java:132) at net.sf.dozer.util.mapping.DozerBeanMapper.map(DozerBeanMapper.java:94) at com.starwood.valhalla.mte.translator.StarguestPMSIntegrationDozerAdapter.adaptInit(StarguestPMSIntegrationDozerAdapter.java:30) How can i map this so that it works?

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  • How to populate Java (web) application with initial data using Spring/JPA/Hibernate

    - by Tuukka Mustonen
    I want to setup my database with initial data programmatically. I want to populate my database for development runs, not for testing runs (it's easy). The product is built on top of Spring and JPA/Hibernate. Developer checks out the project Developer runs command/script to setup database with initial data Developer starts application (server) and begins developing/testing then: Developer runs command/script to flush the database and set it up with new initial data because database structures or the initial data bundle were changed What I want is to setup my environment by required parts in order to call my DAOs and insert new objects into database. I do not want to create initial data sets in raw SQL, XML, take dumps of database or whatever. I want to programmatically create objects and persist them in database as I would in normal application logic. One way to accomplish this would be to start up my application normally and run a special servlet that does the initialization. But is that really the way to go? I would love to execute the initial data setup as Maven task and I don't know how to do that if I take the servlet approach. There is somewhat similar question. I took a quick glance at the suggested DBUnit and Unitils. But they seem to be heavily focused in setting up testing environments, which is not what I want here. DBUnit does initial data population, but only using xml/csv fixtures, which is not what I'm after here. Then, Maven has SQL plugin, but I don't want to handle raw SQL. Maven also has Hibernate plugin, but it seems to help only in Hibernate configuration and table schema creation (not in populating db with data). How to do this?

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  • setOpaque(true/false); Java

    - by Trizicus
    In Java2D when you use setOpaque I am a little confused on what the true and false does. For example I know that in Swing Opaque means that when painting Swing wont paint what is behind the component. Or is this backwards? Which one is it? Thanks

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  • SmartGWT with Rest Data Source Error

    - by Holograham
    I am getting the following error when retrieving data from a rest data source 00:00:52.439 [ERROR] 01:46:57.001:RDQ1:WARN:ResultSet:isc_ResultSet_1 (created by: isc_CustomerDocGrid_0):get: invalid index -1 com.smartgwt.client.core.JsObject$SGWT_WARN: 01:46:57.001:RDQ1:WARN:ResultSet:isc_ResultSet_1 (created by: isc_CustomerDocGrid_0):get: invalid index -1 at sun.reflect.NativeConstructorAccessorImpl.newInsta nce0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInsta nce(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newI nstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Construc tor.java:513) at com.google.gwt.dev.shell.MethodAdaptor.invoke(Meth odAdaptor.java:105) at com.google.gwt.dev.shell.MethodDispatch.invoke(Met hodDispatch.java:71) at com.google.gwt.dev.shell.OophmSessionHandler.invok e(OophmSessionHandler.java:157) at com.google.gwt.dev.shell.BrowserChannel.reactToMes sages(BrowserChannel.java:1668) at com.google.gwt.dev.shell.BrowserChannelServer.proc essConnection(BrowserChannelServer.java:401) at com.google.gwt.dev.shell.BrowserChannelServer.run( BrowserChannelServer.java:222) at java.lang.Thread.run(Thread.java:619) Here is my data source (it extends RestDataSource) Code: public CustomerDataSource(String id) { setID(id); setDataFormat(DSDataFormat.XML); setRecordXPath("customerdoc"); setOperationBindings(); OperationBinding fetch = new OperationBinding(); fetch.setOperationType(DSOperationType.FETCH); fetch.setDataProtocol(DSProtocol.GETPARAMS); setOperationBindings(fetch); setDataURL("/customer"); I know my web service is returning data as I can display the XML file in my browser. This doesnt appear to be a parse error (i have seen those before). Not sure what the error means. Any help is appreciated.

