Search Results

Search found 33141 results on 1326 pages for 'java opts'.

Page 270/1326 | < Previous Page | 266 267 268 269 270 271 272 273 274 275 276 277  | Next Page >

  • Converting a number to a greyscale color in Java

    - by Dave
    Hi, I'm trying to figure out how I can convert a number between 1 and 50 to a greyscale color that could be used here: g.setColor(MyGreyScaleColour); 1 would be lightest (white) and 50 would be darkest (black). e.g. Color intToCol(int colNum) { code here } Any suggestions?

    Read the article

  • Java Future and infinite computation

    - by Chris
    I'm trying to optimize an (infinite) computation algorithm. I have an infinte Sum to calculate ( Summ_{n- infinity} (....) ) My idea was to create several threads using the Future < construct, then combine the intermediate results together. My problem hoewer is that I need a certain precision. So I need to constantly calculate the current result while other threads keep calculating. My question is: Is there some sort of result queue where each finished thread can put its results in, while a main thread can receive those results and then either lets the computation continues or terminate the whole ExecutorService? Any Help would really be appreciated! Thanks!

    Read the article

  • Java Swing - Drawing markers on JSlider.

    - by Tony Day
    Hi, I have a progress bar which inherits from JSlider to provide highlighting functionality. Highlights can be added to the slider at a point (and a Color) and these are then painted onto the control. As follows: The problem is that I cannot get the highlights in the right place, they need to be in the same location as the markers. I also do not know how to retrieve the left and right margins to where the markers start and end. Is there anyway to get the coordinates of each marker? Or perhaps a better way of performing this task? Many Thanks!

    Read the article

  • java Properties - to expose or not to expose?

    - by ring bearer
    This might be an age old problem and I am sure everyone has their own ways. Suppose I have some properties defined such as secret.user.id=user secret.password=password website.url=http://stackoverflow.com Suppose I have 100 different classes and places where I need to use these properties. Which one is good (1) I create a Util class that will load all properties and serve them using a key constant Such as : Util is a singleton that loads all properties and keeps up on getInstance() call. Util myUtil = Util.getInstance(); String user = myUtil.getConfigByKey(Constants.SECRET_USER_ID); String password = myUtil.getConfigByKey(Constants.SECRET_PASSWORD); .. //getConfigByKey() - inturns invokes properties.get(..) doSomething(user, password) So wherever I need these properties, I can do steps above. (2) I create a meaningful Class to represent these properties; say, ApplicationConfig and provide getters to get specific properties. So above code may look like: ApplicationConfig config = ApplicationConfig.getInstance(); doSomething(config.getSecretUserId(), config.getPassword()); //ApplicationConfig would have instance variables that are initialized during // getInstance() after loading from properties file. Note: The properties file as such will have only minor changes in the future. My personal choice is (2) - let me hear some comments?

    Read the article

  • Is java HashMap.clear() and remove() memory effective?

    - by Shaman
    Consider the follwing HashMap.clear() code: /** * Removes all of the mappings from this map. * The map will be empty after this call returns. */ public void clear() { modCount++; Entry[] tab = table; for (int i = 0; i < tab.length; i++) tab[i] = null; size = 0; } It seems, that the internal array (table) of Entrys is never shrinked. So, when I add 10000 elements to a map, and after that call map.clear(), it will keep 10000 nulls in it's internal array. So, my question is, how does JVM handle this array of nothing, and thus, is HashMap memory effective?

    Read the article

  • Java HTTP Requests Buffer size

    - by behrk2
    Hello, I have an HTTP Request Dispatcher class that works most of the time, but I had noticed that it "stalls" when receiving larger requests. After looking into the problem, I thought that perhaps I wasn't allocating enough bytes to the buffer. Before, I was doing: byte[] buffer = new byte[10000]; After changing it to 20000, it seems to have stopped stalling: String contentType = connection.getHeaderField("Content-type"); ByteArrayOutputStream baos = new ByteArrayOutputStream(); InputStream responseData = connection.openInputStream(); byte[] buffer = new byte[20000]; int bytesRead = responseData.read(buffer); while (bytesRead > 0) { baos.write(buffer, 0, bytesRead); bytesRead = responseData.read(buffer); } baos.close(); connection.close(); Am I doing this right? Is there anyway that I can dynamically set the number of bytes for the buffer based on the size of the request? Thanks...

