Search Results

Search found 33472 results on 1339 pages for 'java coder'.

Page 242/1339 | < Previous Page | 238 239 240 241 242 243 244 245 246 247 248 249  | Next Page >

  • Project Euler, Problem 10 java solution not working

    - by Dennis S
    Hi, I'm trying to find the sum of the prime numbers < 2'000'000. This is my solution in java but I can't seem get the correct answer. Please give some input on what could be wrong and general advice on the code is appreciated. Printing 'sum' gives: 1308111344, which is incorrect. /* The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below two million. */ class Helper{ public void run(){ Integer sum = 0; for(int i = 2; i < 2000000; i++){ if(isPrime(i)) sum += i; } System.out.println(sum); } private boolean isPrime(int nr){ if(nr == 2) return true; else if(nr == 1) return false; if(nr % 2 == 0) return false; for(int i = 3; i < Math.sqrt(nr); i += 2){ if(nr % i == 0) return false; } return true; } } class Problem{ public static void main(String[] args){ Helper p = new Helper(); p.run(); } }

    Read the article

  • little java help....

    - by jona
    Hi I am doing some practice problems and trying to print a diagonal line like the example below. I have writen the program you see below and I honestly dont understand what I am doing wrong. I m a java beginner and I cant see how to find the error. Example ( If you only see a straight line of stars...then imagine it diagonally....from top left to bottom right) * * * * * code: class Diagonal{ public static void main(String args[]) { int row, col; for(row = 1; row < 6; row++) { for(col = 1; col <= row; col++) { if(col==row){ System.out.print("*"); } else{ System.out.print(""); } System.out.println(); } } } } I am trying to learn for loops because they really confuse me. Another practice is to print a similar diagonal line but this time from right to left. I cant do that without getting this right however :( I believe they will be pretty similar? Above my reasining is this: As long as the column # is the same as the row number the print the line or otherwise leave a blank....what's wrong with how i did it? THANK YOU!

    Read the article

  • Java Concurrency in practice sample question

    - by andy boot
    I am reading "Java Concurrency in practice" and looking at the example code on page 51. According to the book this piece of code is at risk of of failure if it has not been published properly. Because I like to code examples and break them to prove how they work. I have tried to make it throw an AssertionError but have failed. (Leading me to my previous question) Can anyone post sample code so that an AssertionError is thrown? Rule: Do not modify the Holder class. public class Holder{ private int n; public Holder(int n){ this.n = n; } public void assertSanity(){ if (n != n) { throw new AssertionError("This statement is false"); } } } I have modified the class to make it more fragile but I still can not get an AssertionError thrown. class Holder2{ private int n; private int n2; public Holder2(int n) throws InterruptedException{ this.n = n; Thread.sleep(200); this.n2 = n; } public void assertSanity(){ if (n != n2) { throw new AssertionError("This statement is false"); } } } Is it possible to make either of the above classes throw an AssertionError? Or do we have to accept that they may occasionally do so and we can't write code to prove it?

    Read the article

  • How do I declare "Member Fields" in Java?

    - by Bub
    This question probably reveals my total lack of knowledge in Java. But let me first show you what I thought was the correct way to declare a "member field": public class NoteEdit extends Activity { private Object mTitleText; private Object mBodyText; I'm following a google's notepad tutorial for android (here) and they simply said: "Note that mTitleText and mBodyText are member fields (you need to declare them at the top of the class definition)." I thought I got it and then realized that this little snippet of code wasn't working. if (title != null) { mTitleText.setText(title); } if (body != null) { mBodyText.setText(body); } So either I didn't set the "member fields" correctly which I thought all that was needed was to declare them private Objects at the top of the NoteEdit class or I'm missing something else. Thanks in advance for any help.UPDATE I was asked to show where these fields were being intialized here is another code snippet hope that it's helpful... @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.note_edit); Long mRowId; mTitleText = (EditText) findViewById(R.id.title); mBodyText = (EditText) findViewById(R.id.body);

