Hello everybody,I'm fairly new to Java, and my first real project which also implements jsp was going very well, until...I had to sort an ArrayList, which holds object with only 2 attributes, a String uid, and an int diff.I want to sort this ArrayList in ascending order by int diff.So ...

Hi..I am getting the following exception while running a servlet on Apache tomcat[Fatal Error] :15:184: The element type "HR" must be terminated by the matching end-tag "</HR>".From XMLParserorg.xml.sax.SAXParseException: The element type "HR" must be terminated by the matching end-tag ...

hej,Using the Command Pattern to run DAOs with a bit of business logic so that I can have a different types of Invoker (Command handler) classes depending if transactions are managed a SLSB or a local test client using JTA. Beyond organizing commands there isn't much hassel with using the ...

All,I was just in a meeting where two different approaches to returning data to the view were discussed.In a nutshell, here are the two options presented:1) The service layer should return the Business Entities entirely (which happen to be Hibernate objects).2) The service layer should return ...

I have this classimport java.util.ArrayList;import java.util.List;public class SynchIssues{ private List values = new ArrayList(); private static final SynchIssues singleton = new SynchIssues(); public static SynchIssues getInstance() {return singleton; } public void addValue(String value) ...

I don't know if this is the correct forum for my question.My application has to assign an appointment with a doctor. But there are many users (patients) compeating for this resource. I thought of blocking this resource until I collect all the patient information, but I'm not quite sure that ...

Hello,i have a Problem with the Singleton Pattern.Following situation:I have a class (Commander) which starts all the dialogs of my Swing Application. For this it starts first the BPs and they start the dialogs.The BPs need my mainprocess class in the construtor to set the its parent. So, my ...

Hi for all............Please ,I want from you to explain Polyphace Balanced Merge SortHelp Help Help Help Help Help Help Help Help Help Help Help HelpNote: I hope to give detailed explainationThanks FoRrVeR

All,Is loose coupling/method reuse in the DAO a good thing?In the method example below, methods in the DAO would all invoke this generic method to dynamically build the stored proc to call, and execute it.Is this good design? or overkill? or problematic?private void executeStoredProcedure(Long ...

I am looking for comments/suggestions on appropriate layers and dependencies in a Strus application.We currently have FormBeans, an Action layer, a Service layer, a Business logic layer, some Utilities, the Model objects, a Persistence layer and a Helper layer.The Action layer is supposed to be ...

I got the following code:VectorVector<String> v = new Vector<String>();for (int i = 0; i < 10000; ++i) // For example{v.add(str1 + str2 + str3);}where st1, str2 and str3 are strings that change through every iteration, so they can't be added from before.The adding line is quite ...

hi! I'd like to kill many threads I throw. I use Thread class. do have I to kill them using "join" or "interrupt"? thank you!

is prototype just use clone substitute the "new" operation? but client must know about manager and concrete products and initial manager with products he or she wants,so what's use of this manager and clone-- if client want to get product, he or she must "new" it and then clone it .in my view ...

i am having an issue with yahoo chess ( my fave game and i cannot seem to be able to access the rooms for it.i can pick an actual room like the " rat pack " but it says " please wait while the applet loads (could take 3 minutes) if it does not click here " well it gives me that good ol broken ...

helloIve read about the Model-View-Control Architecture and understood it ,theoretically atleast!! Ive found huge coding fr explaining the concept. Thus I am unable to visualise this pattern in terms of coding. Can someone please explain it to me with a simple example and some method ...

I have no idea where to start with this! I might even be posting in the wrong forum. Anyway - here's my problem.I have algorithms which I have written. They all all perform a task, but have different approaches to it. They all implement an interface I have written.Now. I want to design a GUI ...

Hey guys, i want to write a 2D FPS. Unfortunatly i dont know much about this sort of programming (i do java at universtiy, but its all swing). Does anyone know of any good tutorials in 2D graphics handling , animation etc?Thanks Dave

How is this supposted to be connected with good programming practise on a class-diagram level?Say I have a board game, say tic tac toe. All my logic are in the classes Board, Player and Move. I also need a GameController class that controls the game. Now I want to have an UI for this game. Say ...

Hi, I'm reading a book on EJB patterns, and the motivation for many patterns seem to be minimizing network calls. If my application server and web server which serves as the EJB client are on the same machine, then to what extent should I consider the minimization of network calls as a factor ...

I'm new to this design pattern (and this forum too). I would like to know about your experience and advice on command pattern.Is it OK to implement it this way?TypicalCommand cmd = new TypicalCommand();TypicalInput in = new ...

In java ,Is method overloading is a compile time polymorphism ?I mean all those method calls will be decided at the time of compilation .. am i right ?

Hi everyone,I'm developing a bacth application.This application has to read a file in which each line represents a Business Object.To parse this file i've done a static method which, from a line of this file give me an Object.that's ok !.But, i've also done a Reader (suchn as ...

We are getting out of memory errors that do not seem to be associated with the heap ,because we are monitoring the available space and there is plenty of space.It happens when the class loader is loading a resource.Is this possible?

Hi,I know sounds silly, but what is the difference between Property, Attribute and Parameter? In what cases every of this words is used?Anton

I am looking for a java engine/framework to develop virtual world and war game. Any recommendations?

