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  • Network communication for a turn based board game

    - by randooom
    Hi all, my first question here, so please don't be to harsh if something went wrong :) I'm currently a CS student (from Germany, if this info is of any use ;) ) and we got a, free selectable, programming assignment, which we have to write in a C++/CLI Windows Forms Application. My team, two others and me, decided to go for a network-compatible port of the board game Risk. We divided the work in 3 Parts, namely UI, game logic and network. Now we're on the part where we have to get everything working together and the big question mark is, how to get the clients synchronized with each other? Our approach so far is, that each client has all information necessary to calculate and/or execute all possible actions. Actually the clients have all information available at all, aside from the game-initializing phase (add players, select map, etc.), which needs one "super-client" with some extra stuff to control things. This is the standard scenario of our approach: player performs action, the action is valid and got executed on the players client action is sent over the network action is executed on the other clients The design (i.e. no or code so far) we came up with so far, is something like the following pseudo sequence diagram. Gui, Controller and Network implement all possible actions (i.e. all actions which change data) as methods from an interface. So each part can implement the method in a way to get their job done. Example with Action(): On the player side's Client: Player-->Gui.Action() Gui-->Controller.Action() Controller-->Logic.Action (Logic.Action() == NoError)? Controller-->Network.Action() Network-->Parser.ParseAction() Network.Send(msg) On all other clients: Network.Recv(msg) Network-->Parser.Deparse(msg) Parser-->Logic.Action() Logic-->Gui.Action() The questions: Is this a viable approach to our task? Any better/easier way to this? Recommendations, critique? Our knowledge (so you can better target your answer): We are on the beginner side, in regards to programming on a somewhat larger projects with a small team. All of us have some general programming experience and basic understanding of the .Net Libraries and Windows Forms. If you need any further information, please feel free to ask.

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  • Can a GeneralPath be modified?

    - by Dov
    java2d is fairly expressive, but requires constructing lots of objects. In contrast, the older API would let you call methods to draw various shapes, but lacks all the new features like transparency, stroke, etc. Java has fairly high costs associated with object creation. For speed, I would like to create a GeneralPath whose structure does not change, but go in and change the x,y points inside. path = new GeneralPath(GeneralPath.WIND_EVEN_ODD, 10); path.moveTo(x,y); path.lineTo(x2, y2); double len = Math.sqrt((x2-x)*(x2-x) + (y2-y)*(y2-y)); double dx = (x-x2) * headLen / len; double dy = (y-y2) * headLen / len; double dx2 = -dy * (headWidth/headLen); double dy2 = dx * (headWidth/headLen); path.lineTo(x2 + dx + dx2, y2 + dy + dy2); path.moveTo(x2 + dx - dx2, y2 + dy - dy2); path.lineTo(x2,y2); This one isn't even that long. Imagine a much longer sequence of commands, and only the ones on the end are changing. I just want to be able to overwrite commands, to have an iterator effectively. Does that exist?

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  • Connect two client sockets

    - by Hernán Eche
    Good morning, let's say Java has two kind of sockets... server sockets "ServerSocket" client sockets or just "Socket" ////so Simple ! Imagine the situation of two processes: X Client <-- Y Server The server process Y : has a "ServerSocket", that is listening to a TCP port The client process X : send a connection request through a -client type- "Socket" X ////so Simple ! then the accept() method (in server Y) returns a new client type "Socket", when it occurs, great the two Sockets get "interconected", so the -client socket- in client process, is connected with the -client socket- in the server process then (reading/writing in socket X is like reading/writing in socket Y, and viceversa. ) TWO CLIENT SOCKETS GET INTERCONECTED!! ////so Simple ! BUT... (there is always a But..) What if I create the two CLIENT sockets in same process, and I want to get them "interconected" ? ////mmm Complex =(... even posible? Let's say how to have TWO CLIENT SOCKETS GET INTERCONECTED WITHOUT using an intermediate ServerSocket ? I 've solved it.. by creating two threads for continuously reading A and writing B, and other for reading B and writng A... but I think could be a better way..(or should!) (Those world-energy-consuming threads are not necessary with the client-server aproach) Any help or advice would be appreciated!! Thanks

