Search Results

Search found 44579 results on 1784 pages for 'oracle java'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 660/1784 | < Previous Page | 656 657 658 659 660 661 662 663 664 665 666 667  | Next Page >

  • 2D grid with multiple types of objects

    - by Alexandre P. Levasseur
    This is my first post here in programmers.stackexchange (I'm a regular on SO). I hope this isn't too general. I'm trying a simple project to learn Java from something I've seen done in the past. Basically, it's an AI simulation where there are herbivorous and carnivorous creatures and both must try to survive. The part I am trying to come up with is that of the board itself. Let's assume very simple rules. The board must be of size X by Y and only one element can be in one place at one time. For example, a critter cannot be in the same tile as a food block. There can be obstacles (rocks, trees..), there can be food, there can be critters of any type. Assuming these rules, what would be one good way to represent this situation ? This is what I came up with and want suggestions if possible: Use multiple levels of inheritance to represent all the different possible objects (AbstractObject - (NonMovingObject - (Food, Obstacle) , MovingObject - Critter - (Carnivorous, Herbivorous))) and use polymorphism in a 2D array to store the instances and still have access to lower level methods. Many thanks. Edit: Here is the graphic representation of the structure I have in mind.

    Read the article

  • Coherence Based WebLogic Server Session Management

    - by [email protected]
    Specifications Supported Configurations WebLogic Server 10.3.2( or 10.3.1 ) Coherence 3.5.2/463 If you use other verion above, then please check the following matrix:   WebLogic Server 9.2 MP1 Weblogic Server 10.3 WebLogic Smart Update Patch ID: AJQB Patch ID: 6W2W Minimum Coherence Release Level/MetaLink Patch ID 3.4.2 Patch 2-Patch ID:8429415 3.4.2 Patch6-Patch ID:11399293 Environment Variables %COHERENCE_HOME%: coherence installation directory %DOMAIN_HOME%: weblogic domain foler. Instructions We Will create to weblogic domains: domain_a, domain_b. To configure those domains with coherence-based session management . Then the changings of session variable value in one domain will propagate to another domain. Main Steps WebLogic Server create domain_a The process is ignored copy %COHERENCE_HOME%\lib\coherence.jar to %DOMAIN_HOME%\lib startup domain deploy %COHERENCE_HOME%\lib\coherence-web-spi.war as a Shared Library repeat step 1~4 at domain_b Coherence duplicate %COHERENCE_HOME%\bin\cache-server.cmd at the same folder and rename it to web-cache-server.cmd modify web-cache-server.cmd java -server -Xms512m -Xmx512m -cp %coherence_home%/lib/coherence.jar;%coherence_home%/lib/coherence-web-spi.war -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.cacheconfig=WEB-INF/classes/session-cache-config.xml -Dtangosol.coherence.session.localstorage=true com.tangosol.net.DefaultCacheServer startup web-cache-server.cmd Testing develop a web app  with OEPE or JDeveloper and implment functions: changing, viewing, listing  session variables. ( or download sample codes here ) modify weblogic.xml with following content: <?xml version="1.0" encoding="UTF-8"?> <wls:weblogic-web-app xmlns:wls=http://xmlns.oracle.com/weblogic/weblogic-web-app xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd http://xmlns.oracle.com/weblogic/weblogic-web-app http://xmlns.oracle.com/weblogic/weblogic-web-app/1.0/weblogic-web-app.xsd"> <wls:weblogic-version>10.3.2</wls:weblogic-version> <wls:context-root>CoherenceWeb</wls:context-root> <wls:library-ref> <wls:library-name>coherence-web-spi</wls:library-name> <wls:specification-version>1.0.0.0</wls:specification-version> <wls:exact-match>true</wls:exact-match> </wls:library-ref> </wls:weblogic-web-app> deploy the web app to domain_a and domain_b change session varaible vlaue at domain_a and check whethe if changed at domain_b References Using Oracle Coherence*Web 3.4.2 with Oracle WebLogic Server 10gR3 Oracle Coherence*Web 3.4.2 with Oracle WebLogic Server 10gR3

