Search Results

Search found 32961 results on 1319 pages for 'java'.

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 870/1319 | < Previous Page | 866 867 868 869 870 871 872 873 874 875 876 877  | Next Page >

  • Is it a good idea to close and open hibernate sessions frequently?

    - by Gaurav
    Hi, I'm developing an application which requires that state of entities be read from a database at frequent intervals or triggers. However, once hibernate reads the state, it doesn't re-read it unless I explicitly close the session and read the entity in a new session. Is it a good idea to open a session everytime I want to read the entity and then close it afterwards? How much of an overhead does this put on the application and the database (we use a c3p0 connection pool also)? Will it be enough to simply evict the entity from the session before reading it again?

    Read the article

  • How to create a zip file and keep entries for directories?

    - by NathanZ
    I would like to create a zip archive from a folder and keep entries for (non-empty) directories. In the code below, FileInputStream throws a FileNotFoundException when a directory is passed to AddToZip. I have tried to put a condition around the actual writing of bytes but it makes the whole archive invalid. How can I add directory entries to the archive? public static void addToZip(File directoryToZip, File file, ZipOutputStream zos) throws FileNotFoundException, IOException { String zipFilePath = file.getCanonicalPath().substring(directoryToZip.getCanonicalPath().length() + 1,file.getCanonicalPath().length()); System.out.println("Writing '" + zipFilePath + "' to zip file"); ZipEntry zipEntry = new ZipEntry(zipFilePath); zos.putNextEntry(zipEntry); FileInputStream fis = new FileInputStream(file); // Throws a FileNotFoundException when directory byte[] bytes = new byte[1024]; int length; while ((length = fis.read(bytes)) >= 0) { zos.write(bytes, 0, length); } zos.closeEntry(); fis.close(); }

    Read the article

  • get content from website with utf8 format

    - by zahir
    i want how to get the content from websites with utf8 format,, i have writing the following code is try { String webnames = "http://pathivu.com"; URL url = new URL(webnames); URLConnection urlc = url.openConnection(); //BufferedInputStream buffer = new BufferedInputStream(urlc.getInputStream()); BufferedReader buffer = new BufferedReader(new InputStreamReader(urlc.getInputStream(), "UTF8")); StringBuilder builder = new StringBuilder(); int byteRead; while ((byteRead = buffer.read()) != -1) builder.append((char) byteRead); buffer.close(); String text=builder.toString(); System.out.println(text); } catch (IOException e) { e.printStackTrace(); } but i cant get the correct format... thanks and advance..

    Read the article

  • How to merge JOptionPane and Frame into one

    - by mike_hornbeck
    Hello. Currently I have a very basic file viewer working as follows : - in JOptionPane I browse for files, and set some variables to display (colors, line connecting etc) - previous windows loads a frame with drawn points Code : http://paste.pocoo.org/show/220066/ Now I'd like to throw it into one window, with JMenu for selecting files and changing display parameters. How to get started ? Should I rewrite everything to JDialog ?

    Read the article

  • How should I architect JasperReports with a PHP front+backend system

    - by Itay Moav
    Our system is written completely in PHP. For various business reasons (which are a given) I need to build the reports of the system using JasperReports. What architecture should I use? Should I put the Jasper as a stand alone server (if possible) and let the php query against it, should I have it generate the reports with a cron, and then let the PHP scoop up the files and send them to the web client/browser...

    Read the article

  • Is it possible to optimize maven dependencies automatically?

    - by AlexR
    I am working on a big project that consists of about 40 sub-projects with very not optimized dependencies. There are declared dependencies that are not in use as well as used but undeclared dependencies. The second case is possible when dependency is added via other dependency. I want to remove redundant and add required dependencies. I ran mvn dependency:analyze and got a long list of warnings I have to fix now. I wonder whether there is maven plugin or any other utility that can update my pom.xml files automatically. I tried to do it manually but it takes a lot of time. It seems it will take a couple of days of copy/paste to complete the task. In worse case I can write such script myself but probably ready stuff exists? Here is how mvn dependency:analyze reports dependency warnings: [WARNING] Used undeclared dependencies found: [WARNING] org.apache.httpcomponents:httpcore:jar:4.1:compile [WARNING] Unused declared dependencies found: [WARNING] commons-lang:commons-lang:jar:2.4:compile [WARNING] org.json:json:jar:20090211:compile

    Read the article

  • Whats wrong with this method?

    - by David
    Here's the method: public static String CPUcolor () { System.out.println ("What color am I?") ; String s = getIns() ; System.out.println ("are you sure I'm "+s+"? (Y/N)") ; String a = getIns() ; while (!((a.equals ("y")) || (a.equals ("Y")) || (a.equals ("n")) || (a.equals ("N")))) { System.out.println ("try again") ; a = getIns () ; } if (a.equals ("n") || a.equals("N")) {CPUcolor() ;} System.out.println ("I am "+s) ; return s ; } here is a possible output of this method (y's and n's are user inputs): What color am I? red are you sure I'm red? (Y/N) N What color am I? blue are you sure I'm blue? (Y/N) N What color am I? Yellow are you sure I'm Yellow? (Y/N) y I am Yellow I am blue I am red Why is it that the line's "I am blue" and "I am Blue" printed? Why are they printed in reverse order with red, the first entered, printed last?

