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  • Java FileLock for Reading and Writing

    - by bobtheowl2
    I have a process that will be called rather frequently from cron to read a file that has certain move related commands in it. My process needs to read and write to this data file - and keep it locked to prevent other processes from touching it during this time. A completely separate process can be executed by a user to (potential) write/append to this same data file. I want these two processes to play nice and only access the file one at a time. The nio FileLock seemed to be what I needed (short of writing my own semaphore type files), but I'm having trouble locking it for reading. I can lock and write just fine, but when attempting to create lock when reading I get a NonWritableChannelException. Is it even possible to lock a file for reading? Seems like a RandomAccessFile is closer to what I need, but I don't see how to implement that. Here is the code that fails: FileInputStream fin = new FileInputStream(f); FileLock fl = fin.getChannel().tryLock(); if(fl != null) { System.out.println("Locked File"); BufferedReader in = new BufferedReader(new InputStreamReader(fin)); System.out.println(in.readLine()); ... The exception is thrown on the FileLock line. java.nio.channels.NonWritableChannelException at sun.nio.ch.FileChannelImpl.tryLock(Unknown Source) at java.nio.channels.FileChannel.tryLock(Unknown Source) at Mover.run(Mover.java:74) at java.lang.Thread.run(Unknown Source) Looking at the JavaDocs, it says Unchecked exception thrown when an attempt is made to write to a channel that was not originally opened for writing. But I don't necessarily need to write to it. When I try creating a FileOutpuStream, etc. for writing purposes it is happy until I try to open a FileInputStream on the same file.

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  • saxon java xpath exception :

    - by changed
    Hi I am trying to read XPath queries from a file and run it against a xml data file. I am doing it through Saxon Xpath processor. But i keep getting this error. Code i am using is from sample code provided with the library. Error i am getting is : Exception in thread "main" javax.xml.xpath.XPathExpressionException: Supplied node must be built using the same or a compatible Configuration at net.sf.saxon.xpath.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:283) at net.sf.saxon.xpath.XPathExpressionImpl.evaluate(XPathExpressionImpl.java:375) at edu.xml.XPathExample.go(XPathExample.java:81) at edu.xml.XPathExample.main(XPathExample.java:42) - public void go(String filename) throws Exception { XPathExpression findLine = null; String readLine = null; Object document = new XPathEvaluator().setSource(new StreamSource(new File(dataPath))); System.setProperty("javax.xml.xpath.XPathFactory:" + NamespaceConstant.OBJECT_MODEL_SAXON, "net.sf.saxon.xpath.XPathFactoryImpl"); XPathFactory xpf = XPathFactory.newInstance(NamespaceConstant.OBJECT_MODEL_SAXON); XPath xpe = xpf.newXPath(); if (filename != null) { this.queryPath = filename; } try { fileReader = new BufferedReader(new FileReader(queryPath)); } catch (FileNotFoundException ex) { System.out.println("File not found: " + ex.getMessage()); } xpe.setXPathVariableResolver(this); while (true) { try { readLine = fileReader.readLine(); } catch (IOException ex) { System.out.println("Error while reading file: " + ex.getMessage()); } if (readLine == null) { break; } findLine = xpe.compile(readLine); String resultString = findLine.evaluate(document); System.out.println("<output>"); System.out.println("String Value => " + resultString); System.out.println("</output>"); } }

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  • Making Spring Data JPA work with DataNucleus (GAE) (Spring Boot)