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  • Getting real-time market/stock quotes in C#/Java

    - by David Menard
    Hey, I would like to make an program that acts like a big filter for stocks. To do so, I need to have real-time (or delayed) quotes from the market. I started getting stock quotes by requesting pages from yahoo, accordingand parsing the html to the ticker, and parsing the html. I was wondering how to do this requesting and parsing html. Is there some way I can request only the stock quotes and its info? I know some applications do this, and I am very curious how they do it, because requesting web pages and parsing them is very time-consuming. Thanks, Dave

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  • How to support 3-byte UTF-8 Characters in ANT

    - by efelton
    I am trying to support UTF-8 characters in my ANT script. As long as the character string are made up of 2-byte UTF-8 characters, such as: Lògìñ Ùsèr ÌÐ Then things work fine. When I use Unicode Han Character: ? Which, according to this site: http://www.fileformat.info/info/unicode/char/6211/index.htm Has a UTF-8 encoding of 0xE6 0x88 0x91 I can see in UltraEdit, my input properties file has the values "E6 88 91" all in a row, so I'm fairly confident that my input is correct. And When I open the same file in Notepad++ I can see all the characters correctly. Here is my Build Script: <?xml version="1.0" encoding="UTF-8" ?> <project name="utf8test" default="all" basedir="."> <target name="all"> <loadproperties encoding="UTF-8" srcfile="./apps.properties.all.txt" /> <echo>No encoding ${common.app.name}</echo> <echo encoding="UTF-8">UTF-8 ${common.app.name}</echo> <echo encoding="UnicodeLittle">UnicodeLittle ${common.app.name}</echo> <echo encoding="UnicodeLittleUnmarked">UnicodeLittleUnmarked ${common.app.name}</echo> <echo>${common.app.ServerName}</echo> <echo>${bb.vendor}</echo> <echo>No encoding ${common.app.UserIdText}</echo> <echo encoding="UTF-8">UTF-8 ${common.app.UserIdText}</echo> <echo encoding="UnicodeLittle">UnicodeLittle ${common.app.UserIdText}</echo> <echo encoding="UnicodeLittleUnmarked">UnicodeLittleUnmarked ${common.app.UserIdText}</echo> <echoproperties /> </target> </project> And here is my properties file: common.app=VrvPsLTst common.app.name=?? common.app.description=Pseudo Loc Test App for Build Script testing common.app.ServerName=http://Vèrìvò.com bb.vendor=Vèrìvò common.app.PasswordText=Pàsswòrð bb.override.list=MP_COPYRIGHTTEXT, "Çòpÿrìght 2012 Vèrívó Bùîlð TéàM" common.app.LoginButtonText=Lògìñ common.app.UserIdText=Ùsèr ÌÐ bb.SMSSuccess=Mèssàgéß Sùççêssfúllÿ Sëñt common.app.LoginScreenMessage=WèlçòMé Mêssàgë common.app.LoginProgressMessage=Àùthèñtìçàtíòñ îñ prógréss... ios.RegistrationText=Règìstràtíòñ Téxt ios.RegistrationURL=http://www.josscrowcroft.com/2011/code/utf-8-multibyte-characters-in-url-parameters-%E2%9C%93/ Here is what the output looks like: Buildfile: C:\Temp\utf8\build.xml all: [echo] No encoding ?? [echo] UTF-8 ?? [echo] ÿþU n i c o d e L i t t l e ? ? [echo] U n i c o d e L i t t l e U n m a r k e d ? ? [echo] http://Vèrìvò.com [echo] Vèrìvò [echo] No encoding Ùsèr ÌÐ [echo] UTF-8 Ùsèr ÃŒÃ? [echo] ÿþU n i c o d e L i t t l e Ù s è r Ì Ð [echo] U n i c o d e L i t t l e U n m a r k e d Ù s è r Ì Ð [echoproperties] #Ant properties [echoproperties] #Mon Jun 18 15:25:13 EDT 2012 [echoproperties] ant.core.lib=C\:\\ant\\lib\\ant.jar [echoproperties] ant.file=C\:\\Temp\\utf8\\build.xml [echoproperties] ant.file.type=file [echoproperties] ant.file.type.utf8test=file [echoproperties] ant.file.utf8test=C\:\\Temp\\utf8\\build.xml [echoproperties] ant.home=c\:\\ant\\bin\\.. [echoproperties] ant.java.version=1.6 [echoproperties] ant.library.dir=C\:\\ant\\lib [echoproperties] ant.project.default-target=all [echoproperties] ant.project.invoked-targets=all [echoproperties] ant.project.name=utf8test [echoproperties] ant.version=Apache Ant version 1.8.1 compiled on April 30 2010 [echoproperties] awt.toolkit=sun.awt.windows.WToolkit [echoproperties] basedir=C\:\\Temp\\utf8 [echoproperties] bb.SMSSuccess=M\u00E8ss\u00E0g\u00E9\u00DF S\u00F9\u00E7\u00E7\u00EAssf\u00FAll\u00FF S\u00EB\u00F1t [echoproperties] bb.override.list=MP_COPYRIGHTTEXT, "\u00C7\u00F2p\u00FFr\u00ECght 2012 V\u00E8r\u00EDv\u00F3 B\u00F9\u00EEl\u00F0 T\u00E9\u00E0?" [echoproperties] bb.vendor=V\u00E8r\u00ECv\u00F2 [echoproperties] common.app=VrvPsLTst [echoproperties] common.app.LoginButtonText=L\u00F2g\u00EC\u00F1 [echoproperties] common.app.LoginProgressMessage=\u00C0\u00F9th\u00E8\u00F1t\u00EC\u00E7\u00E0t\u00ED\u00F2\u00F1 \u00EE\u00F1 pr\u00F3gr\u00E9ss... [echoproperties] common.app.LoginScreenMessage=W\u00E8l\u00E7\u00F2?\u00E9 M\u00EAss\u00E0g\u00EB [echoproperties] common.app.PasswordText=P\u00E0ssw\u00F2r\u00F0 [echoproperties] common.app.ServerName=http\://V\u00E8r\u00ECv\u00F2.com [echoproperties] common.app.UserIdText=\u00D9s\u00E8r \u00CC\u00D0 [echoproperties] common.app.description=Pseudo Loc Test App for Build Script testing [echoproperties] common.app.name=?? [echoproperties] file.encoding=Cp1252 [echoproperties] file.encoding.pkg=sun.io [echoproperties] file.separator=\\ [echoproperties] ios.RegistrationText=R\u00E8g\u00ECstr\u00E0t\u00ED\u00F2\u00F1 T\u00E9xt [echoproperties] ios.RegistrationURL=http\://www.josscrowcroft.com/2011/code/utf-8-multibyte-characters-in-url-parameters-%E2%9C%93/ [echoproperties] java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment [echoproperties] java.awt.printerjob=sun.awt.windows.WPrinterJob [echoproperties] java.class.path=c\:\\ant\\bin\\..\\lib\\ant-launcher.jar;C\:\\Temp\\utf8\\.\\;C\:\\Program Files (x86)\\Java\\jre7\\lib\\ext\\QTJava.zip;C\:\\ant\\lib\\ant-antlr.jar;C\:\\ant\\lib\\ant-apache-bcel.jar;C\:\\ant\\lib\\ant-apache-bsf.jar;C\:\\ant\\lib\\ant-apache-log4j.jar;C\:\\ant\\lib\\ant-apache-oro.jar;C\:\\ant\\lib\\ant-apache-regexp.jar;C\:\\ant\\lib\\ant-apache-resolver.jar;C\:\\ant\\lib\\ant-apache-xalan2.jar;C\:\\ant\\lib\\ant-commons-logging.jar;C\:\\ant\\lib\\ant-commons-net.jar;C\:\\ant\\lib\\ant-contrib-1.0b3.jar;C\:\\ant\\lib\\ant-jai.jar;C\:\\ant\\lib\\ant-javamail.jar;C\:\\ant\\lib\\ant-jdepend.jar;C\:\\ant\\lib\\ant-jmf.jar;C\:\\ant\\lib\\ant-jsch.jar;C\:\\ant\\lib\\ant-junit.jar;C\:\\ant\\lib\\ant-launcher.jar;C\:\\ant\\lib\\ant-netrexx.jar;C\:\\ant\\lib\\ant-nodeps.jar;C\:\\ant\\lib\\ant-starteam.jar;C\:\\ant\\lib\\ant-stylebook.jar;C\:\\ant\\lib\\ant-swing.jar;C\:\\ant\\lib\\ant-testutil.jar;C\:\\ant\\lib\\ant-trax.jar;C\:\\ant\\lib\\ant-weblogic.jar;C\:\\ant\\lib\\ant.jar;C\:\\ant\\lib\\bb-ant-tools.jar;C\:\\ant\\lib\\xercesImpl.jar;C\:\\ant\\lib\\xml-apis.jar;C\:\\Program Files\\Java\\jre7\\lib\\tools.jar [echoproperties] java.class.version=51.0 [echoproperties] java.endorsed.dirs=C\:\\Program Files\\Java\\jre7\\lib\\endorsed [echoproperties] java.ext.dirs=C\:\\Program Files\\Java\\jre7\\lib\\ext;C\:\\Windows\\Sun\\Java\\lib\\ext [echoproperties] java.home=C\:\\Program Files\\Java\\jre7 [echoproperties] java.io.tmpdir=C\:\\Users\\efelton\\AppData\\Local\\Temp\\ [echoproperties] java.library.path=C\:\\Windows\\SYSTEM32;C\:\\Windows\\Sun\\Java\\bin;C\:\\Windows\\system32;C\:\\Windows;C\:\\Windows\\SYSTEM32;C\:\\Windows;C\:\\Windows\\SYSTEM32\\WBEM;C\:\\Windows\\SYSTEM32\\WINDOWSPOWERSHELL\\V1.0\\;C\:\\PROGRAM FILES\\INTEL\\WIFI\\BIN\\;C\:\\PROGRAM FILES\\COMMON FILES\\INTEL\\WIRELESSCOMMON\\;C\:\\PROGRAM FILES (X86)\\MICROSOFT SQL SERVER\\100\\TOOLS\\BINN\\;C\:\\PROGRAM FILES\\MICROSOFT SQL SERVER\\100\\TOOLS\\BINN\\;C\:\\PROGRAM FILES\\MICROSOFT SQL SERVER\\100\\DTS\\BINN\\;C\:\\PROGRAM FILES (X86)\\MICROSOFT SQL SERVER\\100\\TOOLS\\BINN\\VSSHELL\\COMMON7\\IDE\\;C\:\\PROGRAM FILES (X86)\\MICROSOFT SQL SERVER\\100\\DTS\\BINN\\;C\:\\Program Files\\ThinkPad\\Bluetooth Software\\;C\:\\Program Files\\ThinkPad\\Bluetooth Software\\syswow64;C\:\\Program Files (x86)\\QuickTime\\QTSystem\\;C\:\\Program Files (x86)\\AccuRev\\bin;C\:\\Program Files\\Java\\jdk1.7.0_04\\bin;C\:\\Program