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  • review of a codility test - pair_sum_even_count

    - by geoaxis
    I recently took an online test on codility as part of a recruitment process. I was given two simple problems to solve in 1 hour. For those who don't know codility, its an online coding test site where you can solve ACM style problems in many different languages. if you have 30 or so mins then check this http://codility.com/demo/run/ My weapon of choice is usually Java. So on of the problems I have is as follows (I will try to remember, should have taken a screenshot) Lets say you have array A[0]=1 A[1]=-1 ....A[n]=x Then what would be the smartest way to find out the number of times when A[i]+A[j] is even where i < j So if we have {1,2,3,4,5} we have 1+3 1+5 2+4 3+5 = 4 pairs which are even The code I wrote was some thing along the lines int sum=0; for(int i=0;i<A.length-1;i++){ for (int j=i+1;j<A.length;j++){ if( ((A[i]+A[j])%2) == 0 && i<j) { sum++; } } } There was one more restriction that if the number of pairs is greater than 1e9 then it should retrun -1, but lets forget it. Can you suggest a better solution for this. The number of elements won't exceed 1e9 in normal cases. I think I got 27 points deducted for the above code (ie it's not perfect). Codility gives out a detailed assessment of what went wrong, I don't have that right now.

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  • Download MMS content on Blackberry

    - by Chris
    Hi I am relatively new to coding for the blackberry and I need to write a java application that can capture all incoming and outgoing MMS data from a Blackberry device. I have gotten the capturing of outgoing MMS's sorted with the use of A sendListener, but the problem comes with the incoming MMS's. If I use a MessageListener that processes only those of type BinaryMessage, i can capture the binary notification SMS that comes in when there is an incoming MMS. From this notification, i can get the senders MSISDN as well as the URL on the MMSC where the content is stored. To get the actual MMS content, i presume i need to download it from this URL, but im unable to get this working. I have tried just opening a HTTPConnetion to this URL, opening an inputStream on it and reading from there, but i retrieve no content. If i manually go to that URL on the blackberry, i can see the content fine (and of course the blackberry can download it automatically anyway). Can anyone please help me asap on how i can get the mms content for incoming MMS's. Thanks alot

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  • SWT: problems with clicking button after using setEnabled() on Linux

    - by Laimoncijus
    Hi, I have a strange case with SWT and Button after using setEnabled() - seems if I disable and enable button at least once - I cannot properly click with mouse on it anymore... Already minify code to very basic: import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class TestButton { public TestButton() { Display display = new Display(); Shell shell = new Shell(display); GridLayout mainLayout = new GridLayout(); shell.setLayout(mainLayout); shell.setSize(100, 100); Button testButton = new Button(shell, SWT.PUSH); testButton.addSelectionListener(new TestClickListener()); testButton.setText("Click me!"); //testButton.setEnabled(false); //testButton.setEnabled(true); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); } class TestClickListener implements SelectionListener { @Override public void widgetDefaultSelected(SelectionEvent e) { } @Override public void widgetSelected(SelectionEvent e) { System.out.println("Click!"); } } public static void main(String[] args) { new TestButton(); } } When I keep these 2 lines commented out - I can properly click on a button and always get "Click!" logged, but if I uncomment them - then I can't click on button properly with mouse anymore - button visually seems to be clicked, but nothing is logged... Am I doing something wrong here? Or maybe it's some kind of bug on Linux platform? Because on Mac running the same code I never experienced such problems... Thanks for any hint! P.S. Running code on Ubuntu 9.10, Gnome + Compiz, Sun Java 1.6.0.16

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  • redoing object model construction to fit with asynchronous data fetching

