Search Results

Search found 45920 results on 1837 pages for 'java design patterns'.

Page 139/1837 | < Previous Page | 135 136 137 138 139 140 141 142 143 144 145 146  | Next Page >

• Psuedo-Backwards Builder Pattern?

  - by Avid Aardvark

  In a legacy codebase I have a very large class with far too many fields/responsibilities. Imagine this is a Pizza object. It has highly granular fields like: hasPepperoni hasSausage hasBellPeppers I know that when these three fields are true, we have a Supreme pizza. However, this class is not open for extension or change, so I can't add a PizzaType, or isSupreme(), etc. Folks throughout the codebase duplicate the same "if(a && b && c) then isSupreme)" logic all over place. This issue comes up for quite a few concepts, so I'm looking for a way to deconstruct this object into many subobjects, e.g. a pseudo-backwards Builder Pattern. PizzaType pizzaType = PizzaUnbuilder.buildPizzaType(Pizza); //PizzaType.SUPREME Dough dough = PizzaUnbuilder.buildDough(Pizza); Is this the right approach? Is there a pattern for this already? Thanks!

  Read the article

• How to improve the builder pattern?

  - by tangens

  Motivation Recently I searched for a way to initialize a complex object without passing a lot of parameter to the constructor. I tried it with the builder pattern, but I don't like the fact, that I'm not able to check at compile time if I really set all needed values. Traditional builder pattern When I use the builder pattern to create my Complex object, the creation is more "typesafe", because it's easier to see what an argument is used for: new ComplexBuilder() .setFirst( "first" ) .setSecond( "second" ) .setThird( "third" ) ... .build(); But now I have the problem, that I can easily miss an important parameter. I can check for it inside the build() method, but that is only at runtime. At compile time there is nothing that warns me, if I missed something. Enhanced builder pattern Now my idea was to create a builder, that "reminds" me if I missed a needed parameter. My first try looks like this: public class Complex { private String m_first; private String m_second; private String m_third; private Complex() {} public static class ComplexBuilder { private Complex m_complex; public ComplexBuilder() { m_complex = new Complex(); } public Builder2 setFirst( String first ) { m_complex.m_first = first; return new Builder2(); } public class Builder2 { private Builder2() {} Builder3 setSecond( String second ) { m_complex.m_second = second; return new Builder3(); } } public class Builder3 { private Builder3() {} Builder4 setThird( String third ) { m_complex.m_third = third; return new Builder4(); } } public class Builder4 { private Builder4() {} Complex build() { return m_complex; } } } } As you can see, each setter of the builder class returns a different internal builder class. Each internal builder class provides exactly one setter method and the last one provides only a build() method. Now the construction of an object again looks like this: new ComplexBuilder() .setFirst( "first" ) .setSecond( "second" ) .setThird( "third" ) .build(); ...but there is no way to forget a needed parameter. The compiler wouldn't accept it. Optional parameters If I had optional parameters, I would use the last internal builder class Builder4 to set them like a "traditional" builder does, returning itself. Questions Is this a well known pattern? Does it have a special name? Do you see any pitfalls? Do you have any ideas to improve the implementation - in the sense of fewer lines of code?

  Read the article

• org.apache.cxf.interceptor.Fault: Unmarshalling Error: Duplicate default namespace declaration.

  - by JohnC

  Not sure why I am receiving this after the webservice ran and I am trying to return back to my client side bean. The webservice works perfectly outside of my webserver in SoapUI. org.apache.cxf.interceptor.Fault: Unmarshalling Error: Duplicate default namespace declaration. at [row,col {unknown-source}]: [1,321] at org.apache.cxf.jaxb.JAXBEncoderDecoder.unmarshall(JAXBEncoderDecoder.java:764) at org.apache.cxf.jaxb.JAXBEncoderDecoder.unmarshall(JAXBEncoderDecoder.java:623) at org.apache.cxf.jaxb.io.DataReaderImpl.read(DataReaderImpl.java:128) at org.apache.cxf.interceptor.DocLiteralInInterceptor.handleMessage(DocLiteralInInterceptor.java:101) at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:236) at org.apache.cxf.endpoint.ClientImpl.onMessage(ClientImpl.java:671) at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleResponseInternal(HTTPConduit.java:2177) at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.handleResponse(HTTPConduit.java:2057) at org.apache.cxf.transport.http.HTTPConduit$WrappedOutputStream.close(HTTPConduit.java:1982) at org.apache.cxf.transport.AbstractConduit.close(AbstractConduit.java:66) at org.apache.cxf.transport.http.HTTPConduit.close(HTTPConduit.java:637) at org.apache.cxf.interceptor.MessageSenderInterceptor$MessageSenderEndingInterceptor.handleMessage(MessageSenderInterceptor.java:62) at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:236) at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:483) at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:309) at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:261) at org.apache.cxf.frontend.ClientProxy.invokeSync(ClientProxy.java:73) at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:124)

  Read the article

• Nice name for `decorator' class?