    - by xybrek
    There are several hints that Spring Data works with Google App Engine like: http://tommysiu.blogspot.com/2014/01/spring-data-on-gae-part-1.html http://blog.eisele.net/2009/07/spring-300m3-on-google-appengine-with.html Much of the examples are not "Spring Boot" so I've been trying to retrofit things with it. However, I've been stuck with this error for days and days: [INFO] Caused by: java.lang.NullPointerException [INFO] at org.datanucleus.api.jpa.metamodel.SingularAttributeImpl.isVersion(SingularAttributeImpl.java:79) [INFO] at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.findVersionAttribute(JpaMetamodelEntityInformation.java:102) [INFO] at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.<init>(JpaMetamodelEntityInformation.java:79) [INFO] at org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getMetadata(JpaEntityInformationSupport.java:65) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation(JpaRepositoryFactory.java:149) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:88) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:68) [INFO] at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:158) [INFO] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:224) [INFO] at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:210) [INFO] at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:92) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$6.run(AbstractAutowireCapableBeanFactory.java:1602) [INFO] at java.security.AccessController.doPrivileged(Native Method) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1599) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1549) [INFO] ... 40 more Where, I'm trying to use Spring Data JPA with DataNucleus/AppEngine: @Configuration @ComponentScan @EnableJpaRepositories @EnableTransactionManagement class JpaApplicationConfig { private static final Logger logger = Logger .getLogger(JpaApplicationConfig.class.getName()); @Bean public EntityManagerFactory entityManagerFactory() { logger.info("Loading Entity Manager..."); return Persistence .createEntityManagerFactory("transactions-optional"); } @Bean public PlatformTransactionManager transactionManager() { logger.info("Loading Transaction Manager..."); final JpaTransactionManager txManager = new JpaTransactionManager(); txManager.setEntityManagerFactory(entityManagerFactory()); return txManager; } } I've tested Persistence.createEntityManagerFactory("transactions-optional"); to see if the app can persist using this EMF, well, it does, so I am sure that this EMF works fine. The problem is the "wiring" up with the Spring Data JPA, can anybody help?

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  • TLS with SNI in Java clients

    - by ftrotter
    There is an ongoing discussion on the security and trust working group for NHIN Direct regarding the IP-to-domain mapping problem that is created with traditional SSL. If an HISP (as defined by NHIN Direct) wants to host thousands of NHIN Direct "Health Domains" for providers, then it will an "artificially inflated cost" to have to purchase an IP for each of those domains. Because Apache and OpenSSL have recently released TLS with support for the SNI extension, it is possible to use SNI as a solution to this problem on the server side. However, if we decide that we will allow server implementations of the NHINDirect transport layer to support TLS+SNI, then we must require that all clients support SNI too. OpenSSL based clients should do this by default and one could always us stunnel to implement an TLS+SNI aware client to proxy if your given programming language SSL implementation does not support SNI. It appears that native Java applications using OpenJDK do not yet support SNI, but I cannot get a straight answer out of that project. I know that there are OpenSSL Java libraries available but I have no idea if that would be considered viable. Can you give me a "state of the art" summary of where TLS+SNI support is for Java clients? I need a Java implementers perspective on this.

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  • Encryption in Java & Flex

    - by Jef
    I want tp encrypt and decrypt string, with defined salt. But the result must be same if the code run in java and adobe flex. The main goal is: the app in adobe flex will be generate a string that can be decrypt in server using java. I use this flex library http://crypto.hurlant.com/demo/ Try to 'Secret Key' Tab. I want to use AES Encryption, 'CBC' or 'PKCS5'. var k:String = "1234567890123456"; var kdata:ByteArray = Hex.toArray(k); var txt:String = "hello"; var data:ByteArray = Hex.toArray(Hex.fromString(txt));; var name:String = "simple-aes-cbc"; var pad:IPad =new PKCS5(); var mode:ICipher = Crypto.getCipher(name, kdata, pad); pad.setBlockSize(mode.getBlockSize()); mode.encrypt(data); encrypted.text=Hex.fromArray(data); trace(Hex.fromArray(data)); And here is the code in java String plaintext = "hello"; String key = "1234567890123456"; SecretKey keyspec = new SecretKeySpec(key.getBytes(), "AES"); Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE,keyspec); byte[] encrypted = cipher.doFinal(plaintext.getBytes()); BASE64Encoder base64 = new BASE64Encoder(); String encodedString = base64.encode(encrypted); System.out.println(encodedString); Why the result is not same? Can you guys provide the sample with the same result both of java and flex (encrypt and decrypt)? And if I want to change the paramater, for example, from cbc to ebc, which line that need to be changed? Thanks!

