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  • Visitor-pattern vs inheritance for rendering

    - by akaltar
    I have a game engine that currently uses inheritance to provide a generic interface to do rendering: class renderable { public: void render(); }; Each class calls the gl_* functions itself, this makes the code hard to optimize and hard to implement something like setting the quality of rendering: class sphere : public renderable { public: void render() { glDrawElements(...); } }; I was thinking about implementing a system where I would create a Renderer class that would render my objects: class sphere { void render( renderer* r ) { r->renderme( *this ); } }; class renderer { renderme( sphere& sphere ) { // magically get render resources here // magically render a sphere here } }; My main problem is where should I store the VBOs and where should I Create them when using this method? Should I even use this approach or stick to the current one, perhaps something else? PS: I already asked this question on SO but got no proper answers.

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  • Should this code/logic be included in Business Objects class or a separate class?

    - by aspdotnetuser
    I have created a small application which has a three tier architecture and I have business object classes to represent entities such as User, Orders, UserType etc. In these classes I have methods that are executed when the Constuctor method of, for example, User is called. These methods perform calculations and generate details that setup data for attributes that are part of each User object. Here is the structure for the project in Visual Studio: Here is some code from the business object class User.cs: Public Class User { public string Name { get; set; } public int RandomNumber { get; set; } etc public User { Name = GetName(); RandomNumber = GetRandomNumber(); } public string GetName() { .... return name; } public int GetRandomNumber() { ... return randomNumber; } } Should this logic be included in the Business Object classes or should it be included in a Utilities class of some kind? Or in the business rules?

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  • Trouble installing Java

    - by BRKsays
    I am running Ubuntu 12.04 LTS. I wanted to install Java and so I downloaded the 32-bit self extracting .bin file from http://www.java.com and tried to install it according to their instruction. First I made the file an executable one. Then created /usr/java/. After that I have to run this command: ./jre-7u<version>-linux-i586.bin. But I'm stuck here. My Java version is Java 6 u32. When I enter the command it says "no such file or directory". What to do? Please help. Also I'm trying to install 32-bit Java on my 64-bit Precise. Could that possibly be the problem? I tried to follow second answer by Jonas Christensen. I tried to open it, it says file is an unknown type. I tried the terminal command: ./jre-6u31-linux-i586.bin. But it gave this: Unpacking... Checksumming... Extracting... ./jre-6u32-linux-i586.bin: 86: ./jre-6u32-linux-i586.bin: ./install.sfx.5736: not found Failed to extract the files. Please refer to the Troubleshooting section of the Installation Instructions on the download page for more information.

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  • Passing arguments between classes - use public properties or pass a properties class as argument?

    - by devoured elysium
    So let's assume I have a class named ABC that will have a list of Point objects. I need to make some drawing logic with them. Each one of those Point objects will have a Draw() method that will be called by the ABC class. The Draw() method code will need info from ABC class. I can only see two ways to make them have this info: Having Abc class make public some properties that would allow draw() to make its decisions. Having Abc class pass to draw() a class full of properties. The properties in both cases would be the same, my question is what is preferred in this case. Maybe the second approach is more flexible? Maybe not? I don't see here a clear winner, but that sure has more to do with my inexperience than any other thing. If there are other good approaches, feel free to share them. Here are both cases: class Abc1 { public property a; public property b; public property c; ... public property z; public void method1(); ... public void methodn(); } and here is approach 2: class Abc2 { //here we make take down all properties public void method1(); ... public void methodn(); } class Abc2MethodArgs { //and we put them here. this class will be passed as argument to //Point's draw() method! public property a; public property b; public property c; ... public property z; } Also, if there are any "formal" names for these two approaches, I'd like to know them so I can better choose the tags/thread name, so it's more useful for searching purposes. That or feel free to edit them.