    Read the article

  • Searchable list of objects in Java

    - by Christian
    I want to create a large (~300,000 entries) List of self defined objects of the class Drug. Every Drug has an ID and I want to be able to search the Drugs in logarithmic time via that ID. What kind of List do I have to use? How do I declare that it should be searchable via the ID?

    Read the article

  • What's the deal with Java's public fields?

    - by Annan
    I've been reading two articles (1)(2) on javaworld.com about how all class fields should be private and getter/setter methods are just as bad. An object should act on the data it has rather than allowing access to it. I'm currently working on a University assignment for Connect Four. In designing the program the Agents playing the Game need access to the Board's state (so they can decide what to move). They also need to pass this move to the Game so it can validate it as a legal move. And during deciding what to move pieces are grouped into Threats with a start and end Points. Board, Threat and Point objects don't really do anything. They are just there to store related data that can be accessed in a human readable way. At the start of design I was representing Points on the board as two element int arrays, however that got annoying when creating points or referencing components of them. So, the class: public class Point { public int x; public int y; public Point(int x, int y){ this.x = x; this.y = y; } } Perfect in every way I can think of. Except it breaks every rule I've learned. Have I sinned?

    Read the article

  • How to convert Facebook created_time to Java Date?

    - by smitty
    Hi, I have a FQL statement like this: String query = "SELECT post_id, actor_id, target_id, created_time, message FROM stream WHERE source_id in (SELECT target_id FROM connection WHERE source_id=<userID>) AND is_hidden = 0"; I just wondering what kind of time Facebook gives to me. The result of my statement will be mapped to a wrapper object (wallpost). myDate.setTime(wallpost.getCreated_time()); gives me no valid date. Does anyone have an idea what kind of date Facebook returns and how to match it to Date()? thanks in advance!

    Read the article

  • Refactor Regex Pattern - Java

    - by UK
    Hello All, I have the following aaaa_bb_cc string to match and written a regex pattern like \\w{4}+\\_\\w{2}\\_\\w{2} and it works. Is there any simple regex which can do this same ?

    Read the article

  • ArrayList in java

    - by fatih-yilmaz
    ArrayList<String> veri1 = new ArrayList<String>(); String[] veri2 = {"Fatih", "Ferhat", "Furkan"}; How can i add "veri2" to "veri1" like one element ? I mean if i call veri.get(0), it returns veri2.. Regards.

    Read the article

  • Java: Get Mainform object from JInternalFrame

    - by rodion
    Can I do this without reference to the object in the constructor? In other words, any class inherited from FrmTaoChild when creating must to add the button on the toolbar of the main window public class FrmTaoMain extends JFrame { JToolBar tbTask = new JToolBar(); public FrmTaoMain(String Caption) { super(Caption); ... FrmTaoChild FrmChild = new FrmTaoChild(tbTask,"test"); } } public class FrmTaoChild extends JInternalFrame { public FrmTaoChild(JToolBar tbTask, String Caption) { super (Caption); JButton btnTask = new JButton(Caption); tbTask.add(btnTask); } }

    Read the article

  • java regular expression

    - by changed
    Hi I have to create a regular expression for some path conversion. Example for path are //name:value /name:value // name:value /name:value /name:value /name:value//name:value thing is how to check for // or / at the start or middle of the string and how can i specify that name can contain any of this a-zA-Z and _ Path also contains white spaces. thanks-

    Read the article

  • What's "@Override" there for in java?

