Search Results

Search found 55437 results on 2218 pages for 'oracle berkeley db java edition'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 518/2218 | < Previous Page | 514 515 516 517 518 519 520 521 522 523 524 525  | Next Page >

  • Java Thread - Memory consistency errors

    - by Yatendra Goel
    I was reading a Sun's tutorial on Concurrency. But I couldn't understand exactly what memory consistency errors are? I googled about that but didn't find any helpful tutorial or article about that. I know that this question is a subjective one, so you can provide me links to articles on the above topic. It would be great if you explain it with a simple example.

    Read the article

  • Java, Massive message processing with queue manager (trading)

    - by Ronny
    Hello, I would like to design a simple application (without j2ee and jms) that can process massive amount of messages (like in trading systems) I have created a service that can receive messages and place them in a queue to so that the system won't stuck when overloaded. Then I created a service (QueueService) that wraps the queue and has a pop method that pops out a message from the queue and if there is no messages returns null, this method is marked as "synchronized" for the next step. I have created a class that knows how process the message (MessageHandler) and another class that can "listen" for messages in a new thread (MessageListener). The thread has a "while(true)" and all the time tries to pop a message. If a message was returned, the thread calls the MessageHandler class and when it's done, he will ask for another message. Now, I have configured the application to open 10 MessageListener to allow multi message processing. I have now 10 threads that all time are in a loop. Is that a good design?? Can anyone reference me to some books or sites how to handle such scenario?? Thanks, Ronny

    Read the article

  • Authorization engine in java

    - by eltados
    In the course of my work i need to develop an authorization engine ( i'm already authenticated and i check access of a user to an action ) in order to store all the authorization logic inside a same place and be able to reuse it and i have created the mini library. http://github.com/eltados/canny what do you think about it? Is there any lightweight Authorization engine library i could have a look at?

    Read the article

  • java: remove current scheduled job in a class that implements IScheduledJob

    - by ufk
    Hi. In the execution of the scheduled job itself i want to stop it from being executed again and again, how can i do so without having the string that i received when i created the job in the first place ? public class UfkJob implements IScheduledJob { public void execute(ISchedulingService service) { if (...) { /* here i want to remove the current running job */ } } I executed the job outside by using the commands: ISchedulingService service = (ISchedulingService) getScope().getContext().getBean(ISchedulingService.BEAN_NAME); service.addScheduledJobAfterDelay(5000,new UfkJob(),200);

    Read the article

  • Convert Java String to Array

    - by Bruce
    This is a weird problem. Here is my code String reply = listen.executeUrl("http://localhost:8080/JavaBridge/reply.php); executeUrl returns as String object whatever is returned by the reply.php file. Now comes the problem. In reply.php I am returning an PHP array and reply is a String. When I do System.out.println("Reply = "+reply); I get Reply = array(2) { [0]=> string(14) "Dushyant Arora" [1]=> string(19 ) "@dushyantarora13 hi"} But reply is still a String. How do I convert it into a String array or an Array.

    Read the article

  • java increase xmx dynamically at runtime

    - by Tomer
    Hi, I have a jvm server in my machine, now I want to have 2 apservers of mine sitting in same machine, however I want the standby one to have a really low amount of memory allocated with xmx because its passive, one the main server (active) goes down I want to allocate more memory to my passive server which is already up without restarting it (I have have them both having too much xmx - note they would consume memory at startup and I cant allow possibility of outOfMemory). So I want passive - low xmx once active goes down I want my passive to receive much more xmx. is there a way for me to achieve that. Thanks

    Read the article

  • Strange Java Socket Behavior (Connects, but Doesn't Send)