Files (x86)\\IDM Computer Solutions\\UltraEdit\\;. [echoproperties] java.runtime.name=Java(TM) SE Runtime Environment [echoproperties] java.runtime.version=1.7.0_04-b22 [echoproperties] java.specification.name=Java Platform API Specification [echoproperties] java.specification.vendor=Oracle Corporation [echoproperties] java.specification.version=1.7 [echoproperties] java.vendor=Oracle Corporation [echoproperties] java.vendor.url=http\://java.oracle.com/ [echoproperties] java.vendor.url.bug=http\://bugreport.sun.com/bugreport/ [echoproperties] java.version=1.7.0_04 [echoproperties] java.vm.info=mixed mode [echoproperties] java.vm.name=Java HotSpot(TM) 64-Bit Server VM [echoproperties] java.vm.specification.name=Java Virtual Machine Specification [echoproperties] java.vm.specification.vendor=Oracle Corporation [echoproperties] java.vm.specification.version=1.7 [echoproperties] java.vm.vendor=Oracle Corporation [echoproperties] java.vm.version=23.0-b21 [echoproperties] line.separator=\r\n [echoproperties] os.arch=amd64 [echoproperties] os.name=Windows 7 [echoproperties] os.version=6.1 [echoproperties] path.separator=; [echoproperties] sun.arch.data.model=64 [echoproperties] sun.boot.class.path=C\:\\Program Files\\Java\\jre7\\lib\\resources.jar;C\:\\Program Files\\Java\\jre7\\lib\\rt.jar;C\:\\Program Files\\Java\\jre7\\lib\\sunrsasign.jar;C\:\\Program Files\\Java\\jre7\\lib\\jsse.jar;C\:\\Program Files\\Java\\jre7\\lib\\jce.jar;C\:\\Program Files\\Java\\jre7\\lib\\charsets.jar;C\:\\Program Files\\Java\\jre7\\lib\\jfr.jar;C\:\\Program Files\\Java\\jre7\\classes [echoproperties] sun.boot.library.path=C\:\\Program Files\\Java\\jre7\\bin [echoproperties] sun.cpu.endian=little [echoproperties] sun.cpu.isalist=amd64 [echoproperties] sun.desktop=windows [echoproperties] sun.io.unicode.encoding=UnicodeLittle [echoproperties] sun.java.command=org.apache.tools.ant.launch.Launcher -cp .;C\:\\Program Files (x86)\\Java\\jre7\\lib\\ext\\QTJava.zip [echoproperties] sun.java.launcher=SUN_STANDARD [echoproperties] sun.jnu.encoding=Cp1252 [echoproperties] sun.management.compiler=HotSpot 64-Bit Tiered Compilers [echoproperties] sun.os.patch.level=Service Pack 1 [echoproperties] user.country=US [echoproperties] user.dir=C\:\\Temp\\utf8 [echoproperties] user.home=C\:\\Users\\efelton [echoproperties] user.language=en [echoproperties] user.name=efelton [echoproperties] user.script= [echoproperties] user.timezone= [echoproperties] user.variant= BUILD SUCCESSFUL Total time: 1 second Thank you for your help EDIT\UPDATE 6/19/2012 I am developing in a Windows environment. I have installed a TTF from: http://freedesktop.org/wiki/Software/CJKUnifonts/Download I have updated UltraEdit to use the TTF and I can see the Chinese characters. <?xml version="1.0" encoding="UTF-8" ?> <project name="utf8test" default="all" basedir="."> <target name="all"> <echo>??</echo> <echo encoding="ISO-8859-1">ISO-8859-1 ??</echo> <echo encoding="UTF-8">UTF-8 ??</echo> <echo file="echo_output.txt" append="true" >?? ${line.separator}</echo> <echo file="echo_output.txt" append="true" encoding="ISO-8859-1">ISO-8859-1 ?? ${line.separator}</echo> <echo file="echo_output.txt" append="true" encoding="UTF-8">UTF-8 ?? ${line.separator}</echo> <echo file="echo_output.txt" append="true" encoding="UnicodeLittle">UnicodeLittle ?? ${line.separator}</echo> <echo file="echo_output.txt" append="true" encoding="UnicodeLittleUnmarked">UnicodeLittleUnmarked ?? ${line.separator}</echo> </target> </project> The output captured by running inside UltraEdit is: Buildfile: E:\temp\utf8\build.xml all: [echo] ?? [echo] ISO-8859-1 ?? [echo] UTF-8 ?? BUILD SUCCESSFUL Total time: 1 second And the echo_output.txt file shows up like this: ?? ISO-8859-1 ?? UTF-8 ?? ÿþU n i c o d e L i t t l e ? ? U n i c o d e L i t t l e U n m a r k e d ? ? So there appears to be somehting fundamentally wrong with how my ANT environment is set up since I cannot simply echo the character to the screen or to a file.

