Search Results

Search found 46178 results on 1848 pages for 'java home'.

Page 891/1848 | < Previous Page | 887 888 889 890 891 892 893 894 895 896 897 898  | Next Page >

• paintComponent on JPanel, image flashes and then disappears

  - by mark

  I have a JApplet (MainClass extends JApplet), a JPanel (ChartWindow extends JPanel) and a Grafico class. The problem is that the Grafico class instance has 2 JPanel that should show 2 images (1 for each panel) but the images are shown and after a little while they disappears: instead of them i get a gray background (like an empty JPanel). This happens for every repaint() call (that are made in the ChartWindow class) the MainClass init() contains chartwindow=new ChartWindow(); add(chartwindow) chartwindow has a Grafico instance. it's the ChartWindow's paintComponent (override) paintComponent(Graphics g) { super.paintComponent(g); Image immagineGrafico=createImage(grafico.pannelloGrafico.getWidth() ,grafico.pannelloGrafico.getHeight()); Image immagineVolumi=createImage(grafico.pannelloVolumi.getWidth() ,grafico.pannelloVolumi.getHeight()); Graphics2D imgGrafico=(Graphics2D)immagineGrafico.getGraphics(); Graphics2D imgVolumi=(Graphics2D)immagineVolumi.getGraphics(); grafico.draw(imgGrafico,imgVolumi,mouseX,mouseY); ((Graphics2D)grafico.pannelloGrafico.getGraphics()).drawImage(immagineGrafico,0,0,this); ((Graphics2D)grafico.pannelloVolumi.getGraphics()).drawImage(immagineVolumi,0,0,this); } grafico's JPanels are added this way in the ChartWindow's constructor grafico=new Grafico() ................ add(grafico.pannelloGrafico); add(grafico.pannelloVolumi); Tell me if you need more information, thank you very much :-)

  Read the article

• Compare two lists.

  - by javaguy

  I want to compare two lists. Since we code to interface using List, which does not inherit the equals from from the Object class. How do I do this?

  Read the article

• correct way of initializing variables

  - by OVERTONE

  ok this is just a shot in the dark but it may be the cause of most of the errors ive gotten. when your initializing something. lets say a smal swing program. would it go liek this variables here { private Jlist contactList; String [] contactArray; ArrayList <String> contactArrayList; ResultSet namesList constructor here public whatever() { GridLayout aGrid = new GridLayout(2,2,10,10); contact1 = new String(); contact2 = new String(); contact3 = new String(); contactArrayList = new ArrayList<String>(); // is something supposed too go in the () of this JList? contactList = new JList(); contactArray = new String[5]; from1 =new JLabel ("From: " + contactArray[1]); gridlayout.add(components)// theres too many components to write onto SO. } // methods here public void fillContactsGui() { createConnection(); ArrayList<String> contactsArrayList = new ArrayList<String>(); while (namesList.next()) { contactArrayList.add(namesList.getString(1)); ContactArray[1] = namesList[1]; } } i know this is probably a huge beginner question but this is the code ive gotten used too. im initializing thigns three and fours times without meaning too because im not sure where they gp. can anyone shed some light on this? p.s. sorry for the messy sample code. i done my best.

  Read the article

• Constructor being called again?

  - by Halo

  I have this constructor; public UmlDiagramEntity(ReportElement reportElement, int pageIndex, Controller controller) { super(reportElement.getX1(), reportElement.getY1(), reportElement.getX2(), reportElement.getY2()); setLayout(null); this.pageIndex = pageIndex; this.controller = controller; reportElements = reportElement.getInternalReportElements(); components = new ArrayList<AbstractEntity>(); changedComponentIndex = -1; PageListener p = new PageListener(); this.addMouseMotionListener(p); this.addMouseListener(p); setPage(); } And I have an update method in the same class; @Override public void update(ReportElement reportElement) { if (changedComponentIndex == -1) { super.update(reportElement); } else { reportElements = reportElement.getInternalReportElements(); if (components.size() == reportElements.size()) { if (!isCommitted) { if (reportElement.getType() == ReportElementType.UmlRelation) { if (checkInvolvementAndSet(changedComponentIndex)) { anchorEntity(changedComponentIndex); } else { resistChanges(changedComponentIndex); } return; } } ..................goes on When I follow the flow from the debugger, I see that when update is called, somewhere in the method, the program goes into the constructor and executes it all over again (super, pageIndex, etc.). Why does it go to the constructor :D I didn't tell it to go there. I can make a deeper analysis and see where it goes to the constructor if you want. By the way, changedComponentIndex is a static variable.