    - by Donald Campbell
    I have a fairly complex project that boils down to a simple Client / Server communicating through object streams. Everything works flawlessly for two consecutive connections (I connect once, work, disconnect, then connect again, work, and disconnect). The client connects, does its business, and then closes. The server successfully closes both the object output stream and the socket, with no IO errors. When I try to connect a third time, the connection appears to go through (the ServerSocket.accept() method goes through and an ObjectOutputStream is successfully created). No data is passed, however. The inputStream.readUnshared() method simply blocks. I have taken the following memory precautions: When it comes time to close the sockets, all running threads are stopped, and all objects are nulled out. After every writeUnshared() method call, the ObjectOutputBuffer is flushed and reset. Has anyone encountered a similar problem, or does anyone have any suggestions? I'm afraid my project is rather large, and so copying code is problematic. The project boils down to this: SERVER MAIN ServerSocket serverSocket = new ServerSocket(port); while (true) { new WorkThread(serverSocket.accept()).start(); } WORK THREAD (SERVER) public void run() { ObjectInputBuffer inputBuffer = new ObjectInputBuffer(new BufferedInputStream(socket.getInputStream())); while (running) { try { Object myObject = inputBuffer.readUnshared(); // do work is not specified in this sample doWork(myObject); } catch (IOException e) { running = false; } } try { inputBuffer.close(); socket.close(); } catch (Exception e) { System.out.println("Could not close."); } } CLIENT public Client() { Object myObject; Socket mySocket = new Socket(address, port); try { ObjectOutputBuffer output = new ObjectOutputBuffer(new BufferedOutputStream(mySocket.getOutputStream())); output.reset(); output.flush(); } catch (Exception e) { System.out.println("Could not get an input."); mySocket.close(); return; } // get object data is not specified in this sample. it simply returns a serializable object myObject = getObjectData(); while (myObject != null) { try { output.writeUnshared(myObject); output.reset(); output.flush(); } catch (Exception e) { e.printStackTrace(); break; } // catch } // while try { output.close(); socket.close(); } catch (Exception e) { System.out.println("Could not close."); } } Thank you to everyone who may be able to help!

    Read the article

  • socket problem in java

    - by stefan89
    I have two classes X and Y, like this: class X implements Serializable { int val1; Y val2; } class Y implements Serializable { int val; } I want to transmit an object of type X from a client to server but i can't because the class X has a field of type Y. I replace the field of type Y with a field of type X in class X and it works.

    Read the article

  • Java Generic Type and Reflection

    - by Tom Tucker
    I have some tricky generic type problem involving reflection. Here's the code. public @interface MyConstraint { Class<? extends MyConstraintValidator<?>> validatedBy(); } public interface MyConstraintValidator<T extends Annotation> { void initialize(T annotation); } /** @param annotation is annotated with MyConstraint. */ public void run(Annotation annotation) { Class<? extends MyConstraintValidator<? extends Annotation>> validatorClass = annotation.annotationType().getAnnotation(MyConstraint.class).validatedBy(); validatorClass.newInstance().initialize(annotation) // will not compile! } The run() method above will not compile because of the following error. The method initialize(capture#10-of ? extends Annotation) in the type MyConstraintValidator<capture#10-of ? extends Annotation> is not applicable for the arguments (Annotation) If I remove the wild cards, then it compiles and works fine. What would be the propert way to declare the type parameter for the vairable validatorClass? Thanks.

    Read the article

  • Formatting a byte array to string in java

    - by rgksugan
    I am using this code to find the MAC address of a machine.This code prints directly the MAC address, but i want to return it as a string.I am completely confused. please help. try { InetAddress add = InetAddress.getByName("10.123.96.102"); NetworkInterface ni1 = NetworkInterface.getByInetAddress(add); if (ni1 != null) { byte[] mac1 = ni1.getHardwareAddress(); if (mac1 != null) { for (int k = 0; k < mac1.length; k++) { System.out.format("%02X%s", mac1[k], (k < mac1.length - 1) ? "-" : ""); } } else { System.out.println("Address doesn't exist "); } System.out.println(); } else { System.out.println("address is not found."); } } catch (UnknownHostException e) { e.printStackTrace(); } catch (SocketException e) { e.printStackTrace(); }

    Read the article

  • Blackberry (Java) - Setting scrolling be not focused on objects on the screen

    - by paullb
    I have a mainscreen which currently scrolls (and I have the arrows on the right) but the scrolling seems to be focused on the ButtonField objects that I have on the page. Is there any way to set the scrolling to be non-focused scrolling (moving a few pixels each time). Is there a way to set this? Other ideas I have had (which sound hacky so I want to avoid): - Placing NullFields around to scroll - Manually listening to the trackwheelRoll event and moving appropriately

    Read the article

  • Java Swing popup visibility

    - by Octavio
    Why a popup created like this is shown in front of all windows applications with JRE 1.6.0_18 but it doesn't using 1.6.0_03 ? PopupFactory popupFactory = new PopupFactory(); Popup popup= popupFactory.getPopup(null,new JPanel(),200,200); popup.show();

    Read the article

  • Java: Convenient way to refactor the application.