    Read the article

  • Nighthacking with James Gosling

    - by Yolande Poirier
    Java Evangelist Stephen Chin is back on the road for a new NightHacking Tour. He is meeting with James Gosling at Kona, Hawaii, the launch base of the Wave Glider. The Glider is an aquatic robot which communicates real-time data from the surface of the ocean. It runs on an ARM chip using Java SE Embedded.  "During this broadcast we will show some of the footage of his aquatic robots, talk through the technologies he is hacking on daily, and do Q&A with folks on the live chat" explains Stephen Chin.  Sign up for the live stream on Wednesday, October 23rd at:  8AM Hawaii Time 11AM PST 2PM EST 20:00 CET Follow @nighthackingtv for the next Nighthacking events

    Read the article

  • How does an optimizing compiler react to a program with nested loops?

    - by D.Singh
    Say you have a bunch of nested loops. public void testMethod() { for(int i = 0; i<1203; i++){ //some computation for(int k=2; k<123; k++){ //some computation for(int j=2; j<12312; j++){ //some computation for(int l=2; l<123123; l++){ //some computation for(int p=2; p<12312; p++){ //some computation } } } } } } When the above code reaches the stage where the compiler will try to optimize it (I believe it's when the intermediate language needs to converted to machine code?), what will the compiler try to do? Is there any significant optimization that will take place? I understand that the optimizer will break up the loops by means of loop fission. But this is only per loop isn't it? What I mean with my question is will it take any action exclusively based on seeing the nested loops? Or will it just optimize the loops one by one? If the Java VM complicates the explanation then please just assume that it's C or C++ code.

    Read the article

  • Distinguishing repetitive code with the same implementation

    - by KyelJmD
    Given this sample code import java.util.ArrayList; import blackjack.model.items.Card; public class BlackJackPlayer extends Player { private double bet; private Hand hand01 = new Hand(); private Hand hand02 = new Hand(); public void addCardToHand01(Card c) { hand01.addCard(c); } public void addCardToHand02(Card c) { hand02.addCard(c); } public void bustHand01() { hand01.setBust(true); } public void bustHand02() { hand02.setBust(true); } public void standHand01() { hand01.setStand(true); } public void standHand02() { hand02.setStand(true); } public boolean isHand01Bust() { return hand01.isBust(); } public boolean isHand02Bust() { return hand02.isBust(); } public boolean isHand01Standing() { return hand01.isStanding(); } public boolean isHand02Standing() { return hand02.isStanding(); } public int getHand01Score(){ return hand01.getCardScore(); } public int getHand02Score(){ return hand02.getCardScore(); } } Is this considered as a repetitive code? providing that each method is operating a seperate field but doing the same implementation ? Note that hand01 and hand02 should be distinct. if this is considered as repetitive code, how would I address this? providing that each hand is a seperate entity

    Read the article

  • Static objects and concurrency in a web application

    - by Ionut
    I'm developing small Java Web Applications on Tomcat server and I'm using MySQL as my database. Up until now I was using a connection singleton for accessing the database but I found out that this will ensure just on connection per Application and there will be problems if multiple users want to access the database in the same time. (They all have to make us of that single Connection object). I created a Connection Pool and I hope that this is the correct way of doing things. Furthermore it seems that I developed the bad habit of creating a lot of static object and static methods (mainly because I was under the wrong impression that every static object will be duplicated for every client which accesses my application). Because of this all the Service Classes ( classes used to handle database data) are static and distributed through a ServiceFactory: public class ServiceFactory { private static final String JDBC = "JDBC"; private static String impl; private static AccountService accountService; private static BoardService boardService; public static AccountService getAccountService(){ initConfig(); if (accountService == null){ if (impl.equalsIgnoreCase(JDBC)){ accountService = new JDBCAccountService(); } } return accountService; } public static BoardService getBoardService(){ initConfig(); if (boardService == null){ if (impl.equalsIgnoreCase(JDBC)){ boardService = new JDBCBoardService(); } } return boardService; } private static void initConfig(){ if (StringUtil.isEmpty(impl)){ impl = ConfigUtil.getProperty("service.implementation"); // If the config failed initialize with standard if (StringUtil.isEmpty(impl)){ impl = JDBC; } } } This was the factory class which, as you can see, allows just one Service to exist at any time. Now, is this a bad practice? What happens if let's say 1k users access AccountService simultaneously? I know that all this questions and bad practices come from a bad understanding of the static attribute in a web application and the way the server handles this attributes. Any help on this topic would be more than welcomed. Thank you for your time!