    - by Andrew Patterson
    I have a modeled a set of objects that correspond with some real world concepts. TradeDrug, GenericDrug, TradePackage, DrugForm Underlying the simple object model I am trying to provide is a complex medical terminology that uses numeric codes to represent relationships and concepts, all accessible via a REST service - I am trying to hide away some of that complexity with an object wrapper. To give a concrete example I can call TradeDrug d = Searcher.FindTradeDrug("Zoloft") or TradeDrug d = new TradeDrug(34) where 34 might be the code for Zoloft. This will consult a remote server to find out some details about Zoloft. I might then call GenericDrug generic = d.EquivalentGeneric() System.Out.WriteLine(generic.ActiveIngredient().Name) in order to get back the generic drug sertraline as an object (again via a background REST call to the remote server that has all these drug details), and then perhaps find its ingredient. This model works fine and is being used in some applications that involve data processing. Recently however I wanted to do a silverlight application that used and displayed these objects. The silverlight environment only allows asynchronous REST/web service calls. I have no problems with how to make the asychhronous calls - but I am having trouble with what the design should be for my object construction. Currently the constructors for my objects do some REST calls sychronously. public TradeDrug(int code) { form = restclient.FetchForm(code) name = restclient.FetchName(code) etc.. } If I have to use async 'events' or 'actions' in order to use the Silverlight web client (I know silverlight can be forced to be a synchronous client but I am interested in asychronous approaches), does anyone have an guidance or best practice for how to structure my objects. I can pass in an action callback to the constructor public TradeDrug(int code, Action<TradeDrug> constructCompleted) { } but this then allows the user to have a TradeDrug object instance before what I want to construct is actually finished. It also doesn't support an 'event' async pattern because the object doesn't exist to add the event to until it is constructed. Extending that approach might be a factory object that itself has an asynchronous interface to objects factory.GetTradeDrugAsync(code, completedaction) or with a GetTradeDrugCompleted event? Does anyone have any recommendations?

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  • How to force an HTML JLabel in a JTree to resize when the font changes

    - by Mike
    I'm updating a Java Swing application to support the user switching the app's font from normal size to a larger size (so the user can switch between the two sizes at runtime). One problem I'm having is with a JTree that uses HTML for the tree nodes to underline the text in some nodes (the HTML is just embedded in the JLabel of each tree node). One extra thing to know about the nodes is that they're a custom component, adding a JCheckBox in front of each JLabel. The problem is that once the JTree is visible, increasing the font size causes the nodes (containing underlined text) to not resize. The HTML for those nodes seems to prevent the node from becoming wider, so when the font changes, the text becomes truncated. I think my options are to either: 1) use another approach to make the text underlined, since removing the HTML from the JLabel causes it to resize properly when the font size changes, or 2) keep the HTML formatting and somehow force the JTree/JLabels to resize when the font size is updated (possibly by firing a property change event?). The code already calls SwingUtilities.updateComponentTreeUI() on the parent JFrame when the font size gets updated. Any help would be greatly appreciated. Thanks in advance! -Mike

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  • Determining whether geographic point is within X meters of a state border (using shapefile for borde

    - by DanM
    So I'm writing a Java app, and I've got an ESRI Shapefile which contains the borders of all the U.S. states. What I need is to be able to determine whether any given lat/lon point is within a specified distance from ANY state border line - i.e., I will not be specifying a particular border line, just need to see whether the point is close to any of them. The solution does NOT have to be very precise at all; e.g. I don't need to be dealing with measuring perpendicular to the border, or whatever. Just checking to see if going X meters north, south, east or west would result in crossing a border would be more than sufficient. The solution DOES have to be computationally efficient, as I'll be performing a huge number of these calculations. I'm planning to use the GeoTools library (though if there's a simpler option, I'm all for it) with the Shapefile plugin. What I don't really understand is: Once I've got the shapefile loaded into memory, how do I check to see whether I'm near a border? Thanks! -Dan

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  • UnsatisfiedLinkError: The specified procedure could not be found