    Read the article

  • Translation of a RoR view to Java

    - by mnml
    Hi, for some reasons I am trying to translate the following RoR view code to a GSP view: List<Object> objectscontains the data I want to display in 3 columns <% modulo_objects = @objects.length % 3 base = @objects.length / 3 base = base.ceil case modulo_objects when 0 cols = [base, base, base] when 1 cols = [base, base + 1, base] when 2 cols = [base + 1, base, base + 1] end counter = 0 %> <% 3.times do |i| %> <td width="220" align="center" style="padding-right: 15px;"> <% cols[i].times do %> <h1><a href="/objects/show/<%= @objects[counter].urlname %>" ><%= @objects[counter].name %></a></h1> <% counter = counter + 1 %> <% end %> </td> <% end %> This is what I got so far: #{extends 'main.html' /} %{ modulo_objects = objects.size() % 3 base = objects.size() / 3 base = Math.ceil(base) if(modulo_objects == 0) cols = [base, base, base] else if(modulo_objects == 1) cols = [base, base + 1, base] else if(modulo_objects == 2) cols = [base + 1, base, base + 1] endif counter = 0 }% #{list items:1..3, as:'i'} <td width="220" align="center" style="padding-right: 15px;"> #{list items:cols[i]} <a href="@{Objects.show(objects.get(counter).name.replaceAll(" ", "-"))}" >${objects.get(counter).name}</a> %{ counter = counter + 1 }% #{/list} </td> #{/list} The idea is to keep the items organised in 3 columns like 1|0|1 4|5|4 or 5|4|5 for example, I don't really understand if #{list items:cols[i]} will reproduce ruby's cols[i].times do. So far the Java view is does not display more than two elements.

    Read the article

  • SWIG interface to receive an opaque struct reference in Java through function argument

    - by Beeo
    I am trying to use SWIG in order to use the Spotify API (libspotify) for Android: https://developer.spotify.com/technologies/libspotify/ I am having trouble defining the SWIG interface file to be able to successfully call the following native C function: sp_error sp_session_create(const sp_session_config * config, sp_session ** sess); Which in C would be called like this: //config struct defined previously sp_session *sess; sp_session_create(&config, &sess); But in Java I would need to call it like this: //config object defined previously sp_session javaSess = new sp_session(); sp_session_create(config, javaSess); sp_session is an opaque struct and is only defined in libspotify's API.h file as: typedef struct sp_session sp_session; I'm expecting the libspotify library to create it and give me a reference to it. The only thing I need that reference for then is to pass to other functions in the API. I believe the answer lies within the SWIG interface and typemaps, but I have been unsuccessful in trying to apply the examples I found in the documentation: http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_struct_pointer_pointer `http://www.swig.org/Doc2.0/SWIGDocumentation.html#Java_using_typemaps_return_arguments Help!

    Read the article

  • Java - Problem in deploying Web Application

    - by Yatendra Goel
    I have built a Java Web Application and packed it in a .war file and tested it on my local tomcat server and it is running fine. But when I deployed it on my client's server, it is showing an error. According to the remote server (my client's server), it is not finding a tld file packed in a jar file which I had placed in WEB-INF/lib directory. But when I checked the WEB-INF/lib directory for the jar file, i found that it was there. The contents of META-INF/MANIFEST.MF is as follows: Manifest-Version: 1.0 Class-Path: I think that there is no need to explicitly mention the classpath of WEB-INF/lib directory as it is in the classpath of any web application by default. Then, why the server can't find the jar file in the lib directory when I deployed it on a remote server and why it is working when I deployed the same application on my local server. I posted a question for this at http://stackoverflow.com/questions/2441254/struts-1-struts-taglib-jar-is-not-being-found-by-my-web-application but found that the problem is unusual as nobody could answer it. So my questions are as follows: Q1. Is WEB-INF/lib still remains on the classpath if I leave the classpath entry blank as shown above in the MANIFEST.MF file or I should delete the classpath entry completely from the file or I should explicitly enter Class-Path: /WEB-INF/lib as the classpath entry? Q2. I have JSP pages, Servlets and some helper classes in the web application. Jsp pages are located at the root. Servlets and helper classes are located in WEB-INF/classes folder. So Is there any problem if my helper classes are located in the WEB-INF/classes folder? Note: Please note that this question is not same as my previous question. It is a follow-up question of my previous question. Both the servers (local and remote) are tomcat servers.