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  • Pattern for loading and handling resources

    - by Enoon
    Many times there is the need to load external resources into the program, may they be graphics, audio samples or text strings. Is there a patten for handling the loading and the handling of such resources? For example: should I have a class that loads all the data and then call it everytime I need the data? As in: GraphicsHandler.instance().loadAllData() ...//and then later: draw(x,y, GraphicsHandler.instance().getData(WATER_IMAGE)) //or maybe draw(x,y, GraphicsHandler.instance().WATER_IMAGE) Or should I assign each resource to the class where it belongs? As in (for example, in a game): Graphics g = GraphicsLoader.load(CHAR01); Character c = new Character(..., g); ... c.draw(); Generally speaking which of these two is the more robust solution? GraphicsHandler.instance().getData(WATER_IMAGE) //or GraphicsHandler.instance().WATER_IMAGE //a constant reference

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  • Entity and pattern validation vs DB constraint

    - by Joerg
    When it comes to performance: What is the better way to validate the user input? If you think about a phone number and you only want numbers in the database, but it could begin with a 0, so you will use varchar: Is it better to check it via the entity model like this: @Size(min = 10, max = 12) @Digits(fraction = 0, integer = 12) @Column(name = "phone_number") private String phoneNumber; Or is it better to use on the database side a CHECK (and no checking in the entity model) for the same feature?

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  • Domain Model and Querying

    - by Tyrsius
    I am new to DDD, having worked only in Transaction-Script apps with an anemic model, or just Big Balls of Mud, so please forgive any terminology I abuse. I am trying to understand the proper separation between the domain model and the repository. What is the proper way to construct a domain object that is coming from a database, assuming the (incredibly simplified) need to query for objects by status (returns enumerable), or by ID. Should a factory be building the objects, exposing methods for GetByStatus() and GetByID(), using a DIed repository? Should a repository be called directly, knowing how to build a domain model from the DTO? Should the domain model have a constructor for get by ID, using a DIed repoistory to load the initial state, using some other (?) method for the list? I am not really sure what the best way would be, and this question has an answer advocating each one (these are certainly mutuallu exclusive).

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  • What is the best way to restore(rollback) data in an application to a specified state(date) ?

    - by panzerschreck
    Hello, An example would set the context right, the example below captures the various states of the entity, which needs to be reverted(rolled back) . State 1 - Recorded on 01-Mar-2010 Column1 Column2 Data1 0.56 State 2 - Recorded on 02-Mar-2010 Column1 Column2 Data1 0.57 State 3 - Recorded on 03-Mar-2010 Column1 Column2 Data1 0.58 User notices that state3 is not what he intended to be in, decides to revert back to state2. One approach that I can think of, without modifying the entity is via "auditing" all the inserts/updates, as below, the rollback information captures the data just before the updates/modifications on the entity, so that it can be applied in an order when you need to revert.Please note that changing the entity's schema, is not an option. Rollback - R1 recorded on 01-Mar-2010 Column1 Column2 Data1 0.56 Rollback - R2 Recorded on 02-Mar-2010 Column1 Column2 Data1 0.56 Rollback - R3 Recorded on 03-Mar-2010 Column1 Column2 Data1 0.57 So, to get to state2 , we would start with rollback information R1,apply R2 onto it. Is there a better approach to achieve this ? Thanks for your time.

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  • Java vs. C# - Productivity perspective

    - by Edin Dazdarevic
    If you have a number of years experience in working with JAVA and a number of years experience in working with C# and .NET, I would value your opinion on software development productivity differences between these two environments. One of our customers is considering to technically replace their existing software solution. As the replacement will require approx. 10 - 15 man years work, a choice for JAVA or .NET, based on productivity differences between the them, may significantly influence the investment required and time-to-market. Would you be able to provide us, based on your honest and expert opinion, an indication of software development productivity differences between JAVA and C#/.NET? I would prefer to receive an answer as follows: My experience is based on X years experience working with JAVA and X years experience working with C#/.NET. JAVA is X% more productive then C#.NET or C#/.NET is X% more productive than JAVA if you take the the following into account . . . . . . . Thanks

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  • Best approach for tracking dependent state