  - by Lajos Nagy

  I would like to separate the API I'm working on into two sections: 'bare-bones' and 'cushy'. The idea is that all method calls in the 'cushy' section could be expressed in terms of the ones in the 'bare-bones' section, that is, they would only serve as convenience methods for the quick-and-dirty. The reason I would like to do this is that very often when people are beginning to use an API for the first time, they are not interested in details and performance: they just want to get it working. Anybody tried anything similar before? I'm particularly interested in naming conventions and organizing the code.

  Read the article

• Strategy pattern and "action" classes explosion

  - by devoured elysium

  Is it bad policy to have lots of "work" classes(such as Strategy classes), that only do one thing? Let's assume I want to make a Monster class. Instead of just defining everything I want about the monster in one class, I will try to identify what are its main features, so I can define them in interfaces. That will allow to: Seal the class if I want. Later, other users can just create a new class and still have polymorphism by means of the interfaces I've defined. I don't have to worry how people (or myself) might want to change/add features to the base class in the future. All classes inherit from Object and they implement inheritance through interfaces, not from mother classes. Reuse the strategies I'm using with this monster for other members of my game world. Con: This model is rigid. Sometimes we would like to define something that is not easily achieved by just trying to put together this "building blocks". public class AlienMonster : IWalk, IRun, ISwim, IGrowl { IWalkStrategy _walkStrategy; IRunStrategy _runStrategy; ISwimStrategy _swimStrategy; IGrowlStrategy _growlStrategy; public Monster() { _walkStrategy = new FourFootWalkStrategy(); ...etc } public void Walk() { _walkStrategy.Walk(); } ...etc } My idea would be next to make a series of different Strategies that could be used by different monsters. On the other side, some of them could also be used for totally different purposes (i.e., I could have a tank that also "swims"). The only problem I see with this approach is that it could lead to a explosion of pure "method" classes, i.e., Strategy classes that have as only purpose make this or that other action. In the other hand, this kind of "modularity" would allow for high reuse of stratagies, sometimes even in totally different contexts. What is your opinion on this matter? Is this a valid reasoning? Is this over-engineering? Also, assuming we'd make the proper adjustments to the example I gave above, would it be better to define IWalk as: interface IWalk { void Walk(); } or interface IWalk { IWalkStrategy WalkStrategy { get; set; } //or something that ressembles this } being that doing this I wouldn't need to define the methods on Monster itself, I'd just have public getters for IWalkStrategy (this seems to go against the idea that you should encapsulate everything as much as you can!) Why? Thanks

  Read the article

• How to store the path of a game pawn in a turn based game ?

  - by panzerschreck

  Hello, I have a square grid, for a turn based game ( grid is similar to the chess board ), but the moves in the games are different based on whether you have lapped your opponent pawn at least once or not. i.e if you have not lapped (beaten any of the opponents pawns) in the outer most grid as below if you have lapped your opponent pawn once at least, then you get to reach home,this way.Any player having all his pawns reaching "home" first wins. The ones in yellow are safe-houses, i.e both the opponent pawn and the player's pawn get to stay in the same grid, this is not considered to be lapping ( the opponent ).The lapped pawn will return to its start point. Now the question is, what is the effective way to store the paths for the all the pawns.we will have 4 pawns for the player and 4 opponent pawns. Is there any pattern to store such static information, in a elegant way ? Thanks for your time

  Read the article

• Factory pattern vs ease-of-use?