    - by matt
    I'm writing some JNI code in C++ to be called from an applet on Windows XP. I've been able to successfully run the applet and have the JNI library loaded and called, even going so far as having it call functions in other DLLs. I got this working by setting up the PATH system environment variable to include the directory all of my DLLs are in. So, the problem, is that I add another call that uses a new external DLL, and suddenly when loading the library, an UnsatisfiedLinkError is thrown. The message is: 'The specified procedure could not be found'. This doesn't seem to be a problem with a missing dependent DLL, because I can remove a dependent DLL and get a different message about dependent DLL missing. From what I've been able to find online, it appears that this message means that a native Java function implementation is missing from the DLL, but it's odd that it works fine without this extra bit of code. Does anyone know what might be causing this? What kinds of things can give a 'The specified procedure could not be found' messages for an UnsatisifedLinkError?

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  • Serialization Performance and Google Android

    - by Jomanscool2
    I'm looking for advice to speed up serialization performance, specifically when using the Google Android. For a project I am working on, I am trying to relay a couple hundred objects from a server to the Android app, and am going through various stages to get the performance I need. First I tried a terrible XML parser that I hacked together using Scanner specifically for this project, and that caused unbelievably slow performance when loading the objects (~5 minutes for a 300KB file). I then moved away from that and made my classes implement Serializable and wrote the ArrayList of objects I had to a file. Reading that file into the objects the Android, with the file already downloaded mind you, was taking ~15-30 seconds for the ~100KB serialized file. I still find this completely unacceptable for an Android app, as my app requires loading the data when starting the application. I have read briefly about Externalizable and how it can increase performance, but I am not sure as to how one implements it with nested classes. Right now, I am trying to store an ArrayList of the following class, with the nested classes below it. public class MealMenu implements Serializable{ private String commonsName; private long startMillis, endMillis, modMillis; private ArrayList<Venue> venues; private String mealName; } And the Venue class: public class Venue implements Serializable{ private String name; private ArrayList<FoodItem> foodItems; } And the FoodItem class: public class FoodItem implements Serializable{ private String name; private boolean vegan; private boolean vegetarian; } IF Externalizable is the way to go to increase performance, is there any information as to how java calls the methods in the objects when you try to write it out? I am not sure if I need to implement it in the parent class, nor how I would go about serializing the nested objects within each object.

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  • executing stored procedure from Spring-Hibernate using Annotations

    - by HanuAthena
    I'm trying to execute a simple stored procedure with Spring/Hibernate using Annotations. Here are my code snippets: DAO class: public class UserDAO extends HibernateDaoSupport { public List selectUsers(final String eid){ return (List) getHibernateTemplate().execute(new HibernateCallback() { public Object doInHibernate(Session session) throws HibernateException, SQLException { Query q = session.getNamedQuery("SP_APPL_USER"); System.out.println(q); q.setString("eid", eid); return q.list(); } }); } } my entity class: @Entity @Table(name = "APPL_USER") @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorFormula(value = "SUBSCRIBER_IND") @DiscriminatorValue("N") @NamedQuery(name = "req.all", query = "select n from Requestor n") @org.hibernate.annotations.NamedNativeQuery(name = "SP_APPL_USER", query = "call SP_APPL_USER(?, :eid)", callable = true, readOnly = true, resultClass = Requestor.class) public class Requestor { @Id @Column(name = "EMPL_ID") public String getEmpid() { return empid; } public void setEmpid(String empid) { this.empid = empid; } @Column(name = "EMPL_FRST_NM") public String getFirstname() { return firstname; } ... } public class Test { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext( "applicationContext.xml"); APFUser user = (APFUser)ctx.getBean("apfUser"); List selectUsers = user.getUserDAO().selectUsers("EMP456"); System.out.println(selectUsers); } } and the stored procedure: create or replace PROCEDURE SP_APPL_USER (p_cursor out sys_refcursor, eid in varchar2) as empId varchar2(8); fname varchar2(50); lname varchar2(50); begin empId := null; fname := null; lname := null; open p_cursor for select l.EMPL_ID, l.EMPL_FRST_NM, l.EMPL_LST_NM into empId, fname, lname from APPL_USER l where l.EMPL_ID = eid; end; If i enter invalid EID, its returning empty list which is OK. But when record is there, following exception is thrown: Exception in thread "main" org.springframework.jdbc.BadSqlGrammarException: Hibernate operation: could not execute query; bad SQL grammar [call SP_APPL_USER(?, ?)]; nested exception is java.sql.SQLException: Invalid column name Do I need to modify the entity(Requestor.class) ? How will the REFCURSOR be converted to the List? The stored procedure is expected to return more than one record.

