Search Results

Search found 48839 results on 1954 pages for 'java ee next'.

Page 325/1954 | < Previous Page | 321 322 323 324 325 326 327 328 329 330 331 332  | Next Page >

  • Java Inheritance doubt in parameterised collection

    - by Gala101
    It's obvious that a parent class's object can hold a reference to a child, but does this not hold true in case of parameterised collection ?? eg: Car class is parent of Sedan So public void doSomething(Car c){ ... } public void caller(){ Sedan s = new Sedan(); doSomething(s); } is obviously valid But public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection<Sedan> s = new ArrayList<Sedan>(); doSomething(s); } Fails to compile Can someone please point out why? and also, how to implement such a scenario where a function needs to iterate through a Collection of parent objects, modifying only the fields present in parent class, using parent class methods, but the calling methods (say 3 different methods) pass the collection of three different subtypes.. Ofcourse it compiles fine if I do as below: public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection s = new ArrayList<Sedan>(); doSomething(s); }

    Read the article

  • Java-Recursion: When does statements after a recursive method call executes

    - by Ruru Morlano
    When are statements after the method call itself going to execute? private void inorderHelper(TreeNode node) { if ( node==null ) return; inorderHelper(node.leftNode); System.out.printf("%d", node.data); inorderHelper(node.rigthNode); } All I can see is that the line of codes inorderHelper(node.leftNode) will continue to iterate until node == null and the method terminates immediately before node.data is printed. I think that I didn't get well recursion but all examples I can find doesn't have statements after the recursive call. All I want to know is when are statements like System.out.printf("%d",node.data) going to execute before the method return?

    Read the article

  • Can you help with regular expressions in Java?

    - by Matt
    I have a bunch of strings which may of may not have random symbols and numbers in them. Some examples are: contains(reserved[j])){ close(); i++){ letters[20]=word I want to find any character that is NOT a letter, and replace it with a white space, so the above examples look like: contains reserved j close i letters word What is the best way to do this?

    Read the article

  • java objects, shared variables

    - by raven
    hello, I have a simple question here. If I declare a variable inside an object which was made [declared] in the main class, like this: public static int number; ( usually I declare it like this : private int number; ) can it be used in a different object which was also made [declared] in the main class? btw I do not care about security atm, I just want to make something work, don't care about protection)

    Read the article

  • Java regular expression: how to include '-'

    - by changed
    I am using this pattern and matching a string. String s = "//name:value /name:value"; if (s.matches("(//?\\s*\\w+:\\w+\\s*)+")) { // it fits } This works properly. But if I want to have a string like "/name-or-address:value/name-or-address:value" which has this '-' in second part, it doesn't work. I am using \w to match A-Za-z_, but how can I include - in that?

    Read the article

  • Java: Friendlier way to get an instance of FontMetrics

    - by Martijn Courteaux
    Hi people, Is there a friendlier way to get an instance of FontMetrics than FontMetrics fm = Graphics.getFontMetrics(Font); I hate this way because of the following example: If you want to create in a game a menu and you want all the menuitems in the center of the screen you need fontmetrics. But, mostly, menuitems are clickable. So I create an array of Rectangles and all the rectangles fits around the items, so when the mouse is pressed, I can simply use for (int i = 0; i < rects.length; i++) if (rects[i].contains(mouseX, mouseY)) { ... } But to create the rects I also need FontMetrics for their coordinates. So this mean that I have to construct all my rectangles in the paint-method of my menu. So I want a way to get the FontMetrics so I can construct the Rectangles in a method called by the constructor. Hope you understand. Thanks in advance.

    Read the article

  • Regular expressions in java

    - by rookie
    String s= "(See <a href=\"/wiki/Grass_fed_beef\" title=\"Grass fed beef\" " + "class=\"mw-redirect\">grass fed beef.) They have been used for " + "<a href=\"/wiki/Paper\" title=\"Paper\">paper-making since " + "2400 BC or before."; In the string above I have inter-mixed html with text. Well the requirement is that the output looks like:- They have been used for paper-making since 2400 BC or before. Could some one help me with a generic regular expression that would produce the desired output from the given input? Thanks in advance!