Well, Daffy up and got that thread deleted for us. Too bad the admins could not save a few of Loko's excellent explanations that were contained therein. Starting a new thread in case anyone wanted to post a recap. Nice job Daffy.- Saish

What happened with the latest daFei's thread? It was not so useful thread, but at least there were a lot of interesting and important replies there, posted by the others.Did someone here ask to delete that thread? Or did Sun decide to do that, without our request?

Hello,The problem at hand is the following. I need to run 1 million search and return back only top 100 scores. I do not wish to store all million scores, sort them and only return top 100. I'd like to maintain a "list" of top 100 scores. As new search produces a score, I'd like to very ...

HI all, i am designing a messenging application which has following modules : UI Module DB Module Messenging Module UI to DB connector UI to Messenging connectorMy problem lies in Messenging module. The purpose this modules is, it should provide a destination for the messages and an interface ...

Hi all you algorithm gurus - I'm looking for ideas for an algorithm to solve the following problem. It's specifically meant to "spread out" or "declutter" the overlapping vertices in a graph visualization system, but I'll state it in more general terms.In a rectangular area of the screen ...

Hello wondering if anybody can advise me on how to get started with this ?I am starting a project where using Steganography as digital watermarking tool to insert text into an image.I am using the quantization index modulation method with the colt maths package to implement the equations ...

This is very non-specific question, I'm sorry. Still, it's something that comes up from time to time when I write java.Basically, suppose an object takes a list of something in it's constructor. The object expects that that list of something contains no nulls - ie it calls a method on each ...

Hello. I'm doing an insersion sort for an array of pet's in a store. Im running into two problems. My first problems is im trying to use the compareTo() to compare the name of each of these pets. Im running into a null pointer exception but dont know what to do about that or why im getting ...

Hi, I've been thinking about how to write a reusable composite object. Basically this would be a simple implementation of the composite pattern, but would be general enough that you could reuse it in many places. Here is an example?after the examples I talk about my problem./** * Composite ...

I need to develop a application using swing and SQlserver.Though it is not web based one,three computers connected to my computer will run the application parallely.ProblemI have a JTable which will show the database table contents.I have two designs:1) To have a helper class( contains static ...

Hello,does anyone know about libraries or methods to evalutate a random sequence for weeknesses in the sequence? E.g. java.util.Random is a far from perfect pseudo random generator, and such a method might be able to detect that.Gil

Hi,this is my question:I have some heterogen classes lets say:class A, class B, class C and class Dclass A implementsmethod amethod bmethod cmethod dmethod zclass B implements method emethod fmethod cmethod dmethod zclass C implements method gmethod hmethod imethod jmethod zclass C implements ...

Hi..How to make the 4 way of bomb and continue bomb in the game like bombermanplease help me....if ((keyStates==FIRE_PRESSED)){ ?}

Hi all,I'm currently refactoring an application which uses two different libraries according to the user input.There is a Factory class who returns instances of, let's say, MetadataB and MetadataB, both subclass of Metadata.This is fine if the user calls one of the method exposed by the ...

Hi there,I am a college student. I am currently working on a project that involves me programming the Dijkstra's algorithm and then producing a GUI that will show this algorithm running on a pre-defined graph.I have looked on the web and have found code but I still don't know where to begin. ...

Hi all,I need to implement an application such as Rational Rose or Visio.I am intending to use the mvc pattern as all the info i have points in this direction.I think MVC, Decorator, mediator, builder, etc are all possible candidates but susspect that MVC is the best. Can someone please either ...

Hi guys,When we want to initiliase an array P which consists of N positions,do we have to initilaise all the positions in order to point to NULL?This demands O(n) time although we may not use all the positions.Thanks,in advance!

I am trying to avoid using busy wait when, after opening a child thread's input stream, I wait for it it to be ready before I start reading from it. A segment of the code follows:BufferedReader reader=new BufferedReader(new InputStreamReader(child.getInputStream()));while (true) {while ...

I'm trying to write a method that finds the square root of a number using recursion. So far i have the following:public double rootMeth(double a) {if (a < = 1)return a;elsereturn a / rootMeth(a-2);}I know this is not right, but it does work for a few numbers, if you can help it would be ...

hiIf I run the following Queryselect P.ECMSKU ITEM_ID, P.ECMLDS ITEM_TITLE, 'ESH' ITEM_TYPEfrom ECMMST PwhereP.ECMSTS = 'A'AND UPPER(P.ECMLDS) LIKE UPPER('%?%');Result:suppose if I pass " yamaha uprirht piano"The result set contain so many records.I want to get reuslt like thisfirst ...

hi there..what is the best or most efficient algorithm for separating a string into words? the string contains a sentences and phrases, and i would like to have them separated into words..how can i do this manually? without using a native java method?

I am currrently working on a project to solve an 'advanced' TSP problem using ACO.I have been unable to find any source code as yet for an implementation of ACO using Java. I intend to use some existing free to use code and build on top of this the features I need to solve the new TSP ...

I am currently looking for one or more algorithms in detecting a stable drift in the voltage/potential of a electrical measure device. I have googled a bit but I am having problems finding something relevant.I must admit that drift is a relative new term for me, so there are perhaps some ...

public class Wrapper{public static MyClass createInstance(){return new MyClass();}}I have seen this , this is not a singleton, since im creating a new MyClass, whenever i call the static method createInstance(). Am i right?this is , right?public class Singleton { private static Singleton ...

Hi GuysNeed a bit of help in designing a framework to save and subsequently restore the state of an object in a relational database.To elaborate, the object is a JButton. It's property of interest are background color, label and whether or not it is enabled. I have created a bean to represent ...