Search Results

Search found 46894 results on 1876 pages for 'java native interface'.

Page 339/1876 | < Previous Page | 335 336 337 338 339 340 341 342 343 344 345 346  | Next Page >

  • java multiple operations depending on the type of the object passed

    - by mixm
    assuming i create a method which is passed an object, and that method would perform an action depending on the object passed. how should i identify the object? i thought of using the class name to identify the object, but may be impractical since i could easily change the class name of objects, and generate headaches during future development. am i right?

    Read the article

  • Java generic return tpye

    - by Colby77
    Hi, I'd like to write a method that can accept a type param (or whatever the method can figure out the type from) and return a value of this type so I don't have to cast the return type. Here is a method: public Object doIt(Object param){ if(param instanceof String){ return "string"; }else if(param instanceof Integer){ return 1; }else{ return null; } } When I call this method, and pass in it a String, even if I know the return type will be a String I have to cast the return Object. This is similar to the int param. How shall I write this method to accept a type param, and return this type?

    Read the article

  • Sorting an array of strings in reverse alphabetical order in Java

    - by Quacky
    I've been tasked with turning this code into a reverse sort, but for the life of me cannot figure out how to do it. These are my sort, findlargest and swap methods. I have a feeling I am missing something glaringly obvious here, any help would be really appreciated. public static void sort(String[] arr) { for (int pass = 1; pass < arr.length; pass++) { int largestPos = findLargest(arr, arr.length - pass); if (largestPos != arr.length - pass) { swap(arr, largestPos, arr.length - pass); } } } public static int findLargest(String[] arr, int num) { int largestPos = 0; for (int i = 1; i <= num; i++) { if (arr[i].compareToIgnoreCase(arr[largestPos]) > 0) { largestPos = i; } } return largestPos; } public static void swap(String[] arr, int first, int second) { String temp = arr[first]; arr[first] = arr[second]; arr[second] = temp; } }

    Read the article

  • Real life Java Swing Project

    - by santiagobasulto
    Hi everybody! I've been working with swing for the last 2 years, but i'm still not satisfy with my own work. The apps are "fast" enough, but the development isn't enough "clean". Can you recommend me any real world project, book, or something similar that shows me how a real world swing app work. May be a framework, something structured, etc. For example, i'm thinking i may code a "window manager" that has all the window of the app in an unified resource, may be cached, etc. I think all those good ideas must be implemented already. Thanks!

    Read the article

  • Garbage Collection in Java

    - by simion
    On the slides I am revising from it says the following: Live objects can be identified either by maintaining a count of the number of references to each object, or by tracing chains of references from the roots. Reference counting is expensive – it needs action every time a reference changes and it doesn’t spot cyclical structures, but it can reclaim space incrementally. Tracing involves identifying live objects only when you need to reclaim space – moving the cost from general access to the time at which the GC runs, typically only when you are out of memory. I understand the principles of why reference counting is expensive but do not understand what "doesn’t spot cyclical structures, but it can reclaim space incrementally." means. Could anyone help me out a little bit please? Thanks

    Read the article

  • Access check on folder in java

    - by Bhaskar
    I'm using the following code to check the access on selected folder. but it's not working. private boolean writeAccess(String path){ try { AccessController.checkPermission(new FilePermission(path, "read,write"));/*,*/ // Has permission return true; } catch (SecurityException e) { // Does not have permission return false; } } wt is prblm in it. and is there any other options to check the existance and access on the folders/directories?

    Read the article

  • Java convert time format to integer or long

    - by behrk2
    Hello, I'm wondering what the best method is to convert a time string in the format of 00:00:00 to an integer or a long? My ultimate goal is to be able to convert a bunch of string times to integers/longs, add them to an array, and find the most recent time in the array... I'd appreciate any help, thanks! Ok, based on the answers, I have decided to go ahead and compare the strings directly. However, I am having some trouble. It is possible to have more than one "most recent" time, that is, if two times are equal. If that is the case, I want to add the index of both of those times to an ArrayList. Here is my current code: days[0] = "15:00:00"; days[1] = "17:00:00"; days[2] = "18:00:00"; days[3] = "19:00:00"; days[4] = "19:00:00"; days[5] = "15:00:00"; days[6] = "13:00:00"; ArrayList<Integer> indexes = new ArrayList<Integer>(); String curMax = days[0]; for (int x = 1; x < days.length1; x++) { if (days[x].compareTo(curMax) > 0) { curMax = days[x]; indexes.add(x); System.out.println("INDEX OF THE LARGEST VALUE: " + x); } } However, this is adding index 1, 2, and 3 to the ArrayList... Can anyone help me?

