Search Results

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

Page 894/1319 | < Previous Page | 890 891 892 893 894 895 896 897 898 899 900 901  | Next Page >

  • Wait between tasks with SingleThreadExecutor

    - by Lord.Quackstar
    I am trying to (simply) make a blocking thread queue, where when a task is submitted the method waits until its finished executing. The hard part though is the wait. Here's my 12:30 AM code that I think is overkill: public void sendMsg(final BotMessage msg) { try { Future task; synchronized(msgQueue) { task = msgQueue.submit(new Runnable() { public void run() { sendRawLine("PRIVMSG " + msg.channel + " :" + msg.message); } }); //Add a seperate wait so next runnable doesn't get executed yet but //above one unblocks msgQueue.submit(new Runnable() { public void run() { try { Thread.sleep(Controller.msgWait); } catch (InterruptedException e) { log.error("Wait to send message interupted", e); } } }); } //Block until done task.get(); } catch (ExecutionException e) { log.error("Couldn't schedule send message to be executed", e); } catch (InterruptedException e) { log.error("Wait to send message interupted", e); } } As you can see, there's alot of extra code there just to make it wait 1.7 seconds between tasks. Is there an easier and cleaner solution out there or is this it?

    Read the article

  • How can I get an error or a warning from a PreparedStatement?

    - by Geo
    I had an update like this: update table set col1=?,col2=?,col3=? where col4=?; and I filled it up like this: statement.setString(1,"some_value"); statement.setString(2,"some_value"); statement.setString(3,"some_value"); and I forgot to add a fourth value.I did a executeUpdate and of course nothing happened to the database. I spent about 1 hour debugging it, to see where it goes wrong. I then modified my code to print the SQLWarning object returned by the getWarnings method. It always returned null. I even modified the code to the buggy state it was, before I set the fourth parameter, and still no warning. Does anyone know how one can get an error/warning? If it matters, my Connection is set to autoCommit.

    Read the article

  • Can I have two names for the same variable?

    - by Roman
    The short version of the question: I do: x = y. Then I change x, and y is unchanged. What I want is to "bind" x and y in such a way that I change y whenever I change x. The extended version (with some details): I wrote a class ("first" class) which generates objects of another class ("second" class). In more details, every object of the second class has a name as a unique identifier. I call a static method of the first class with a name of the object from the second class. The first class checks if such an object was already generated (if it is present in the static HashMap of the first class). If it is already there, it is returned. If it is not yet there, it is created, added to the HashMap and returned. And then I have the following problem. At some stage of my program, I take an object with a specific name from the HashMap of the first class. I do something with this object (for example change values of some fields). But the object in the HashMap does not see these changes! So, in fact, I do not "take" an object from the HashMap, I "create a copy" of this object and this is what I would like to avoid.

    Read the article

  • Log4j Properties in a Custom Place

    - by Azder
    I'm using Apache Commons Logging and SLF4J with log4j, but I also want to use the log4j.properties in a custom place like conf/log4.properties. Here is the problem: If i use PropertyConfigurator.configure("conf/log4j.properties"); then my app is tied to log4j and defets the purpose of having ACL and SLF4J. What is the best way to configure it withouth the app ever knowing what the logging implementation is?

    Read the article

  • Complete list of Fonts which support

    - by Yan Cheng CHEOK
    Currently, if I change the locale setting of my application by Locale.setDefault(Locale.ENGLISH); Locale.setDefault(Locale.SIMPLIFIED_CHINESE); What I understand from this JFreeChart forum is that, I am not using correct font. Once you get the reference of the LegentTitle, you can set it to any font. Apparently, JFreeChart's default is "Tahoma" and it doesn't support Chinese characters. May I know, how I can programmatic determine, as list of available Fonts in my system, which support Chinese? I can hard code it to Serif (It fully support Chinese, doesn't it?), its look n feel doesn't looks good to me. I would like to have more choices.

    Read the article

  • How to merge arraylist element ?