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  • java Filter URL pattern specific to request params

    - by Rohit Desai
    Hi All, We have a situation where we want to use filter for URL's containing some specific request parameters. e.g htt://mydomain.com/?id=78&formtype=simple_form&....... htt://mydomain.com/?id=788&formtype=special_form&....... and so on , id are fetched at run time, I want configure filter in web.xml only if formtype=special_form. How should achieve the solution . Can filter be configure with regex patterns? Really appreciate your help on this. Thanks, Rohit

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  • CheckBox menu item Decrypt in JAVA GUI

    - by Nick
    I am working on a project and part of ask for: add a CheckBox menu item Decrypt which can be checked for decrypt or unchecked for Encrypt. This item should be tied to the toggle button in the GUI. Both should reflect the current status of encrypting/decrypting in the application which is I not sure how to begin with

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  • Playing a .wav sound file in JPanel/JFrame using Java (Swing)

    - by JavaIceCream
    I need some code example on how I would use a filepath from a harddrive location to then play a .wav sound file when opened in swing GUI. I don't need it to show a play button, or pause or stop. I just want it to play when I select the 'Sound' option from my 'Files' in my window (I know how to do that already, no need to explain that). So basically, just how to play a .wav sound file from a filepath (i.e. c:/cake/thereisnone.wav) inside of a JFrame. And how can I easily apply methods to that sound file afterwards. Also, if anyone knows how to apply methods on a BufferedImage in a JFrame, that would be helpful too. Thank you very much everyone!

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  • Need Java Swing HTML canvas with support for integrated swing controls

    - by Iggy Ma
    I would like to create an application in swing in the style of web 2.0 but have the power and functionality of a thick client. I know substance and some other look and feels help with this some, but I was wondering if there is a way I can actually use some kind of html panel / canvas to create the content in html, embedding swing controls in the rendering so as to still use listeners and get the functionality. Anybody know of a way to do this?