    Read the article

  • Two entities with @ManyToOne joins the same table

    - by Ivan Yatskevich
    I have the following entities Student @Entity public class Student implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Teacher @Entity public class Teacher implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Task @Entity public class Task implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "student_id") }) private Student author; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "teacher_id") }) private Teacher curator; //getters and setters } Consider that author and curator are already stored in DB and both are in the attached state. I'm trying to persist my Task: Task task = new Task(); task.setAuthor(author); task.setCurator(curator); entityManager.persist(task); Hibernate executes the following SQL: insert into student_task (teacher_id, id) values (?, ?) which, of course, leads to null value in column "student_id" violates not-null constraint Can anyone explain this issue and possible ways to resolve it?

    Read the article

  • copy child collection to another object

    - by Bogdan
    Hi everyone, I have a one-to-many relationship between Part and Params (a "Part" has many "Params). I'm trying to do something naive like this: Part sourcePart = em.find(Part.class, partIdSource); Part destPart = em.find(Part.class, partIdDest); Collection<Param> paramListSource = sourcePart.getParamList(); destPart.setParamList(paramListSource); Basically I want to copy all the parameters from sourcePart to destPart. Hopefully the persistence provider will automatically set the right foreign keys in the Param table/entity. The above code will obviously not work. Is there any easy way of doing this, or do I have to do create a new collection, then add each Param (creating new Param, setting attributes, etc) ?

    Read the article

  • Thread sleep and thread join.

    - by Dhruv Gairola
    hi guys, if i put a thread to sleep in a loop, netbeans gives me a caution saying Invoking Thread.sleep in loop can cause performance problems. However, if i were to replace the sleep with join, no such caution is given. Both versions compile and work fine tho. My code is below (check the last few lines for "Thread.sleep() vs t.join()"). public class Test{ //Display a message, preceded by the name of the current thread static void threadMessage(String message) { String threadName = Thread.currentThread().getName(); System.out.format("%s: %s%n", threadName, message); } private static class MessageLoop implements Runnable { public void run() { String importantInfo[] = { "Mares eat oats", "Does eat oats", "Little lambs eat ivy", "A kid will eat ivy too" }; try { for (int i = 0; i < importantInfo.length; i++) { //Pause for 4 seconds Thread.sleep(4000); //Print a message threadMessage(importantInfo[i]); } } catch (InterruptedException e) { threadMessage("I wasn't done!"); } } } public static void main(String args[]) throws InterruptedException { //Delay, in milliseconds before we interrupt MessageLoop //thread (default one hour). long patience = 1000 * 60 * 60; //If command line argument present, gives patience in seconds. if (args.length > 0) { try { patience = Long.parseLong(args[0]) * 1000; } catch (NumberFormatException e) { System.err.println("Argument must be an integer."); System.exit(1); } } threadMessage("Starting MessageLoop thread"); long startTime = System.currentTimeMillis(); Thread t = new Thread(new MessageLoop()); t.start(); threadMessage("Waiting for MessageLoop thread to finish"); //loop until MessageLoop thread exits while (t.isAlive()) { threadMessage("Still waiting..."); //Wait maximum of 1 second for MessageLoop thread to //finish. /*******LOOK HERE**********************/ Thread.sleep(1000);//issues caution unlike t.join(1000) /**************************************/ if (((System.currentTimeMillis() - startTime) > patience) && t.isAlive()) { threadMessage("Tired of waiting!"); t.interrupt(); //Shouldn't be long now -- wait indefinitely t.join(); } } threadMessage("Finally!"); } } As i understand it, join waits for the other thread to complete, but in this case, arent both sleep and join doing the same thing? Then why does netbeans throw the caution?

    Read the article

  • How can I make CAPTCHA work across multiple pages?

    - by jm04469
    Ever visit a website such as myspace where they leverage CAPTCHA to prevent spam? The typical pattern is to present a challenge to each URL that is opened, yet the challenge doesn't actually belong to the page itself which causes additional bandwidth usage. So, if I open up six pages at the same time and want to present a challenge on each page. I want the challenge to be tied to the page and not to the session. How can I make this work with Spring and/or Struts.

    Read the article

  • How can i make projects bound to eachother in eclipse?

    - by ikky
    Hi! I have 3 projects in Eclipse that are bound to eachother. With bound i mean this: Everytime i add a class in one of the projects, the other projects also updates themselves and add the class Now i want to add another project to these, but i don't know how to bind it together with the other projects. Any suggestions? Thanks in advance!