    Read the article

  • Java Flow Control Problem

    - by Kyle_Solo
    I am programming a simple 2d game engine. I've decided how I'd like the engine to function: it will be composed of objects containing "events" that my main game loop will trigger when appropriate. A little more about the structure: Every GameObject has an updateEvent method. objectList is a list of all the objects that will receive update events. Only objects on this list have their updateEvent method called by the game loop. I’m trying to implement this method in the GameObject class (This specification is what I’d like the method to achieve): /** * This method removes a GameObject from objectList. The GameObject * should immediately stop executing code, that is, absolutely no more * code inside update events will be executed for the removed game object. * If necessary, control should transfer to the game loop. * @param go The GameObject to be removed */ public void remove(GameObject go) So if an object tries to remove itself inside of an update event, control should transfer back to the game engine: public void updateEvent() { //object's update event remove(this); System.out.println("Should never reach here!"); } Here’s what I have so far. It works, but the more I read about using exceptions for flow control the less I like it, so I want to see if there are alternatives. Remove Method public void remove(GameObject go) { //add to removedList //flag as removed //throw an exception if removing self from inside an updateEvent } Game Loop for(GameObject go : objectList) { try { if (!go.removed) { go.updateEvent(); } else { //object is scheduled to be removed, do nothing } } catch(ObjectRemovedException e) { //control has been transferred back to the game loop //no need to do anything here } } // now remove the objects that are in removedList from objectList 2 questions: Am I correct in assuming that the only way to implement the stop-right-away part of the remove method as described above is by throwing a custom exception and catching it in the game loop? (I know, using exceptions for flow control is like goto, which is bad. I just can’t think of another way to do what I want!) For the removal from the list itself, it is possible for one object to remove one that is farther down on the list. Currently I’m checking a removed flag before executing any code, and at the end of each pass removing the objects to avoid concurrent modification. Is there a better, preferably instant/non-polling way to do this?

    Read the article

  • update attribute a element in arraylist on java ?

    - by tiendv
    I have a class Class TextChunks extends Token { ArrayList<Token> arrt = new ArrayList<Token>(); } extent fron class : class Token { String s; int frequency = 1 ;// Tern frequency in TextChunk } Now in token i have arraylist token , i want to update attribute frequency of token in Texchunks when have more than one tokens same . For clearly a give a example : Texchunks :" in particular in domain and range in some " So have 8 token : in,particular,in,domain,and,range,in,some i want update attribute frequency for token : in this example when i get attribute frequency of token "in" must return 3 it mean when i call : get frequency of Texchunks when dislay : in 3 particular 1 in 3 domain 1 and 1 range 1 in 3 some 1 here my code : public TextChunks updateFrequencyOfTokenInTextChunks (TextChunks tc) throws CloneNotSupportedException { TextChunks result = (TextChunks) tc.clone(); for (int i =0 ; i< result.arrt.size() ; i++ ){ int j=i+1; if (result.arrt.get(i).compareTwoToken(result.arrt.get(j))== true ) { // help here how to update attribute result.arrt.get(i) // and result.arrt.get(J) = ++ and } } return tc; } Thanks in advandce

    Read the article

  • Java Disabled JLabel Reports Mouse Clicked

    - by ikurtz
    colLabels[i].addMouseListener(new MyAdapter()); private class MyAdapter extends MouseAdapter { @Override public void mouseClicked(MouseEvent event) { ColJLabel colJLabel = (ColJLabel)event.getComponent(); System.out.println(colJLabel.ColID); setColumnHeader(false); } } colLabels[i].setEnabled(flag); The situation is this: Mouse clicks are trapped correctly but when i have the JLabel (ColJLabel) control disabled it still reports mouse clicks. How can I make so that mouse clicks are only reported when the control is enabled? Thanks.

    Read the article

  • Dynamically assembling SQL queries in Java

    - by kd
    What is the best way to assemble an SQL query with join conditions dynamically? I don't want to hard code the query for each different condition on a webpage or a set of webpages. Is it even feasible? I got as far as being able to assemble simple queries but i got stumped when i needed to insert join conditions, i.e. how to figure out dependencies for joins etc.

