Search Results

Search found 46894 results on 1876 pages for 'java native interface'.

Page 839/1876 | < Previous Page | 835 836 837 838 839 840 841 842 843 844 845 846  | Next Page >

  • Servlet requests are executed sequentially for no apparent reason in Glassfish v3

    - by Fabien Benoit
    Hi, I'm using Glassfish 3 Web profile and can't get http workers to execute concurrently requests on a servlet. This is how i observed the problem. I've made a very simple servlet, that writes the current thread name to the standard output and sleep for 10 seconds : protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println(Thread.currentThread().getName()); try { Thread.sleep(10000); // 10 sec } catch (InterruptedException ex) {} } } And when i'm running several simultaneous requests, I clearly see in the logs that the requests are sequentially executed (one trace every 10 seconds). INFO: http-thread-pool-8080-(2) (10 seconds later...) INFO: http-thread-pool-8080-(1) (10 seconds later...) INFO: http-thread-pool-8080-(2) etc. All my GF settings are untouched - it's the out-of-the-box config (the default thread pool is 2 threads min, 5 max if I recall properly). ...I really don't understand why the sleep() block all the others worker threads. Any insight would be greatly appreciated ! Thanks, Fabien

    Read the article

  • Infinispan equivalent to ehcache's copyOnRead and copyOnWrite

    - by waxwing
    Hi, I am planning to implement a cache solution into an existing web app. Nothing complicated: basically a concurrent map that supports overflowing to disk and automatic eviction. Clustering the cache could be requirement in the future, but not now. I like ehcache's copyOnRead and copyOnWrite features, because it means that I don't have to manually clone things before modifying something I take out of the cache. Now I have started to look at Infinispan, but I have not found anything equivalent there. Does it exist? I.e., the following unit tests should pass: @Test public void testCopyOnWrite() { Date date = new Date(0); cache.put(0, date); date.setTime(1000); date = cache.get(0); assertEquals(0, date.getTime()); } @Test public void testCopyOnRead() { Date date = new Date(0); cache.put(0, date); assertNotSame(cache.get(0), cache.get(0)); }

    Read the article

  • Confused about Huffman Trees

    - by ShrimpCrackers
    A quick tutorial on generating a huffman tree Confused about Huffman Trees. Near the end of that link above, it shows the tree with 2 elements left, and then the completed tree. I'm confused about the way that it is branched. Is there a specific way a huffman tree needs to be branched? For example, 57:* with its right child 35:* is branched off to the right. Could it have been 35 branched to the left with 22 branched to the right? Also, why wasn't 22:* paired up with 15:4 - it just paired with 20:5 to create a new tree. From initial obersvations it seems the tree does not need to be balanced or have any specific order other than that the frequencies of a leaf add up to the value of the parent node. Could two people creating a huffman tree with the same data end up with different encoding values?

    Read the article

  • What situations does a Monostate pattern model?

    - by devoured elysium
    I know what both a Singleton or a Monostate are and how to implement them. Although I can see many uses for a Singleton, I can't imagine a situation where I would want to let the user create as many instances of my class although in reality only one really exists behind the scenes. Can anybody help me here? I know that for several reasons one should stay away from both patterns, but in theory, what kind of problems does the Monostate model? Thanks

    Read the article

  • How convince other developers not to ignore Exceptions?

    - by Mnementh
    Recently I encountered a bug in an application I took over from another developer. I debugged for the reason and over an hour later I realized, that the problem wasn't the code producing the exception, but some code executed before this returning wrong data. If I dived into this, I encountered the following: try { ... } catch (XYException e){} If the Exception would have been propagated (a change I did), I would have found the reason for the bugs in a few minutes, as the stacktrace had pointed me to the problem. So how can I convince other developers to never catch and ignore exceptions in this way?

    Read the article

  • How to make enemies?

    - by Meko
    Hi..I made shoot em up like game.But I have only one ememy which fallows me on screen.But I want to make lots of enemys like each 10 second they will across on screen together 5 or 10 enemys. ArrayList<Enemies> enemy = new ArrayList<Enemies>(); for (Enemies e : enemy) { e.draw(g); } is it good creating array list and then showing on screen? And Do I have to make some planing movements thoose enemies in my code ? I want that they vill appear not on same pozition.Like First 5 enemies will come top of screen then the other 5 or 10 enemies will come from left side.. so on.What is best solution for this?