    - by Harshal
    Hi, Everyone We have an agile enterprise application built on JSP and Servlet without any design strategy. This application was built in early 2002 considering 1000 users. After 2002, we received lots of requests from the marketing partners. Currently, the application has lots of spaghetti code with lots of Ifs and elses. One class has more than 20,000 lines of code with a huge body of functions without abstraction. Now, we need to support billions of records, what we need to do immediately and gradually? We have to refactor the application? Which framework, we need to use? How the usage of the framework will be helpful to the end users? How to convince the leaders to do the refactoring? How to gain the faster response time as compare to the current system?

    Read the article

  • java multiple operations depending on the type of the object passed

    - by mixm
    assuming i create a method which is passed an object, and that method would perform an action depending on the object passed. how should i identify the object? i thought of using the class name to identify the object, but may be impractical since i could easily change the class name of objects, and generate headaches during future development. am i right?

    Read the article

  • Java: how to read BufferedReader faster

    - by Cata
    Hello, I want to optimize this code: InputStream is = rp.getEntity().getContent(); BufferedReader reader = new BufferedReader(new InputStreamReader(is)); String text = ""; String aux = ""; while ((aux = reader.readLine()) != null) { text += aux; } The thing is that i don't know how to read the content of the bufferedreader and copy it in a String faster than what I have above. I need to spend as little time as possible. Thank you

    Read the article

  • iBatis not populating object when there are no rows found.

    - by Omnipresent
    I am running a stored procedure that returns 2 cursors and none of them have any data. I have the following mapping xml: <resultMap id="resultMap1" class="HashMap"> <result property="firstName" columnIndex="2"/> </resultMap> <resultMap id="resultMap2" class="com.somePackage.MyBean"> <result property="unitStreetName" column="street_name"/> </resultMap> <parameterMap id="parmmap" class="map"> <parameter property="id" jdbcType="String" javaType="java.lang.String" mode="IN"/> <parameter property="Result0" jdbcType="ORACLECURSOR" javaType="java.sql.ResultSet" mode="OUT" resultMap="resultMap1"/> <parameter property="Result1" jdbcType="ORACLECURSOR" javaType="java.sql.ResultSet" mode="OUT" resultMap="resultMap2"/> </parameterMap> <procedure id="proc" parameterMap="parmmap"> { call my_sp (?,?,?) } </procedure> First result set is being put in a HashMap...second resultSet is being put in a MyBean class. code in my DAO follows: HashMap map = new HashMap() map.put("id", "1234"); getSqlMapClientTemplate().queryForList("mymap.proc", map); HashMap result1 = (HashMap)((List)parmMap.get("Result0")).get(0); MyBean myObject = (MyBean)((List)parmMap.get("Result1")).get(0);//code fails here in the last line above..my code fails. It fails because second cursor has no rows and thats why nothing is put into the list. However, first cursor returns nothing as well but since results are being put into a HashMap the list for first cursor atleast has HashMap object inside it.. Why this difference? is there a way to make iBatis put an object of MyBean inside the list even if there are no rows returned? Or should I be handling this in my DAO...I want to avoid handling it in the DAO because I have whole bunch of DAO's like these.

    Read the article

  • Java static method parameters

    - by Blitzkr1eg
    Why does the following code return 100 100 1 1 1 and not 100 1 1 1 1 ? public class Hotel { private int roomNr; public Hotel(int roomNr) { this.roomNr = roomNr; } public int getRoomNr() { return this.roomNr; } static Hotel doStuff(Hotel hotel) { hotel = new Hotel(1); return hotel; } public static void main(String args[]) { Hotel h1 = new Hotel(100); System.out.print(h1.getRoomNr() + " "); Hotel h2 = doStuff(h1); System.out.print(h1.getRoomNr() + " "); System.out.print(h2.getRoomNr() + " "); h1 = doStuff(h2); System.out.print(h1.getRoomNr() + " "); System.out.print(h2.getRoomNr() + " "); } } Why does it appear to pass Hotel by-value to doStuff() ?