  Read the article

• What is the difference between the Facade and Addapter Pattern?

  - by devoured elysium

  I've been reading both definitions and they seem quite the same. Could anyone point out what are their differences? Thanks

  Read the article

• Netbeans GUI editor problems

  - by RenegadeAndy

  Hey guys. Im making a portion of my app using the netbeans gui editor. Great so far. However ive added a new checkbox - and when i load the panel in my app the text attribute isnt shown...its just blank as if i have no caption on it... all the other ones display - so this is very annoying. It kind of seems that I have hit the limit on gui items or something, becasue any new items I add I cannot seem then, If i add new labels they dont show either :S! The other problems Im having are that the size of the window im editting appears to be fixed - every time i change it, it jumps back to the same size - how do i stop this from happening? Cheers Andy

  Read the article

• Enum exeeding the 65535 bytes limit of static initializer... what's best to do?

  - by Daniel Bleisteiner

  I've started a rather large Enum of so called Descriptors that I've wanted to use as a reference list in my model. But now I've come across a compiler/VM limit the first time and so I'm looking for the best solution to handle this. Here is my error : The code for the static initializer is exceeding the 65535 bytes limit It is clear where this comes from - my Enum simply has far to much elements. But I need those elements - there is no way to reduce that set. Initialy I've planed to use a single Enum because I want to make sure that all elements within the Enum are unique. It is used in a Hibernate persistence context where the reference to the Enum is stored as String value in the database. So this must be unique! The content of my Enum can be devided into several groups of elements belonging together. But splitting the Enum would remove the unique safety I get during compile time. Or can this be achieved with multiple Enums in some way? My only current idea is to define some Interface called Descriptor and code several Enums implementing it. This way I hope to be able to use the Hibernate Enum mapping as if it were a single Enum. But I'm not even sure if this will work. And I loose unique safety. Any ideas how to handle that case?

  Read the article

• static variable lose its value

  - by user542719

  I have helper class with this static variable that is used for passing data between two classes. public class Helper{ public static String paramDriveMod;//this is the static variable in first calss } this variable is used in following second class mathod public void USB_HandleMessage(char []USB_RXBuffer){ int type=USB_RXBuffer[2]; MESSAGES ms=MESSAGES.values()[type]; switch(ms) { case READ_PARAMETER_VALUE: // read parameter values switch(prm){ case PARAMETER_DRIVE_MODE: // paramet drive mode Helper.paramDriveMod =(Integer.toString(((USB_RXBuffer[4]<< 8)&0xff00))); System.out.println(Helper.paramDriveMod+"drive mode is selectd ");//here it shows the value that I need. ..........}}//let say end switch and method and the following is an third class method use the above class method public void buttonSwitch(int value) throws InterruptedException{ boolean bool=true; int c=0; int delay=(int) Math.random(); while(bool){ int param=3; PARAMETERS prm=PARAMETERS.values()[param]; switch(value){ case 0: value=1; while(c<5){ Thread.sleep(delay); protocol.onSending(3,prm.PARAMETER_DRIVE_MODE.ordinal(),dataToRead,dataToRead.length);//read drive mode System.out.println(Helper.paramDriveMod+" drive mode is ..........in wile loop");//here it shows null value }}//let say end switch and method what is the reason that this variable lose its value?

  Read the article

• Count Occurence of Needle String in Haystack String, most optimally?

  - by Taranfx

  The Problem is simple Find "ABC" in "ABCDSGDABCSAGAABCCCCAAABAABC" Here is the solution I propose, I'm looking for any solutions that might be better than this one. public static void main(String[] args) { String haystack = "ABCDSGDABCSAGAABCCCCAAABAABC"; String needle = "ABC"; char [] needl = needle.toCharArray(); int needleLen = needle.length(); int found=0; char hay[] = haystack.toCharArray(); int index =0; int chMatched =0; for (int i=0; i<hay.length; i++){ if (index >= needleLen || chMatched==0) index=0; System.out.print("\nchar-->"+hay[i] + ", with->"+needl[index]); if(hay[i] == needl[index]){ chMatched++; System.out.println(", matched"); }else { chMatched=0; index=0; if(hay[i] == needl[index]){ chMatched++; System.out.print("\nchar->"+hay[i] + ", with->"+needl[index]); System.out.print(", matched"); }else continue; } if(chMatched == needleLen){ found++; System.out.println("found. Total ->"+found); } index++; } System.out.println("Result Found-->"+found); } It took me a while creating this one. Can someone suggest a better solution (if any) P.S. Drop the sysouts if they look messy to you.