    Read the article

  • Java default Integer value is int

    - by Chris Okyen
    My code looks like this import java.util.Scanner; public class StudentGrades { public static void main(String[] argv) { Scanner keyboard = new Scanner(System.in); byte q1 = keyboard.nextByte() * 10; } } It gives me an error "Type mismatch: cannot convert from int to byte." Why the heck would Java store a literal operand that is small enough to fit in a byte,. into a int type? Do literals get stored in variables/registers before the ALU performs arithmatic operations.

    Read the article

  • How is IntelliJ better than Eclipse?

    - by NickC
    I know there have been questions like What is your favorite editor/IDE?, but none of them have answered this question: Why spend the money on IntelliJ when Eclipse is free? I'm personally a big IntelliJ fan, but I haven't really tried Eclipse. I've used IntelliJ for projects that were Java, JSP, HTML/CSS, Javascript, PHP, and Actionscript, and the latest version, 9, has been excellent for all of them. Many coworkers in the past have told me that they believe Eclipse to be "pretty much the same" as IntelliJ, but, to counter that point, I've occasionally sat behind a developer using Eclipse who's seemed comparably inefficient (to accomplish roughly the same task), and I haven't experienced this with IntelliJ. They may be on par feature-by-feature but features can be ruined by a poor user experience, and I wonder if it's possible that IntelliJ is easier to pick up and discover time-saving features. For users who are already familiar with Eclipse, on top of the real cost of IntelliJ, there is also the cost of time spent learning the new app. Eclipse gets a lot of users who simply don't want to spend $250 on an IDE. If IntelliJ really could help my team be more productive, how could I sell it to them? For those users who've tried both, I'd be very interested in specific pros or cons either way.

    Read the article

  • Learning Smalltalk as a Java programmer

    - by VeeKay
    I am a Java programmer willing to learn smalltalk. As of now I am working within the Pharo environment. Trying to switch from Java to Smalltalk is being a bit of a headache, honestly. I would like to learn Smalltalk with the help of a code base available but I believe that there aren't many Smalltalk example projects available on the web. So are there any particular websites that involve learning Smalltalk (Pharo) based on some simple examples? Currently I am taking the help of Pharo By Example doc but I feel it is just not sufficient for me. I am looking for more some code examples in Smalltalk.

    Read the article

  • How to deal with static utility classes when designing for testability

    - by Benedikt
    We are trying to design our system to be testable and in most parts developed using TDD. Currently we are trying to solve the following problem: In various places it is necessary for us to use static helper methods like ImageIO and URLEncoder (both standard Java API) and various other libraries that consist mostly of static methods (like the Apache Commons libraries). But it is extremely difficult to test those methods that use such static helper classes. I have several ideas for solving this problem: Use a mock framework that can mock static classes (like PowerMock). This may be the simplest solution but somehow feels like giving up. Create instantiable wrapper classes around all those static utilities so they can be injected into the classes that use them. This sounds like a relatively clean solution but I fear we'll end up creating an awful lot of those wrapper classes. Extract every call to these static helper classes into a function that can be overridden and test a subclass of the class I actually want to test. But I keep thinking that this just has to be a problem that many people have to face when doing TDD - so there must already be solutions for this problem. What is the best strategy to keep classes that use these static helpers testable?

    Read the article

  • How do I apply different probability factors in an algorithm for a cricket simulation game?