    Read the article

  • Designing a chain of states

    - by devoured elysium
    I want to model a kind of FSM(Finite State Machine). I have a sequence of states (let's say, from StateA to StateZ). This sequence is called a Chain and is implemented internally as a List. I will add states by the order I want them to run. My purpose is to be able to make a sequence of actions in my computer (for example, mouse clicks). (I know this has been done a zillion times). So a state is defined as a: boolean Precondition() <- Checks to see if for this state, some condition is true. For example, if I want to click in the Record button of a program, in this method I would check if the program's process is running or not. If it is, go to the next state in the chain list, otherwise, go to what was defined as the fail state (generally is the first state of them all). IState GetNextState() <- Returns the next state to evaluate. If Precondition() was sucessful, it should yield the next state in the chain otherwise it should yield the fail state. Run() Simply checks the Precondition() and sets the internal data so GetNextState() works as expected. So, a naive approach to this would be something like this: Chain chain = new Chain(); //chain.AddState(new State(Precondition, FailState, NextState) <- Method structure chain.AddState(new State(new WinampIsOpenCondition(), null, new <problem here, I want to referr to a state that still wasn't defined!>); The big problem is that I want to make a reference to a State that at this point still wasn't defined. I could circumvent the problem by using strings when refrering to states and using an internal hashtable, but isn't there a clearer alternative? I could just pass only the pre-condition and failure states in the constructor, having the chain just before execution put in each state the correct next state in a public property but that seems kind of awkward.

    Read the article

  • Changing JTextArea to JScrollPane Causes it to not be visible

    - by user1806716
    I am having an issue with JScrollPanes and JTextArea objects and getting them to work together. If I just add a JTextArea to my JPanel, it works fine and shows up where I tell it to. However, if I change the contentPane.add(textArea) to contentPane.add(new JScrollPane(textArea)), the textArea is not longer visible and there is no sign of the textarea either. Here is my code: public docToolGUI() { setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setBounds(100, 100, 611, 487); contentPane = new JPanel(); contentPane.setBorder(new EmptyBorder(5, 5, 5, 5)); setContentPane(contentPane); contentPane.setLayout(null); textField = new JTextField(); textField.setBounds(253, 323, 86, 20); contentPane.add(textField); textField.setColumns(10); JLabel lblEnterRootDirectory = new JLabel("Enter Root Directory"); lblEnterRootDirectory.setBounds(253, 293, 127, 20); contentPane.add(lblEnterRootDirectory); JButton btnGo = new JButton("Go"); btnGo.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent arg0) { new ToolWorker().execute(); } }); btnGo.setBounds(253, 361, 89, 23); contentPane.add(btnGo); textArea = new JTextArea(); textArea.setWrapStyleWord(true); textArea.setEditable(false); textArea.setBounds(25, 11, 560, 276); contentPane.add(new JScrollPane(textArea)); }

    Read the article

  • Should I use a modified singleton design pattern that only allows one reference to its instance?

    - by Graham
    Hi, I have a class that would normally just generate factory objects, however this class should only used once throughout the program in once specifix place. What is the best design pattern to use in this instance? I throught that having a modified singleton design which only allows one reference to instance throughout the program would be the correct way to go. So only the first call to getInstance() returns the factory library. Is this a good or bad idea? Have I missed out another fundermental design pattern for solving this problem? Thanks for your help.

    Read the article

  • Can I use Pub/Sub model with Many Publishers and Only One Subscriber?

    - by rauch
    I need to send some files from different machines to only one Server. As I understand, I can use JMS api + (for example) ActiveMQ as broker. There are two models: p2p and pub/sub. I would like to use pub/sub model, but the problem is that I haven`t few subscribers, I have only one Subscriber(Server) and many Publishers. The question is the following: can I use pub/sub model for my situation and How can I send files from different machines to Only One Topic, on that Server sibscribed? May be any other ideas, thanks a lot.

    Read the article

  • Hibernate is performing unwanted SELECTs on call to saveOrUpdate

    - by digiarnie
    Let's say I have a House entity which maps to many Person entities. I then load an existing House which has 20 occupants. beginTransaction(); House house = houseDao.find(1L); commitTransaction(); Later in the code, I can then add a new Person to the House: ... List<Person> people = house.getPeople(); people.add(new Person("Dilbert")); .... When I make the call: session.saveOrUpdate(house); Hibernate performs 21 queries: 1 to SELECT the House and 20 to SELECT each existing Person in the House. I'm sure it's a small issue on my part, however, what should I do so that I can add a new Person to the house without having such a heavy hit on the database in this situation? This is all done within the same session.

    Read the article

  • How do I find resources in a .jar on the classpath?

    - by Brabster
    If I have a collection of resource files in a directory on my classpath, I can enumerate them using ClassLoader.getResources(location). For example if I have /mydir/myresource.properties on the classpath, I can call the classloader's getResources("mydir") and get an enumeration of URLs containing myresource.properties. When I pack up the exact same resources into a .jar, I don't get anything in the enumeration of URLs when I make the call. I've only replaced the folder structure with a jar containing those folders (it's a webapp, so the jar is going into /WEB-INF/lib). I've also got a number of other calls using getResourceAsStream(location) to get other resources individually by name and they're all working fine. What's different about enumerating resources when the resources are in a .jar?

    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 | 866 867 868 869 870 871 872 873 874 875 876 877  | Next Page >