Search Results

Search found 38025 results on 1521 pages for 'java mouse'.

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 483/1521 | < Previous Page | 479 480 481 482 483 484 485 486 487 488 489 490  | Next Page >

  • How to generate a random BigInteger value in Java?

    - by Bill the Lizard
    I need to generate arbitrarily large random integers in the range 0 (inclusive) to n (exclusive). My initial thought was to call nextDouble and multiply by n, but once n gets to be larger than 253, the results would no longer be uniformly distributed. BigInteger has the following constructor available: public BigInteger(int numBits, Random rnd) Constructs a randomly generated BigInteger, uniformly distributed over the range 0 to (2numBits - 1), inclusive. How can this be used to get a random value in the range 0 - n, where n is not a power of 2?

    Read the article

  • Java Persistence: Cast to something the result of Query.getResultList() ?

    - by GuiSim
    Hey everyone, I'm new to persistence / hibernate and I need your help. Here's the situation. I have a table that contains some stuff. Let's call them Persons. I'd like to get all the entries from the database that are in that table. I have a Person class that is a simple POJO with a property for each column in the table (name, age,..) Here's what I have : Query lQuery = myEntityManager.createQuery("from Person") List<Person> personList = lQuery.getResultList(); However, I get a warning saying that this is an unchecked conversion from List to List<Person> I thought that simply changing the code to Query lQuery = myEntityManager.createQuery("from Person") List<Person> personList = (List<Person>)lQuery.getResultList(); would work.. but it doesn't. Is there a way to do this ? Does persistence allow me to set the return type of the query ? (Through generics maybe ? )

    Read the article

  • Java. Writing a matrix in a file using column information. ( matrix transposition )

    - by Dmitry
    Hello, everybody! I have a file in which a matrix is stored. This file has a RandomAccessFile type. This matrix is stored by columns. I mean that in an i-th row of this matrix an i-th column (of a real matrix) is stored. There is an example: i-th row: 1 2 3 4 (in the file). That means that the real matrix has an i-th column: (1 2 3 4)(is transposed). I need to save this matrix in a natural way (by rows) in a new file, which I will then open with FileReader and display with TextArea. Do you know, how to do that? If so, please help =)

    Read the article

  • Multithreaded java cache for objects that are heavy to create ?

    - by krosenvold
    I need a cache some objects with fairly heavy creation times, and I need exactly-once creation semantics. It should be possible to create objects for different CacheKeys concurrently. I think I need something that (under the hood) does something like this: ConcurrentHashMap<CacheKey, Future<HeavyObject>> Are there any existing open-source implementations of this that I can re-use ?

    Read the article

  • How to set session timeout dinamically in java web applications?

    - by Jonathas Carrijo
    Hi, I need to give my user a web interface to change the session timeout interval. So, each installation of the application might have different timeouts for their sessions, but they web.xml cannot be different. Is there a way to set the session timeout programatically, so that I could use, say, ServletContextListener.contextInitialized() to read the configured interval and set it upon application startup? Thanks a lot.

    Read the article

  • How can two programs talk to each other in Java?

    - by Arnon
    I want to ?reduce? the CPU usage/ROM usage/RAM usage - generally?, all system resources that my app uses - who doesn't? :) For this reason I want to split the preferences window from the rest of the application, and let the preferences window to run as ?independent? program. The preferences program ?should? write to a Property file(not a problem at all) and to send a "update signal" to the main program - which means it should call the update method (that i wrote) that found in the Main class. How can I call the update method in the Main program from the preferences program? To put it another way, is a way to build preferences window that take system resources just when the window appears? Is this approach - of separating programs and let them talk to each other (somehow) - the right approach for speeding up my programs?

    Read the article

  • Java, How to Instance HttpCookie from a String, any convenient ways?

    - by user435657
    Hi all, I have got a cookie string from HTTP response header like the following line: name=value; path=/; domain=.g.cn; expire=... I can parse the above line to key-value pairs, and, also it's easy to set the name and value to HttpCookie instance as this pair comes the first. But how to set the other pairs since I don't know which set-method corresponds to the name of the next name-value pair. Traverse all possible keys a cookie may contian and call the matched set-method, like below snippet? if (key.equalsIgnoreCase("path")) cookie.setPath(value); else if (key.equalsIgnoreCase("domain")) cookie.setDomain(value); That's foolish, any convenient ways? Thanks in advance.

    Read the article

  • Why am I getting a Java NoSuchPortException when the port exists?

    - by user258526
    Got the following production code below, I'm using it for a new driver. portName is COM4 and this port exists on the PC (and I can connect to it with hyperterminal), so why does Javacomm throw a NoSuchPortException? COM4 shows up fine in device mgr. too final String portName = getSerialPort(); try { final CommPortIdentifier id = CommPortIdentifier.getPortIdentifier(portName); port = (SerialPort) id.open(getName(), 1000); } catch (NoSuchPortException nspe) { report(SeverityCode.LEVEL2, getName(), "PIN Pad is not connected to " + portName + " port, or the port does not exist."); return; } catch (PortInUseException piue) { report(SeverityCode.LEVEL2, getName(), portName + " port is already in-use by some other device. Reason: " + piue.getMessage()); return; }

    Read the article

  • My java program seems to be skipping over the try{}, executing the catch{} and then throwing a NullPointerException. What should I do?