    Read the article

  • exception in thread "main" java.lang.NoclassDefFoundError: cal/class

    - by Gaurav
    enter import java.io.*; class eval { double add(double a,double b) { return (a+b); } double sub(double a,double b) { return (a-b); } double mul(double a,double b) { return (a*b); } double div(double a,double b) { return (a/b); } } class cal extends eval { public static void main(String args[])throws IOException { eval a1=new eval(); try{ System.out.println("1) Add"); System.out.println("2) Subtract"); System.out.println("3) Multiply"); System.out.println("4) Divide"); System.out.println("5) Enter your choice"); BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); int ch;ch=Integer.parseInt(br.readLine()); System.out.println("Enter two number"); double a;a=Integer.parseInt(br.readLine()); double b;b=Integer.parseInt(br.readLine()); switch(ch) { case 1: a1.add(a,b); break; case 2: a1.sub(a,b); break; case 3: a1.mul(a,b); break; case 4: a1.div(a,b); break; } } catch (IOException e) { System.out.println("Error occured, please restart application."); } } }

    Read the article

  • Java Generics Class Parameter Type Inference

    - by Pindatjuh
    Given the interface: public interface BasedOnOther<T, U extends BasedList<T>> { public T getOther(); public void staticStatisfied(final U list); } The BasedOnOther<T, U extends BasedList<T>> looks very ugly in my use-cases. It is because the T type parameter is already defined in the BasedList<T> part, so the "uglyness" comes from that T needs to be typed twice. Problem: is it possible to let the Java compiler infer the generic T type from BasedList<T> in a generic class/interface definition? Ultimately, I'd like to use the interface like: class X implements BasedOnOther<BasedList<SomeType>> { public SomeType getOther() { ... } public void staticStatisfied(final BasedList<SomeType> list) { ... } } // Does not compile, due to invalid parameter count. Instead: class X implements BasedOnOther<SomeType, BasedList<SomeType>> { public SomeType getOther() { ... } public void staticStatisfied(final BasedList<SomeType> list) { ... } }

    Read the article

  • Converting to a column oriented array in Java

    - by halfwarp
    Although I have Java in the title, this could be for any OO language. I'd like to know a few new ideas to improve the performance of something I'm trying to do. I have a method that is constantly receiving an Object[] array. I need to split the Objects in this array through multiple arrays (List or something), so that I have an independent list for each column of all arrays the method receives. Example: List<List<Object>> column-oriented = new ArrayList<ArrayList<Object>>(); public void newObject(Object[] obj) { for(int i = 0; i < obj.length; i++) { column-oriented.get(i).add(obj[i]); } } Note: For simplicity I've omitted the initialization of objects and stuff. The code I've shown above is slow of course. I've already tried a few other things, but would like to hear some new ideas. How would you do this knowing it's very performance sensitive?

    Read the article

  • Java if statement strings and more

    - by user1820578
    I have decided to try and learn a little in java tonight and i have just been trying some stuff with things i have learned. My question is in an if statement how to i make two stings to be true. Here is what i have so far. if ("male".equals(gender)) && ("brendan".equals(name)) the problem i am pretty sure is the && but i am not sure. also my other question is with gender it should either be male or female. I want to have if statement with male and another for female. For this do i just do another if. For eg if ("male".equals(gender)) && ("brendan".equals(name)) { System.out.println("blah blah"); } else { System.out.println(" wrong wrong"); } if ("female".equals(gender)) { System.out.println("blah blah2"); } else { System.out.println(" wrong wrong 2"); } hope that makes sense. Any help would be great.