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  • HashMap key problems

    - by Peterdk
    I'm profiling some old java code and it appears that my caching of values using a static HashMap and a access method does not work. Caching code (a bit abstracted): static HashMap<Key, Value> cache = new HashMap<Key, Value>(); public static Value getValue(Key key){ System.out.println("cache size="+ cache.size()); if (cache.containsKey(key)) { System.out.println("cache hit"); return cache.get(key); } else { System.out.println("no cache hit"); Value value = calcValue(); cache.put(key, value); return value; } } Profiling code: for (int i = 0; i < 100; i++) { getValue(new Key()); } Result output: cache size=0 no cache hit (..) cache size=99 no cache hit It looked like a standard error in Key's hashing code or equals code. However: new Key().hashcode == new Key().hashcode // TRUE new Key().equals(new Key()) // TRUE What's especially weird is that cache.put(key, value) just adds another value to the hashmap, instead of replacing the current one. So, I don't really get what's going on here. Am I doing something wrong?

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  • Using prepared statements with JDBCTemplate

    - by Bernhard V
    Hi. I'm using the Jdbc template and want to read from the database using prepared statements. I iterate over many lines in a csv file and on every line I execute some sql select queries with it's values. Now I want to speed up my reading from the database but I just can't get the Jdbc template to work with prepared statements. Actually I even don't know how to do it. There is the PreparedStatementCreator and the PreparedStatementCreator. As in this example both of them are created with anonymous inner classes. But inside the PreparedStatementCreator class I don't have access to the values I want to set in the prepared statement. Since I'm iterating through a csv file I can't hard code them as a String because I don't know them. I also can't pass them to the PreparedStatementCreator because there are no arguments for the constructor. I was used to the creation of prepared statements being fairly simple. Something like PreparedStatement updateSales = con.prepareStatement( "UPDATE COFFEES SET SALES = ? WHERE COF_NAME LIKE ? "); updateSales.setInt(1, 75); updateSales.setString(2, "Colombian"); updateSales.executeUpdate(): as in the Java tutorial. Your help would be very appreciated.

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  • Terminal / Panel PC - Single Server Solution: Client/Server or RDP?

    - by StillLearning
    Hi, Our current setup involves a touch screen panel pc with embedded windows, that is connected via network to a server / dedicated pc, within the same physical location. Each of our 'units' has this hardware setup. For a quick resolution we deploy our application to the dedicated pc, and have the panel pc remote desktop to an account which then activates the application. This works but seems a little clunky / rough approach. We did this because the panel pc is rather limited. Now that we have more time, I was wondering if I should separate the application into a gui / application. Deploy the gui logic on the panel pc, and the business/database logic on the dedicated pc. The app is in Java so I was wondering what technology would be best? I was thinking of using RMI, but its not really a client/server app, as there is only one client. Should I stick with RMI, or use Sockets or something else? It will be easy to implement as the application is old, and manually wraps and unwraps data which passes through one class / method call to remote services. All I would have to do is 'RMI' this one method call, and the app will do its own stuff. Cheers.

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  • JPA - Setting entity class property from calculated column?