    - by Pace
    Let's pretend I work on a project tracking application. The application is a database backed, server hosted, web application. In this application there are Projects which have many Activities which have many Tasks. A Task has two date fields an originalDueDate and a projectedDueDate. In addition, there are dynamic fields on the Activities and the Projects which indicate whether the Activity or Project is behind schedule based on the projected due dates of the child tasks and various other variables such as remaining buffer time, etc. There are a number of things that can cause the projectedDueDate to change. For example, an employee working on the project may (via a server request) enter in a shipping delay. Alternatively, a site may (via a server request) enter in an unexpected closure. When any of these things occur I need to not only update the projectedDueDate of the Task but also trigger the corresponding Project and Activity to update as well. What is the best way to do this? I've thought of the observer pattern but I don't keep a single copy of all these objects in memory. When a request comes in, I query the Task in from the database, at that point there is no associated Activity in memory that would be a listener. I could remove the ability to query for Tasks and force the application to query first by Project, then by Activity (in context of Project), then by task (in context of Activity) adding the observer relationships at each step but I'm not sure if that is the best way. I could setup a database event listening system so when a Task modified event is dispatched I have a handler which queries for the Activity at that point. I could simply setup a two-way relationship between Task and Activity so that the Task knows about the parent Activity and when the Task updates his state the Task grabs his parent and updates state. Right now I'm stuck considering all the options and am wondering if any single approach (doesn't have to be a listed approach) is jumping out at others as the best approach.

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  • Is there a pattern to restrict which classes can update another class?

    - by Mike
    Say I have a class ImportantInfo with a public writable property Data. Many classes will read this property but only a few will ever set it. Basically, if you want to update Data you should really know what you're doing. Is there a pattern I could use to make this explicit other than by documenting it? For example, some way to enforce that only classes that implement IUpdateImportantData can do it (this is just an example)? I'm not talking about security here, but more of a "hey, are you sure you want to do that?" kind of thing.

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  • How to implement string matching based on a pattern

    - by Vincent Rischmann
    I was asked to build a tool that can identify if a string match a pattern. Example: {1:20} stuff t(x) {a,b,c} would match: 1 stuff tx a 20 stuff t c It is a sort of regex but with a different syntax Parentheses indicate an optional value {1:20} is a interval; I will have to check if the token is a number and if it is between 1 and 20 {a,b,c} is just an enumeration; it can be either a or b or c Right now I implemented this with a regex, and the interval stuff was a pain to do. On my own time I tried implementing some kind of matcher by hand, but it turns out it's not that easy to do. By experimenting I ended up with a function that generates a state table from the pattern and a state machine. It worked well until I tried to implement the optional value, and I got stuck and how to generate the state table. After that I searched how I could do this, and that led me to stuff like LL parser, LALR parser, recursive-descent parser, context-free grammars, etc. I never studied any of this so it's hard to know what is relevant here, but I think this is what I need: A grammar A parser which generates states from the grammar and a pattern A state machine to see if a string match the states So my first question is: Is this right ? And second question, what do you recommend I read/study to be able to implement this ?

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  • How to separate and maintain customer specific code

    - by WYSIWYG
    I am implementing customer specific code and currently following simple approach like if (cusomterId == 23) do it. I want to separate out all the customer related code in separate place. But I have following problems. In code is in 1. Stored procs 2. Plain old classes. 3. Controllers 4. Views I came up with two solutions. First is to create table CustomerFunctionlity with columns CustomerId, FunctionalityName, method/Proc, inputs/outputs With this table I can simply check if exists, execute given function. Another way is creating a factory which returns customer related object for an interface. I am writting small end to end customer specific functionalities. How can I write maintenable code. Thanks

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  • Is it better to return NULL or empty values from functions/methods where the return value is not present?

    - by P B
    I am looking for a recommendation here. I am struggling with whether it is better to return NULL or an empty value from a method when the return value is not present or cannot be determined. Take the following two methods as an examples: string ReverseString(string stringToReverse) // takes a string and reverses it. Person FindPerson(int personID) // finds a Person with a matching personID. In ReverseString(), I would say return an empty string because the return type is string, so the caller is expecting that. Also, this way, the caller would not have to check to see if a NULL was returned. In FindPerson(), returning NULL seems like a better fit. Regardless of whether or not NULL or an empty Person Object (new Person()) is returned the caller is going to have to check to see if the Person Object is NULL or empty before doing anything to it (like calling UpdateName()). So why not just return NULL here and then the caller only has to check for NULL. Does anyone else struggle with this? Any help or insight is appreciated.