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  • Hudson plugin, Java error "... disagree on InnerClasses attribute"

    - by StackedCrooked
    I am trying to be able to step through the code of a Hudson plugin called SVNPublisher. I checked out the code for SVNPublisher, used Netbeans to open the project, and clicked "Debug Main project". This results in a Firefox window opening address http://localhost:8080 which shows the Hudson main page. Clicking the "New Job" link results in an error page: HTTP ERROR: 500 jar:file:/home/francis/svn/svnpublisher/target/work/webapp/WEB-INF/lib/hudson-core-1.319.jar!/lib/hudson/newFromList/form.jelly:43:47: <j:forEach> hudson.scm.SubversionTagAction and hudson.scm.SubversionTagAction$DescriptorImpl disagree on InnerClasses attribute RequestURI=/newJob Caused by: org.apache.commons.jelly.JellyTagException: jar:file:/home/francis/svn/svnpublisher/target/work/webapp/WEB-INF/lib/hudson-core-1.319.jar!/lib/hudson/newFromList/form.jelly:43:47: hudson.scm.SubversionTagAction and hudson.scm.SubversionTagAction$DescriptorImpl disagree on InnerClasses attribute at org.apache.commons.jelly.impl.TagScript.handleException(TagScript.java:713) at org.apache.commons.jelly.impl.TagScript.run(TagScript.java:282) at org.apache.commons.jelly.impl.ScriptBlock.run(ScriptBlock.java:95) ... I am very new to Hudson and not very experienced with Java so I'm pretty much clueless on the meaning of this error. Can anyone help?

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  • Java Robot key activity seems to stop working while certain software is running

    - by Mike Turley
    I'm writing a Java application to automate character actions in an online game overnight (specifically, it catches fish in Final Fantasy XI). The app makes heavy use of java's Robot class both for emulating user keyboard input and for detecting color changes on certain parts of the screen. It also uses multithreading and a swing GUI. The application seems to work perfectly when I test it without the game running, just using screenshots to trigger the apps responses into notepad. But for some reason, when I actually launch FFXI and start the program, all of my keyboard and mouse manipulations just stop working altogether. The program is still running, and the Robot class is still able to read pixel colors. But Robot.keyPress, Robot.keyRelease, Robot.mouseMove, Robot.mousePress and Robot.mouseRelease all do nothing. It's the strangest thing-- to test it, I wrote a simple loop that just keeps typing letters, and focused notepad. I'd then start the game, refocus notepad, and it would do nothing. Then I'd exit the game, and it'd start working again immediately. Has anyone else come across something like this, where specific software will stop certain functions of java from working? Also, to make this more interesting-- Last year I wrote a very similar program using the same classes and programming techniques to automate healing a party in the game as they fight. Last year, this program worked perfectly. After running into these problems I dug up that old program, ran it without making any changes, and found that it too was having the same problems. The only differences between now and when it was working: I was running Windows Vista and now I'm running Windows 7, and several new Java versions as well as FFXI versions have been released. What the hell is going on? (if anyone needs to see my source code, email me at [email protected]. I'm trying to keep it to myself.)

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  • Interpolation of scattered data: What could I do?

    - by Simon
    Hi! I need your help. I'm working on a 3D chart in Java using Java 3D. It should be able to display a bunch of measured values. As measured, the data I get is scattered. This means I will have to interpolate the missing points in order to get my surface plotted nicely. I didn't study all that 3D-Geometry stuff yet and I don't know where to start. My idea is to triangulate the points to a surface and then, based on the triangulation, interpolate the missing points. (see this to have a rough idea of what I want to achieve) Does someone have experiences with the interpolation of scattered data? Is my approach the right one? If yes, what kind of data structures and algorithms will I need in order to triangulate my points cloud?

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  • I/O between AIR client using Native process and executable java .jar

    - by aseem behl
    I am using Adobe AIR 2.0 native process API to launch a java executable jar. I/O is handled by writing to the input stream of the java process and reading from the output stream. The application is event based where several events are fired from the server. We catch these events in java code, handle them and write the output to the outputstream using the synchronized static method below. public class ReaderWriter { static Logger logger = Logger.getLogger(ReaderWriter.class); public synchronized static void writeToAir(String output){ try{ byte[] byteArray = output.getBytes(); DataOutputStream dataOutputStream = new DataOutputStream(System.out); dataOutputStream.write(byteArray); dataOutputStream.flush(); } catch (IOException e) { logger.info("Exception while writing the output. " + e); } } } The issue is that some messages are lost between the transfer and not all messages reach the AIR client. If I run the java application from the console I am receiving all the messages. It would be great if somebody could point out what I am missing. Following are some of the listeners used to send the event data to the AIR client. // class used to process Shutdown events from the Session private class SessionShutdownListener implements SessionListener{ public void onEvent(Event e) { Session.Shutdown sd = (Session.Shutdown) e; Session.ShutdownReason sr = sd.getReason(); String eventOutput = "eo;" + "Session Shutdown event ocurred reason=" + sr.strValue() + "\n"; ReaderWriter.writeToAir(eventOutput); } } // class used to process OperationSucceeded events from the Session private class SessionOperationSucceededListener implements SessionListener{ public void onEvent(Event e) { Session.OperationSucceeded os = (Session.OperationSucceeded) e; String eventOutput = "eo;" + "Session OperationSucceeded event ocurred" + "\n"; ReaderWriter.writeToAir(eventOutput); } }