  - by Curtis White

  Background, I am extending the ASP.NET Membership with custom classes and extra tables. The ASP.NET MembershipUser has a protected constructor and a public method to read the data from the database. I have extended the database structure with custom tables and associated classes. Instead of using a static method to create a new member, as in the original API: I allow the code to instantiate a simple object and fill the data because there are several entities. Original Pattern #1 Protected constructor > static CreateUser(string mydata, string, mydata, ...) > User.Data = mydata; > User.Update() My Preferred Pattern #2 Public constructor > newUser = new MembershipUser(); > newUser.data = ... > newUser.ComplextObject.Data = ... > newUser.Insert() > newUser.Load(string key) I find pattern #2 to be easier and more natural to use. But method #1 is more atomic and ensured to contain proper data. I'd like to hear any opinions on pros/cons. The problem in my mind is that I prefer a simple CRUD/object but I am, also, trying to utilize the underlying API. These methods do not match completely. For example, the API has methods, like UnlockUser() and a readonly property for the IsLockedOut

  Read the article

• OOP Design of items in a Point-of-Sale system

  - by Jonas

  I am implementing a Point-of-Sale system. In the system I represent an Item in three places, and I wounder how I should represent them in OOP. First I have the WarehouseItem, that contains price, purchase price, info about the supplier, suppliers price, info about the product and quantity in warehouse. Then I have CartItem, which contains the same fields as WarehouseItem, but adds NrOfItems and Discount. And finally I have ReceiptItem, thats contains an item where I have stripped of info about the supplier, and only contains the price that was payed. Are there any OOP-recommendations, best-practices or design patterns that I could apply for this? I don't really know if CartItem should contain (wrap) an WarehouseItem, or extend it, or if I just should copy the fields that I need. Maybe I should create an Item-class where I keep all common fields, and then extend it to WarehouseItem, CartItem and ReceiptItem. Sometimes I think that it is good to keep the field of the item and just display the information that is needed.

  Read the article

• What makes static initialization functions good, bad, or otherwise?

  - by Richard Levasseur

  Suppose you had code like this: _READERS = None _WRITERS = None def Init(num_readers, reader_params, num_writers, writer_params, ...args...): ...logic... _READERS = new ReaderPool(num_readers, reader_params) _WRITERS = new WriterPool(num_writers, writer_params) ...more logic... class Doer: def __init__(...args...): ... def Read(self, ...args...): c = _READERS.get() try: ...work with conn finally: _READERS.put(c) def Writer(...): ...similar to Read()... To me, this is a bad pattern to follow, some cons: Doers can be created without its preconditions being satisfied The code isn't easily testable because ConnPool can't be directly mocked out. Init has to be called right the first time. If its changed so it can be called multiple times, extra logic has to be added to check if variables are already defined, and lots of NULL values have to be passed around to skip re-initializing. In the event of threads, the above becomes more complicated by adding locking Globals aren't being used to communicate state (which isn't strictly bad, but a code smell) On the other hand, some pros: its very convenient to call Init(5, "user/pass", 2, "user/pass") It simple and "clean" Personally, I think the cons outweigh the pros, that is, testability and assured preconditions outweigh simplicity and convenience.

  Read the article

• An alternative to reading input from Java's System.in

  - by dvanaria

  I’m working on the UVa Online Judge problem set archive as a way to practice Java, and as a way to practice data structures and algorithms in general. They give an example input file to submit to the online judge to use as a starting point (it’s the solution to problem 100). Input from the standard input stream (java.lang.System.in) is required as part of any solution on this site, but I can’t understand the implementation of reading from System.in they give in their example solution. It’s true that the input file could consist of any variation of integers, strings, etc, but every solution program requires reading basic lines of text input from System.in, one line at a time. There has to be a better (simpler and more robust) method of gathering data from the standard input stream in Java than this: public static String readLn(int maxLg) { byte lin[] = new byte[maxLg]; int lg = 0, car = -1; String line = “”; try { while (lg < maxLg) { car = System.in.read(); if ((car < 0) || (car == ‘\n’)) { break; } lin[lg++] += car; } } catch (java.io.IOException e) { return (null); } if ((car < 0) && (lg == 0)) { return (null); // eof } return (new String(lin, 0, lg)); } I’m really surprised by this. It looks like something pulled directly from K&R’s “C Programming Language” (a great book regardless), minus the access level modifer and exception handling, etc. Even though I understand the implementation, it just seems like it was written by a C programmer and bypasses most of Java’s object oriented nature. Isn’t there a better way to do this, using the StringTokenizer class or maybe using the split method of String or the java.util.regex package instead?

