Search Results

Search found 46178 results on 1848 pages for 'java home'.

Page 794/1848 | < Previous Page | 790 791 792 793 794 795 796 797 798 799 800 801  | Next Page >

  • May the FileInputStream.available foolish me?

    - by Tom Brito
    This FileInputStream.available() javadoc says: Returns an estimate of the number of remaining bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes. In some cases, a non-blocking read (or skip) may appear to be blocked when it is merely slow, for example when reading large files over slow networks. I'm not sure if in this check: if (new FileInputStream(xmlFile).available() == 0) can I rely that empty files will always return zero?

    Read the article

  • Jersey (Jax-RS) & EL

    - by smeg4brains
    Hi there! im trying to get a controller to return a view through a Expression Language-Filter, but have no idea on how to get jersey to use EL for filtering a view. View with EL-tags: <html> <title>%{msg}</title> </html> Controller: @GET @Produces("text/html") public Response viewEventsAsHtml(){ String view=null; try { view=getViewAsString("events"); }catch(IOException e){ LOG.error("unable to load view from file",e); return null; } Response.ResponseBuilder builder=Response.ok(view, MediaType.TEXT_HTML); return builder.build(); } How would one go about in order to get the controller to replace the ${msg} part in the view by some arbitrary value?

    Read the article

  • Python code translation to JVM

    - by jldupont
    Is there such a thing as a "translator" (for lack of a better word in my mind now) that translates Python code directly to JVM / Dalvik bytecode? Would be great for writing Android applications in Python! NOTE: I know about the scripting capabilities of the Android platform but I am looking for something that would generate a '.apk' without having to install the 'scripting' package... annoying for end-users.

    Read the article

  • Representing game states in Tic Tac Toe

    - by dacman
    The goal of the assignment that I'm currently working on for my Data Structures class is to create a of Quantum Tic Tac Toe with an AI that plays to win. Currently, I'm having a bit of trouble finding the most efficient way to represent states. Overview of current Structure: AbstractGame Has and manages AbstractPlayers (game.nextPlayer() returns next player by int ID) Has and intializes AbstractBoard at the beginning of the game Has a GameTree (Complete if called in initialization, incomplete otherwise) AbstractBoard Has a State, a Dimension, and a Parent Game Is a mediator between Player and State, (Translates States from collections of rows to a Point representation Is a StateConsumer AbstractPlayer Is a State Producer Has a ConcreteEvaluationStrategy to evaluate the current board StateTransveralPool Precomputes possible transversals of "3-states". Stores them in a HashMap, where the Set contains nextStates for a given "3-state" State Contains 3 Sets -- a Set of X-Moves, O-Moves, and the Board Each Integer in the set is a Row. These Integer values can be used to get the next row-state from the StateTransversalPool SO, the principle is Each row can be represented by the binary numbers 000-111, where 0 implies an open space and 1 implies a closed space. So, for an incomplete TTT board: From the Set<Integer> board perspective: X_X R1 might be: 101 OO_ R2 might be: 110 X_X R3 might be: 101, where 1 is an open space, and 0 is a closed space From the Set<Integer> xMoves perspective: X_X R1 might be: 101 OO_ R2 might be: 000 X_X R3 might be: 101, where 1 is an X and 0 is not From the Set<Integer> oMoves perspective: X_X R1 might be: 000 OO_ R2 might be: 110 X_X R3 might be: 000, where 1 is an O and 0 is not Then we see that x{R1,R2,R3} & o{R1,R2,R3} = board{R1,R2,R3} The problem is quickly generating next states for the GameTree. If I have player Max (x) with board{R1,R2,R3}, then getting the next row-states for R1, R2, and R3 is simple.. Set<Integer> R1nextStates = StateTransversalPool.get(R1); The problem is that I have to combine each one of those states with R1 and R2. Is there a better data structure besides Set that I could use? Is there a more efficient approach in general? I've also found Point<-State mediation cumbersome. Is there another approach that I could try there? Thanks! Here is the code for my ConcretePlayer class. It might help explain how players produce new states via moves, using the StateProducer (which might need to become StateFactory or StateBuilder). public class ConcretePlayerGeneric extends AbstractPlayer { @Override public BinaryState makeMove() { // Given a move and the current state, produce a new state Point playerMove = super.strategy.evaluate(this); BinaryState currentState = super.getInGame().getBoard().getState(); return StateProducer.getState(this, playerMove, currentState); } } EDIT: I'm starting with normal TTT and moving to Quantum TTT. Given the framework, it should be as simple as creating several new Concrete classes and tweaking some things.