    - by symfony
    public class Animal { public void eat() { System.out.println("I eat like a generic Animal."); } } public class Wolf extends Animal { @Override public void eat() { System.out.println("I eat like a wolf!"); } } Does @Override actually have some functionality or it's just kinda comment?

    Read the article

  • Transposing and Untransposing a String in java

    - by Will
    I have been working on two methods that will Transpose and Untranspose a String respectively. The solutions that I have come up with both work to the best of my knowledge. I just want to know if I could have solved these problems in a simpler way. My code seems like it is too long for the task that is being performed. The first method, transpose(), will take a String as a parameter and transpose it. If "bridge" is entered, the output will be "bergid". Likewise, with the unTranspose() method, if the user enters "bergid", the output will be "bridge". public void transpose( String s ) { String t = ""; int end = s.length() - 1; for ( int i = 0; i < s.length() / 2; i++ ) { t += Character.toString( s.charAt( i ) ) + Character.toString( s.charAt( end ) ); end--; } // Lenth of String is odd if ( s.length() % 2 == 1 ) { // add character in middle of String to the end of the new String t+= Character.toString( s.charAt( s.length() / 2 ) ); } System.out.println( t ); } public void unTranspose( String s ) { String t = ""; // Length of String is odd if ( s.length() % 2 == 1 ) { for ( int i = 0; i < s.length(); i+=2 ) { t+= Character.toString( s.charAt( i ) ); } for ( int i = s.length() - 2; i > 0; i -= 2 ) { t += Character.toString( s.charAt( i ) ); } System.out.println( t ); } // Length of String is even else if ( s.length() % 2 == 0 ) { for ( int i = 0; i < s.length() - 1; i+=2 ) { t+= Character.toString( s.charAt( i ) ); } for ( int i = s.length() - 1; i > 0; i -= 2 ) { t+= Character.toString( s.charAt( i ) ); } System.out.println( t ); } } My code looks horrible. I'm still not used to formatting my code correctly. Please bear with me. Thanks for your time

    Read the article

  • Java: CSV file read & write.

    - by battousai622
    Im reading in 2 csv file: store_inventory & new_acquisitions... I want to be able to compare the store_inventory csv file with new_acquisitions. 1) If the item names match just update the quantity in store_inventory. 2) If new_acquisitions has a new item that does not exist in store_inventory, then add it to the store_inventory. Heres what i have so far but its not very good. I added comments where i need to add taks 1) & 2). Any advice or code would be great, thanks. File new_acq = new File("/src/test/new_acquisitions.csv"); Scanner acq_scan = null; try { acq_scan = new Scanner(new_acq); } catch (FileNotFoundException ex) { Logger.getLogger(mainpage.class.getName()).log(Level.SEVERE, null, ex); } String itemName; int quantity; Double cost; Double price; File store_inv = new File("/src/test/store_inventory.csv"); Scanner invscan = null; try { invscan = new Scanner(store_inv); } catch (FileNotFoundException ex) { Logger.getLogger(mainpage.class.getName()).log(Level.SEVERE, null, ex); } String itemNameInv; int quantityInv; Double costInv; Double priceInv; while (acq_scan.hasNext()) { String line = acq_scan.nextLine(); if (line.charAt(0) == '#') { continue; } String[] split = line.split(","); itemName = split[0]; quantity = Integer.parseInt(split[1]); cost = Double.parseDouble(split[2]); price = Double.parseDouble(split[3]); while(invscan.hasNext()) { String line2 = invscan.nextLine(); if (line2.charAt(0) == '#') { continue; } String[] split2 = line2.split(","); itemNameInv = split2[0]; quantityInv = Integer.parseInt(split2[1]); costInv = Double.parseDouble(split2[2]); priceInv = Double.parseDouble(split2[3]); if(itemName == itemNameInv) { //update quantity } } //add new entry into csv file } Thanks again for any help. =]

    Read the article

  • How to trace the connection pool in a Java Web application - DBMS_APPLICATION_INFO