    Read the article

  • Circle to move when mouse clicked Java

    - by Myt
    So I am really new to Java and I need a circle to move around JFrame when it's clicked, but the circle has to get random cordinates. So far this code generates a new circle every time it's clicked, but all the other circles stay there aswell, but I only need one circle to move around the frame. So maybe someone can help me a little :) public class test2 extends JFrame implements MouseListener { int height, width; public test2() { this.setTitle("Click"); this.setSize(400,400); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setVisible(true); addMouseListener(this); width = getSize().width; height = getSize().height; } public void paint (Graphics g) { setBackground (Color.red); g.setColor(Color.yellow); int a, b; a = -50 + (int)(Math.random()*(width+40)); b = (int)(Math.random()*(height+20)); g.fillOval(a, b, 130, 110); } public void mouseClicked(MouseEvent e) { int a, b; a = -50 + (int)(Math.random()*(width+40)); b = (int)(Math.random()*(height+20)); repaint(); } public void mouseReleased(MouseEvent e){} public void mouseEntered(MouseEvent e){} public void mouseExited(MouseEvent e){} public void mousePressed(MouseEvent e){} public static void main(String arg[]){ new test2(); } }

    Read the article

  • Skipping the BufferedReader readLine() method in java

    - by DDP
    Is there a easy way to skip the readLine() method in java if it takes longer than, say, 2 seconds? Here's the context in which I'm asking this question: public void run() { boolean looping = true; while(looping) { for(int x = 0; x<clientList.size(); x++) { try { Comm s = clientList.get(x); String str = s.recieve(); // code that does something based on the string in the line above } // other stuff like catch methods } } } Comm is a class I wrote, and the receive method, which contains a BufferedReader called "in", is this: public String recieve() { try { if(active) return in.readLine(); } catch(Exception e) { System.out.println("Comm Error 2: "+e); } return ""; } I've noticed that the program stops and waits for the input stream to have something to read before continuing. Which is bad, because I need the program to keep looping (as it loops, it goes to all the other clients and asks for input). Is there a way to skip the readLine() process if there's nothing to read? I'm also pretty sure that I'm not explaining this well, so please ask me questions if I'm being confusing.

    Read the article

  • Java getInputStream 400 errors

    - by Bill Szerdy
    When I contact a web service using a Java HttpUrlConnection it just returns a 400 Bad Request (IOException). How do I get the XML information that the server is returning; it does not appear to be in the getErrorStream of the connection nor is it in any of the exception information. When I run the following PHP code against a web service: <?php $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, "https://www.myclientaddress.com/here/" ); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1 ); curl_setopt($ch, CURLOPT_POST,1 ); curl_setopt($ch, CURLOPT_POSTFIELDS,"username=ted&password=scheckler&type=consumer&id=123456789&zip=12345"); $result=curl_exec ($ch); echo $result; ?> it returns the following: <?xml version="1.0" encoding="utf-8"?> <response> <status>failure</status> <errors> <error name="RES_ZIP">Zip code is not valid.</error> <error name="ZIP">Invalid zip code for residence address.</error> </errors> </response> so I know the information exists

    Read the article

  • Wildcards vs. generic methods

    - by FredOverflow
    Is there any practical difference between the following approaches to print all elements in a range? public static void printA(Iterable<?> range) { for (Object o : range) { System.out.println(o); } } public static <T> void printB(Iterable<T> range) { for (T x : range) { System.out.println(x); } } Apparently, printB involves an additional checked cast to Object (see line 16), which seems rather stupid to me -- isn't everything an Object anyway? public static void printA(java.lang.Iterable); Code: 0: aload_0 1: invokeinterface #18, 1; //InterfaceMethod java/lang/Iterable.iterator:()Ljava/util/Iterator; 6: astore_2 7: goto 24 10: aload_2 11: invokeinterface #24, 1; //InterfaceMethod java/util/Iterator.next:()Ljava/lang/Object; 16: astore_1 17: getstatic #30; //Field java/lang/System.out:Ljava/io/PrintStream; 20: aload_1 21: invokevirtual #36; //Method java/io/PrintStream.println:(Ljava/lang/Object;)V 24: aload_2 25: invokeinterface #42, 1; //InterfaceMethod java/util/Iterator.hasNext:()Z 30: ifne 10 33: return public static void printB(java.lang.Iterable); Code: 0: aload_0 1: invokeinterface #18, 1; //InterfaceMethod java/lang/Iterable.iterator:()Ljava/util/Iterator; 6: astore_2 7: goto 27 10: aload_2 11: invokeinterface #24, 1; //InterfaceMethod java/util/Iterator.next:()Ljava/lang/Object; 16: checkcast #3; //class java/lang/Object 19: astore_1 20: getstatic #30; //Field java/lang/System.out:Ljava/io/PrintStream; 23: aload_1 24: invokevirtual #36; //Method java/io/PrintStream.println:(Ljava/lang/Object;)V 27: aload_2 28: invokeinterface #42, 1; //InterfaceMethod java/util/Iterator.hasNext:()Z 33: ifne 10 36: return