    Read the article

  • performing auditing in java with sql server DB - before and/or after do not get audited

    - by Domingos
    When auditing, sometimes the before value does not get audited, other times the after value does not get audited, other times both values do not get audited at all. After researching, I found out that only values from a specific codes table get audited. the code was: compareCodesTableInteger(audit, int, int, objectBefore, objectAfter, stringDescription, stringCodesTable); I then changed it to: compareCodesTableInteger(audit, int, int, objectBefore, objectAfter, stringDescription, booleanCheck ? stringCodesTableIfTrue : stringCodesTableIfFalse); Description: if objectBefore AND objectAfter are both from stringCodesTableIfTrue OR from stringCodesTableIfFalse, auditing takes place as expected. The problem is: most of the times, objectBefore is from stringCodesTableIfTrue, and objectAfter is from stringCodesTableIfFalse, or vice-versa. In this scenario auditing fails. How do I go around this? Please assist

    Read the article

  • Java Font Display Problem

    - by Yan Cheng CHEOK
    I realize that, in my certain customer side, when I use the font provided by Graphics2D itself, and decrease the size by 1, it cannot display properly. private void drawInformationBox(Graphics2D g2, JXLayer<? extends V> layer) { if (MainFrame.getInstance().getJStockOptions().getYellowInformationBoxOption() == JStockOptions.YellowInformationBoxOption.Hide) { return; } final Font oldFont = g2.getFont(); final Font paramFont = new Font(oldFont.getFontName(), oldFont.getStyle(), oldFont.getSize()); final FontMetrics paramFontMetrics = g2.getFontMetrics(paramFont); final Font valueFont = new Font(oldFont.getFontName(), oldFont.getStyle() | Font.BOLD, oldFont.getSize() + 1); final FontMetrics valueFontMetrics = g2.getFontMetrics(valueFont); /* * This date font cannot be displayed properly. Why? */ final Font dateFont = new Font(oldFont.getFontName(), oldFont.getStyle(), oldFont.getSize() - 1); final FontMetrics dateFontMetrics = g2.getFontMetrics(dateFont); Rest of the font is OK. Here is the screen shoot (See the yellow box. There are 3 type of different font within the yellow box) :

    Read the article

  • Using enums in Java across multiple classes

    - by Richard Mar.
    I have the following class: public class Card { public enum Suit { SPACES, HEARTS, DIAMONDS, CLUBS }; public Card(Suit nsuit, int nrank) { suit = nsuit; rank = nrank; } private Suit suit; private int rank; } I want to instantiate it in another class, but that class doesn't understand the Suit enum. Where should I put the enum to make it publicly visible?

    Read the article

  • Transfering a set with a Wildcarded Generic to a List in Java

    - by Daniel Bingham
    I have a data type that contains a set and a method that expects List<? extends MyClass>. The data type has Set<? extends MyClass>. I need to be able to move the stuff out of the set and into the List. The order it goes into the list doesn't matter, it just needs to start keeping track of it so that it can be reordered when displayed. Suffice to say that changing the Set into a List in the data type is out of the question here. This seems pretty easy at first. Create a new method that takes a Set instead of a List, changes it into a list and then passes it on to the old method that just took a list. The problem comes in changing the set to a list. public void setData(Set<? extends MyClass> data) { List<? extends Myclass> newData = ArrayList< /* What goes here? */ >(); for(ConcordaEntityBean o : data) { newData.add(o); } setData(newData); } Obviously, I can't instantiate an ArrayList with a wildcard, it chokes. I don't know the type at that point. Is there some way to pull the type out of data and pass it to ArrayList? Can I just instantiate it with MyClass? Is there some other way to do this?

    Read the article

  • Java/Android get array from xml

    - by Ashley
    I have a list of longitude and longitude points in an xml file that is used throughout my application. I find my self repeating this code to get points often and think there must be a better way? String[] mTempArray = getResources().getStringArray(R.array.stations); int len = mTempArray.length; mStationArray = new ArrayList<Station>(); for(int i = 0; i < len; i++){ Station s = new Station(); String[] fields = mTempArray[i].split("[\t ]"); s.setValuesFromArray(fields); Log.i("ADD STATION", ""+s); mStationArray.add(s); } XML is in the format of: <?xml version="1.0" encoding="utf-8"?> <resources> <array name="stations"> <item> <name>Station name</name> <longitude>1111111</longitude> <latitude>11111</latitude> <code>1</code> </item> And another (possible) problem is that to get just one station I have to get all of them and pull the one I want from the array. Is this going to be considerably slower? Can I make this array consistent throughout the app? (But keeping the separate Intent methodology)

    Read the article

  • java beginner- in which folder should I place a "database.properties" file

    - by Arvind
    I read some tutorials on how to read data from a database.properties file- which basically stored key-value pairs. What i want to know is, in which folder should I place this file? Is it in the root (ie "src") or within a package... And how do I access this file, if it is placed in "src"- my code will be within a package (and the package's directory will be under src)- so how do I access the properties file, which is in "src", from a class within a package?