    Read the article

  • can this keyword be used in an abstract class in java

    - by Reddy
    I tried with below example, it is working fine. I expected it to pick sub-class's value since object won't be created for super class (as it is abstract). But it is picking up super class's field value only. Please help me understand what is the concepts behind this? abstract class SuperAbstract { private int a=2; public void funA() { System.out.println("In SuperAbstract: this.a "+a); } } class SubClass extends SuperAbstract { private int a=34; } I am calling new SubClass.funA(); I am expecting it to print 34, but it is printing 2.

    Read the article

  • java table question

    - by kate
    hello i have a issue and i want your help i have a table which is called citylink[10][2] and i want to make a check before i move on in my code if it's full to continue if it's not to break!!i know that i should use an if loop but i don't know what to put inside it!!

    Read the article

  • Need to split a string into two parts in java

    - by Reddy
    I have a string which contains a contiguous chunk of digits and then a contiguous chunk of characters. I need to split them into two parts (one integer part, and one string). I tried using String.split("\D", 1), but it is eating up first character. I checked all the String API and didn't find a suitable method. Is there any method for doing this thing?

    Read the article

  • Covariant return types in Java enums

    - by Kelvin Chung
    As mentioned in another question on this site, something like this is not legal: public enum MyEnum { FOO { public Integer doSomething() { return (Integer) super.doSomething(); } }, BAR { public String doSomething() { return (String) super.doSomething(); } }; public Object doSomething(); } This is due to covariant return types apparently not working on enum constants (again breaking the illusion that enum constants are singleton subclasses of the enum type...) So, how about we add a bit of generics: is this legal? public enum MyEnum2 { FOO { public Class<Integer> doSomething() { return Integer.class; } }, BAR { public Class<String> doSomething() { return String.class; } }; public Class<?> doSomething(); } Here, all three return Class objects, yet the individual constants are "more specific" than the enum type as a whole...

    Read the article

  • Download Large Files using java

    - by angelina
    Dear All, I M building a application in which i want to download large files on handset (mobile),but if size of file is large i m getting exception socket exception-broken pipe . inputStream = new FileInputStream(path); byte[] buffer = new byte[1024]; int bytesRead = 0; do { bytesRead = inputStream.read(buffer, offset, buffer.length); resp.getOutputStream().write(buffer, 0, bytesRead); } while (bytesRead == buffer.length); resp.getOutputStream().flush(); }