    - by Komal Sharma
    I am trying to write the algorithm for a cricket simulation game which generates runs on each ball between 0 to 6. The run rate or runs generated changes when these factors come into play like skill of the batsman, skill of the bowler, target to be chased. Wickets left. If the batsman is skilled more runs will be generated. There will be a mode of play of the batsman aggressive, normal, defensive. If he plays aggressive chances of getting out will be more. If the chasing target is more the run rate should be more. If the overs are final the run rate should be more. I am using java random number function for this. The code so far I've written is public class Cricket { public static void main(String args[]) { int totalRuns=0; //i is the balls bowled for (int i = 1; i <= 60 ; i++) { int RunsPerBall = (int)(Math.random()*6); //System.out.println(Random); totalRuns=totalRuns+RunsPerBall; } System.out.println(totalRuns); } } Can somebody help me how to apply the factors in the code. I believe probability will be used with this. I am not clear how to apply the probability of the factors stated above in the code.

    Read the article

  • Blocking row navigation in af:table , synchronize row selection with model in case of validation failure- Oracle ADF by Ashish Awasthi

    - by JuergenKress
    In ADF we often work on editable af:table and when we use af:table to insert ,update or delete data, it is normal to use some validation but problem is when some validation failure occurs on page (in af:table) ,still we can select another row and it shows as currently selected Row this is a bit confusing for user as Row Selection of af:table is not synchronized with model or binding layer See Problem- i have an editable table on page Read the complete article here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: ADF,Ashish Awasthi,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

    Read the article

  • Designing application flow

    - by Umesh Awasthi
    I am creating a web application in java where I need to mock the following flow. When user trigger a certain process (add product to cart), I need to pass through following steps Need to see in HTTP Session if user is logged in. Check HTTP Session if shopping cart is there If user exist in HTTP Session and his/her cart do not exist in HTTP Session Get user cart from the database. add item to cart and save it to HTTP session and update cart in DB. If cart does not exist in DB, create new cart and and save in it HTTP Session. Though I missed a lot of use cases here (do not want question length to increase a lot), but most of the flow will be same as I described in above steps. My flow will start from the Controller and will go towards Service Layer and than ends up in the DAO layer. Since there will be a lot of use cases where I need to check HTTP session and based on that need to call Service layer, I was planning to add a Facade layer which should be responsible to do this for me like checking Session and interacting with Service layer. Please suggest if this is a valid approach or any other best approach can be implemented here? One more point where I am confused is how to handle HTTP session in facade layer? do I need to pass HTTP session object each time I call my Facade or any other approach can be used here?

    Read the article

  • Stack Trace Logger [migrated]

    - by Chris Okyen
    I need to write a parent Java class that classes using recursion can extend. The parent class will be be able to realize whenever the call stack changes ( you enter a method, temporarily leave it to go to another method call, or you are are finsihed with the method ) and then print it out. I want it to print on the console, but clear the console as well every time so it shows the stack horizantaly so you can see the height of each stack to see what popped off and what popped on... Also print out if a baseline was reached for recursive functions. First. How can I using the StackTraceElements and Thread classes to detect automatically whenever the stack has popped or pushed an element on without calling it manually? Second, how would I do the clearing thing? For instance , if I had the code: public class recursion(int i) { private static void recursion(int i) { if( i < 10) System.out.println('A'); else { recursion(i / 10 ); System.out.println('B'); } } public static void main(String[] argv) { recursion(102); } } It would need to print out the stack when entering main(), when entering recursion(102) from main(), when it enters recursion(102 / 10), which is recursion(10), from recursion(102), when it enters recursion(10 / 10), which is recursion(1) from recursion(10). Print out a message out when it reaches the baseline recursion(1).. then print out the stacks of reversed revisitation of function recursion(10), recursion(102) and main(). finally print out we are exiting main().