    - by growse
    I'm just getting to grips with JPA in a simple Java web app running on Glassfish 3 (Persistence provider is EclipseLink). So far, I'm really liking it (bugs in netbeans/glassfish interaction aside) but there's a thing that I want to be able to do that I'm not sure how to do. I've got an entity class (Article) that's mapped to a database table (article). I'm trying to do a query on the database that returns a calculated column, but I can't figure out how to set up a property of the Article class so that the property gets filled by the column value when I call the query. If I do a regular "select id,title,body from article" query, I get a list of Article objects fine, with the id, title and body properties filled. This works fine. However, if I do the below: Query q = em.createNativeQuery("select id,title,shorttitle,datestamp,body,true as published, ts_headline(body,q,'ShortWord=0') as headline, type from articles,to_tsquery('english',?) as q where idxfti @@ q order by ts_rank(idxfti,q) desc",Article.class); (this is a fulltext search using tsearch2 on Postgres - it's a db-specific function, so I'm using a NativeQuery) You can see I'm fetching a calculated column, called headline. How do I add a headline property to my Article class so that it gets populated by this query? So far, I've tried setting it to be @Transient, but that just ends up with it being null all the time.

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  • Incremental Timer

    - by Donal Rafferty
    I'm currently using a Timer and TimerTask to perform some work every 30 seconds. My problem is that after each time I do this work I want to increment the interval time of the Timer. So for example it starts off with 30 seconds between the timer firing but I want to add 10 seconds to the interval then so that the next time the Timer takes 40 seconds before it fires. Here is my current code: public void StartScanning() { scanTask = new TimerTask() { public void run() { handler.post(new Runnable() { public void run() { wifiManager.startScan(); scanCount++; if(SCAN_INTERVAL_TIME <= SCAN_MAX_INTERVAL){ SCAN_INTERVAL_TIME = SCAN_INTERVAL_TIME + SCAN_INCREASE_INTERVAL; t.schedule(scanTask, 0, SCAN_INTERVAL_TIME); } } }); }}; Log.d("SCAN_INTERVAL_TIME ** ", "SCAN_INTERVAL_TIME ** = " + SCAN_INTERVAL_TIME); t.schedule(scanTask, 0, SCAN_INTERVAL_TIME); } But the above gives the following error: 05-26 11:48:02.472: ERROR/AndroidRuntime(4210): java.lang.IllegalStateException: TimerTask is scheduled already Calling cancel or purge doesn't help. So I was wondering if anyone can help me find a solution? Is a timer even the right way to approach this?

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  • ExecutorService - scaling

    - by Stanciu Alexandru-Marian
    I am trying to write a program in Java using ExecutorService and it's function invokeAll. My question is: does the invokeAll functions solve the tasks simultaneously? I mean, if i have two processors, there will be two workers in the same time? Because a can't make it to scale correct. It takes the same time to complete the problem if i give newFixedThreadPool(2) or 1. List<Future<PartialSolution>> list = new ArrayList<Future<PartialSolution>>(); Collection<Callable<PartialSolution>> tasks = new ArrayList<Callable<PartialSolution>>(); for(PartialSolution ps : wp) { tasks.add(new Map(ps, keyWords)); } list = executor.invokeAll(tasks); Map is a class that implements Callable and wp is a vector of Partial Solutions, a class that holds some informations in different times. Why doesn't it scale? What could be the problem? Thank you, Alex

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  • Covariance and Contravariance type inference in C# 4.0

    - by devoured elysium
    When we define our interfaces in C# 4.0, we are allowed to mark each of the generic parameters as in or out. If we try to set a generic parameter as out and that'd lead to a problem, the compiler raises an error, not allowing us to do that. Question: If the compiler has ways of inferring what are valid uses for both covariance (out) and contravariance(in), why do we have to mark interfaces as such? Wouldn't it be enough to just let us define the interfaces as we always did, and when we tried to use them in our client code, raise an error if we tried to use them in an un-safe way? Example: interface MyInterface<out T> { T abracadabra(); } //works OK interface MyInterface2<in T> { T abracadabra(); } //compiler raises an error. //This makes me think that the compiler is cappable //of understanding what situations might generate //run-time problems and then prohibits them. Also, isn't it what Java does in the same situation? From what I recall, you just do something like IMyInterface<? extends whatever> myInterface; //covariance IMyInterface<? super whatever> myInterface2; //contravariance Or am I mixing things? Thanks

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  • Basic example of placing two component on one JPanel container?