    Read the article

  • can not run java program from command line which resides in package

    - by kshitij
    See following code with resides in fillowing directory mypack.pack1 package mypack.pack1; public class myclass { public static void main(String args[]) { System.out.println("KKKKKKKKKKKKKKKKKKKKKKKKKKKKKK"); } } See following screen shot. that is giving error. And i dont want to add anything in class path because i am in particular directory and it has to work. why it is not working.??????

    Read the article

  • Clone List Elements in Java

    - by Amir Rachum
    Hi all, I have a variable of type List<RelationHeader>. Now I want to copy all the elements in this list to a new list, but I want to actually copy all the members by value (clone them). Is there a quick command to do this, or do I need to iterate over the list and copy them one at a time?

    Read the article

  • Need a hand understanding this Java code please :-)

    - by Brian
    Hi all, Just wondering if anyone would be able to take a look at this code for implementing the quicksort algorithm and answer me a few questions, please :-) public class Run { /*************************************************************************** * Quicksort code from Sedgewick 7.1, 7.2. **************************************************************************/ public static void quicksort(double[] a) { //shuffle(a); // to guard against worst-case quicksort(a, 0, a.length - 1, 0); } static void quicksort(final double[] a, final int left, final int right, final int tdepth) { if (right <= left) return; final int i = partition(a, left, right); if ((tdepth < 4) && ((i - left) > 1000)) { final Thread t = new Thread() { public void run() { quicksort(a, left, i - 1, tdepth + 1); } }; t.start(); quicksort(a, i + 1, right, tdepth + 1); try { t.join(); } catch (InterruptedException e) { throw new RuntimeException("Cancelled", e); } } else { quicksort(a, left, i - 1, tdepth); quicksort(a, i + 1, right, tdepth); } } // partition a[left] to a[right], assumes left < right private static int partition(double[] a, int left, int right) { int i = left - 1; int j = right; while (true) { while (less(a[++i], a[right])) // find item on left to swap ; // a[right] acts as sentinel while (less(a[right], a[--j])) // find item on right to swap if (j == left) break; // don't go out-of-bounds if (i >= j) break; // check if pointers cross exch(a, i, j); // swap two elements into place } exch(a, i, right); // swap with partition element return i; } // is x < y ? private static boolean less(double x, double y) { return (x < y); } // exchange a[i] and a[j] private static void exch(double[] a, int i, int j) { double swap = a[i]; a[i] = a[j]; a[j] = swap; } // shuffle the array a[] private static void shuffle(double[] a) { int N = a.length; for (int i = 0; i < N; i++) { int r = i + (int) (Math.random() * (N - i)); // between i and N-1 exch(a, i, r); } } // test client public static void main(String[] args) { int N = 5000000; // Integer.parseInt(args[0]); // generate N random real numbers between 0 and 1 long start = System.currentTimeMillis(); double[] a = new double[N]; for (int i = 0; i < N; i++) a[i] = Math.random(); long stop = System.currentTimeMillis(); double elapsed = (stop - start) / 1000.0; System.out.println("Generating input: " + elapsed + " seconds"); // sort them start = System.currentTimeMillis(); quicksort(a); stop = System.currentTimeMillis(); elapsed = (stop - start) / 1000.0; System.out.println("Quicksort: " + elapsed + " seconds"); } } My questions are: What is the purpose of the variable tdepth? Is this considered a "proper" implementation of a parallel quicksort? I ask becuase it doesn't use implements Runnable or extends Thread... If it doesn't already, is it possible to modify this code to use multiple threads? By passing in the number of threads you want to use as a parameter, for example...? Many thanks, Brian

    Read the article

  • object construct a class of objects in java

    - by Mgccl
    There is a super class, A, and there are many subclasses, B,C,D... people can write more subclasses. Each of the class have the method dostuff(), each is different in some way. I want an object that constructs any object that belong to A or any of it's subclass. For example I can pass the name of the subclass, or a object of that class, and it will construct another object of the class. Of course I can write A construct(A var){ stuff = var.dostuff(); domorestuff(stuff) return new A(stuff); } B construct(B var){ stuff = var.dostuff(); domorestuff(stuff) return new B(stuff); } C construct(C var){ stuff = var.dostuff(); domorestuff(stuff) return new C(stuff); } but this is not efficient. I have to write a few new lines every time I make a new subclass. It seems I can't use generics either. Because I can't use dostuff() on objects not in any of the subclass of A. What should I do in this situation?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 514 515 516 517 518 519 520 521 522 523 524 525  | Next Page >