    Read the article

  • Implementing MVC pattern in SWT application

    - by Pradeep Simha
    I am developing an SWT application (it's basically an Eclipse plugin, so I need to use SWT). Currently my design is as follows: Model: In model, I have POJOs which represents the actual fields in views. View: It is a dumb layer, it contains just UI and contains no logic (not even event handlers) Controller: It acts as a mediator b/w those two layers. Also it is responsible for creating view layer, handling events etc. Basically I have created all of the controls in view as a static like this public static Button btnLogin and in controller I have a code like this: public void createLoginView(Composite comp) { LoginFormView.createView(comp); //This createView method is in view layer ie LoginFormView LoginFormView.btnLogin.addSelectionListener(new SelectionListener() { //Code goes here }); } Similalrly I have done for other views and controls. So that in main class and other classes I am calling just createLoginView of controller. I am doing similar thing for other views. So my question, is what I am doing is correct? Is this design good? Or I should have followed any other approach. Since I am new to SWT and Eclipse plugin development (basically I am Java EE developer having 4+ years of exp). Any tips/pointers would be appreciated.

    Read the article

  • How to Handle frame rates and synchronizing screen repaints

    - by David Kroukamp
    I would first off say sorry if the title is worded incorrectly. Okay now let me give the scenario I'm creating a 2 player fighting game, An average battle will include a Map (moving/still) and 2 characters (which are rendered by redrawing a varying amount of sprites one after the other). Now at the moment I have a single game loop limiting me to a set number of frames per second (using Java): Timer timer = new Timer(0, new AbstractAction() { @Override public void actionPerformed(ActionEvent e) { long beginTime; //The time when the cycle begun long timeDiff; //The time it took for the cycle to execute int sleepTime; //ms to sleep (< 0 if we're behind) int fps = 1000 / 40; beginTime = System.nanoTime() / 1000000; //execute loop to update check collisions and draw gameLoop(); //Calculate how long did the cycle take timeDiff = System.nanoTime() / 1000000 - beginTime; //Calculate sleep time sleepTime = fps - (int) (timeDiff); if (sleepTime > 0) {//If sleepTime > 0 we're OK ((Timer)e.getSource()).setDelay(sleepTime); } } }); timer.start(); in gameLoop() characters are drawn to the screen ( a character holds an array of images which consists of their current sprites) every gameLoop() call will change the characters current sprite to the next and loop if the end is reached. But as you can imagine if a sprite is only 3 images in length than calling gameLoop() 40 times will cause the characters movement to be drawn 40/3=13 times. This causes a few minor anomilies in the sprited for some charcters So my question is how would I go about delivering a set amount of frames per second in when I have 2 characters on screen with varying amount of sprites?

    Read the article

  • Constructor vs setter validations

    - by Jimmy
    I have the following class : public class Project { private int id; private String name; public Project(int id, String name, Date creationDate, int fps, List<String> frames) { if(name == null ){ throw new NullPointerException("Name can't be null"); } if(id == 0 ){ throw new IllegalArgumentException("id can't be zero"); } this.name = name; this.id = id; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } I have three questions: Do I use the class setters instead of setting the fields directly. One of the reason that I set it directly, is that in the code the setters are not final and they could be overridden. If the right way is to set it directly and I want to make sure that the name filed is not null always. Should I provide two checks, one in the constructor and one in the setter. I read in effective java that I should use NullPointerException for null parameters. Should I use IllegalArgumentException for other checks, like id in the example.

    Read the article

  • Representing and executing simple rules - framework or custom?

    - by qtips
    I am creating a system where users will be able to subscribe to events, and get notified when the event has occured. Example of events can be phone call durations and costs, phone data traffic notations, and even stock rate changes. Example of events: customer 13532 completed a call with duration 11:45 min and cost $0.4 stock rate for Google decreased with 0.01% Customers can subscribe to events using some simple rules e.g. When stock rate of Google decreases more than 0.5% When the cost of a call of my subscription is over $1 Now, as the set of different rules is currently predefined, I can easily create a custom implemention that applies rules to an event. But if the set of rules could be much larger, and if we also allow for custom rules (e.g. when stock rate of Google decreses more than 0.5% AND stock rate of Apple increases with 0.5%), the system should be able to adapt. I am therefore thinking of a system that can interpret rules using a simple grammer and then apply them. After som research I found that there exists rule-based engines that can be used, but I am unsure as they seem too complicated and may be a little overkill for my situation. Is there a Java framework suited for this area? Should we use framework, a rule engine, or should we create something custom? What are the pros and cons?