    Read the article

  • Calling class in Java after editing file used in as source for table

    - by user2892290
    I'm currently working on a project, I'll try to subrscibe first. I save data into text file, that I use as a source for browser of that data. The browser is based on table that contains the data. I have to rewrite the source file everytime I delete or edit data. That's where the problem comes in. After deleting or editing data I call a method to create the table again, but the table never creates. Is it possibly made by editing the file and calling the method right after that? If I restart my app the table is successfully created with right data. Take in note that I don't get any error message. This is the method I use for loading data from source file: try (BufferedReader input1 = new BufferedReader(new FileReader("./src/data.src"))) { int lines = 0; while (input1.read() != -1) { if (!(input1.readLine()).equals("")) { lines++; } } input1.close(); if (lines == 0) { JOptionPane.showMessageDialog(null, "No data to load, create a note first!"); new Writer().build(frame); } else { try (BufferedReader input = new BufferedReader(new FileReader("./src/data.src"))) { Game[] g = new Game[lines]; String currentLine; String[] help; int counter = 0; while (lines > 0) { currentLine = input.readLine(); help = currentLine.split("#"); g[counter] = new Game(help[0],help[1], help[2], help[3], help[4], help[5], help[6], help[7], help[8], help[9]); counter++; lines--; } input.close(); final JButton bButton = new backButton().create(frame, mPanel); build(g, frame, bButton); mPanel.add(panel); mPanel.add(panel2); mPanel.add(searchPanel); mPanel.add(bButton); bButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { frame.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR)); panel.removeAll(); frame.setCursor(Cursor.getDefaultCursor()); } }); mPanel.setPreferredSize(new Dimension(1000, 750)); panel.setBorder(new EmptyBorder(10, 10, 10, 10)); frame.setLayout(new FlowLayout()); frame.add(mPanel); frame.pack(); JMenuBar menuBar = new Menu().create(frame, mPanel); frame.setJMenuBar(menuBar); frame.setVisible(true); Rectangle rec = GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds(); int width = (int) rec.getWidth(); int height = (int) rec.getHeight(); frame.setBounds(1, 3, width, height); frame.addComponentListener(new ComponentAdapter() { @Override public void componentMoved(ComponentEvent e) { frame.setLocation(1, 3); } }); And this is the method I use for creating the table: String[][] tableData = new String[g.length][9]; for (int i = 0; i < tableData.length; i++) { tableData[i][0] = g[i].getChampion(); tableData[i][1] = g[i].getRole(); tableData[i][2] = g[i].getEnemy(); tableData[i][3] = g[i].getDifficulty(); tableData[i][4] = g[i].getResult(); tableData[i][5] = g[i].getScore(); tableData[i][6] = g[i].getGameType(); tableData[i][7] = g[i].getPoints(); tableData[i][8] = g[i].getLeague(); } final JLabel searchLabel = new JLabel("Search for champion played."); final JButton searchButton = new JButton("Search"); final JTextField searchText = new JTextField(20); frame.setTitle("LoL Notepad - reading your notes"); JTable table = new JTable(tableData, columnNames); final JScrollPane scrollPane = new JScrollPane(table); scrollPane.setPreferredSize(new Dimension(980, 500)); panel2.setPreferredSize(new Dimension(1000, 550)); panel2.setVisible(false); panel2.setBorder(new EmptyBorder(10, 10, 10, 10)); panel3.setVisible(false); panel.setLayout(new FlowLayout()); panel.add(scrollPane); searchPanel.add(searchLabel); searchPanel.add(searchText); searchPanel.add(searchButton); searchButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { try { frame.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR)); search(g, searchText.getText(), frame, bButton); frame.setCursor(Cursor.getDefaultCursor()); } catch (IOException ex) { Logger.getLogger(Reader.class.getName()).log(Level.SEVERE, null, ex); } } }); table.addMouseListener(new MouseAdapter() { @Override public void mousePressed(MouseEvent e) { if (e.getClickCount() == 1) { JTable target = (JTable) e.getSource(); panel.setVisible(false); searchPanel.setVisible(false); bButton.setVisible(false); int row = target.getSelectedRow(); specific(row, g, frame, bButton); } } });

    Read the article

  • Java Swing UI Changing Method

    - by vigilant
    I would like to use Swing to program a simple learning game. I am wondering what would be best way to switch between UI screens. For example, I would have a screen for the Main Menu, and then when the user presses a button on that screen, I would swap out the whole screen for a completely different one. Then, arbitrary screens can be swapped in at any moment, and all of their event handlers would be reactivated while the inactive screen's event handlers will be deactivated. What type of Swing component/control would I use for each of the 'screens'. Is this even doable?

    Read the article

  • Java BCEL creating method with sipush?

    - by user1446924
    Well, I'm trying to recreate this method : public int getBaseX() { return this.x + 10000; } and it returns these instructions 0 aload_0 1 getfield #18 <TestClass.x> 4 sipush 10000 7 iadd 8 ireturn Now I'm having trouble withe the sipush, iadd. ClassGen injCG = cg; ConstantPoolGen cpg = injCG.getConstantPool(); InstructionList il = new InstructionList(); MethodGen mg = new MethodGen(Constants.ACC_PUBLIC, f.getType(), Type.NO_ARGS, null, name, injCG.getClassName(), il, cpg); InstructionFactory instrF = new InstructionFactory(injCG, cpg); if (!f.isStatic()) il.append(new org.apache.bcel.generic.ALOAD(0)); il.append(instrF.createFieldAccess(cg.getClassName(), f.getName(), f.getType(), (f.isStatic() ? Constants.GETSTATIC : Constants.GETFIELD))); il.append(InstructionFactory.createPop(1000)); il.append(InstructionFactory.createReturn(f.getType())); //il.append(InstructionFactory.createReturn(f.getType()), InstructionFactory.createDup(1000)); mg.setMaxLocals(); mg.setMaxStack(); injCG.addMethod(mg.getMethod()); that's what I have tried, but failed.

