Search Results

Search found 32961 results on 1319 pages for 'newlearner java'.

Page 291/1319 | < Previous Page | 287 288 289 290 291 292 293 294 295 296 297 298  | Next Page >

• replace values in a String from a Hashtable in Java

  - by Adnan

  My string looks like; String values = "I am from UK, and you are from FR"; and my hashtable; Hashtable countries = new Hashtable(); countries.put("United Kingdom", new String("UK")); countries.put("France", new String("FR")); What would be the most effective way to change the values in my string with the values from the hashtable accordingly. These are just 2 values to change, but in my case I will have 100+

  Read the article

• Java: charAt convert to int?

  - by sling

  Hi, I would like to key in my nirc number eg.S1234567I and then put 1234567 individualy as a integer as indiv1 as charAt(1), indiv2 as charAt(2), indiv as charAt(3), etc. However, when I do as the codes below, I cant seem to get even the first the number out? Any idea? Scanner console = new Scanner(System.in); System.out.println("Enter your NRIC number: "); String nric = console.nextLine(); int indiv1 = nric.charAt(1); System.out.println(indiv1);

  Read the article

• Java: Ignoring escapes when parsing XML

  - by Personman

  I'm using a DocumentBuilder to parse XML files. However, the specification for the project requires that within text nodes, strings like " and < be returned literally, and not turned into the corresponding ASCII values. A previous similar question, http://stackoverflow.com/questions/1979785/read-escaped-quote-as-escaped-quote-from-xml, received one answer that seems to be specific to Apache, and another that appears to simply not not do what it says it does. I'd love to be proven wrong on either count, however :) For reference, here is some code: file = new File(fileName); DocBderFac = DocumentBuilderFactory.newInstance(); DocBder = DocBderFac.newDocumentBuilder(); doc = DocBder.parse(file); NodeList textElmntLst = doc.getElementsByTagName(text); Element textElmnt = (Element) textElmntLst.item(0); NodeList txts = textElmnt.getChildNodes(); String txt = ((Node) txts.item(0)).getNodeValue(); System.out.println(txt); I would like that println() to produce things like &quot;3&gt;2&quot; instead of "3>2" which is what currently happens. Thanks!

  Read the article

• Require a default constructor in java?

  - by jdc0589

  Is there any way to require that a class have a default (no parameter) constructor, aside from using a reflection check like the following? (the following would work, but it's hacky and reflection is slow) boolean valid = false; for(Constructor<?> c : TParse.class.getConstructors()) { if(c.getParameterTypes().length == 0) { valid = true; break; } } if(!valid) throw new MissingDefaultConstructorException(...);

  Read the article

• Math operation in Java

  - by joroj

  Hello, what "^" operator does? when I try this: int a = 5^n; it gives me: for n = 5, returns 0 for n = 4, returns 1 for n = 6, returns 3 What is this?

  Read the article

• Are there any libraries for parsing "number expressions" like 1,2-9,33- in Java

  - by mihi

  Hi, I don't think it is hard, just tedious to write: Some small free (as in beer) library where I can put in a String like 1,2-9,33- and it can tell me whether a given number matches that expression. Just like most programs have in their print range dialogs. Special functions for matching odd or even numbers only, or matching every number that is 2 mod 5 (or something like that) would be nice, but not needed. The only operation I have to perform on this list is whether the range contains a given (nonnegative) integer value; more operations like max/min value (if they exist) or an iterator would be nice, of course. What would be needed that it does not occupy lots of RAM if anyone enters 1-10000000 but the only number I will ever query is 12345 :-) (To implement it, I would parse a list into several (min/max/value/mod) pairs, like 1,10,0,1 for 1-10 or 11,33,1,2 for 1-33odd, or 12,62,2,10 for 12-62/10 (i. e. 12, 22, 32, ..., 62) and then check each number for all the intervals. Open intervals by using Integer.MaxValue etc. If there are no libs, any ideas to do it better/more efficient?)