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  • How to propagate .java file change to .class under eclipse, tomcat & stripes

    - by BigBourin
    Hi, i'm new to java and i got some problems. i'm developping a web application using the framework stripes on tomcat 6.0. I'm working with eclipse EE on windows. i successfully managed to get the stripes example application (called Bugzooky) up and running on my tomcat server. I imported the .war file and stripes libs in Eclipse. Here is the stripes archive containing the examples and libs But now i'm trying to change the example source files to learn how does it work. but whatever the modification made to the source files "WebContent/WEB-INF/src/*.java", nothing change! even after restarting the server. i noticed that the classes are compiled into .class files in the "ImportedClasses" folder, and tomcat always use these files, they are never updated, and if i removed one of them, the application just don't start. it look like my source files don't exists! I also tried to build my webapp from scratch, but when i tried to use the features used in the example files (like SecurityFilter.java): import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import ... It ends up with plenty of: the import javax.servlet.Filter cannot be resolved I checked the Librairies and it look like i'm using exactly the same as the example. It's probably something i didn't understood about java but i googled 100 times yesterday, and i can't find the solution (i probably didn't search the right place because i don't really understand my problem). I hope you'll be able to help me.

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  • How to use URLClassLoader to load a *.class file?

    - by DeletedAccount
    I'm playing around with Reflection and I thought I'd make something which loads a class and prints the names of all fields in the class. I've made a small hello world type of class to have something to inspect: kent@rat:~/eclipsews/SmallExample/bin$ ls IndependentClass.class kent@rat:~/eclipsews/SmallExample/bin$ java IndependentClass Hello! Goodbye! kent@rat:~/eclipsews/SmallExample/bin$ pwd /home/kent/eclipsews/SmallExample/bin kent@rat:~/eclipsews/SmallExample/bin$ Based on the above I draw two conclusions: It exists at /home/kent/eclipsews/SmallExample/bin/IndependentClass.class It works! (So it must be a proper .class-file which can be loaded by a class loader) Then the code which is to use Reflection: (Line which causes an exception is marked) import java.lang.reflect.Field; import java.net.MalformedURLException; import java.net.URL; import java.net.URLClassLoader; public class InspectClass { @SuppressWarnings("unchecked") public static void main(String[] args) throws ClassNotFoundException, MalformedURLException { URL classUrl; classUrl = new URL("file:///home/kent/eclipsews/SmallExample/bin/IndependentClass.class"); URL[] classUrls = { classUrl }; URLClassLoader ucl = new URLClassLoader(classUrls); Class c = ucl.loadClass("IndependentClass"); // LINE 14 for(Field f: c.getDeclaredFields()) { System.out.println("Field name" + f.getName()); } } } But when I run it I get: Exception in thread "main" java.lang.ClassNotFoundException: IndependentClass at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:251) at InspectClass.main(InspectClass.java:14) My questions: What am I doing wrong above? How do I fix it? Is there a way to load several class files and iterate over them?

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  • yet another question about migrating to Java

    - by aloneguid
    Hi, There are plenty similar questions, but maybe responses to this one will save a developer's life :) I want to migrate to Java. The reasons are very clear: all the .NET vacancies are client and windows oriented (Silverlight developer, ASP.NET developer, WPF developer etc.) and none of them are any interest to me. I worked with .NET since it's beginning as our company decided to invest in .NET having C++ stack and all the natual problems, so I was just blindly following and actually enjoyed it as the products were mostly server oriented with mixed C++/C# code. Today I have beforementioned problem - can't find an inspiring job. I'd rather kill myself than start working on a Silverlight or WPF project. Searching Java vacancies shows promising results, however they all require a huge java-related technology stack and experience. The question is is there any chance to find a job quickly and without dramatic salary drop (I know that Java guys are usually better paid, so there must be a kind of a credit) and if not, how must time and effort does it take to migrate (my .NET knowledge mostly includes server-oriented technologies like NHibernate, WCF, threading, sockets, ASP.NET web services, Enterprise Library, NInject etc etc etc, and (still) some C++ leftovers). Thanks!