  Read the article

• Database Design sugessition

  - by Manoj kumar

  I am in the plan of building a information service website similar to http://us.justdial.com/, I was in the confusion of designing the database. The datas stored in the database are List of categories Name of the company and its address, phone number, category, etc... (i am going to use MYSQL Database) how could i design the database that makes the accessing of those data easier ? Thanks in advance

  Read the article

• Embedding a flowchart design surface in a .NET application

  - by PaulB

  I need to incorporate a flowchart design surface into an application we're developing to allow users to create what are essentially workflows/schedules. I need to be able to create my own 'shapes', set custom properties on them and possibly have a bit of logic in there too (if, while etc). I know I need to take a look at hosting WF in the application. It looks like a good fit, but what other designer compoments out there could I use?

  Read the article

• Suggestions for Single-Page Web Application Design?

  - by DaveDev

  My view is that unless you need to change the basic structure of the user interface, you should not have to reload the page at all for any user interactions. I'd like to approach my next ASP.NET MVC project with this in mind. Can anyone suggest any principles, patterns or practices* I should consider? Excellent book, btw. Still trying to wrap my head around some of the concepts though. I thought a question like this would help link the theory to a practical design. Thanks

  Read the article

• Connect to a site using proxy code in java

  - by Nithin

  I want to connect to as site through proxy in java.This is the code which I have written public class ConnectThroughProxy { Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("proxy ip", 8080)); public static void main(String[] args) { try{ URL url = new URL("http://www.rgagnon.com/javadetails/java-0085.html"); URLConnection connection=url.openConnection(); String encoded = new String(Base64.encode(new String("user_name:pass_word").getBytes())); connection.setDoOutput(true); connection.setRequestProperty("Proxy-Authorization","Basic "+encoded); String page=""; String line; StringBuffer tmp = new StringBuffer(); BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); while ((line=in.readLine()) != null){ page.concat(line + "\n"); } System.out.println(page); }catch(Exception ex){ ex.printStackTrace(); } } while trying to run this code it throws the following error java.lang.IllegalArgumentException: Illegal character(s) in message header value: Basic dXNlcl9uYW1lOnBhc3Nfd29yZA== at sun.net.www.protocol.http.HttpURLConnection.checkMessageHeader(HttpURLConnection.java:323) at sun.net.www.protocol.http.HttpURLConnection.setRequestProperty(HttpURLConnection.java:2054) at test.ConnectThroughProxy.main(ConnectThroughProxy.java:30) Any Idea how to do it.

  Read the article

• programming logic and design pleas friends i need a flowcharts or pseudocode

  - by alex

  ***the midvile park maintains records containing info about players on it's soccer teams . each record contain a players first name,last name,and team number . the team are team number team name 1 goal getters 2 the force 3 top gun 4 shooting stars 5 midfield monsters design a proggram that accept player data and creates a report that lists each** player a long with his or her team number and team name**

  Read the article

• Removing Design Outlining

  - by Kevin

  Is there a way to remove the outlining in Visual Studio in the design page of a form? If it is possible, it would save me some time so that I would not have to keep compiling and running the program every time I wanted to see if I put my form together correctly without any caps between images, etc. For example, something like this. I want to remove the lines that surround each image (yes, those are separate images put together).

  Read the article

• How to avoid using this in a contructor

  - by Paralife

  I have this situation: interface MessageListener { void onMessageReceipt(Message message); } class MessageReceiver { MessageListener listener; public MessageReceiver(MessageListener listener, other arguments...) { this.listener = listener; } loop() { Message message = nextMessage(); listener.onMessageReceipt(message); } } and I want to avoid the following pattern: (Using the this in the Client constructor) class Client implements MessageListener { MessageReceiver receiver; MessageSender sender; public Client(...) { receiver = new MessageReceiver(this, other arguments...); sender = new Sender(...); } . . . @Override public void onMessageReceipt(Message message) { if(Message.isGood()) sender.send("Congrtulations"); else sender.send("Boooooooo"); } } The reason why i need the above functionality is because i want to call the sender inside the onMessageReceipt() function, for example to send a reply. But I dont want to pass the sender into a listener, so the only way I can think of is containing the sender in a class that implements the listener, hence the above resulting Client implementation. Is there a way to achive this without the use of 'this' in the constructor? It feels bizare and i dont like it, since i am passing myself to an object(MessageReceiver) before I am fully constructed. On the other hand, the MessageReceiver is not passed from outside, it is constructed inside, but does this 'purifies' the bizarre pattern? I am seeking for an alternative or an assurance of some kind that this is safe, or situations on which it might backfire on me.