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  • Does C++ support subtyping?

    - by the_naive
    I know it might be a silly question to ask, but I didn't quite get an a absolute clear answer on this matter, so I thought I'd put it here. Does c++ support the subtyping in the sense that it fulfills Liskov's principle fully? I understand how parametric polymorphism, inclusion polymorphism(subclassing and overriding) work in c++ but I'm not entirely sure or understand if subtyping exists in the context of C++. Could you please explain?

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  • is it valid that a state machine can have more than one possible state for some transition?

    - by shankbond
    I have a requirement for a workflow which I am trying to model as a state machine, I see that there is more than one outcome of a given transition(or activity). Is it valid for a state machine to have more than one possible states, but only one state will be true at a given time? Note: This is my first attempt to model a state machine. Eg. might be: s1-t1-s2 s1-t1-s3 s1-t1-s4 where s1, s2, s3, s4 are states and t1 is transition/activity. A fictitious real world example might be: For a human, there can be two states: hungry, not hungry A basket can have only one item from: apple, orange. So, to model it we will have: hungry-pick from basket-apple found hungry-pick from basket-orange found apple found-eat-not hungry orange found-take juice out of it and then drink- not hungry

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  • Normalized class design and code first

    - by dc7a9163d9
    There are the following two classes. public class Employee { int EmployeeId { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public string Street { get; set; } public string Street2 { get; set; } public string City { get; set; } public string State { get; set; } public string Zip { get; set; } } public class Company { int CompanyId { get; set; } public string Name { get; set; } public string Street { get; set; } public string Street2 { get; set; } public string City { get; set; } public string State { get; set; } public string Zip { get; set; } } In a DDD seminar, the speaker said the better design should be, class PersonName { public string FirstName { get; set; } public string LastName { get; set; } } class Address { public string Street { get; set; } public string Street2 { get; set; } public string City { get; set; } public string State { get; set; } public string Zip { get; set; } } public class Employee { int EmployeeId { get; set; } public PersonName Name { get; set; } [ForeignKey("EmployerAddress")] public int EmployerAddressId { get; set; } public virtual Address EmployerAddress { get; set; } } public class Company { int CompanyId { get; set; } public string Name { get; set; } [ForeignKey("CompanyAddress")] public int CompanyAddressId { get; set; } public virtual Address CompanyAddress { get; set; } } Is it the optimized design? How the code first generate the PersonName table and link it to Employee?

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  • Java: immutability, overuse of stack -- better data structure?

    - by HH
    I overused hashSets but it was slow, then changed to Stacks, speed boost-up. Poly's reply uses Collections.emptyList() as immutable list, cutting out excess null-checkers. No Collections.emptyStack(). Combining the words stack and immutability, from the last experiences, gets "immutable stack" (probably not related to functional prog). Java Api 5 for list interface shows that Stack is an implementing class for list and arraylist, here. The java.coccurrent pkg does not have any immutable Stack data structure. The first hinted of misusing stack. The lack of immutabily in the last and poly's book recommendation leads way to list. Something very primitive, fast, no extra layers, with methods like emptyThing(). Overuse of stack and where I use it DataFile.java: public Stack<DataFile> files; FileObject.java: public Stack<String> printViews = new Stack<String>(); FileObject.java:// private static Stack<Object> getFormat(File f){return (new Format(f)).getFormat();} Format.java: private Stack<Object> getLine(File[] fs,String s){return wF;} Format.java: private Stack<Object> getFormat(){return format;} Positions.java: public static Stack<Integer[]> getPrintPoss(String s,File f,Integer maxViewPerF) Positions.java: Stack<File> possPrint = new Stack<File>(); Positions.java: Stack<Integer> positions=new Stack<Integer>(); Record.java: private String getFormatLine(Stack<Object> st) Record.java: Stack<String> lines=new Stack<String>(); SearchToUser.java: public static final Stack<File> allFiles = findf.getFs(); SearchToUser.java: public static final Stack<File> allDirs = findf.getDs(); SearchToUser.java: private Stack<Integer[]> positionsPrint=new Stack<Integer[]>(); SearchToUser.java: public Stack<String> getSearchResults(String s, Integer countPerFile, Integer resCount) SearchToUser.java: Stack<File> filesToS=Fs2Word.getFs2W(s,50); SearchToUser.java: Stack<String> rs=new Stack<String>(); View.java: public Stack<Integer[]> poss = new Stack<Integer[4]>(); View.java: public static Stack<String> getPrintViewsFileWise(String s,Object[] df,Integer maxViewsPerF) View.java: Stack<String> substrings = new Stack<String>(); View.java: private Stack<String> printViews=new Stack<String>(); View.java: MatchView(Stack<Integer> pss,File f,Integer maxViews) View.java: Stack<String> formatFile; View.java: private Stack<Search> files; View.java: private Stack<File> matchingFiles; View.java: private Stack<String> matchViews; View.java: private Stack<String> searchMatches; View.java: private Stack<String> getSearchResults(Integer numbResults) Easier with List: AllDirs and AllFs, now looping with push, but list has more pow. methods such as addAll [OLD] From Stack to some immutable data structure How to get immutable Stack data structure? Can I box it with list? Should I switch my current implementatios from stacks to Lists to get immutable? Which immutable data structure is Very fast with about similar exec time as Stack? No immutability to Stack with Final import java.io.*; import java.util.*; public class TestStack{ public static void main(String[] args) { final Stack<Integer> test = new Stack<Integer>(); Stack<Integer> test2 = new Stack<Integer>(); test.push(37707); test2.push(80437707); //WHY is there not an error to remove an elment // from FINAL stack? System.out.println(test.pop()); System.out.println(test2.pop()); } }