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  • java RMI connection to server

    - by user85116
    I have a very simple rmi client / server application. I don't use the "rmiregistry" application though, I use this to create the server: server = new RemoteServer(); registry = LocateRegistry.createRegistry(PORT); registry.bind("RemoteServer", server); The client part is: registry = LocateRegistry.getRegistry(IPADDRESS, PORT); remote = (IRemoteServer) registry.lookup("RemoteServer"); Here is the fascinating problem: The application works perfectly when both server and client are running in my (private) local network. As soon as I put the server on a public server, the application hangs for a minute, then gives me the following error: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: java.rmi.ConnectException: Connection refused to host: 192.168.x.y; nested exception is: java.net.ConnectException: Connection timed out: connect at sun.rmi.server.UnicastServerRef.dispatch(Unknown Source) at sun.rmi.transport.Transport$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Unknown Source) at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source ... (the rest is truncated) The key I think is that the client (running on my private network) cannot connect to myself (my address is 192.168.x.y where x.y is some other numbers, but the real error message shows my ip address listed there) If I kill the rmi server on the public internet, then I instantly get a "connection refused to host: a.b.c.d") message, so I know that something at the server end is at least working. Any suggestions? EDIT: just to make this a little more clear: 192.168.x.y is the client address, a.b.c.d is the server address. The stacktrace shows the client cannot connect to the client.

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  • Installing ant; clearly misunderstanding JAVA_HOME

    - by StormShadow
    Hey all, I am installing ant on a Windows XP machine, and am following the instructions at Apache's manual site. It said to set JAVA_HOME, so I checked, saw there was no environment variable named JAVA_HOME, made one, and set it to "C:\Program Files\Java\jdk1.6.0_19" When I try to run ant debug, however, it tells me that JAVA_HOME is currently set to "C:\Program Files\Java\jre6" I'm guessing JAVA_HOME isn't an environment variable. But if it isn't one, I'm at a loss as to where to start looking for it. Anybody know? Edit: Oh yeah - it's bugging me for tools.jar as well, but I'm guessing that when I fix the JAVA_HOME issue, that will help the terminal find tools.jar as well. Or maybe I'm wrong. Thanks

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  • How to fix this java.lang.LinkageError?

    - by Péter Török
    I am trying to configure a custom layout class to Log4J as described in my previous post. The class uses java.util.regex.Matcher to identify potential credit card numbers in log messages. It works perfectly in unit tests (I can also programmatically configure a logger to use it and produce the expected output). However when I try to deploy it with our app in JBoss, I get the following error: --- MBEANS THAT ARE THE ROOT CAUSE OF THE PROBLEM --- ObjectName: jboss.web.deployment:war=MyWebApp-2010_02-SNAPSHOT.war,id=476602902 State: FAILED Reason: java.lang.LinkageError: java/util/regex/Matcher I couldn't even find any info on this form of the error - typically LinkageError seems to show up with a "loader constrain violation" message, like in here. Technical details: we use JBoss 4.2, Java 5, Log4J 1.2.12. We deploy our app in an .ear, which contains (among others) the above mentioned .war file, and the custom layout class in a separate jar file. We override the default settings in jboss-log4J.xml with our own log4j.properties located in a different folder, which is added to the classpath at startup, and is provided via Carbon. I can only guess: are two different Matcher class versions loaded from somewhere, or is Matcher loaded by two different classloaders when it is used from the jar and the war? What does this error message mean, and how can I fix it?