    Read the article

  • autocommit and @Transactional and Cascading with spring, jpa and hibernate

    - by subes
    Hi, what I would like to accomplish is the following: have autocommit enabled so per default all queries get commited if there is a @Transactional on a method, it overrides the autocommit and encloses all queries into a single transaction, thus overriding the autocommit if there is a @Transactional method that calls other @Transactional annotated methods, the outer most annotation should override the inner annotaions and create a larger transaction, thus annotations also override eachother I am currently still learning about spring-orm and couldn't find documentation about this and don't have a test project for this yet. So my questions are: What is the default behaviour of transactions in spring? If the default differs from my requirement, is there a way to configure my desired behaviour? Or is there a totally different best practice for transactions? --EDIT-- I have the following test-setup: @javax.persistence.Entity public class Entity { @Id @GeneratedValue private Integer id; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } @Repository public class Dao { @PersistenceContext private EntityManager em; public void insert(Entity ent) { em.persist(ent); } @SuppressWarnings("unchecked") public List<Entity> selectAll() { List<Entity> ents = em.createQuery("select e from " + Entity.class.getName() + " e").getResultList(); return ents; } } If I have it like this, even with autocommit enabled in hibernate, the insert method does nothing. I have to add @Transactional to the insert or the method calling insert for it to work... Is there a way to make @Transactional completely optional?

    Read the article

  • Enum in Hibernate, persisting as an enum

    - by niklassaers
    In my MySQL database, there's the column "gender enum('male','female')" I've created my enum "com.mydomain.myapp.enums.Gender", and in my Person entity I'm defined "Gender gender". Now I'd want to keep the enum type in my MySQL database, but when I launch my application I get: Wrong column type in MyApp.Person for column Gender. Found: enum, expected: integer Why is this? This would be the equivalent as if I'd annotated my "Gender gender" with "@Enumerated(EnumType.ORDINAL)", which I haven't. EnumType seems only to be able to be either ORDINAL or STRING, so how do I specify that it should treat the field as an enum, not as an int? (not that there's much difference, but enough for it to get upset about it.)

    Read the article

  • Testing JavaMail Related Modules

    - by Hamza Yerlikaya
    Part of my application depends on JavaMail, moving arranging messages etc. Is it possible to test this module without firing a IMAP server to run the tests on? I am always stuck when it comes to testing stuff that depends on external servers or modules.

    Read the article

  • problem while rerendering the form in jsf1.1?

    - by Hari
    In my application I have to show a panel on same page after click of a button. For that I am passing my form id on rerender attribute of the button. the funtionalty is working fine but the problem is the whole form get resized and all component come close to each other. the same page i refresh the same page, then it look's fine, or if i redirect the same page again from my bean it stays fine. but i should not follow this appoach.

    Read the article

  • Textbox height in a small browser window

    - by Fritz H
    Hi folks, I have here a peculiar problem. We have a RAP application intended for use on a PDA/phone, but when it is displayed in a small browser window, all the textboxes on the form(s) are too tall (around twice the height they should be). I've stepped through the code (The form is using GridLayout, number of columns=1, make columns equal=false) and have found that the TextSizeDetermination.getCharHeight() method returns an incorrect font size if the browser window is too small - 13px if the window is large, 26px (exactly double) if the window is too small. Interestingly enough, it seems that if the window is too small, probeStore.containsProbeResult(font) in that method returns true and uses probeStore.getProbeResult(...).getSize().y for the font size. Otherwise, if the window is larger, it returns false and uses TextSizeEstimation.getCharHeight(...). Does anyone have a pointer or two for getting around this? Dialog with a properly-sized window: Dialog with a small window:

    Read the article

  • Displaying large file in JTextArea.

    - by Sathish Gopal
    Hi All, I'm currently working in Swing UI Assignment. This work involves showing large file content in JTextArea. The file size can be as large as 2 GB. My initial idea is to lazily load content from the file, say 1 MB of content will be shown to the user. As the user scrolls i will retrieve the next 1 MB of content to be shown. All these operation will be happening in background thread (Swing Worker). I looked at the JTextArea API, the method insert takes String and int(position of the insert) as the parameter. This will suffice, but i'm worried about performance, because the content (1 MB at a time) retrieved will have to be converted to String object. Is there any other work around or any other alternative/better solution for this.