    Read the article

  • Why is Collection<String>.class Illegal?

    - by Peter
    I am puzzled by generics. You can declare a field like: Class<Collection<String>> clazz = ... It seems logical that you could assign this field with: Class<Collection<String>> clazz = Collection<String>.class; However, this generates an error: Syntax error on token ">", void expected after this token So it looks like the .class operator does not work with generics. So I tried: class A<S> {} class B extends A<String> {} Class<A<String>> c = B.class; Also does not work, generates: Type mismatch: cannot convert from Class<Test.StringCollection> to Class<Collection<String>> Now, I really fail to see why this should not work. I know generic types are not reified but in both cases it seems to be fully type safe without having access to runtime generic types. Anybody an idea? Peter Kriens

    Read the article

  • How to create an aspect on class, that is not a bean using Spring AOP?

    - by Ula Krukar
    Hello, I work on an legacy application, where Spring AOP (namely ProxyFactoryBean) is used. I need to add an aspect around a method of a certain class. This class is not a bean however. The AspecjJ pointcut expression would be like this: execution(* xyz.package.Class.method()) I created a MethodInterceptor and AspectJExpressionPointcut, but I don't know how make those two work together. EDIT: I do not have source code for this class, it is a 3rd party library. The instances of this class are not created by me, neither in source code, nor in spring configuration as beans. It is used internally by the library. Any help appreciated.

    Read the article

  • How does this code break the Law of Demeter?

    - by Dave Jarvis
    The following code breaks the Law of Demeter: public class Student extends Person { private Grades grades; public Student() { } /** Must never return null; throw an appropriately named exception, instead. */ private synchronized Grades getGrades() throws GradesException { if( this.grades == null ) { this.grades = createGrades(); } return this.grades; } /** Create a new instance of grades for this student. */ protected Grades createGrades() throws GradesException { // Reads the grades from the database, if needed. // return new Grades(); } /** Answers if this student was graded by a teacher with the given name. */ public boolean isTeacher( int year, String name ) throws GradesException, TeacherException { // The method only knows about Teacher instances. // return getTeacher( year ).nameEquals( name ); } private Grades getGradesForYear( int year ) throws GradesException { // The method only knows about Grades instances. // return getGrades().getForYear( year ); } private Teacher getTeacher( int year ) throws GradesException, TeacherException { // This method knows about Grades and Teacher instances. A mistake? // return getGradesForYear( year ).getTeacher(); } } public class Teacher extends Person { public Teacher() { } /** * This method will take into consideration first name, * last name, middle initial, case sensitivity, and * eventually it could answer true to wild cards and * regular expressions. */ public boolean nameEquals( String name ) { return getName().equalsIgnoreCase( name ); } /** Never returns null. */ private synchronized String getName() { if( this.name == null ) { this.name == ""; } return this.name; } } Questions How is the LoD broken? Where is the code breaking the LoD? How should the code be written to uphold the LoD?

    Read the article

  • unable to add objects to saved collection in GAE using JDO

    - by Jeffrey Chee
    I have a ClassA containing an ArrayList of another ClassB I can save a new instance of ClassA with ClassB instances also saved using JDO. However, When I retrieve the instance of Class A, I try to do like the below: ClassA instance = PMF.get().getPersistenceManager().GetObjectByID( someid ); instance.GetClassBArrayList().add( new ClassB(...) ); I get an Exception like the below: Uncaught exception from servlet com.google.appengine.api.datastore.DatastoreNeedIndexException: no matching index found.. So I was wondering, Is it possible to add a new item to the previously saved collection? Or was it something I missed out. Best Regards

    Read the article

  • IVR-style dialog system / workflow / menu

    - by unbeli
    I need to build a dialog system similar to IVR used in call centers. My system is not phone-based, but the dialog is similar. Something like System: "Main menu: Enter [1] for menu1, [2] for menu2" User: [1] System: "menu1: enter [1] for apples, [2] for oranges, [3] for main menu" User: [7] System: "What??" System: "menu1: enter [1] for apples, [2] for oranges, [3] for main menu" User: [2] ... and so on I want to have a nice declarative description of all the possible options and a nice way to run through that tree, guided by user input. Already considered: ANTLR-generated lexer/parser (seems to be an overkill), SCXML-based state machine (seems like only transitions can be declared, the rest needs to be coded)