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  • Simple typemap example in swig java

    - by celil
    I am trying to wrap a native C++ library using swig, and I am stuck at trying to convert time_t in C, to long in Java. I have successfully used swig with python, but so far I am unable to get the above typemap to work in Java. In python it looks like this %typemap(in) time_t { if (PyLong_Check($input)) $1 = (time_t) PyLong_AsLong($input); else if (PyInt_Check($input)) $1 = (time_t) PyInt_AsLong($input); else if (PyFloat_Check($input)) $1 = (time_t) PyFloat_AsDouble($input); else { PyErr_SetString(PyExc_TypeError,"Expected a large number"); return NULL; } } %typemap(out) time_t { $result = PyLong_FromLong((long)$1); } I guess the in map from Java to C would be: %typemap(in) time_t { $1 = (time_t) $input; } How would I complete the out map from C to Java? %typemap(out) time_t ??? Would I need typemaps like the ones below? %typemap(jni) %typemap(jtype) %typemap(jstype) I need this in order to wrap C functions like this: time_t manipulate_time (time_t dt);

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  • Which Java library for Binary Decision Diagrams?

    - by reprogrammer
    A Binary Decision Diagram (BDD) is a data structure to represent boolean functions. I'd like use this data structure in a Java program. My search for Java based BDD libraries resulted into the following packages. Java Decision Diagram Libraries JavaBDD JDD If you know of any other BDD libraries available for Java programs, please let me know so that I add it to the list above. If you have used any of these libraries, please tell me about your experience with the library. In particular, I'd like you to compare the available libraries along the following dimensions. Quality. Is the library mature and reasonably bug free? Performance. How do you evaluate the performance of the library? Support. Could you easily get support whenever you encountered a problem with the library? Was the library well documented? Ease of use. Was the API well designed? Could you install and use the library quickly and easily? Please mention the version of the library that you are evaluating.

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  • Hibernate Auto-Increment Setup

    - by dharga
    How do I define an entity for the following table. I've got something that isn't working and I just want to see what I'm supposed to do. USE [BAMPI_TP_dev] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[MemberSelectedOptions]( [OptionId] [int] NOT NULL, [SeqNo] [smallint] IDENTITY(1,1) NOT NULL, [OptionStatusCd] [char](1) NULL ) ON [PRIMARY] GO SET ANSI_PADDING OFF This is what I have already that isn't working. @Entity @Table(schema="dbo", name="MemberSelectedOptions") public class MemberSelectedOption extends BampiEntity implements Serializable { @Embeddable public static class MSOPK implements Serializable { private static final long serialVersionUID = 1L; @Column(name="OptionId") int optionId; @GeneratedValue(strategy=GenerationType.IDENTITY) @Column(name="SeqNo", unique=true, nullable=false) BigDecimal seqNo; //Getters and setters here... } private static final long serialVersionUID = 1L; @EmbeddedId MSOPK pk = new MSOPK(); @Column(name="OptionStatusCd") String optionStatusCd; //More Getters and setters here... } I get the following ST. [5/25/10 15:49:40:221 EDT] 0000003d JDBCException E org.slf4j.impl.JCLLoggerAdapter error Cannot insert explicit value for identity column in table 'MemberSelectedOptions' when IDENTITY_INSERT is set to OFF. [5/25/10 15:49:40:221 EDT] 0000003d AbstractFlush E org.slf4j.impl.JCLLoggerAdapter error Could not synchronize database state with session org.hibernate.exception.SQLGrammarException: could not insert: [com.bob.proj.ws.model.MemberSelectedOption] at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:90) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2285) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2678) at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:79) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:167) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137) at com.bcbst.bamp.ws.dao.MemberSelectedOptionDAOImpl.saveMemberSelectedOption(MemberSelectedOptionDAOImpl.java:143) at com.bcbst.bamp.ws.common.AlertReminder.saveMemberSelectedOptions(AlertReminder.java:76) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

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  • Simple Java Applet not loading in FireFox / Safari on MacOS

    - by Sleepless
    Hello all, I'm probably missing something very basic here. I'm trying to get my first applet to run inside a local HTML page in Firefox 3.6 on Mac OS 10.5.8. Here's the applet's code: package SimpleApplet; import java.applet.Applet; import java.awt.*; public class MyApplet extends Applet { private static final long serialVersionUID = 1L; public void init() { } public void stop() { } public void paint(Graphics g) { g.drawString("Tweedle-Dee!",20,40); } } Here's the HTML page: <html> <body> Here's the applet: <br/> <applet code="MyApplet.class" width="300" height="150"> </applet> </body> </html> Both files (.class and .html) are in the same folder on my local machine. Now when I load the .html file into Firefox, a rectangle with a red X gets displayed. The applet works when started from Eclipse (using JRE 1.5 BTW). Also, it's not a general problem with my browser, as several pages with applets (e.g. http://java.sun.com/applets/jdk/1.4/demo/applets/Blink/example1.html) work. This is also difficult to troubleshoot because there is no output at all on the Java console... Any suggestions are appreciated!