    Read the article

  • Difference in output from use of synchronized keyword and join()

    - by user2964080
    I have 2 classes, public class Account { private int balance = 50; public int getBalance() { return balance; } public void withdraw(int amt){ this.balance -= amt; } } and public class DangerousAccount implements Runnable{ private Account acct = new Account(); public static void main(String[] args) throws InterruptedException{ DangerousAccount target = new DangerousAccount(); Thread t1 = new Thread(target); Thread t2 = new Thread(target); t1.setName("Ravi"); t2.setName("Prakash"); t1.start(); /* #1 t1.join(); */ t2.start(); } public void run(){ for(int i=0; i<5; i++){ makeWithdrawl(10); if(acct.getBalance() < 0) System.out.println("Account Overdrawn"); } } public void makeWithdrawl(int amt){ if(acct.getBalance() >= amt){ System.out.println(Thread.currentThread().getName() + " is going to withdraw"); try{ Thread.sleep(500); }catch(InterruptedException e){ e.printStackTrace(); } acct.withdraw(amt); System.out.println(Thread.currentThread().getName() + " has finished the withdrawl"); }else{ System.out.println("Not Enough Money For " + Thread.currentThread().getName() + " to withdraw"); } } } I tried adding synchronized keyword in makeWithdrawl method public synchronized void makeWithdrawl(int amt){ and I keep getting this output as many times I try Ravi is going to withdraw Ravi has finished the withdrawl Ravi is going to withdraw Ravi has finished the withdrawl Ravi is going to withdraw Ravi has finished the withdrawl Ravi is going to withdraw Ravi has finished the withdrawl Ravi is going to withdraw Ravi has finished the withdrawl Not Enough Money For Prakash to withdraw Not Enough Money For Prakash to withdraw Not Enough Money For Prakash to withdraw Not Enough Money For Prakash to withdraw Not Enough Money For Prakash to withdraw This shows that only Thread t1 is working... If I un-comment the the line saying t1.join(); I get the same output. So how does synchronized differ from join() ? If I don't use synchronize keyword or join() I get various outputs like Ravi is going to withdraw Prakash is going to withdraw Prakash has finished the withdrawl Ravi has finished the withdrawl Prakash is going to withdraw Ravi is going to withdraw Prakash has finished the withdrawl Ravi has finished the withdrawl Prakash is going to withdraw Ravi is going to withdraw Prakash has finished the withdrawl Ravi has finished the withdrawl Account Overdrawn Account Overdrawn Not Enough Money For Ravi to withdraw Account Overdrawn Not Enough Money For Prakash to withdraw Account Overdrawn Not Enough Money For Ravi to withdraw Account Overdrawn Not Enough Money For Prakash to withdraw Account Overdrawn So how does the output from synchronized differ from join() ?

    Read the article

  • toString method for varargs contructor

    - by owca
    I have a varargs contructor like this : public class Sentence { public String[] str; public Sentence(Object... text){ StringBuilder sb = new StringBuilder(); for (Object o : text) { sb.append(o.toString()) .append(" "); } System.out.println(sb.toString()); } } Contructor can get various types of data (ints, strings, and Sentence objects as well). How to do a proper toString method for such class ?

    Read the article

  • Google datastore stats

    - by Keyur
    I am querying the __Stat_Kind__ kind. It does not return me entities about kinds that currently exist in the datastore but it includes entities about kinds that I had deleted more than a week ago. I am not so much concerned about it returning me the non-existent kinds - the doc does mention this scenario after all. But I am concerned that it does not return me info about my current kinds. Is this a known issue or am I doing something wrong? To folks on the app engine team: Also, on the dev server neither __Stat_Kind__ nor __Stat_Total__ return any entities. Which means I need to deploy my app to appspot before I can test this behavior. It would be nice if the dev server did return some basic info. Thanks, Keyur

    Read the article

  • Eclipse RCP: Actions vs Commands - would like an update

    - by nEm
    I know this question has been asked before but it was in 2009 and I haven't found anything more recent either on the web. I was wondering if the answer in that still holds or can it be updated? I am just starting work on an RCP and I haven't been able to decide between actions and commands for my menu items. I will be using a lot of the ones provided by Eclipse such as the Edit, File and some of their sub menu items as well. Since it has been nearly two years for the answer provided in the '09 question, I just wanted to make sure there is nothing else that could sway my decision in either direction or maybe if there have been some new developments that I am not aware of.