  Read the article

• RSA implementations for Java, alternative to BC

  - by Tom Brito

  The RSA implementation that ships with Bouncy Castle only allows the encrypting of a single block of data. The RSA algorithm is not suited to streaming data and should not be used that way. In a situation like this you should encrypt the data using a randomly generated key and a symmetric cipher, after that you should encrypt the randomly generated key using RSA, and then send the encrypted data and the encrypted random key to the other end where they can reverse the process (ie. decrypt the random key using their RSA private key and then decrypt the data). I can't use the workarond of using symmetric key. So, are there other implementations of RSA than Bouncy Castle?

  Read the article

• Java: Embedding Soundbank file in JAR

  - by Pyroclastic

  If I have a soundbank stored in a JAR, how would I load that soundbank into my application using resource loading...? I'm trying to consolidate as much of a MIDI program into the jar file as I can, and the last thing I have to add is the soundbank file I'm using, as users won't have the soundbanks installed. I'm trying to put it into my jar file, and then load it with getResource() in the Class class, but I'm getting an InvalidMidiDataException on a soundbank that I know is valid. Here's the code, it's in the constructor for my synthesizer object: try { synth = MidiSystem.getSynthesizer(); channels = synth.getChannels(); instrument = MidiSystem.getSoundbank(this.getClass().getResource("img/soundbank-mid.gm")).getInstruments(); currentInstrument = instrument[0]; synth.loadInstrument(currentInstrument); synth.open(); } catch (InvalidMidiDataException ex) { System.out.println("FAIL"); instrument = synth.getAvailableInstruments(); currentInstrument = instrument[0]; synth.loadInstrument(currentInstrument); try { synth.open(); } catch (MidiUnavailableException ex1) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex1); } } catch (IOException ex) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex); } catch (MidiUnavailableException ex) { Logger.getLogger(MIDISynth.class.getName()).log(Level.SEVERE, null, ex); }

  Read the article

• Java ternary operator and boxing Integer/int?

  - by Markus

  I tripped across a really strange NullPointerException the other day caused by an unexpected type-cast in the ternary operator. Given this (useless exemplary) function: Integer getNumber() { return null; } I was expecting the following two code segments to be exactly identical after compilation: Integer number; if (condition) { number = getNumber(); } else { number = 0; } vs. Integer number = (condition) ? getNumber() : 0; . Turns out, if condition is true, the if-statement works fine, while the ternary opration in the second code segment throws a NullPointerException. It seems as though the ternary operation has decided to type-cast both choices to int before auto-boxing the result back into an Integer!?! In fact, if I explicitly cast the 0 to Integer, the exception goes away. In other words: Integer number = (condition) ? getNumber() : 0; is not the same as: Integer number = (condition) ? getNumber() : (Integer) 0; . So, it seems that there is a byte-code difference between the ternary operator and an equivalent if-else-statement (something I didn't expect). Which raises three questions: Why is there a difference? Is this a bug in the ternary implementation or is there a reason for the type cast? Given there is a difference, is the ternary operation more or less performant than an equivalent if-statement (I know, the difference can't be huge, but still)?

  Read the article

• Implementing Iterable in Java

  - by Artium

  I have the following code public class A extends Iterable<Integer> { ... public Iterator<Integer> iterator() { return new Iterator<Integer>() { A a; public boolean hasNext() { ... } public Integer next() { ... } public void remove(){ ... } }; I would like to initialize the "a" field in the anonymous class with the instance of A that iterator method was called on. Is it possible? Thank you.