    - by Matt Bolopue
    I am writing a program that calculates the number of words, syllables, and sentences in any given text file. I don't need help finding those numbers, however my program (which currently should only find the number of words in the text file) will not import the text file even when I type in the name of the file correctly. The text file is in the same folder as the source code. Instead it tells me every time that what I typed in has the wrong file extension (see my catch{}) and then proceeds to throw a null pointer. I am at a loss for what could be causing it. Any suggestions? import java.io.*; import java.util.*; public class Reading_Lvl_Calc { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int words = 0; String fileName; Scanner scan; Scanner keyread = new Scanner(System.in); System.out.println("Please enter a file name (or QUIT to exit)"); fileName = keyread.nextLine(); File doc = new File(fileName); //while(scan.equals(null)){ try { scan = new Scanner(doc); } catch(Exception e) { if(fileName.substring(fileName.indexOf(".")) != ".txt") System.out.println("I'm sorry, the file \"" + fileName + "\" has an invalid file extension."); else System.out.println("I am sorry, the file \"" + fileName + " \" cannot be found.\n The file must be in the same directory as this program"); scan = null; } // } while(scan.hasNext()){ words++; scan.next(); } System.out.println(words); } }

    Read the article

  • java: how to make srollable panel with radio button and labels inside?

    - by Lucia
    Hi, I got a JScrollPane in which I want to place a list of radio buttons and labels. My problem is the panel doesn't scroll, I suppose it's because i didn't set a viewport, but how can I set it when I have to many components? My code looks something like this: JScrollPane panel = new JScrollPane(); JRadioButton myRadio; JLabel myLabel; for(int i = 0; i<100; i++){ myRadio = new JRadioButton(); myLabel = new JLabel("text"); panel.add(myRadio); panel.add(myLabel); } Thanks.

    Read the article

  • Java JIT compiler compiles at compile time or runtime ?

    - by Tony
    From wiki: In computing, just-in-time compilation (JIT), also known as dynamic translation, is a technique for improving the runtime performance of a computer program. So I guess JVM has another compiler, not javac, that only compiles bytecode to machine code at runtime, while javac compiles sources to bytecode,is that right?

    Read the article

  • How to implement event listener in background of the main program in java?

    - by Johny
    Hi im a beginner so sorry for my question if it sounds naive. I want to implement a thread that runs in the background and listens all the time. By listening i mean, say it keeps check on a value returned from main thread and if the vaue exceeds certain figure, it executes some method, or say exits the program. If you could give me some idea or at least refer me to something useful, that'll be great.

    Read the article

  • Is there an easy way to copy an iterator into a list in Java?

    - by Space_C0wb0y
    I want something like this: public void CopyIteratorIntoList(Iterator<Foo> fooIterator) { List<Foo> fooList = new ArrayList<Foo>(); fooList.addAll(fooIterator); } which should be equivalent to: public void CopyIteratorIntoList(Iterator<Foo> fooIterator) { List<Foo> fooList = new ArrayList<Foo>(); while(fooIterator.hasNext()) fooList.add(fooIterator.next()); } Is there any method in the API to achieve that, or is this the only way?

    Read the article

  • How to access a subset of XML data in Java when the XML data is too large to fit in memory?

    - by Michael Jones
    What I would really like is a streaming API that works sort of like StAX, and sort of like DOM/JDom. It would be streaming in the sense that it would be very lazy and not read things in until needed. It would also be streaming in the sense that it would read everything forwards (but not backwards). Here's what code that used such an API would look like. URL url = ... XMLStream xml = XXXFactory(url.inputStream()) ; // process each <book> element in this document. // the <book> element may have subnodes. // You get a DOM/JDOM like tree rooted at the next <book>. while (xml.hasContent()) { XMLElement book = xml.getNextElement("book"); processBook(book); } Does anything like this exist?

    Read the article

  • Java: most efficient way to defensively copy an int[]?

    - by Jason S
    I have an interface DataSeries with a method int[] getRawData(); For various reasons (primarily because I'm using this with MATLAB, and MATLAB handles int[] well) I need to return an array rather than a List. I don't want my implementing classes to return the int[] array because it is mutable. What is the most efficient way to copy an int[] array (sizes in the 1000-1000000 length range) ? Is it clone()?

    Read the article

  • Remove successive 0th entries in args[] for a Java command line interface?

    - by Bill IV
    I recall seeing, somewhere, an example that stepped through String args[] by deleting the lowest numbered value(s) public static void main( String args[]) { while (args.length > 0 ) { // do something and obliterate elements from args[] } } Obviously, a variable tracking current position in args and compared to args.length will do it; or an ArrayList made from args[]'s contents, with argsAL.size(). Am I mis-remembering an ArrayList example? I know this is a borderline question, the likely answer is, "No, there isn't and there shouldn't be either!". Maybe I'm over-focused... Bill

    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 | 479 480 481 482 483 484 485 486 487 488 489 490  | Next Page >