    Read the article

  • How do I determine if a JDialog has children?

    - by Morinar
    I've got a custom window class that is a couple levels down extending a JDialog. We have windows that we create and sometimes we create new windows as children of existing windows using the constructor that takes a parent argument. I need to put some code somewhere in our custom class that does something different depending on whether not the window has children. I know of getParent(), etc, and I can see that I can loop through the components of the window, but for the life of me, I can't seem to figure out how to determine whether or not my current window has any child windows. Is there a way to do this? Any help is, as always, much appreciated.

    Read the article

  • JPA - Performance with using multiple entity manager

    - by Nguyen Tuan Linh
    My situation is: The code is not mine I have two kinds of database: one is Dad, one is Son. In Dad, I have a table to store JNDI name. I will look up Dad using JNDI, create entity manager, and retrieve this table. From these retrieved JNDI names, I will create multiple entity managers using multiple Son databases. The problem is: Son have thousands of entities. It takes each Son database around 10 minutes to load all entities. If there is 4 Son databases, it will be 40 minutes. My question: Is there any way to load all entities and use them for all entity manager? Please look at the code below For each Son JNDI: Map<String, String> puSonProperties = new HashMap<String, String>(); puSonProperties.put("javax.persistence.jtaDataSource", sonJndi); EntityManagerFactory emf = Persistence.createEntityManagerFactory("PUSon", puSonProperties); PUSon - All of them use the same persistence unit log.info("Verify entity manager for son: {0} - {1}", sonCode, emSon.find(Son_configuration.class, 0) != null ? "ok" : "failed!"); This is the actual code where the loading of all entities begins. 10 mins.

    Read the article

  • Space-based architecture?

    - by rcampbell
    One chapter in Pragmatic Programmer recommends looking at a blackboard/space-based architecture + a rules engine as a more flexible alternative to a traditional workflow system. The project I'm working on currently uses a workflow engine, but I'd like to evaluate alternatives. I really feel like a SBA would be a better solution to our business problems, but I'm worried about a total lack of community support/user base/venders/options. JavaSpaces is dead, and the JINI spin-off Apache River seems to be on life support. SemiSpace looks perfect, but it's a one-man show. The only viable solution seems to be GigaSpaces. I'd like to hear your thoughts on space based architecture and any experiences you've had with real world implementations.

    Read the article

  • Creating queries using Criteria API (JPA 2.0)

    - by Pym
    Hello there ! I'm trying to create a query with the Criteria API from JPA 2.0, but I can't make it work. The problem is with the "between" conditionnal method. I read some documentation to know how I have to do it, but since I'm discovering JPA, I don't understand why it does not work. First, I can't see "creationDate" which should appear when I write "Transaction_." I thought it was maybe normal, since I read the metamodel was generated at runtime, so I tried to use 'Foo_.getDeclaredSingularAttribute("value")' instead of 'Foo_.value', but it still doesn't work at all. Here is my code : public List<Transaction> getTransactions(Date startDate, Date endDate) { EntityManager em = getEntityManager(); try { CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<Transaction> cq = cb.createQuery(Transaction.class); Metamodel m = em.getMetamodel(); EntityType<Transaction> Transaction_ = m.entity(Transaction.class); Root<Transaction> transaction = cq.from(Transaction.class); // Error here. cannot find symbol. symbol: variable creationDate cq.where(cb.between(transaction.get(Transaction_.creationDate), startDate, endDate)); // I also tried this: // cq.where(cb.between(Transaction_.getDeclaredSingularAttribute("creationDate"), startDate, endDate)); List<Transaction> result = em.createQuery(cq).getResultList(); return result; } finally { em.close(); } } Can someone help me to figure this out? Thanks.

    Read the article

  • Should I use a collection here?