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  • Problem launch Java on Debian: "error while loading shared libraries: libjli.so"

    - by aetaur
    I'm trying to launch Java: $ java -version java: error while loading shared libraries: libjli.so: cannot open shared object file: No such file or directory $ ldd /usr/lib/jvm/java-6-openjdk/jre/bin/java linux-gate.so.1 => (0xb779f000) libz.so.1 => /usr/lib/libz.so.1 (0xb7780000) libpthread.so.0 => /lib/i686/cmov/libpthread.so.0 (0xb7767000) libjli.so => /usr/lib/jvm/java-6-openjdk/jre/bin/../lib/i386/jli/libjli.so (0xb7762000) libdl.so.2 => /lib/i686/cmov/libdl.so.2 (0xb775e000) libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb7603000) /lib/ld-linux.so.2 (0xb77a0000 $ ls /usr/lib/jvm/java-6-openjdk/jre/bin/../lib/i386/jli/ libjli.so However Java does work under root: $ sudo java -version java version "1.6.0_18" OpenJDK Runtime Environment (IcedTea6 1.8.7) (6b18-1.8.7-2~lenny1) OpenJDK Client VM (build 14.0-b16, mixed mode, sharing) How can I launch Java as a regular user without errors?

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  • Wrong java -version being reported

    - by Malachi
    I am running Windows 7 Professional x64 and have the following Java versions installed: x64 C:\Program Files\Java jdk1.6.0_24 jdk1.7.0_04 jdk1.7.0_07 jre6 jre7 x86 C:\Program Files (x86)\Java jre1.6.0_07 jre6 jre7 in my environment variables I have my PATH containing C:\Program Files\Java\jdk1.6.0_24\bin and JAVA_HOME set to C:\Program Files\Java\jdk1.6.0_24\bin However running java -version reports java version "1.7.0_07" Java(TM) SE Runtime Environment (build 1.7.0_07-b10) Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode) How is this the case when there is no reference to this version of Java in my Environment variables. Any help on this issue would be great as I am trying to run Apache ANT using Java 1.6.