  Read the article

• How to access files in Java ME

  - by cancelledout

  I want to access the files encircled in this screenshot. What path should I use? This is for my JavaME application. file:///ParseExample/service1.xml doesn't seem to be the right one. http://www.fileden.com/files/2010/5/28/2872707//projectfiles.JPG

  Read the article

• Java io ugly try-finally block

  - by Tom Brito

  Is there a not so ugly way of treat the close() exception to close both streams then: InputStream in = new FileInputStream(inputFileName); OutputStream out = new FileOutputStream(outputFileName); try { copy(in, out); } finally { try { in.close(); } catch (Exception e) { try { // event if in.close fails, need to close the out out.close(); } catch (Exception e2) {} throw e; // and throw the 'in' exception } out.close(); }

  Read the article

• Java threads not working correctly with linkedlist

  - by user69514

  Hi I am working on the sleeping barber problem. with the addition of having priority customer when they arrive they go in the front of the line and they are the next ones to get a haircut. I'm using a linkedlist and if I see a priority customer I put him in the beginning of the list, if the customer is not priority he goes to the end of the list. then I call the wantHaircut method getting the first element of the list. my problem is that the customer are being processed in the order they arrive, and the priority customer have to wait. here is the code where it all happens. any ideas what I am doing wrong? thanks public void arrivedBarbershop(Customer c){ if(waiting < numChairs && c.isPriority()){ System.out.println("Customer " + c.getID() + ": is a priority customer - SITTING -"); mutex.up(); customer_list.addFirst(c); } else if(waiting >= numChairs && c.isPriority()){ System.out.println("Customer " + c.getID() + ": is a priority customer - STANDING -"); mutex.up(); customer_list.addFirst(c); } else if(waiting < numChairs && !c.isPriority()){ waiting++; System.out.println("Customer " + c.getID() + ": arrived, sitting in the waiting room"); customer_list.addLast(c); customers.up(); // increment waiting customers } else if(waiting >= numChairs && !c.isPriority()) { System.out.println("Customer " + c.getID() + ": went to another barber because waiting room was full - " + waiting + " waiting"); mutex.up(); } if(!customer_list.isEmpty()){ this.wantHairCut(customer_list.removeFirst()); } } public void wantHairCut(Customer c) { mutex.up(); barber.down(); // waits for being allowed in barber chair System.out.println("Customer " + c.getID() + ": getting haircut"); try { /** haircut takes between 1 and 2 seconds **/ Thread.sleep(Barbershop.randomInt(1, 2) * 1000); } catch (InterruptedException e) { } System.out.println("Barber: finished cutting customer " + c.getID() + "'s hair"); c.gotHaircut = true; cutting.up(); // signals cutting has finished /** customer must pay now **/ this.wantToCashout(c); }

  Read the article

• Java FileFilter

  - by Mr CooL

  public class DocFilter extends FileFilter { public boolean accept(File f) { if (f.isDirectory()) { return true; } String extension = Utils.getExtension(f); if (extension != null) { if (extension.equals(Utils.doc) || extension.equals(Utils.docx) ) { return true; } else { return false; } } return false; } //The description of this filter public String getDescription() { return "Just Document Files"; } } Netbeans compiler warned with the error, "No interface expected here" for above code Anyone has idea what was the problem?? I tried changing the 'extends' to 'implements', however, it didn't seem to work that way. and when I changed to implements, the following code cannot work, chooser.addChoosableFileFilter(new DocFilter()); and with this error, "method addChoosableFileFilter in class javax.swing.JFileChooser cannot be applied to given types required: javax.swing.filechooser.FileFilter" Can anyone help on this? Thanks..

  Read the article

• Java Data Structure

  - by Joe

  Hi there, I'm looking for a data structure that will act like a Queue so that I can hava First In First Out behaviour, but ideally I would also be able to see if an element exists in that Queue in constant time as you can do with a HashMap, rather than the linear time that you get with a LinkedList. I thought a LinkedHashMap might do the job, but although I could make an iterator and just take and then remove the first element of the iteration to produce a sort of poll() method, I'm wondering if there is a better way. Many thanks in advance

  Read the article

• Date conversion in Java

  - by llm

  How can I take a string in a format such as: 2008-06-02 00:00:00.0 and convert it to: 02-Jun-2008? Can I somehow take the original string, convert it to a Date object, then use a formatter to get the final output (rather than parsing the string myself)? Thanks!