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  • Size Mismatch Between Swing Fonts and Printable Fonts in Java

    - by Caleb Rackliffe
    Hi All, I've got a panel displaying a JTextPane backed by a StyledDocument. When I print a string of text in, say Arial 16, the text it prints is of a different size than the Arial 16 Word prints. Is there some sort of flaw in the translation of Swing fonts to Windows system fonts or something of the sort that makes it difficult (or impossible) to print accurately? I can achieve an approximation by scaling down the size of my font before printing, but this never quite gets me the results I would like, as it's not possible in all cases to reproduce things like equivalent numbers of words on a line, etc. Has anybody run into this before?

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  • Java ReentrantReadWriteLocks - how to safely acquire write lock?

    - by Andrzej Doyle
    I am using in my code at the moment a ReentrantReadWriteLock to synchronize access over a tree-like structure. This structure is large, and read by many threads at once with occasional modifications to small parts of it - so it seems to fit the read-write idiom well. I understand that with this particular class, one cannot elevate a read lock to a write lock, so as per the Javadocs one must release the read lock before obtaining the write lock. I've used this pattern successfully in non-reentrant contexts before. What I'm finding however is that I cannot reliably acquire the write lock without blocking forever. Since the read lock is reentrant and I am actually using it as such, the simple code lock.getReadLock().unlock(); lock.getWriteLock().lock() can block if I have acquired the readlock reentrantly. Each call to unlock just reduces the hold count, and the lock is only actually released when the hold count hits zero. EDIT to clarify this, as I don't think I explained it too well initially - I am aware that there is no built-in lock escalation in this class, and that I have to simply release the read lock and obtain the write lock. My problem is/was that regardless of what other threads are doing, calling getReadLock().unlock() may not actually release this thread's hold on the lock if it acquired it reentrantly, in which case the call to getWriteLock().lock() will block forever as this thread still has a hold on the read lock and thus blocks itself. For example, this code snippet will never reach the println statement, even when run singlethreaded with no other threads accessing the lock: final ReadWriteLock lock = new ReentrantReadWriteLock(); lock.getReadLock().lock(); // In real code we would go call other methods that end up calling back and // thus locking again lock.getReadLock().lock(); // Now we do some stuff and realise we need to write so try to escalate the // lock as per the Javadocs and the above description lock.getReadLock().unlock(); // Does not actually release the lock lock.getWriteLock().lock(); // Blocks as some thread (this one!) holds read lock System.out.println("Will never get here"); So I ask, is there a nice idiom to handle this situation? Specifically, when a thread that holds a read lock (possibly reentrantly) discovers that it needs to do some writing, and thus wants to "suspend" its own read lock in order to pick up the write lock (blocking as required on other threads to release their holds on the read lock), and then "pick up" its hold on the read lock in the same state afterwards? Since this ReadWriteLock implementation was specifically designed to be reentrant, surely there is some sensible way to elevate a read lock to a write lock when the locks may be acquired reentrantly? This is the critical part that means the naive approach does not work.

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  • X.509 Certificate validation with Java and Bouncycastle

    - by Rob
    Hi, through the bouncycastle wiki page I was able to understand how to create a X.509 root certificate and a certification request, but I do not quite understand how to proceed concept- and programming wise after that. Lets assume party A does a cert request and gets his client certificate from the CA. How can some party B validate A's certificate? What kind of certificate does A need? A root certificate? A 'normal' client certificate? And how does the validation work on programming level, if we assume that A has successfully send his certificate in DER or PEM format to B? Any help is much appreciated. Best Regards, Rob

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  • Java Graphics2D DrawString....

    - by user69514
    Hey guys I have a little issue here. I have a panel where I am drawing a string. This is a game so I keep redrawing the score in order to update it. However when I draw it again it is drawn on top of the previous score so it looked all garbled up. Any ideas how to fix this? comp2d.drawString(GetScore(Score),ScoreX,ScoreY);

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  • Java - How to change context root of a dynamic web project in eclipse

    - by Yatendra Goel
    I have developed a dynamic web project in eclipse. Now I can access it through my browser using the following url: http://localhost:8080/MyDynamicWebApp Now I want to change the access url to http://localhost:8080/app I changed the context root from the project properties | Web Project Settings | Context Root But it is not working. The web app still has the access url as earlier. I have re-deployed the application on tomcat, re-started the tomcat and have done everything that should be done but the access url is the same as earlier. I found that there were no server.xml file attached with the WARfile. The how the tomcat is determining that the context root of my web app is /MyDynamicWebApp and is allowing me to access the application through that url