    Read the article

  • Java Regex for matching hexadecimal numbers in a file

    - by Ranman
    So I'm reading in a file (like java program < trace.dat) which looks something like this: 58 68 58 68 40 c 40 48 FA If I'm lucky but more often it has several whitespace characters before and after each line. These are hexadecimal addresses that I'm parsing and I basically need to make sure that I can get the line using a scanner, buffered reader... whatever and make sure I can then convert the hexadecimal to an integer. This is what I have so far: Scanner scanner = new Scanner(System.in); int address; String binary; Pattern pattern = Pattern.compile("^\\s*[0-9A-Fa-f]*\\s*$", Pattern.CASE_INSENSITIVE); while(scanner.hasNextLine()) { address = Integer.parseInt(scanner.next(pattern), 16); binary = Integer.toBinaryString(address); //Do lots of other stuff here } //DO MORE STUFF HERE... So I've traced all my errors to parsing input and stuff so I guess I'm just trying to figure out what regex or approach I need to get this working the way I want.

    Read the article

  • Java Scanner newline parsing with regex (Bug?)

    - by SEK
    I'm developing a syntax analyzer by hand in Java, and I'd like to use regex's to parse the various token types. The problem is that I'd also like to be able to accurately report the current line number, if the input doesn't conform to the syntax. Long story short, I've run into a problem when I try to actually match a newline with the Scanner class. To be specific, when I try to match a newline with a pattern using the Scanner class, it fails. Almost always. But when I perform the same matching using a Matcher and the same source string, it retrieves the newline exactly as you'd expect it too. Is there a reason for this, that I can't seem to discover, or is this a bug, as I suspect? FYI: I was unable to find a bug in the Sun database that describes this issue, so if it is a bug, it hasn't been reported. Example Code: Pattern newLinePattern = Pattern.compile("(\\r\\n?|\\n)", Pattern.MULTILINE); String sourceString = "\r\n\n\r\r\n\n"; Scanner scan = new Scanner(sourceString); scan.useDelimiter(""); int count = 0; while (scan.hasNext(newLinePattern)) { scan.next(newLinePattern); count++; } System.out.println("found "+count+" newlines"); // finds 7 newlines Matcher match = newLinePattern.matcher(sourceString); count = 0; while (match.find()) { count++; } System.out.println("found "+count+" newlines"); // finds 5 newlines

    Read the article

  • Java Enumeration of Musical Notes

    - by Crupler
    How would you create an enumeration of the musical notes in Java, with each notes having an octave and then a keyed variable? This is what I have so far... public enum Notes { c, cS, d, dS, e, f, fS, g, gS, a, aS, b; int octave; boolean isPlaying; } So when I access the enums in my code I write something like this... Notes.c.octave = 4; Notes.c.isPlaying = true; Now here is my question: How can I have an isPlaying boolean for each note in each octave? Like so: Notes.c.octave.isPlaying = true; Or would I have to go like: public enum Notes { c1, cS1, d1, dS1, e1, f1, fS1, g1, gS1, a1, aS1, b1 c2, cS2, d2, dS2, e2, f2, fS2, g2, gS2, a2, aS2, b2; etc... boolean isPlaying; } Thank you in advance for taking your time to answer this question!