  Read the article

• Incorrect sizing of a JPanel in a JScrollPane In Java 1.5

  - by Coder

  Hi, I am making an image loading component which consists of a JPanel containing a JScrollPane, which in turn contains another JPanel. What this component does is allows images to be dropped on top of it, after which point the image is loaded and the inner most JPanel is set to the size of the image dropped. This in turn causes the scroll bars to show up and the user can scroll the image. This all works fine. The problem comes in when i try to auto-shrink the image to the maximum visible area in the outer JPanel. In this case i do a uniform scale of the image to be less than or equal to the width and height of the outer JPanel. What happens now is that both the horizontal and vertical scroll bars show up indicating the the inner JPanel is bigger than the visible area (which should not be the case). I verified that the image is scale to the proper dimensions(ie. the maximum width and height is respected). I also verified that if i decrease the maximum height by 3 pixels, then no scroll bars appear. What i believe the problem is, is that panel.getWidth() and panel.getHeight() don't actually return the visible area (maximum area) that sub components can take up. Ie. there is likely some more width and height taken up by the border around the JPanel or something like that. My question is, how do i get around this problem. Functionally all i want is to determine the maximum size a JPanel can be in a JScrollPane, then set the panel to that size and paint an image over top of it and be assured that the scroll bars of the scroll pane will not show up. Right now the scroll bars are set to AS_NEEDED. Thanks!

  Read the article

• Java downcasting dilemma

  - by Shades88

  please have a look at this code here. class Vehicle { public void printSound() { System.out.print("vehicle"); } } class Car extends Vehicle { public void printSound() { System.out.print("car"); } } class Bike extends Vehicle{ public void printSound() { System.out.print("bike"); } } public class Test { public static void main(String[] args) { Vehicle v = new Car(); Bike b = (Bike)v; v.printSound(); b.printSound(); Object myObj = new String[]{"one", "two", "three"}; for (String s : (String[])myObj) System.out.print(s + "."); } } Executing this code will give ClassCastException saying inheritance.Car cannot be cast to inheritance.Bike. Now look at the line Object myObj = new String[]{"one", "two", "three"};. This line is same as Vehicle v = new Car(); right? In both lines we are assigning sub class object to super class reference variable. But downcasting String[]myObj is allowed but (Bike)v is not. Please help me understand what is going on around here.

  Read the article

• Beginner Java Question about Integer.parseInt() and casting

  - by happysoul

  so when casting like in the statement below :- int randomNumber=(int) (Math.random()*5) it causes the random no. generated to get converted into an int.. Also there's this method I just came across Integer.parseInt() which does the same ! i.e return an integer Why two different ways to make a value an int ? Also I made a search and it says parseInt() takes string as an argument.. So does this mean that parseInt() is ONLY to convert String into integer ? What about this casting then (int) ?? Can we use this to convert a string to an int too ? sorry if it sounds like a dumb question..I am just confused and trying to understand Help ?

  Read the article

• Compile error in java application using netbeans - linked project

  - by Malachi

  I have a project which has shared functionality between three other projects and have linked these to existing projects as I normally would using the add project functionality of the libraries folder. This all used to work however when I started up Netbeans yesterday it just wasn't working as in the other projects won't compile even though the projects are linked. It can recognise the packages - just the actual classes themselves were not recognised. I have checked the dist folder of the shared project and the Shared.jar file exists. Any suggestions?