    Read the article

  • implementing keepalives with Java

    - by Bilal
    Hi All, I am biulding a client-server application where I have to implement a keepalive mechanism in order to detect that the client has crashed or not. I have separate threads on both client and server side. the client thread sends a "ping" then sleeps for 3 seconds, while the server reads the BufferedInput Stream and checks whether ping is received, if so it makes the ping counter eqauls zero, else it increments the counter by +1, the server thread then sleeps for 3 seconds, if the ping counter reaches 3, it daclares the client as dead. The problem is that when the server reads the input stream, its a blocking call, and it blocks untill the next ping is received, irrespective of how delayed it is, so the server never detects a missed ping. any suggestions, so that I can read the current value of the stream and it doesn't block if there is nothing on the incoming stream. Thanks,

    Read the article

  • java: how to parse html-like xml

    - by Yang
    I have an html-like xml, basically it is html. I need to get the elements in each . Each element looks like this: <line tid="744476117"> <attr>1414</attr> <attr>31</attr><attr class="thread_title">title1</attr><attr>author1</attr><attr>date1</attr></line> My code is as below, it does recognize that there are 50 in the file, but it gives me NULLPointException when parsing NodeList fstNmElmntLst = fstElmnt.getElementsByTagName("attr"); Any idea why this is happening? The same code has been used for other applications without problems. DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = dbf.newDocumentBuilder(); InputSource is = new InputSource(); is.setCharacterStream(new StringReader(cleanxml)); Document doc = db.parse(is); doc.getDocumentElement().normalize(); System.out.println("Root element " + doc.getDocumentElement().getNodeName()); NodeList nodeLst = doc.getElementsByTagName("line"); for (int s = 0; s < nodeLst.getLength(); s++) { System.out.println(nodeLst.getLength()); Node fstNode = nodeLst.item(s); if (fstNode.getNodeType() == Node.ELEMENT_NODE) { Element fstElmnt = (Element) fstNode; NodeList fstNmElmntLst = fstElmnt.getElementsByTagName("attr"); Element fstNmElmnt = (Element) fstNmElmntLst.item(0); NodeList fstNm = fstNmElmnt.getChildNodes(); System.out.println("attr : " + ((Node) fstNm.item(0)).getNodeValue()); } }

    Read the article

  • How to end a thread in java?

    - by beagleguy
    hi all, I have 2 pools of threads ioThreads = (ThreadPoolExecutor)Executors.newCachedThreadPool(); cpuThreads = (ThreadPoolExecutor)Executors.newFixedThreadPool(numCpus); I have a simple web crawler that I want to create an iothread, pass it a url, it will then fetch the url and pass the contents over to a cpuThread to be processed and the ioThread will then fetch another url, etc... At some point the IO thread will not have any new pages to crawl and I want to update my database that this session is complete. How can I best tell when the threads are all done processing and the program can be ended?

    Read the article

  • permute data for a HashMap in Java

    - by tuxou
    hi i have a linkedhashmap and i need to permute (change the key of the values) between 2 random values example : key 1 value 123 key 2 value 456 key 3 value 789 after random permutation of 2 values key 1 value 123 key 2 value 789 key 3 value 456 so here I permuted values between key 2 and key 3 thank you; sample of the code of my map : Map map = new LinkedHashMap(); map =myMap.getLinkedHashMap(); Set key = map.keySet(); for(Iterator it = cles.iterator(); it.hasNext();) { Integer cle = it.next(); ArrayList values = (ArrayList)map.get(cle);//an arrayList of integers int i = 0; while(i < values.size()) { //i donno what to do here i++; } }

    Read the article

  • Java Variable Initialization

    - by Samuel Brainard
    Here's a piece of code I wrote. public class cube { private int length; private int breadth; private int height; private int volume; private int density; private int weight; public cube(int l,int b,int h, int d) { length=l; breadth=b; height=h; density=d; } public void volmeShow(){ volume=length*breadth*height; System.out.println("The Volume of the cube is "+this.volume); So if I implement the above cube class like this, public class cubeApp { public static void main(String[] args){ cube mycube = new cube(5,6,9,2); mycube.volumeShow(); I get an output that tells me Volume is 270. But I get an output that says Volume is 0 if I define the volume variable like this: public class cube { private int length; private int breadth; private int height; private int volume=length*breadth*height; private int density; private int weight; public cube(int l,int b,int h, int d) { length=l; breadth=b; height=h; density=d; } public void volmeShow(){ System.out.println("The Volume of the cube is "+this.volume); Can somebody please explain why this is happening? Thanks, Samuel.

    Read the article

< Previous Page | 335 336 337 338 339 340 341 342 343 344 345 346  | Next Page >