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  • Error while opening port in Java

    - by Deepak
    I am getting the following error while trying to open the cash drawer. Error loading win32com: java.lang.UnsatisfiedLinkError: C:\Program Files\Java\jdk1.6.0_15\jre\bin\win32com.dll: Can't load IA 32-bit .dll on a AMD 64-bit platform The code i am using is as follows `import javax.comm.; import java.util.; /** Check each port to see if it is open. **/ public class openPort { public static void main (String [] args) { Enumeration port_list = CommPortIdentifier.getPortIdentifiers (); while (port_list.hasMoreElements ()) { // Get the list of ports CommPortIdentifier port_id = (CommPortIdentifier) port_list.nextElement (); // Find each ports type and name if (port_id.getPortType () == CommPortIdentifier.PORT_SERIAL) { System.out.println ("Serial port: " + port_id.getName ()); } else if (port_id.getPortType () == CommPortIdentifier.PORT_PARALLEL) { System.out.println ("Parallel port: " + port_id.getName ()); } else System.out.println ("Other port: " + port_id.getName ()); // Attempt to open it try { CommPort port = port_id.open ("PortListOpen",20); System.out.println (" Opened successfully"); port.close (); } catch (PortInUseException pe) { System.out.println (" Open failed"); String owner_name = port_id.getCurrentOwner (); if (owner_name == null) System.out.println (" Port Owned by unidentified app"); else // The owner name not returned correctly unless it is // a Java program. System.out.println (" " + owner_name); } } } //main } // PortListOpen`

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  • UnsupportedEncodingException thrown when using Resin and Grails

    - by knorv
    I've encountered a strange problem in a Grails webapp running under Grails: java.io.UnsupportedEncodingException is thrown quite frequently due to various unknown encoding strings (such as "ISO8859_10", "ISO-8859-10"), and the strange thing is that this is done entirely within the Resin and Grails code. That is - no custom code is involved when the exception is thrown. I'm not sure if it is Grails or the servlet container's code that should handle the exception. But I'd assume that the exception should be handled somewhere and not bubble up all the way to stderr. This is the exception in full: java.io.UnsupportedEncodingException: ISO-8859-10 at com.caucho.vfs.i18n.JDKWriter$OutputStreamEncodingWriter.<init>(JDKWriter.java:112) at com.caucho.vfs.i18n.JDKWriter.create(JDKWriter.java:79) at com.caucho.vfs.Encoding.getWriteEncoding(Encoding.java:231) at com.caucho.server.connection.ToByteResponseStream.setEncoding(ToByteResponseStream.java:137) at com.caucho.server.connection.AbstractHttpResponse.setLocale(AbstractHttpResponse.java:1683) at com.caucho.server.connection.HttpServletResponseImpl.setLocale(HttpServletResponseImpl.java: 115) at javax.servlet.ServletResponseWrapper.setLocale(ServletResponseWrapper.java:139) at javax.servlet.ServletResponseWrapper.setLocale(ServletResponseWrapper.java:139) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1035) at org.codehaus.groovy.grails.web.servlet.GrailsDispatcherServlet.doDispatch(GrailsDispatcherServlet.java:290) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:647) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:552) at javax.servlet.http.HttpServlet.service(HttpServlet.java:114) My questions: Should the exception be handled? If so, is it the responsibility of the servlet container (Resin) or the web framework (Grails)? How would you go about solving this? (I'd rather not having the exception log cluttered with exceptions that I can do nothing about.)