    - by Bernard
    Here is my code to add to component (JTextArea and JList) to a panel and put it on the frame. Can I divide half/half by BorderLayout? If yes why mine looks messy one stays up one down? What is the other alternative? Regards, Bernard import java.awt.*; import javax.swing.BorderFactory; import javax.swing.border.Border; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.JPanel; import javax.swing.JFrame; import javax.swing.JTextArea; public class SimpleBorder { public static void main(String[] args) { JFrame frame = new JFrame(); frame.setSize(500,500); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Border etched = (Border) BorderFactory.createEtchedBorder(); String[] items = {"A", "B", "C", "D"}; JList list = new JList(items); JTextArea text = new JTextArea(10, 40); JScrollPane scrol = new JScrollPane(text); JScrollPane scrol2 = new JScrollPane(list); JPanel panel= new JPanel(); panel.add(scrol2,BorderLayout.WEST); panel.add(scrol, BorderLayout.EAST); panel.setBorder(etched); frame.add(panel); frame.setVisible(true); } }

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  • Glassfish: Defining Custom JNDI Names for Session Beans

    - by Adeel Ansari
    Background: Want to use GF3 in development, where as actual SIT, UAT, and production is using WAS. Problem: With the remote session beans everything is good to go, as GF3 gives a non-standard JNDI name, which is same as what WAS suggests, i.e. an absolute class name. Now for the local session beans WAS use the same absolute class name but with the prefix, i.e. ejblocal:. Whereas GF3 doesn't give any non-standard JNDI name for local session beans. GF3 came up with only portable name, java:global/..I need to find a way so I can use the same names for both. I am using EJB 3.0, WAS 7.9, and Glassfish 3. Don't have any xml confiuration for ejbs. Using Spring to inject the bean in Struts2 actions. With remote interfaces both servers are okay and agreed on a single convention, but for locals they differ. Is there any solution for this? Or just sun-ejb-jar.xml will solve it? Thanks.

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  • Have problems designing input and output for a calculator app

    - by zoul
    Hello! I am writing a button calculator. I have the code split into model, view and a controller. The model knows nothing about formatting, it is only concerned with numbers. All formatting is done in the view. The model gets its input as keypresses, each keypress is a part of an enum: typedef enum { kButtonUnknown = 0, kButtonMemoryClear = 100, kButtonMemoryPlus = 112, kButtonMemoryMinus = 109, kButtonMemoryRecall = 114, kButtonClear = 99, … }; When the user presses a button (say 1), the model receives a button code (kButtonNum1), adds the corresponding number to a string input buffer ("1") and updates the numeric output value (1.0). The controller then passes the numeric output value to the view that formats it (1). This is all plain, simple and clean, but does not really work. The problem is that when user enters a part of a number (say 0.00, going to enter 0.001), the input does not survive the way through model to view and the display says 0 instead of 0.00. I know why this happens ("0.00"::string parses to 0::double and that gets formatted as 0). What I don’t know is how to design the calculator so that the code stays clean and simple and the numbers will show up on screen exactly as the user types them. I’ve already come with some kind of solution, but that’s essentially a hack and breaks the beautiful and simple flow from the calculator model to the display. Ideas? Current solution keeps track of the calculator state. If the calculator is building a number, I take the calculator input buffer (a string) and directly set the display contents (also a string). Otherwise I take the proper path, ie. take the numeric calculator output, pass it to the view as a double and the view uses its internal formatter to create a string for the display. Example input: input | display | mode ------+---------+------------ 0 | 0 | from string 0. | 0. | from string 0.0 | 0.0 | from string 0.0+ | 0 | from number This is ugly. (1) The calculator has to expose its input buffer and state. (2) The view has to expose its display and allow setting its contents directly using a string. (3) I have to duplicate some of the formatting code to format the string I got from the calculator input buffer. If user enters 12345.000, I have to display 12,345.000 and therefore I’ve got to have a commification code for strings. Yuck.