  Read the article

• Encountering NullPointerException when trying to add polynoms

  - by Ayler Cruz

  I need to add two polynomials, which is composed of two ints. For example, the coefficient and the exponent 3x^2 would be constructed using 3 and 2 as parameters. I am getting a NullPointerException but I can't figure out why. Any help would be appreciated! public class Polynomial { private Node poly; public Polynomial() { } private Polynomial(Node p) { poly = p; } private class Term { int coefficient; int exponent; private Term(int coefficient, int exponent) { this.coefficient = coefficient; this.exponent = exponent; } } private class Node { private Term data; private Node next; private Node(Term data, Node next) { this.data = data; this.next = next; } } public void addTerm(int coeff, int exp) { Node pointer = poly; if (pointer.next == null) { poly.next = new Node(new Term(coeff, exp), null); } else { while (pointer.next != null) { if (pointer.next.data.exponent < exp) { Node temp = new Node(new Term(coeff, exp), pointer.next.next); pointer.next = temp; return; } pointer = pointer.next; } pointer.next = new Node(new Term(coeff, exp), null); } } public Polynomial polyAdd(Polynomial p) { return new Polynomial(polyAdd(this.poly, p.poly)); } private Node polyAdd(Node p1, Node p2) { if (p1 == p2) { Term adding = new Term(p1.data.coefficient + p2.data.coefficient, p1.data.exponent); p1 = p1.next; p2 = p2.next; return new Node(adding, null); } if (p1.data.exponent > p2.data.exponent) { p2 = p2.next; } if (p1.data.exponent < p2.data.exponent) { p1 = p1.next; } if (p1.next != null && p2.next != null) { return polyAdd(p1, p2); } return new Node(null, null); } }

  Read the article

• Going "behind Hibernate's back" to update foreign key values without an associated entity

  - by Alex Cruise

  Updated: I wound up "solving" the problem by doing the opposite! I now have the entity reference field set as read-only (insertable=false updatable=false), and the foreign key field read-write. This means I need to take special care when saving new entities, but on querying, the entity properties get resolved for me. I have a bidirectional one-to-many association in my domain model, where I'm using JPA annotations and Hibernate as the persistence provider. It's pretty much your bog-standard parent/child configuration, with one difference being that I want to expose the parent's foreign key as a separate property of the child alongside the reference to a parent instance, like so: @Entity public class Child { @Id @GeneratedValue Long id; @Column(name="parent_id", insertable=false, updatable=false) private Long parentId; @ManyToOne(cascade=CascadeType.ALL) @JoinColumn(name="parent_id") private Parent parent; private long timestamp; } @Entity public class Parent { @Id @GeneratedValue Long id; @OrderBy("timestamp") @OneToMany(mappedBy="parent", cascade=CascadeType.ALL, fetch=FetchType.LAZY) private List<Child> children; } This works just fine most of the time, but there are many (legacy) cases when I'd like to put an invalid value in the parent_id column without having to create a bogus Parent first. Unfortunately, Hibernate won't save values assigned to the parentId field due to insertable=false, updatable=false, which it requires when the same column is mapped to multiple properties. Is there any nice way to "go behind Hibernate's back" and sneak values into that field without having to drop down to JDBC or implement an interceptor? Thanks!