    Read the article

  • Maven String Replace of Text Web Resources

    - by Jaco van Niekerk
    I have a Maven web application with text files in src/main/webapp/textfilesdir As I understand it, during the package phase this textfilesdir directory will be copied into the target/project-1.0-SNAPSHOT directory, which is then zipped up into a target/project-1.0-SNAPSHOT.war Problem Now, I need to do a string replacement on the contents of the text files in target/project-1.0-SNAPSHOT/textfilesdir. This must then be done after the textfilesdir is copied into target/project-1.0-SNAPSHOT, but prior to the target/project-1.0-SNAPSHOT.war file being created. I believe this is all done during the package phase. How can a plugin (potentially maven-antrun-plugin), plug into the package phase to do this. The text files don't contain properties, like ${property-name} to filter on. String replacement is likely the only option. Options Modify the text files after the copy into target/project-1.0-SNAPSHOT directory, yet prior to the WAR creation. After packaging, extract the text files from WAR, modify them, and add them back into the WAR. I'm thinking there is another option here I'm missing. Thoughts anyone?

    Read the article

  • Selenium WebDriver Element

    - by cxyz
    How do i configure selenium WebDriver.I have automated test cases using Selenium.Now i need to automate upload and download of a file.So i have to automate using WebDriver.I had added webdriver-common-0.9.7376.jar.Now how do i instantiate for Internet Explorer? Am just decalring variable and using driver private static WebDriver driver; driver.findElement(By.id(upload)).sendKeys("file to be upload"); Is this correct?

    Read the article

  • Hibernate save() and transaction rollback

    - by Marco
    Hi, In Hibernate when i save() an object in a transaction, and then i rollback it, the saved object still remains in the DB. It's strange because this issue doesn't happen with the update() or delete() method, just with save(). Here is the code i'm using: DbEntity dbEntity = getDbEntity(); HibernateUtil.beginTransaction(); Session session = HibernateUtil.getCurrentSession(); session.save(dbEntity); HibernateUtil.rollbackTransaction(); And here is the HibernateUtil class (just the involved functions, i guarantee the getSessionFactory() method works well - there is an Interceptor handler, but it doesn't matter now): private static final ThreadLocal<Session> threadSession = new ThreadLocal<Session>(); private static final ThreadLocal<Transaction> threadTransaction = new ThreadLocal<Transaction>(); /** * Retrieves the current Session local to the thread. * <p/> * If no Session is open, opens a new Session for the running thread. * * @return Session */ public static Session getCurrentSession() throws HibernateException { Session s = (Session) threadSession.get(); try { if (s == null) { log.debug("Opening new Session for this thread."); if (getInterceptor() != null) { log.debug("Using interceptor: " + getInterceptor().getClass()); s = getSessionFactory().openSession(getInterceptor()); } else { s = getSessionFactory().openSession(); } threadSession.set(s); } } catch (HibernateException ex) { throw new HibernateException(ex); } return s; } /** * Start a new database transaction. */ public static void beginTransaction() throws HibernateException { Transaction tx = (Transaction) threadTransaction.get(); try { if (tx == null) { log.debug("Starting new database transaction in this thread."); tx = getCurrentSession().beginTransaction(); threadTransaction.set(tx); } } catch (HibernateException ex) { throw new HibernateException(ex); } } /** * Rollback the database transaction. */ public static void rollbackTransaction() throws HibernateException { Transaction tx = (Transaction) threadTransaction.get(); try { threadTransaction.set(null); if ( tx != null && !tx.wasCommitted() && !tx.wasRolledBack() ) { log.debug("Tyring to rollback database transaction of this thread."); tx.rollback(); } } catch (HibernateException ex) { throw new HibernateException(ex); } finally { closeSession(); } } Thanks

    Read the article

  • Is selling a "website screen scraper" is illegal?

    - by Yatendra Goel
    I have coded a "website screen scraper" and want to sell it commercially. I know that webpages scraped by the screen scraper are restricted to be scraped by the webmaser of that website. The robots.txt file of the website says that its webpages must not be scraped. So my question is whether selling that screen scraper is a crime or using that screen scraper is a crime in legal terms. I know that this question is related to law but I thought the software experts on SO must also have answer to this question.

    Read the article

< Previous Page | 835 836 837 838 839 840 841 842 843 844 845 846  | Next Page >