    Read the article

  • Oracle dans une nouvelle bataille juridique sur l'utilisation du Java avec une société suisse d'édition de logiciels pour mobiles

    Oracle dans une nouvelle bataille juridique sur l'utilisation du Java Avec une société suisse d'édition de logiciels pour mobiles Depuis l'acquisition de Sun par Oracle, les droits de propriété intellectuelle d'Oracle sur Java sont au coeur d'un procès avec Google. Ces droits viennent de donner lieu à une autre procédure. La société suisse d'édition de logiciels pour mobiles Myriad a en effet annoncé hier avoir lancé des poursuites judiciaires contre Oracle. La firme a annoncé qu'elle avait déposé plainte auprès du tribunal du district du Delaware. Une plainte qui accuse Oracle d'avoir violé ses obligations dans le cadre de l'accord JSPA (Java Spécification Participation Ag...

    Read the article

  • The road to become a programmer [closed]

    - by user68991
    I'm looking for a 'career' change, I don't actually have a career at the moment since I haven't been able to find a job since I graduated with a degree in Materials Engineering. One of my loves has always been computers and programming, though I have never studied it seriously. When I was 11 I wrote a very basic graphical 'game' using notepad and HTML, where I drew each possible position of the main character on the different 'maze' level in MSPaint, using pictures of arrows as links to a new page with the character in a new position, and various other buttons would pop up 'search box', 'press button' etc. At the time I thought this was an amazing achievement of my programming skills. I've used a little bit of FORTRAN 90 whilst I was at university, which rekindled my interest in programming. When I was a kid I mainly used C and HTML, but only very basically as my 'game' suggests. I want to learn a new programming language, I'm not entirely sure where I want to go with it, but the number one contender at the moment is android apps. I'm looking at learning Java, but I've read that it's a difficult place to begin with; so I've also looked at learning Visual Basic, which I believe is also object oriented(?) but a little easier to understand? (not that I know what an object is anyway). Any information people could give me regarding which language to learn, and if there are any good online tutorial for that language I'd really appreciate it. Some of the tutorials I've used so far are full or jargon I can't understand. Also, I'm not afraid of maths having got an engineering degree. Thanks in advance for any help/advice. James

    Read the article

  • Slick2D + LWJGL collision system

    - by Connor W
    So I've been learning java for a while and have explored slick and lwjgl before but went away from using Slick for a while. But I've recently gone back to using it (as I'm making a platformer and Tiled will be really helpful). But here's where my problems begin: collision. I have a player polygon and I check to see if it's colliding with my tiled map with this method: public static boolean playerCollisionWith() { for(int i = 0; i < Blockmap.entities.size(); i++) { Block entity1 = (Block) Blockmap.entities.get(i); if(playerPoly.intersects(entity1.poly)) { return true; } } return false; } This would work normally but I'm using a different method for movement. Instead of just adding a speed variable to the player's x axis. I move like this: if(Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) { speedX = Math.min(5, speedX + 1); moving = true; playerPoly.setX(x); if(playerCollisionWith()) { speedX = -5; playerPoly.setX(x); } } That Math.min call is what is messing me up =. I can't just call speedX = -5, because when I do the player "bounces" when the right mouse button is down and it's colliding. Bounces as in flashes back and forth REALLY quickly. But I don't really know how I would make it so that collisions on the y axis would work either, whether the player is jumping or not. So if I could get some help with how to fix this problem that would be great. Thank you for the help!

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 656 657 658 659 660 661 662 663 664 665 666 667  | Next Page >