    Read the article

  • Bizzare Java invalid Assignment Operator Error

    - by Kay
    public class MaxHeap<T extends Comparable<T>> implements Heap<T>{ private T[] heap; private int lastIndex; private static final int defaultInitialCapacity = 25; public void add(T newItem) throws HeapException{ if (lastIndex < Max_Heap){ heap[lastIndex] = newItem; int place = lastIndex; int parent = (place – 1)/2; //ERROR HERE********** while ( (parent >=0) && (heap[place].compareTo(heap[parent])>0)){ T temp = heap[place]; heap[place] = heap[parent]; heap[parent] = temp; place = parent; parent = (place-1)/2; }else { throw new HeapException(“HeapException: Heap full”); } } } Eclipse complains that there is a: "Syntax error on token "Invalid Character", invalid AssignmentOperator" With the red line beneath the '(place-1)' There shouldn't be an error at all since it's just straight-forward arithmetic. Or is it not that simple?

    Read the article

  • Java Generics error when implementing Hibernate message interpolator

    - by Jayaprakash
    Framework: Spring, Hibernate. O/S: Windows I am trying to implement hibernate's Custom message interpolator following the direction of this Link. When implementing the below class, it gives an error "Cannot make a static reference to the non-static type Locale". public class ClientLocaleThreadLocal<Locale> { private static ThreadLocal tLocal = new ThreadLocal(); public static void set(Locale locale) { tLocal.set(locale); } public static Locale get() { return tLocal.get(); } public static void remove() { tLocal.remove(); } } As I do not know generics enough, not sure how is being used by TimeFilter class below and the purpose of definition in the above class. public class TimerFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest req, ServletResponse res, FilterChain filterChain) throws IOException, ServletException { try { ClientLocaleThreadLocal.set(req.getLocale()); filterChain.doFilter(req, res); }finally { ClientLocaleThreadLocal.remove(); } } public void init(FilterConfig arg0) throws ServletException { } } Will doing the following be okay? Change static method/field in ClientLocaleThreadLocal to non-static method/fields In TimeFilter, set locale by instantiating new object as below. new ClientLocaleThreadLocal().set(req.getLocale()) Thanks for your help in advance

    Read the article

  • can the keyword 'this' be used in an abstract class in java

    - by Reddy
    I tried with below example, it is working fine. I expected it to pick sub-class's value since object won't be created for super class (as it is abstract). But it is picking up super class's field value only. Please help me understand what is the concepts behind this? abstract class SuperAbstract { private int a=2; public void funA() { System.out.println("In SuperAbstract: this.a "+a); } } class SubClass extends SuperAbstract { private int a=34; } I am calling new SubClass.funA(); I am expecting it to print 34, but it is printing 2.

    Read the article

  • Elements of a Java Object Array are created but without correct names

    - by Greenhouse Gases
    Hi all Im having rather an annoying problem. I have a class called Person and a class called Event which serve to create objects to be used for competitors that compete in a certain event. When I add a competitor thats fine and the GUI list updates accordingly, however when I add an event the element in the array does not take on the value of the instance variable name in the class Event and so the GUI does not show the event name, though it is being added in the array correctly. How can I make it so that the event object in each element of the listOfEvents array (which is an array of event objects) has the name of the event. I should add this is for university though this isnt the part for which we will be assessed, it is somethign i have come across and due to not being able to see the code for the GUI, I've hit the proverbial brick wall. I wont include the whole load of code Ive been writing but hopefully my description and snippets below will suffice. Any advice I would appreciate greatly. No doubt I have overlooked something simple! Many thanks. listOfEvents is declared as: Event[] listOfEvents = new Event[20]; A snippet from the Event class: public class Event { String name; Person[] participants = new Person[10]; // array of competitors for the event public Event(String name) { this.name = name; } } and its use in the addEvent method (p is a global variable): public void addEvent(String eventName) { listOfEvents[p] = new Event(eventName); p++; }

    Read the article

< Previous Page | 321 322 323 324 325 326 327 328 329 330 331 332  | Next Page >