    - by Eva
    So I have code set up like this: public interface IInterface { public void setField(Object field); } public abstract class AbstractClass extends JPanel implements IInterface { private Object field_; public void setField(Object field) { field_ = field; } } public class ClassA extends AbstractClass { public ClassA() { // unique ClassA constructor stuff } public Dimension getPreferredSize() { return new Dimension(1, 1); } } public class ClassB extends AbstractClass { public ClassB() { // unique ClassB constructor stuff } public Dimension getPreferredSize() { return new Dimension(42, 42); } } public class ConsumerA { public ConsumerA(Collection<AbstractClass> collection) { for (AbstractClass abstractClass : collection) { abstractClass.setField(this); abstractClass.repaint(); } } } All hunky-dory so far, until public class ConsumerB { // Option 1 public ConsumerB(ClassA a, ClassB b) { methodThatOnlyTakesA(a); methodThatOnlyTakesB(b); } // Option 2 public ConsumerB(Collection<AbstractClass> collection) { for (IInterface i : collection) { if (i instanceof ClassA) { methodThatOnlyTakesA((ClassA) i); else if (i instanceof ClassB) { methodThatOnlyTakesB((ClassB) i); } } } } public class UsingOption1 { public static void main(String[] args) { ClassA a = new ClassA(); ClassB b = new ClassB(); Collection<AbstractClass> collection = Arrays.asList(a, b); ConsumerA consumerA = new ConsumerA(collection); ConsumerB consumerB = new ConsumerB(a, b); } } public class UsingOption2 { public static void main(String[] args) { Collection<AbstractClass> collection = Arrays.asList(new ClassA(), new ClassB()); ConsumerA = new ConsumerA(collection); ConsumerB = new ConsumerB(collection); } } With a lot more classes extending AbstractClass, both options get unwieldly. Option1 would make the constructor of ConsumerB really long. Also UsingOption1 would get long too. Option2 would have way more if statements than I feel comfortable with. Is there a viable Option3? If it helps, ClassA and ClassB have all the same methods, they're just implemented differently. Thanks for slogging through my code!

    Read the article

  • Interface Design Problem: Storing Result of Transactions

    - by jboyd
    Requirements: multiple sources of input (social media content) into a system multiple destinations of output (social media api's) sources and destinations WILL be added some pseudo: IContentProvider contentProvider = context.getBean("contentProvider"); List<Content> toPost = contentProvider.getContent(); for (Content c : toPost) { SocialMediaPresence smPresence = socialMediaService.getSMPresenceBySomeId(c.getDestId()); smPresence.hasTwitter(); smPresence.hasFacebook(); //just to show what this is smPresence.postContent(c); //post content could fail for some SM platforms, but shoulnd't be lost forever } So now I run out of steam, I need to know what content has been successfully posted, and if it hasn't gone too all platforms, or if another platform were added in the future that content needs to go out for it as well (therefore my content provider will need to not only know if content has gone out, but for what platforms). I'm not looking for code, although sample/pseudo is fine... I'm looking for an approach to this problem that I can implement

    Read the article

  • Apache with JBOSS using AJP (mod_jk) giving spikes in thread count.

    - by Beginner
    We used Apache with JBOSS for hosting our Application, but we found some issues related to thread handling of mod_jk. Our website comes under low traffic websites and has maximum 200-300 concurrent users during our website's peak activity time. As the traffic grows (not in terms of concurrent users, but in terms of cumulative requests which came to our server), the server stopped serving requests for long, although it didn't crash but could not serve the request till 20 mins. The JBOSS server console showed that 350 thread were busy on both servers although there was enough free memory say, more than 1-1.5 GB (2 servers for JBOSS were used which were 64 bits, 4 GB RAM allocated for JBOSS) In order to check the problem we were using JBOSS and Apache Web Consoles, and we were seeing that the thread were showing in S state for as long as minutes although our pages take around 4-5 seconds to be served. We took the thread dump and found that the threads were mostly in WAITING state which means that they were waiting indefinitely. These threads were not of our Application Classes but of AJP 8009 port. Could somebody help me in this, as somebody else might also got this issue and solved it somehow. In case any more information is required then let me know. Also is mod_proxy better than using mod_jk, or there are some other problems with mod_proxy which can be fatal for me if I switch to mod__proxy? The versions I used are as follows: Apache 2.0.52 JBOSS: 4.2.2 MOD_JK: 1.2.20 JDK: 1.6 Operating System: RHEL 4 Thanks for the help.

    Read the article

< Previous Page | 790 791 792 793 794 795 796 797 798 799 800 801  | Next Page >