    - by tiendv
    I have a string example = " Can somebody provide an algorithm sample code in your reply ", after token and do some i want on string example i have arraylist like : ArrayList <token > arl = " "Can somebody provide ", "code in your ", "somebody provide an algorith", " in your reply" ) "Can somebody provide ", i know position start and end in string test : star = 1 end = 3 " code in your ", i know position stat = 7 end = 10, "somebody provide an algorith", i know position stat = 7 end = 10, "in your reply" i know position stat = 11 end = 14, we can see,some element in arl overlaping :"Can somebody provide "," code in your ","somebody provide an algorith". The problem here is how can i merge overlaping element to recived arraylist like ArrayList result ="" Can somebody provide an algorithm sample code","" in your reply""; Here my code : but it only merge fist elecment if check is overloaping public ArrayList<TextChunks> finalTextChunks(ArrayList<TextChunks> textchunkswithkeyword) { ArrayList<TextChunks > result = (ArrayList<TextChunks>) textchunkswithkeyword.clone(); //System.out.print(result.size()); int j; for(int i=0;i< result.size() ;i++) { int index = i; if(i+1>=result.size()){ break; } j=i+1; if(result.get(i).checkOverlapingTwoTextchunks(result.get(j))== true) { TextChunks temp = new TextChunks(); temp = handleOverlaping(textchunkswithkeyword.get(i),textchunkswithkeyword.get(j),resultSearchEngine); result.set(i, temp); result.remove(j); i = index; continue; } } return result; } Thanks in avadce

    Read the article

  • Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?

    - by Mulmoth
    It is said to be a good habit to close all JDBC resources after usage. But if I have the following code, is it necessary to close the Resultset and the Statement? Connection conn = null; PreparedStatement stmt = null; ResultSet rs = null; try { conn = // Retrieve connection stmt = conn.prepareStatement(// Some SQL); rs = stmt.executeQuery(); } catch { // Error Handling } finally { try { if (rs != null) rs.close(); } catch (Exception e) {}; try { if (stmt != null) stmt.close(); } catch (Exception e) {}; try { if (conn != null) conn.close(); } catch (Exception e) {}; } The question is if the closing of the connection does the job or if it leaves some resources in use.

    Read the article

  • Data structure for unrooted trees

    - by Esmond
    I'm having problems figuring out how to build an unrooted tree with weighted edges and what data structure to store such a tree. An example of an unrooted tree would be like the one here: http://www.bio.davidson.edu/courses/GENOMICS/seq/unrooted.gif The problem i am having is the leaves would only have 1 link to the internal nodes and the internal nodes would have 3 links(the internal nodes would have 2 children and a link to another internal node). Do i have to distinguish between the 2 different kinds of nodes or can i have one class having the function of both types of nodes?

    Read the article

  • Creating objects makes the VM faster?

    - by Sudhir Jonathan
    Look at this piece of code: MessageParser parser = new MessageParser(); for (int i = 0; i < 10000; i++) { parser.parse(plainMessage, user); } For some reason, it runs SLOWER (by about 100ms) than for (int i = 0; i < 10000; i++) { MessageParser parser = new MessageParser(); parser.parse(plainMessage, user); } Any ideas why? The tests were repeated a lot of times, so it wasn't just random. How could creating an object 10000 times be faster than creating it once?

    Read the article

  • What is an appropriate way to separate lifecycle events in the logging system?

    - by Hanno Fietz
    I have an application with many different parts, it runs on OSGi, so there's the bundle lifecycles, there's a number of message processors and plugin components that all can die, can be started and stopped, have their setup changed etc. I want a way to get a good picture of the current system status, what components are up, which have problems, how long they have been running for etc. I think that logging, especially in combination with custom appenders (I'm using log4j), is a good part of the solution and does help ad-hoc analysis as well as live monitoring. Normally, I would classify lifecycle events as INFO level, but what I really want is to have them separate from what else is going on in INFO. I could create my own level, LIFECYCLE. The lifecycle events happen in various different areas and on various levels in the application hierarchy, also they happen in the same areas as other events that I want to separate them from. I could introduce some common lifecycle management and use that to distinguish the events from others. For instance, all components that have a lifecycle could implement a particular interface and I log by its name. Are there good examples of how this is done elsewhere? What are considerations?

    Read the article

  • change a frame's attribute by pressing a button

    - by asavu
    Hi. Suppose we have a JFrame named frame1 with a String attribute named credentials set inittially to null. I have a jButton named button1 attached to the frame and I want to change the frame1 String credentials attribute by pressing button1. I need some piece of advice regarding the ActionListener code especially. Could you guys pls help me? Thank you.