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  • NetBeans Tips and Tricks

    - by cdmckay
    I just saw an Eclipse tips & tricks post and was wondering if anyone had any tips & tricks for my IDE of choice: NetBeans. Here's a few I know and find to be useful: Removing a package: After you remove a package in NetBeans, it sticks around as a grayed-out package in your Project view. To get rid of that, switch to Files view and delete the directory. Alt-Insert (in Windows) opens up a Generate submenu at your cursor. A nice shortcut for quickly generating getters/setters (among other things). Selecting a chunk of code, right-clicking and then clicking "Refactor Introduce Method" will have NetBeans introduce a method, complete with arguments and return value. Of course you have to make sure the chunk of code only has one return value. Sometimes when you run a build and it crashes, the Java window sticks around at the bottom. I used to just click X until Windows let me End Task, but there's a nicer way to get rid of them. Click "Run Stop Build/Run" and NetBeans will close the window for you. It'll even let you close multiple applications at once. These may seem obvious to grizzled NetBeans developers, but I thought they might be useful for NetBeans newbs like me. Anyone else have any tips/tricks to share? Here are some from the comments: NetBeans allows for code templates. You can even add yours on the Code Templates tab under the Editor settings on the Options window. Some examples: Type sout and hit the tab key as a shorcut for System.out.println("") Type psvm and hit the tab key as a shorcut for public static void main(String args[]) {} Ctrl Shift C: Comments out the selected block of code. Alt Shift F: Formats the selected block of code. Ctrl E: Deletes current line. Ctrl Shift I: Fixes your imports, handy if you've just written a piece of code that needs a lot of packages imported.

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  • Adding an annotation to a runtime generated method/class using Javassist

    - by Idan K
    I'm using Javassist to generate a class foo, with method bar, but I can't seem to find a way to add an annotation (the annotation itself isn't runtime generated) to the method. The code I tried looks like this: ClassPool pool = ClassPool.getDefault(); // create the class CtClass cc = pool.makeClass("foo"); // create the method CtMethod mthd = CtNewMethod.make("public Integer getInteger() { return null; }", cc); cc.addMethod(mthd); ClassFile ccFile = cc.getClassFile(); ConstPool constpool = ccFile.getConstPool(); // create the annotation AnnotationsAttribute attr = new AnnotationsAttribute(constpool, AnnotationsAttribute.visibleTag); Annotation annot = new Annotation("MyAnnotation", constpool); annot.addMemberValue("value", new IntegerMemberValue(ccFile.getConstPool(), 0)); attr.addAnnotation(annot); ccFile.addAttribute(attr); // generate the class clazz = cc.toClass(); // length is zero java.lang.annotation.Annotation[] annots = clazz.getAnnotations(); And obviously I'm doing something wrong since annots is an empty array. This is how the annotation looks like: @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface MyAnnotation { int value(); }

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  • JLabel not greyed out when disabled, when HTML text displayed

    - by bguiz
    How do I get a JLabel displaying a HTML string to appear greyed out (which is the behaviour of JLabels that don't display HTML text)? Is there another way than actually changing the colour myself by modifying the foreground property? JLabel label1 = new JLabel("Normal text"); JLabel label2 = new JLabel("<html>HTML <b>text</b>"); // Both labels are now black in colour label1.setEnabled(false); label2.setEnabled(false); // label1 is greyed out, label2 is still black in colour Thank you very much for all of your responses. From what I gather, it seems that Java doesn't support automatic greying out of JLabels when they use HTML text. Suraj's solution has come closest to the fix considering the limitations. I have however, tried a different out-of-the box approach, where I have put the HTML text JLabels inside of an inner JPanel and did this: mInnerPanel.setEnabled(shouldShow); //shouldShow is a boolean value Which hasn't worked. Any suggestions for this way? EDIT: Added implemented solution.

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