    Read the article

  • Scale an image which is stored as a byte[] in Java

    - by Sergio del Amo
    I upload a file with a struts form. I have the image as a byte[] and I would like to scale it. FormFile file = (FormFile) dynaform.get("file"); byte[] fileData = file.getFileData(); fileData = scale(fileData,200,200); public byte[] scale(byte[] fileData, int width, int height) { // TODO } Anyone knows an easy function to do this? public byte[] scale(byte[] fileData, int width, int height) { ByteArrayInputStream in = new ByteArrayInputStream(fileData); try { BufferedImage img = ImageIO.read(in); if(height == 0) { height = (width * img.getHeight())/ img.getWidth(); } if(width == 0) { width = (height * img.getWidth())/ img.getHeight(); } Image scaledImage = img.getScaledInstance(width, height, Image.SCALE_SMOOTH); BufferedImage imageBuff = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); imageBuff.getGraphics().drawImage(scaledImage, 0, 0, new Color(0,0,0), null); ByteArrayOutputStream buffer = new ByteArrayOutputStream(); ImageIO.write(imageBuff, "jpg", buffer); return buffer.toByteArray(); } catch (IOException e) { throw new ApplicationException("IOException in scale"); } } If you run out of Java Heap Space in tomcat as I did, increase the heap space which is used by tomcat. In case you use the tomcat plugin for Eclipse, next should apply: In Eclipse, choose Window Preferences Tomcat JVM Settings Add the following to the JVM Parameters section -Xms256m -Xmx512m

    Read the article

  • implementing a Intelligent File Transfer Software in java over TCP/IP

    - by whyjava
    Hello I am working on a proposal where we have to implement a software which can move files between one source to destination.The overall goal of this project is to create intelligent file transfer.This software will have three components :- 1) Broker : Broker is the module that communicates with other brokers, monitors files, moves files, retrieves configurations from the Configuration Manager, supplies process information for the monitor, archives files, writes all process data to log files and escalates issues if necessary 2) Configuration Manager :Configuration Manager is a web-based application used to configure and deploy the configuration to all brokers. 3) Monitor : Monitor is a web-based application used to monitor each Broker in the environment. This project has to be built up in java and protocol for file transfer in tcp/ip. Client does not want to use FTP. File Transfer seems very easy, until there are several processes who are waiting to pick the file up automatically. Several problems arise: How can we guarantee the file is received at the destination? If a file isn’t received the first time, we should try it again (even after a restart or power breakdown) ? How does the receiver knows the file that is received is complete? How can we transfer multiple files synchronously? How can we protect the bandwidth, so file transfer isn’t blocking other processes? How does one interoperate between multiple OS platforms? What about authentication? How can we monitor het workflow? Auditing / logging Archiving Can you please provide answer to some of these? Thanks

    Read the article

  • Java applet loading images from external jars

    - by Mathias
    I have a jar on a server, and users should be able to develop extensions for it. Therefore the jars main class should be extended and some resources should be added to a second user created jar which will be loaded from another server or locally. Now I have problems accessing the resources (images) from the user loaded jars. Heres is the structure: My Server: game.jar containing game.class images.class ... image1.png (...) Local: user.jar containing: user.class extends game userimage.png The extension is loaded via Greasemonkey, it modifies the "archive" attribute to "/home/username/user.jar, game.jar" and the "code" attribute to "user.class". The user should be able to overwrite already defined images. If the image does not exist in game.jar, it is loaded correctly from user.jar. But the images loaded early in the game are always loaded from the game.jar, others seem to be overwritten correctly by the user. Is there a way to make sure they are always loaded in the correct order? This might be because of some caching mechanism. Because Greasemonkey removes the game from the page, changes the archive and code and reinsert it, the game is loaded without a mod for a brief second. In that time, images are loaded as expected from game jar, but those are the ones not being overwritable by the user. But how to avoid it? Another thing: If I overwrite the "run" method in user.class, the game is unable to load any image at all. Not from the user.jar and not from the game.jar. Java doesn't find the image, as the URL object "getClass().getResource(imagename)" returns with null. I tried to overwrite the image.class, but that doesn't fix the problem, unless I overwrite every class from game.class involved into calling the image.class