  Read the article

• problem to create session of facebook

  - by khoyendra

  try { HttpClient http = new HttpClient(); http.setParams(new HttpClientParams()); //http.getHostConfiguration().setHost("http://www.facebook.com/"); http.setState(new HttpState()); String api_key = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; String secret = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; // String appId=124812364218050; //http://www.facebook.com/developers/editapp.php?app_id=124812364218050 FacebookRestClient client = new FacebookRestClient(api_key, secret); client.setIsDesktop(true); // String sessionKey = request.getParameter(FacebookParam.SESSION_KEY.toString()); // boolean b = client.users_setStatus("This is a test..."); // System.out.println("User Status RESULT : " + b); String token = client.auth_createToken(); final String loginId = "http://www.facebook.com/login.php"; GetMethod get = new GetMethod(loginId + "?api_key=" + api_key + "&v=1.0&auth_token=" +token); System.out.println("Get="+get); http.executeMethod(get); PostMethod post = new PostMethod(loginId); post.addParameter(new NameValuePair("api_key", api_key)); post.addParameter(new NameValuePair("v", "1.0")); post.addParameter(new NameValuePair("auth_token", token)); post.addParameter(new NameValuePair("fbconnect","true")); post.addParameter(new NameValuePair("return_session","true")); post.addParameter(new NameValuePair("session_key_only","true")); post.addParameter(new NameValuePair("req_perms","read_stream,publish_stream")); post.addParameter(new NameValuePair("email", email)); post.addParameter(new NameValuePair("pass", password)); System.out.println("Token ="+token); int postStatus = http.executeMethod(post); System.out.println("Response : " + postStatus); session = client.auth_getSession(token); // Here I am getting error System.out.println("Session string: " + session); long userid = client.users_getLoggedInUser(); System.out.println("User Id is : " + userid); } catch (Exception e) { e.printStackTrace(); } please solve my problem i cannot create session of facebook.

  Read the article

• write behind cache Ehcache new feature?

  - by cometta

  Hi, i looking for guide/document/tutorial on how to use this new feature write-behind-cache in ehcache? Is there any demo in spring+jpa+ehcache+hibernate? just to clariyfing, write-behind-cache mean each time we persist entity, it will be written into cache rather than into database correct?

  Read the article

• Catching an exception that is nested into another exception

  - by Bernhard V

  Hi, I want to catch an exception, that is nested into another exception. I'm doing it currently this way: } catch (RemoteAccessException e) { if (e != null && e.getCause() != null && e.getCause().getCause() != null) { MyException etrp = (MyException) e.getCause().getCause(); ... } else { throw new IllegalStateException("Error at calling service 'beitragskontonrVerwalten'"); } } Is there a way to do this more efficient and elegant?

  Read the article

• How to find out the subclass from the base class object

  - by Vaishak Suresh

  Is there a way to find out the derived class's name from a base class object? ex: class A{ .... } class B extends A{ ... } class c extends A{ ... } now if a method returns an object of A, can I find out if it is of type B or C?

  Read the article

• Alternatives to static variables in Android

  - by Mocha

  I am using static Arrays and HashMaps to store some values in my AppWidgetProvider class. But they are becoming null when the process dies, so the widget does not work anymore. Are there any alternatives to using static members to store data for an AppWidgetProvider in Android?

  Read the article

• regex for matching strings that have illegal filename characters.

  - by cchampion

  I been trying to figure out how this blasted regex for two hours!!! It's midnight I gotta figure this out and go to bed!!! String str = new String("filename\\"); if(str.matches(".*[?/<>|*:\"{\\}].*")) { System.out.println("match"); }else { System.out.println("no match"); } ".*[?/<>|*:\"{\\}].*" is my regex expression. It catches everything correctly except the backslash!!! I need to know how to make it catch the backslash correctly please help! FYI, the illegal characters i'm trying to catch are ? \ / < | * : " I've got it working exception for the backslash

  Read the article

• Killing Mysql processes staying in sleep command.

  - by Shino88

  Hey I am connecting a MYSQL database through hibernate and i seem to have processes that are not being killed after they are finished in the session. I have called flush and close on each session but when i check the server the last processes are still there with a sleep command. This is a new problem which i am having and was not the case yesterday. Is there any way i can ensure the killng of theses processes when i am done with a session. Below is an example of one of my classes. public JSONObject check() { //creates a new session needed to add elements to a database Session session = null; //holds the result of the check in the database JSONObject check = new JSONObject(); try{ //creates a new session needed to add elements to a database SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session = sessionFactory.openSession(); if (justusername){ //query created to select a username from user table String hquery = "Select username from User user Where username = ? "; //query created Query query = session.createQuery(hquery); //sets the username of the query the values JSONObject contents query.setString(0, username); // executes query and adds username string variable String user = (String) query.uniqueResult(); //checks to see if result is found (null if not found) if (user == null) { //adds false to Jobject if not found check.put("indatabase", "false"); } else { check.put("indatabase", "true"); } //adds check to Jobject to say just to check username check.put("justusername", true); } else { //query created to select a username and password from user table String hquery = "Select username from User user Where username = :user and password = :pass "; Query query = session.createQuery(hquery); query.setString("user", username); query.setString("pass", password); String user = (String) query.uniqueResult(); if(user ==null) { check.put("indatabase", false); } else { check.put("indatabase", true); } check.put("justusername", false); } }catch(Exception e){ System.out.println(e.getMessage()); //logg.log(Level.WARNING, " Exception", e.getMessage()); }finally{ // Actual contact insertion will happen at this step session.flush(); session.close(); } //returns Jobject return check; }

  Read the article

• real time scenario between interface/abstract class ?