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  • java.io.EOFException while writing and reading froma servlet

    - by mithun1538
    Hello everyone, I have the following code on the applet side: URL servlet = new URL(appletCodeBase, "FormsServlet?form=requestRoom"); URLConnection con = servlet.openConnection(); con.setDoOutput(true); con.setDoInput(true); con.setUseCaches(false); con.setRequestProperty("Content-Type", "application/octet-stream"); ObjectOutputStream out = new ObjectOutputStream(con.getOutputStream()); out.writeObject(user);//user is an object of a serializable class out.flush(); out.close(); ObjectInputStream in = new ObjectInputStream(con.getInputStream()); status = (String)in.readObject(); in.close(); if("success".equals("status")) { JOptionPane.showMessageDialog(rootPane, "Request submitted successfully."); } else { JOptionPane.showMessageDialog(rootPane, "ERROR! Request cannot be made at this time"); } In the servlet side I recieve the code as follows: form = request.getParameter("form"); if("requestRoom".equals(form)) { String fullName, eID, reason; UserRequestingRoom user; try { in = new ObjectInputStream(request.getInputStream()); user = (UserRequestingRoom)in.readObject(); fullName = user.getFullName(); eID = user.getEID(); reason = user.getReason(); Class.forName("com.mysql.jdbc.Driver"); Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/chat_applet","root",""); PreparedStatement statement = con.prepareStatement("INSERT INTO REQCONFROOM VALUES(\"" + fullName + "\",\"" + eID + "\",\"" + reason + "\")"); statement.execute(); out = new ObjectOutputStream(response.getOutputStream()); out.writeObject("success"); out.flush(); } catch (Exception e) { e.printStackTrace(); out = new ObjectOutputStream(response.getOutputStream()); out.writeObject("fail"); out.flush(); } } When I click on the button that calls the code in the applet side, I get the following error: java.io.EOFException at java.io.ObjectInputStream$PeekInputStream.readFully(Unknown Source) at java.io.ObjectInputStream$BlockDataInputStream.readShort(Unknown Source) at java.io.ObjectInputStream.readStreamHeader(Unknown Source) at java.io.ObjectInputStream.<init>(Unknown Source) at com.org.RequestRoomForm.requestActionPerformed(RequestRoomForm.java:151) **//Line 151 is "ObjectInputStream in..." line in the applet code** at com.org.RequestRoomForm.access$000(RequestRoomForm.java:7) at com.org.RequestRoomForm$1.actionPerformed(RequestRoomForm.java:62) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.setPressed(Unknown Source) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source) at javax.swing.JComponent.processMouseEvent(Unknown Source) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Window.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) Why am I getting this error? I have flushed when I output, I have closed the connections also, yet I get the error. Any reason for this?

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  • Java Polymorphism - Selecting correct method based on subtype

    - by Marty Pitt
    Hi Given the following Class and Service layer signatures: public class PersonActionRequest { PersonVO person // ... other fields } public class MyServiceLayerClass { public void requestAction(PersonActionRequest request) { PersonVO abstractPerson = request.getPerson(); // call appropriate executeAction method based on subclass of PersonVO } private void executeAction(PersonVO person) {} private void executeAction(EmployeeVO employee) {} private void executeAction(ManagerVO manager) {} private void executeAction(UnicornWranglerVO unicornWrangler) {} } As discussed here, java will select the best method based on type info at compile time. (Ie., it will always select executeAction(PersonVO person) ). What's the most appropriate way to select the correct method? The internet tells me that using instanceof gets me slapped. However, I don't see the appropraite way to select the method without explictly casting abstractPerson to one of the other concrete types. Thanks Marty

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  • Class Not found exception in JApplet.

    - by Nitesh Panchal
    Hello, I created a simple Applet using JApplet and everything seems to work fine but as soon i create an object of my userdefined class named ChatUser in my applet, i get this error :- SEVERE: java.lang.ClassNotFoundException: applet.ChatUser at com.sun.enterprise.loader.ASURLClassLoader.findClassData(ASURLClassLoader.java:713) at com.sun.enterprise.loader.ASURLClassLoader.findClass(ASURLClassLoader.java:626) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:604) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1575) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351) at misc.ChatClient.run(ChatClient.java:43) Any idea what can be wrong? It only happens when i create an object of any user defined class. Do i need to set some security settings or something? Please help :(

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  • Quickie Guide Getting Java Embedded Running on Raspberry Pi