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  • Beyond core java

    - by Paul
    Coming to the end of the first year of my CS degree, we've done some Java but just the core stuff; manipulating strings and arrays, inheritance, implementing logic etc. I visit this website daily and I see so much stuff that is beyond me; using frameworks; managing databases etc. It makes me feel like I've just learned the syntax of Java, and there is so much more to do with it. My question is though, how do I get there? I don't think I'm advanced enough to join an open source project, which seems to be suggested often (though I'd love to) and I've looked at other similar questions on here (like this one) but even then I don't think that'd work for me.. firstly, could somebody try give me some commonly used frameworks etc and how and what they are used for? Where would be a good place to start? How did you get started in using the things you do? Or perhaps you think I'm going down the wrong route. Should I learn another language, and just wait until the moment occurs where it's clear what I should be doing? I'm only in the first year of my degree, so far we've lightly covered Haskell and Java, and I've done a little HTML and CSS in my free time. I know that next year we cover python, so perhaps I should just wait till then and see if I prefer that? I feel like I also risk learning something in depth and then never using it... I suppose I'm also asking for personal experiences; was there a point where you felt you'd exceeded the basic grasp of a language (does not necessarily have to be Java related) and reach a more "advanced" level? I guess I'll put subjective tag on this, but really I just want to know how to get beyond the basic understanding of a language.

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  • How to use a linkedList and multiple classes with my Java GUI

    - by Asj
    How should I use a linked list with my GUI program? The program is supposed to have blocks with textareas and dropdown menus. The number of blocks depends on the number of times the user presses a button. It's supposed to be possible to put blocks within blocks. I want to store the information created, using a linked list and then saving to a file. I'm thinking, for the sub blocks, there would be linked lists within the linked list. Should I use Java.util.LinkedList? How do I add the information? A Node class? Should that be in a separate file? I started to try sitting up a linked list, but it's getting me confused. I'm still unsure about how a person is supposed to make GUI's. I've only seen really simple GUI's. Can anyone tell me how I should arrange things? At the moment, I have three files, one for the main GUI window, one for the question blocks to be inserted within that, and one for some tools to use within those two files to make the code easier to understand. But, there seems to be something wrong with the question block file, because I've been making the background white for each JPanel, and there's a gray outline around the question blocks when I run the program. I probably shouldn't paste a ton of code here... These are my files: http://asj127.webs.com/BuildAssessmentWindow.java http://asj127.webs.com/QuestionBlock.java http://asj127.webs.com/JPanelTools.java

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  • Java OutOfMemoryError message changes when trying to create Arrays of different sizes

    - by Gordon
    In the question by DKSRathore How to simulate the Out Of memory : Requested array size exceeds VM limit some odd behavior was noted when creating an arrays. When creating an array of size Integer.MAX_VALUE an exception with the error java.lang.OutOfMemoryError Requested array size exceeds VM limit was thrown. However when an array was created with a size less than the max but still above the virtual machine memory limit the error message read java.lang.OutOfMemoryError: Java heap space. Testing further I managed to narrow down where the error messages changes. long[] l = new long[2147483645]; exceptions message reads - Requested array size exceeds VM limit long[] l = new long[2147483644]; exceptions message reads - Java heap space errors I increased my virtual machine memory and still produced the same result. Has anyone any idea why this happens? Some extra info: Integer.MAX_VALUE = 2147483647. Edit: Here's the code I used to find the value, might be helpful. int max = Integer.MAX_VALUE; boolean done = false; while (!done) { try { max--; // Throws an error long[] l = new long[max]; // Exit if an error is no longer thrown done = true; } catch (OutOfMemoryError e) { if (!e.getMessage().contains("Requested array size exceeds VM limit")) { System.out.println("Message changes at " + max); done = true; } } }

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  • Groovy / Scala / Java under the hood

    - by Jack
    I used Java for like 6-7 years, then some months ago I discovered Groovy and started to save a lot of typing.. then I wondered how certain things worked under the hood (because groovy performance is really poor) and understood that to give you dynamic typing every Groovy object is a MetaClass object that handles all the things that the JVM couldn't handle by itself. Of course this introduces a layer in the middle between what you write and what you execute that slows down everything. Then somedays ago I started getting some infos about Scala. How these two languages compare in their byte code translations? How much things they add to the normal structure that it would be obtained by plain Java code? I mean, Scala is static typed so wrapper of Java classes should be lighter, since many things are checked during compile time but I'm not sure about the real differences of what's going inside. (I'm not talking about the functional aspect of Scala compared to the other ones, that's a different thing) Can someone enlighten me? From WizardOfOdds it seems like that the only way to get less typing and same performance would be to write an intermediate translator that translates something in Java code (letting javac compile it) without alterating how things are executed, just adding synctatic sugar withour caring about other fallbacks of the language itself.

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