    Read the article

  • Decimal problem in Java

    - by Jerome
    I am experimenting with writing a java class for financial engineering (hobby of mine). The algorithm that I desire to implement is: 100 / 0.05 = 2000 Instead I get: 100 / 0.05 = 2000.9999999999998 I understand the problem to be one with converting from binary numbers to decimals (float -- int). I have looked at the BigDecimal class on the web but have not quite found what I am looking for. Attached is the program and a class that I wrote: // DCF class public class DCF { double rate; double principle; int period; public DCF(double $rate, double $principle, int $period) { rate = $rate; principle = $principle; period = $period; } // returns the console value public double consol() { return principle/rate; } // to string Method public String toString() { return "(" + rate + "," + principle + "," + period + ")"; } } Now the actual program: // consol program public class DCFmain { public static void main(String[] args) { // create new DCF DCF abacus = new DCF(0.05, 100.05, 5); System.out.println(abacus); System.out.println("Console value= " + abacus.consol() ); } } Output: (0.05,100.05,5) Console value= 2000.9999999999998 Thanks!

    Read the article

  • Java Socket Returns True

    - by ikurtz
    I hope you can help. Im fairly new to progamming and Im playing around with java Sockets. The problem is the code below. for some reason commSocket = new Socket(hostName, portNumber); is returning true even when it has not connected with the server (server not implemented yet!). Any ideas regarding this situation? For hostName Im passing my local machine IP and for port a manually selected port. public void networkConnect(String hostName, int portNumber){ try { networkConnected = false; netMessage = "Attempting Connection"; NetworkMessage networkMessage = new NetworkMessage(networkConnected, netMessage); commSocket = new Socket(hostName, portNumber); // this returns true!! System.out.println(commSocket.isConnected()); networkConnected = true; netMessage = "Connected: "; System.out.println("hellooo"); } catch (UnknownHostException e){ System.out.println(e.getMessage()); } catch (IOException e){ System.out.println(e.getMessage()); } } Many thanks. EDIT: new Socket(.., ..); is blocking isnt it? i thought in that case if that was processed without exceptions then we have a true connection?

    Read the article

  • Java HashMap containsKey always false

    - by Dennis
    I have the funny situation, that I store a Coordinate into a HashMap<Coordinate, GUIGameField>. Now, the strange thing about it is, that I have a fragment of code, which should guard, that no coordinate should be used twice. But if I debug this code: if (mapForLevel.containsKey(coord)) { throw new IllegalStateException("This coordinate is already used!"); } else { ...do stuff... } ... the containsKey always returns false, although I stored a coordinate with a hashcode of 9731 into the map and the current coord also has the hashcode 9731. After that, the mapForLevel.entrySet() looks like: (java.util.HashMap$EntrySet) [(270,90)=gui.GUIGameField@29e357, (270,90)=gui.GUIGameField@ca470] What could I have possibly done wrong? I ran out of ideas. Thanks for any help! public class Coordinate { int xCoord; int yCoord; public Coordinate(int x, int y) { ...store params in attributes... } ...getters & setters... @Override public int hashCode() { int hash = 1; hash = hash * 41 + this.xCoord; hash = hash * 31 + this.yCoord; return hash; } }

    Read the article

  • java url connection, wait for data being sent through the outputstream

    - by Mateu
    I'm writting a java class that tests uploading speed connection to a server. I want to check how many data can be send in 5 seconds. I've written a class which creates a URL, creates a connection, and sends data trough the outPutStream. There is a loop where I writte data to the stream for 5 seconds. However I'm not able to see when data has been send (I writte data to the output stream, but data is not send yet). How can I wait untill data is really sent to the server? Here goes my code (which does not work): URL u = new URL(url) HttpURLConnection uc = (HttpURLConnection) u.openConnection(); uc.setDoOutput(true); uc.setDoInput(true); uc.setUseCaches(false); uc.setDefaultUseCaches(false); uc.setRequestMethod("POST"); uc.setRequestProperty("Content-Type", "application/octet-stream"); uc.connect(); st.start(); // Send the request OutputStream os = uc.getOutputStream(); //This while is incorrect cause it does not wait for data beeing sent while (st.getElapsedTime() < miliSeconds) { os.write(buffer); os.flush(); st.addSize(buffer.length); } os.close(); Thanks

    Read the article

< Previous Page | 238 239 240 241 242 243 244 245 246 247 248 249  | Next Page >