    Read the article

  • How to define a class with variable properties?

    - by user1723326
    I'm making a database program. I want the user to be able to define their own columns, as many as they want. How would I then define each record in its class file?(Since the properties would be different user to user) EDIT: It's part of a school assignment-it's going to hold different scores and the likes for the teacher for different students they can add, but they will also be able to add a new assignment, test(a column) .

    Read the article

  • Servlet Session behavior and Session.invalidate

    - by EugeneP
    Suppose I have a web app with a servlet defined in web.xml. Then I deploy it on Tomcat. Then I open my browser and go to the link to this servlet, it is invoked. Then I close my browser window. How Session behaves ? How is it created, destroyed in this case? if this servlet is "detached" from all the web app, and gets parameters only using post & get, so it does not need Session at all, should one use Session.invalidate at the end of doGet(), doPost() ?

    Read the article

  • How to use SQLiteOpenHelper without or less restrictive use of Context?

    - by Pentium10
    If you extend SQLiteOpenHelper, for the Constructor you have to use a Context. I am wondering if there is a way to leave this out, and be able to work with database tables without a Context. Or at least be least restrictive, I mean a way of project/class structure that will make history the several context passings I have to do now. As it is my application has several level of classes, chained in each other, and there are a few that connects to the database, but have no whatsoever influence on the interface, so they don't actually need the Context. Are you creating your classes in the way that you pass each time a Context to them? If not, how you do, how you reuse a Context in a short class?

    Read the article

  • Passing.getText() String to another class

    - by DanMc
    I'm currently working on a first year university project and I have a problem, although I doubt it's a very complicated one, but I've been searching and I just can't find a suitable answer to it. The problem concerns two classes. A gui class (class1) and another class (class2). I have a JTextField in class1 and am trying to pass through the .getText() value to class2 and store it in a String type variable. The current code I'm trying to achieve this with is the following: (Class1) private JTextField textField = new JTextField("Something"); ... public String getTextFieldString() { return textField.getText(); } (Class2) private c1 Class1 = new Class1(); private String s = new String(); ... s = c1.getTextFieldString(); I'm pretty new to coding, I've read that maybe I need to pass through an argument somewhere and I assume that's because textField is not static in itself, it changes when somebody enters a new value. (sorry for stating the obvious there.) Anyway, help is appreciated. Thanks a lot!

    Read the article

  • Can't add libraries to Eclipse Android project

    - by neuromancer
    I'm trying to get the Hackbook for Android project to work in Eclipse. One of the things I need to do is remove that invalid reference and include that project I made. I did this before, but then I started over and now it doesn't work. Here is where I add the project. If I click "Apply" and then "OK" everything seems to be fine, but it isn't, because when I go back to this screen, none of the changes I made are there. Why isn't it saving my changes? How am I supposed to do this?

    Read the article

  • What else I must do allow my method to handle any type of objects

    - by NewHelpNeeder
    So to allow any type object I must use generics in my code. I have rewrote this method to do so, but then when I create an object, for example Milk, it won't let me pass it to my method. Ether there's something wrong with my generic revision, or Milk object I created is not good. How should I pass my object correctly and add it to linked list? This is a method that causes error when I insert an item: public void insertFirst(T dd) // insert at front of list { Link newLink = new Link(dd); // make new link if( isEmpty() ) // if empty list, last = newLink; // newLink <-- last else first.previous = newLink; // newLink <-- old first newLink.next = first; // newLink --> old first first = newLink; // first --> newLink } This is my class I try to insert into linked list: class Milk { String brand; double size; double price; Milk(String a, double b, double c) { brand = a; size = b; price = c; } } This is test method to insert the data: public static void main(String[] args) { // make a new list DoublyLinkedList theList = new DoublyLinkedList(); // this causes: // The method insertFirst(Comparable) in the type DoublyLinkedList is not applicable for the arguments (Milk) theList.insertFirst(new Milk("brand", 1, 2)); // insert at front theList.displayForward(); // display list forward theList.displayBackward(); // display list backward } // end main() } // end class DoublyLinkedApp Declarations: class Link<T extends Comparable<T>> {} class DoublyLinkedList<T extends Comparable<T>> {}

    Read the article

< Previous Page | 890 891 892 893 894 895 896 897 898 899 900 901  | Next Page >