  - by JavaUser

  Hi , Please give me a real time simple example for the below questions : Where to use interface rather abstract class Where to use abstract class rather interface I need code snippet for both . Which takes low memory and which performs well . Do I need to consider the design aspect also? What is the conceptual difference not the syntactical difference .

  Read the article

• coloring buttens

  - by asm_debuger

  i want to color the text inside the button how can i do that? i made that code: for(int i=0; i<10 ;i++) { arr[i]=new Button(""+i); arr[i]. arr[i].setBackground(Color.LIGHT_GRAY); p1.add(arr[i]); this.arr[i].addActionListener(this); } the buttens text color are colored in clack if i want to color the text in the button from black to blue what i need to write?

  Read the article

• How to know file type without extension

  - by Ayusman

  While trying to come-up with a servlet based application to read files and manipulate them (image type conversion) here is a question that came up to me: Is it possible to inspect a file content and know the filetype? Is there a standard that specifies that each file MUST provide some type of marker in their content so that the application will not have to rely on the file extension constraints? Consider an application scenario: I am creating an application that will be able to convert different file formats to a set of output formats. Say user uploads an PDF, my application can suggest that the possible conversion formats are microsoft word or TIFF or JPEG etc. As my application will gradually support different file formats (over a period of time), I want my application to inspect the input file instead of having the user to specify the format. And suggest to user the possible formats of output. I understand this is an open ended, broad question. Please let me know if it needs to be modified. Thanks, Ayusman

  Read the article

• Where to handle fatal exceptions

  - by Stephen Swensen

  I am considering a design where all fatal exceptions will be handled using a custom UncaughtExceptionHandler in a Swing application. This will include unanticipated RuntimeExceptions but also custom exceptions which are thrown when critical resources are unavailable or otherwise fail (e.g. a settings file not found, or a server communication error). The UncaughtExceptionHandler will do different things depending on the specific custom exception (and one thing for all the unanticipated), but in all cases the application will show the user an error message and exit. The alternative would be to keep the UncaughtExceptionHandler for all unanticipated exceptions, but handle all other fatal scenarios close to their origin. Is the design I'm considering sound, or should I use the alternative?

  Read the article

• Use PermGen space or roll-my-own intern method?

  - by Adamski

  I am writing a Codec to process messages sent over TCP using a bespoke wire protocol. During the decode process I create a number of Strings, BigDecimals and dates. The client-server access patterns mean that it is common for the client to issue a request and then decode thousands of response messages, which results in a large number of duplicate Strings, BigDecimals, etc. Therefore I have created an InternPool<T> class allowing me to intern each class of object. Internally, the pool uses a WeakHashMap<T, WeakReferemce<T>>. For example: InternPool<BigDecimal> pool = new InternPool<BigDecimal>(); ... // Read BigDecimal from in buffer and then intern. BigDecimal quantity = pool.intern(readBigDecimal(in)); My question: I am using InternPool for BigDecimal but should I consider also using it for String instead of String's intern() method, which I believe uses PermGen space? What is the advantage of using PermGen space?

  Read the article

• JList with custom renderer

  - by AhmadAssaf

  Hello, I have a JList that shows multiple JPanels on them , i have created a custom renderer that returns a new JPanel. The JPanels are displayed in the JList but they are not accessible, i cant select them and if i have a button or a text area in it i can not press it. I want to try if this works in a JList because i want to do further pagination. I managed to get it work by adding panels to a Jscroll pane, but would love to make the JList thing work. Thanks

  Read the article

• URL of the website calling Restlet API

  - by Christopher McCann

  I have a Restlet API and the methods exposed on it are called by a PHP web app. This web app is accessible by several domain names and depending on the domain certain aspects of the app are changed (look and feel, content etc). Is there a way for Restlet to determine the URL of the calling web app? I have used getReference() but all I can get is the (internal) IP address of the calling web server (not the domain name). My only other alternative is to pass the URL of the web app with every request to the API but it would be cleaner if Restlet already knew. Thanks

  Read the article

< Previous Page | 887 888 889 890 891 892 893 894 895 896 897 898  | Next Page >