  Read the article

• Confused about this factory, as it doesn't look like an Abstract Factory nor Factory Method

  - by Pin

  I'm looking into Guice and I've been reading its documentation recently. Reading the motivation section I don't understand the factories part, why they name it that way. To me that factory is just a wrapper for the implementing class they want it to return after calling getInstance(). public class CreditCardProcessorFactory { private static CreditCardProcessor instance; public static void setInstance(CreditCardProcessor creditCardProcessor) { instance = creditCardProcessor; } public static CreditCardProcessor getInstance() { if (instance == null) { throw new IllegalStateException("CreditCardProcessorFactory not initialized. " + "Did you forget to call CreditCardProcessor.setInstance() ?"); } return instance; } } Why do they call it factory as well if it is neither an abstract factory nor a factory method? Or am I missing something? Thanks.

  Read the article

• Trouble with Berkeley DB JE Base API Secondary Databases and Sequences

  - by milosz

  I have a class Document which consists of Id (int) and Url (String). I would like to have a primary index on Id and secondary index on Url. I would also like to have a sequence for Id auto-incrementation. So I create a SecondaryDatabase and then I create a Sequence. During initialisation of the Sequence I get an exception: Exception in thread "main" java.lang.IllegalArgumentException at com.sleepycat.util.UtfOps.getCharLength(UtfOps.java:137) at com.sleepycat.util.UtfOps.bytesToString(UtfOps.java:259) at com.sleepycat.bind.tuple.TupleInput.readString(TupleInput.java:152) at pl.edu.mimuw.zbd.berkeley.zadanie.rozwiazanie.MyDocumentBiding.entryToObject(MyDocumentBiding.java:12) at pl.edu.mimuw.zbd.berkeley.zadanie.rozwiazanie.MyDocumentBiding.entryToObject(MyDocumentBiding.java:1) at com.sleepycat.bind.tuple.TupleBinding.entryToObject(TupleBinding.java:76) at pl.edu.mimuw.zbd.berkeley.zadanie.rozwiazanie.UrlKeyCreator.createSecondaryKey(UrlKeyCreator.java:20) at com.sleepycat.je.SecondaryDatabase.updateSecondary(SecondaryDatabase.java:835) at com.sleepycat.je.SecondaryTrigger.databaseUpdated(SecondaryTrigger.java:42) at com.sleepycat.je.Database.notifyTriggers(Database.java:2004) at com.sleepycat.je.Cursor.putNotify(Cursor.java:1692) at com.sleepycat.je.Cursor.putInternal(Cursor.java:1616) at com.sleepycat.je.Cursor.putNoOverwrite(Cursor.java:663) at com.sleepycat.je.Sequence.<init>(Sequence.java:188) at com.sleepycat.je.Database.openSequence(Database.java:546) at pl.edu.mimuw.zbd.berkeley.zadanie.rozwiazanie.MyFullTextSearchEngine.init(MyFullTextSearchEngine.java:131) at pl.edu.mimuw.zbd.berkeley.zadanie.testy.MyFullTextSearchEngineTest.main(MyFullTextSearchEngineTest.java:18) It seems that during the initialisation of the sequence the secondary database is forced to update. When I debug the entryToObject method of MyDocumentBiding the bytes that it tries to convert to object seem random. What am I doing wrong?

  Read the article

• Example with Visitor Pattern

  - by devoured elysium

  public class Song { public string Genre { get; protected set; } public string Name { get; protected set; } public string Band { get; protected set; } public Song(string name, string band, string genre) { Name = name; Genre = genre; Band = band; } } public interface IMusicVisistor { void Visit(List<Song> items); } public class MusicLibrary { List<Song> _songs = new List<Song> { ...songs ... }; public void Accept(IMusicVisitor visitor) { visitor.Visit(_songs); } } and now here's one Visitor I made: public class RockMusicVisitor : IMusicVisitor { public List<Song> Songs { get; protected set; } public void Visit(List<Song> items) { Songs = items.Where(x => x.Genre == "Rock").ToList(); } } Why is this any better than just putting a public property Songs and then letting any kind of class do with it anything that it wants to? This example comes from this post.

  Read the article

• Switching from Java to .NET from a career change point of view

  - by Joe

  Could anyone share with me their experience with switching from Java to .NET from a career point of view? I've been a Java developer for 12 years and am just getting tired of how fragmented the Java world has become. For my liking, there's just too many frameworks, tools, application servers, etc.. And it seems each new tool just adds complexity and time to even the simplest of projects. I'm not trying to start any wars - I'm just giving you the reason I ask the main question. I've read a few books on .NET and have done one WebForms job. I love the integrated environment and would like to hear how others transitioned from Java to .NET. What I mean by that is did you do it somehow as a contractor or did you join a company as a beginner .NET developer with much Java experience? Personally, I'm ready to take the leap if I can figure out how to not lose too much income in the process (Senior Java developer to beginner .NET developer). I would really appreciate hearing your stories.