    - by Cleiton Garcia
    Hello, I need improve the traceability in a Web Application that usually run on fixed db user. The DBA should have a fast access for the information about the heavy users that are degrading the database. 5 years ago, I implemented a .NET ORM engine which makes a log of user and the server using the DBMS_APPLICATION_INFO package. Using a wrapper above the connection manager with the following code: DBMS_APPLICATION_INFO.SET_MODULE('" + User + " - " + appServerMachine + "',''); Each time that a connection get a connection from the pool, the package is executed to log the information in the V$SESSION. Has anyone discover or implemented a solution for this problem using the Toplink or Hibernate? Is there a default implementation for this problem? I found here a solutions as I implemented 5 years ago, but I'd like to know with anyone have a better solution and integrated with the ORM. http://stackoverflow.com/questions/53379/using-dbmsapplicationinfo-with-jboss My application is above Spring, the DAO are implemented with JPA (using hibernate) and actually running directly in Tomcat, with plans to (next year) migrate to SAP Netwevare Application Server. Thanks.

    Read the article

  • Regular Expression in java

    - by Sunil
    I have a HTML page and I want to fetch the result between two tags <b> and <BR> <b>Defendants Name:</b>Donahue, Leah A <BR> What is the regular expression to fetch the words between these two tags

    Read the article

  • Java Collections Sort not accepting comparator constructor with arg

    - by harmzl
    I'm getting a compiler error for this line: Collections.sort(terms, new QuerySorter_TFmaxIDF(myInteger)); My customized Comparator is pretty basic; here's the signature and constructor: public class QuerySorter_TFmaxIDF implements Comparator<Term>{ private int numberOfDocs; QuerySorter_TFmaxIDF(int n){ super(); numberOfDocs = n; } } Is there an error because I'm passing an argument into the Comparator? I need to pass an argument...

    Read the article

  • Java HotSpot 1.6 VM, Garbage Collection - Scary PermGen

    - by Gala101
    Hi, My app shows rising 'Old Generation'/'Tenured Generation' size, and when this reaches the max limit for 'Old Gen', then suddenly PermGen size increases. Here are my generation sizings: -Xmx1200m -Xms1200m -Xmn450m -XX:MaxPermSize=600m -XX:+UseParallelGC This is on 32 bit Fedora so can't have a bigger heap than this. The app is not doing any fancy classloading, though it is using Spring IOC and Hibernate, the Spring App-context.xml defines some 1000 Beans. This app starts with 175MB PermGen, which steadily increases to ~250MB in few hrs, stays that way till Tenured Generation reached ~780 MB, then permgen jumps to ~500MB while Old Gen drops to ~500MB. This forces me to restart the App on daily basis, and gives me real scare of looming OutOfMemory Error.. Any insights would be very helpful. Thanks Gala101

    Read the article

  • Java resource closing

    - by Bob
    Hi, I'm writing an app that connect to a website and read one line from it. I do it like this: try{ URLConnection connection = new URL("www.example.com").openConnection(); BufferedReader rd = new BufferedReader(new InputStreamReader(connection.getInputStream())); String response = rd.readLine(); rd.close(); }catch (Exception e) { //exception handling } Is it good? I mean, I close the BufferedReader in the last line, but I do not close the InputStreamReader. Should I create a standalone InputStreamReader from the connection.getInputStream, and a BufferedReader from the standalone InputStreamReader, than close all the two readers? I think it will be better to place the closing methods in the finally block like this: InputStreamReader isr = null; BufferedReader br = null; try{ URLConnection connection = new URL("www.example.com").openConnection(); isr = new InputStreamReader(connection.getInputStream()); br = new BufferedReader(isr); String response = br.readLine(); }catch (Exception e) { //exception handling }finally{ br.close(); isr.close(); } But it is ugly, because the closing methods can throw exception, so I have to handle or throw it. Which solution is better? Or what would be the best solution?

    Read the article

< Previous Page | 266 267 268 269 270 271 272 273 274 275 276 277  | Next Page >