  Read the article

• Help with method logic in Java, hw

  - by Crystal

  I have a Loan class that in its printPayment method, it prints the amortization table of a loan for a hw assignment. We are also to implement a print first payment method, and a print last payment method. Since my calculation is done in the printPayment method, I didn't know how I could get the value in the first or last iteration of the loop and print that amount out. One way I can think of is to write a new method that might return that value, but I wasn't sure if there was a better way. Here is my code: public abstract class Loan { public void setClient(Person client) { this.client = client; } public Person getClient() { return client; } public void setLoanId() { loanId = nextId; nextId++; } public int getLoanId() { return loanId; } public void setInterestRate(double interestRate) { this.interestRate = interestRate; } public double getInterestRate() { return interestRate; } public void setLoanLength(int loanLength) { this.loanLength = loanLength; } public int getLoanLength() { return loanLength; } public void setLoanAmount(double loanAmount) { this.loanAmount = loanAmount; } public double getLoanAmount() { return loanAmount; } public void printPayments() { double monthlyInterest; double monthlyPrincipalPaid; double newPrincipal; int paymentNumber = 1; double monthlyInterestRate = interestRate / 1200; double monthlyPayment = loanAmount * (monthlyInterestRate) / (1 - Math.pow((1 + monthlyInterestRate),( -1 * loanLength))); System.out.println("Payment Number | Interest | Principal | Loan Balance"); // amortization table while (loanAmount >= 0) { monthlyInterest = loanAmount * monthlyInterestRate; monthlyPrincipalPaid = monthlyPayment - monthlyInterest; newPrincipal = loanAmount - monthlyPrincipalPaid; loanAmount = newPrincipal; System.out.printf("%d, %.2f, %.2f, %.2f", paymentNumber++, monthlyInterest, monthlyPrincipalPaid, loanAmount); } } /* //method to print first payment public double getFirstPayment() { } method to print last payment public double getLastPayment() { }*/ private Person client; private int loanId; private double interestRate; private int loanLength; private double loanAmount; private static int nextId = 1; } Thanks!

  Read the article

• Getting specific values with regex [JAVA, ANDROID]

  - by David

  I need to knowingly isolate each row of the vcard and get its value. For instance, I want to get "5555" from X-CUSTOMFIELD. So far, my thoughts are: "X-CUSTOMFIELD;\d+" I have been looking at some tutorials and I am a little confused with what function to use? What would my regex above return? Would it give me the whole line or just the numerical part (5555)? I was thinking I i get the whole row, I can use substring to get the digits? BEGIN:VCARD VERSION:2.1 N:Last;First; FN:First Last TEL;HOME;VOICE:111111 TEL;MOBILE;VOICE:222222 X-CUSTOMFIELD;5555 END:VCARD

  Read the article

• java: speed up reading foreign characters

  - by Yang

  My current code needs to read foreign characters from the web, currently my solution works but it is very slow, since it read char by char using InputStreamReader. Is there anyway to speed it up and also get the job done? // Pull content stream from response HttpEntity entity = response.getEntity(); InputStream inputStream = entity.getContent(); StringBuilder contents = new StringBuilder(); int ch; InputStreamReader isr = new InputStreamReader(inputStream, "gb2312"); // FileInputStream file = new InputStream(is); while( (ch = isr.read()) != -1) contents.append((char)ch); String encode = isr.getEncoding(); return contents.toString();

  Read the article

• Java; casting base class to derived class

  - by incrediman

  Why can't I cast a base class instance to a derived class? For example, if I have a class B which extends a class C, why can't I do this? B b=(B)(new C()); or this? C c=new C(); B b=(B)c;

  Read the article

• Read / Write XML file from Java application bundle

  - by Peter

  Hi there! I've got an XML file that is parsed and written in my application. From within my IDE (Eclipse) I simply address it like this: Reading: private String xmlFile = "file.xml"; and then I build the document: doc = sax.build(xmlFile); Writing is done like this: writer = new FileWriter("file.xml"); Runs great so far, but after bundling my application, the file is no longer accessible. What exactly do I have to do to make it accessible from within an application bundle? I'm absolutely not familiar with the classpath or whatever I need for that, so please go easy on me! Thank you very much!

  Read the article

< Previous Page | 287 288 289 290 291 292 293 294 295 296 297 298  | Next Page >