  Read the article

• Java - how to design your own type?

  - by Walter White

  Hi all, Is it possible to design your own Java Type, say an extensible enum? For instance, I have user roles that a certain module uses and then a sub-package provides additional roles. What would be involved on the JDK side of things? Walter

  Read the article

• java serialization problems with different JVMs

  - by Alberto

  I am having trouble using serialization in Java. I've searched the web for a solution but haven't found an answer yet. The problem is this - I have a Java library (I have the code and I export it to an archive prior to executing the code) which I need to use with two differents JVMs. One JVM is on the server (Ubuntu, running Java(TM) JRE SE Runtime Environment (build 1.7.0_09-b05)) and the other on Android 2.3.3. I compiled the library in Java 1.6. Now, I am trying to import to the client, an object exported from the server, but I receive this error: java.io.InvalidClassException: [Lweka.classifiers.functions.MultilayerPerceptron$NeuralEnd;; Incompatible class (SUID): [Lweka.classifiers.functions.MultilayerPerceptron$NeuralEnd;: static final long serialVersionUID =-359311387972759020L; but expected [Lweka.classifiers.functions.MultilayerPerceptron$NeuralEnd;: static final long serialVersionUID =1920571045915494592L; I do have an explicit serial version UID declared on the class MultilayerPerceptron$NeuralEnd, like this: protected class NeuralEnd extends NeuralConnection { private static final long serialVersionUID = 7305185603191183338L; } Where NeuralConnection implements the java.io.Serializable interface. If I do a serialver on MultilayerPerceptron$NeuralEnd I receive the serialVersionUID which I declared. So, why have both JVMs changed this value? Can you help me? Thanks, Alberto

  Read the article

• how to aviod infinite loop in observer pattern?

  - by joseph

  Hello. I have only one class with many instances. Every instance is observer of couple of other instances. As well every instance can be observable by couple of another instances. How to avoid infinite loop of calling update() in observers?

  Read the article

• Register all GUI components as Observers or pass current object to next object as a constructor argu

  - by Jack

  First, I'd like to say that I think this is a common issue and there may be a simple or common solution that I am unaware of. Many have probably encountered a similar problem. Thanks for reading. I am creating a GUI where each component needs to communicate (or at least be updated) by multiple other components. Currently, I'm using a Singleton class to accomplish this goal. Each GUI component gets the instance of the singleton and registers itself. When updates need to be made, the singleton can call public methods in the registered class. I think this is similar to an Observer pattern, but the singleton has more control. Currently, the program is set up something like this: class c1 { CommClass cc; c1() { cc = CommClass.getCommClass(); cc.registerC1( this ); C2 c2 = new c2(); } } class c2 { CommClass cc; c2() { cc = CommClass.getCommClass(); cc.registerC2( this ); C3 c3 = new c3(); } } class c3 { CommClass cc; c3() { cc = CommClass.getCommClass(); cc.registerC3( this ); C4 c4 = new c4(); } } etc. Unfortunately, the singleton class keeps growing larger as more communication is required between the components. I was wondering if it's a good idea to instead of using this singleton, pass the higher order GUI components as arguments in the constructors of each GUI component: class c1 { c1() { C2 c2 = new c2( this ); } } class c2 { C1 c1; c2( C1 c1 ) { this.c1 = c1 C3 c3 = new c3( c1, this ); } } class c3 { C1 c1; C2 c2; c3( C1 c1, C2 c2 ) { this.c1 = c1; this.c2 = c2; C4 c4 = new c4( c1, c2, this ); } } etc. The second version relies less on the CommClass, but it's still very messy as the private member variables increase in number and the constructors grow in length. Each class contains GUI components that need to communicate through CommClass, but I can't think of a good way to do it. If this seems strange or horribly inefficient, please describe some method of communication between classes that will continue to work as the project grows. Also, if this doesn't make any sense to anyone, I'll try to give actual code snippets in the future and think of a better way to ask the question. Thanks.

  Read the article

< Previous Page | 135 136 137 138 139 140 141 142 143 144 145 146  | Next Page >