    - by hinkmond
    Gary C. and I did a Bay Area Java User Group presentation of how to get Java Embedded running on a RPi. See: here. But, if you want the Quickie Guide on how to get Java up and running on the RPi, then follow these steps (which I'm doing right now as we speak, since I got my RPi in the mail on Monday. Woo-hoo!!!). So, follow along at home as I do the same steps here on my board... 1. Download the Win32DiskImager if you are on Windows, or use dd on a Linux PC: https://launchpad.net/win32-image-writer/0.6/0.6/+download/win32diskimager-binary.zip 2. Download the RPi Debian Wheezy image from here: http://files.velocix.com/c1410/images/debian/7/2012-08-08-wheezy-armel/2012-08-08-wheezy-armel.zip 3. Insert a blank 4GB SD Card into your Windows or Linux PC. 4. Use either Win32DiskImager or Linux dd to burn the unzipped image from #2 to the SD Card. 5. Insert the SD Card into your RPi. Connect an Ethernet cable to your RPi to your network. Connect the RPi Power Adapter. 6. The RPi will boot onto your network. Find its IP address using Windows Wireshark or Linux: sudo tcpdump -vv -ieth0 port 67 and port 68 7. ssh to your RPi: ssh <ip_addr_rpi> -l pi <Password: "raspberry"> 8. Download Java SE Embedded: http://www.oracle.com/technetwork/java/embedded/downloads/javase/index.html NOTE: First click accept, then choose the first bundle in the list: ARMv6/7 Linux - Headless EABI, VFP, SoftFP ABI, Little Endian - ejre-7u6-fcs-b24-linux-arm-vfp-client_headless-10_aug_2012.tar.gz 9. scp the bundle from #8 to your RPi: scp <ejre-bundle> pi@<ip_addr_rpi> 10. mkdir /usr/local, untar the bundle from #9 and rename (move) the ejre1.7.0_06 directory to /usr/local/java That's it! You are ready to roll with Java Embedded on your RPi. Hinkmond

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  • Loose Coupling and UX Patterns for Applications Integrations

    - by ultan o'broin
    I love that software architecture phrase loose coupling. There’s even a whole book about it. And, if you’re involved in enterprise methodology you’ll know just know important loose coupling is to the smart development of applications integrations too. Whether you are integrating offerings from the Oracle partner ecosystem with Fusion apps or applications coexistence scenarios, loose coupling enables the development of scalable, reliable, flexible solutions, with no second-guessing of technology. Another great book Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions tells us about loose coupling benefits of reducing the assumptions that integration parties (components, applications, services, programs, users) make about each other when they exchange information. Eliminating assumptions applies to UI development too. The days of assuming it’s enough to hard code a UI with linking libraries called code on a desktop PC for an office worker are over. The book predates PaaS development and SaaS deployments, and was written when web services and APIs were emerging. Yet it calls out how using middleware as an assumptions-dissolving technology “glue" is central to applications integration. Realizing integration design through a set of middleware messaging patterns (messaging in the sense of asynchronously communicating data) that enable developers to meet the typical business requirements of enterprises requiring integrated functionality is very Fusion-like. User experience developers can benefit from the loose coupling approach too. User expectations and work styles change all the time, and development is now about integrating SaaS through PaaS. Cloud computing offers a virtual pivot where a single source of truth (customer or employee data, for example) can be experienced through different UIs (desktop, simplified, or mobile), each optimized for the context of the user’s world of work and task completion. Smart enterprise applications developers, partners, and customers use design patterns for user experience integration benefits too. The Oracle Applications UX design patterns (and supporting guidelines) enable loose coupling of the optimized UI requirements from code. Developers can get on with the job of creating integrations through web services, APIs and SOA without having to figure out design problems about how UIs should work. Adding the already user proven UX design patterns (and supporting guidelines to your toolkit means ADF and other developers can easily offer much more than just functionality and be super productive too. Great looking application integration touchpoints can be built with our design patterns and guidelines too for a seamless applications UX. One of Oracle’s partners, Innowave Technologies used loose coupling architecture and our UX design patterns to create an integration for a customer that was scalable, cost effective, fast to develop and kept users productive while paving a roadmap for customers to keep pace with the latest UX designs over time. Innowave CEO Basheer Khan, a Fusion User Experience Advocate explains how to do it on the Usable Apps blog.

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