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  • Handling multiple column data with Java

    - by Ender
    I am writing an application that reads in a large number of basic user details in the following format; once read in it then allows the user to search for a user's details using their email: NAME ROLE EMAIL --------------------------------------------------- Joe Bloggs Manager [email protected] John Smith Consultant [email protected] Alan Wright Tester [email protected] ... The problem I am suffering is that I need to store a large number of details of all people that have worked at the company. The file containing these details will be written on a yearly basis simply for reporting purposes, but the program will need to be able to access these details quickly. The way I aim to access these files is to have a program that asks the user for the name of the unique email of the member of staff and for the program to then return the name and the role from that line of the file. I've played around with text files, but am struggling with how I would handle multiple columns of data when it comes to searching this large file. What is the best format to store such data in? A text file? XML? The size doesn't bother me, but I'd like to be able to search it as quickly as possible. The file will need to contain a lot of entries, probably over the 10K mark over time.

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  • dividing double by double gives weird results - Java

    - by Aly
    Hi, I am trying to do the following 33.33333333333333/100.0 to get 0.333333333333333 however when I run System.out.println(33.33333333333333/100.0); I get 0.33333333333333326 as the output, similarly when I run System.out.println(33.33333333333333/1000.0); I get 0.033333333333333326 as the output. Does anyone know why, and how I can get the correct value (without loss of decimal places). Thanks

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  • Why doesn't this method print its text? (java)

    - by David
    here's the method: public static int chooseStrat () { String[] strats = new String[1] ; strats[0] = "0 - Blob" ; int n ; boolean a = false ; while (a == false) ; { System.out.println ("Which strategy should the AI use?(#)") ; printArrayS (strats) ; n = getInt () ; System.out.println ("you selected "+n+"."+" are you sure you want the computer to use the "+ strats[n]+ " ?(Y/N)") ; String c = getIns () ; while ((((!( (c.equals ("y")) || (c.equals ("Y")) )) && (!( (c.equals ("n")) || (c.equals ("N")) ) ) ))) ; { System.out.println ("try again") ; c = getIns () ; } if ( (c.equals ("Y")) || (c.equals ("y")) ) a = true ; } return n ; } When i run this it never prints "Which strategy should the AI use?(#)" it just tries to get an entry from the keyboard. why does it do this?

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  • printing in the same line in java.

    - by sil3nt
    Hi there, I have a base class called Items and 3 derived classes, and within the Items base class i have a print function of the form public void print(){ System.out.println("ID " + id + " Title " + title + " <" + year + "> "); } and within every derived class I call the Items print function through super.print(); which is followed by a specific print function relating to the derived class. My problem is, whenever the printing is executed from one of the derived classes the printed text is not on the same line. So super.print() will be in the line above the derived class print function. How do I get them both to be on the same line?

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  • java arraylist : same values to a new arraylist

    - by j0hns3n
    public static void rechnung(List<String> array) { for (int i = 0; i < array.size(); i++) { for (int j = 0; j < array.size(); j++) { if (i != j) { System.out.println(array.get(i) + " gleich " + array.get(j) + " " + (array.get(i).substring(0, 9).equals(array.get(j) .substring(0, 9)))); } } } } My Intension is to put the same values with the same date from a List in a new List. At the end I've for example three new Lists. List content: 03.07.2007 00001.tif 03.07.2007 00002.tif 18.02.2008 00003.tif 18.02.2008 00004.tif 18.02.2008 00005.tif 11.03.2009 00004.tif 11.03.2009 00005.tif

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  • Java JDBC: Reply.fill()

    - by Harv
    Hi, I get the following exception at times: com.ibm.db2.jcc.b.gm: [jcc][t4][2030][11211][3.50.152] A communication error occurred during operations on the connection's underlying socket, socket input stream, or socket output stream. Error location: Reply.fill(). Message: Connection reset. ERRORCODE=-4499, SQLSTATE=08001 The problem is that, the code executes successfully for quite some time and then suddenly I get this exception. However it runs perfrectly when I run the code again. Could some one please tell me what could be wrong and provide me some pointers to resolve this. Thanks, Harveer

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