Search Results

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

Page 919/1319 | < Previous Page | 915 916 917 918 919 920 921 922 923 924 925 926  | Next Page >

  • I want a function to return a type of the subclass its invoked from

    - by Jay
    I want to have a function defined in a superclass that returns a value of the type of the subclass that is used to invoke the function. That is, say I have class A with a function plugh. Then I create subclasses B and C that extend A. I want B.plugh to return a B and C.plugh to return a C. Yes, they could return an A, but then the caller would have to either cast it to the right subtype, which is a pain when used a lot, or declare the receiving variable to be of the supertype, which loses type safety. So I was trying to do this with generics, writing something like this: class A<T extends A> { private T foo; public T getFoo() { return foo; } } class B extends A<B> { public void calcFoo() { foo=... whatever ... } } class C extends A<C> { public void calcFoo() { foo=... whatever ... } } This appears to work but it looks pretty ugly. For one thing, I get warnings on "class A". The compiler says that A is generic and I should specify the type. I guess it wants me to say "class A". But what would I put in for x? I think I could get stuck in an infinite loop here. It seems weird to write "class B extends A", but this causes no complaints, so maybe that's just fine. Is this the right way to do it? Is there a better way?

    Read the article

  • String Object. Clarification needed

    - by mac
    Guys, help me clarify. Say i have the following line in my program: jobSetupErrors.append("abc"); In the case above where jobSetupErrors is a StringBuilder(), what i see happen is: New String Object is created and assigned value "abc" value of that String object is assigned to the existing StringBuilder object If that is correct, and I add 1 more line ... jobSetupErrors.append("abc"); logger.info("abc"); In the above example are we creating String object separately 2 times? If so, would it be more proper to do something like this? String a = "abc"; jobSetupErrors.append(a); logger.info(a); Is this a better approach? Please advise

    Read the article

  • Looking for an appropriate design pattern

    - by user1066015
    I have a game that tracks user stats after every match, such as how far they travelled, how many times they attacked, how far they fell, etc, and my current implementations looks somewhat as follows (simplified version): Class Player{ int id; public Player(){ int id = Math.random()*100000; PlayerData.players.put(id,new PlayerData()); } public void jump(){ //Logic to make the user jump //... //call the playerManager PlayerManager.jump(this); } public void attack(Player target){ //logic to attack the player //... //call the player manager PlayerManager.attack(this,target); } } Class PlayerData{ public static HashMap<int, PlayerData> players = new HashMap<int,PlayerData>(); int id; int timesJumped; int timesAttacked; } public void incrementJumped(){ timesJumped++; } public void incrementAttacked(){ timesAttacked++; } } Class PlayerManager{ public static void jump(Player player){ players.get(player.getId()).incrementJumped(); } public void incrementAttacked(Player player, Player target){ players.get(player.getId()).incrementAttacked(); } } So I have a PlayerData class which holds all of the statistics, and brings it out of the player class because it isn't part of the player logic. Then I have PlayerManager, which would be on the server, and that controls the interactions between players (a lot of the logic that does that is excluded so I could keep this simple). I put the calls to the PlayerData class in the Manager class because sometimes you have to do certain checks between players, for instance if the attack actually hits, then you increment "attackHits". The main problem (in my opinion, correct me if I'm wrong) is that this is not very extensible. I will have to touch the PlayerData class if I want to keep track of a new stat, by adding methods and fields, and then I have to potentially add more methods to my PlayerManager, so it isn't very modulized. If there is an improvement to this that you would recommend, I would be very appreciative. Thanks.

    Read the article

  • How do I add an object to a binary tree based on the value of a member variable?

    - by Max
    How can I get a specific value from an object? I'm trying to get a value of an instance for eg. ListOfPpl newListOfPpl = new ListOfPpl(id, name, age); Object item = newListOfPpl; How can I get a value of name from an Object item?? Even if it is easy or does not interest you can anyone help me?? Edited: I was trying to build a binary tree contains the node of ListOfPpl, and need to sort it in the lexicographic. Here's my code for insertion on the node. Any clue?? public void insert(Object item){ Node current = root; Node follow = null; if(!isEmpty()){ root = new Node(item, null, null); return; }boolean left = false, right = false; while(current != null){ follow = current; left = false; right = false; //I need to compare and sort it if(item.compareTo(current.getFighter()) < 0){ current = current.getLeft(); left = true; }else { current = current.getRight(); right = true; } }if(left) follow.setLeft(new Node(item, null, null)); else follow.setRight(new Node(item, null, null)); }

    Read the article

  • Directories with random numbers as foldername being created that contain .ser files

    - by Dur4ndal
    Hi all: So in our server there are folders being generated with random names (such as "7nxxd", "tpy16q"). Inside each of these is the same subdirectory structure: <randomfilename>/.tld_cache/WEB-INF/tld/ c.tld/ fn.tld/ spring-form.tld/ fmt.tld/ spring.tld/ tiles-jsp.tld/ Each of these directories has 2 files: crc.ser and des.ser. Why are these files being created? Is there a way to specify the directory that they get written to besides the random name?

    Read the article

  • How to set message when I get Exception

    - by user1748932
    public class XMLParser { // constructor public XMLParser() { } public String getXmlFromUrl(String url) { String responseBody = null; getset d1 = new getset(); String d = d1.getData(); // text String y = d1.getYear(); // year String c = d1.getCircular(); String p = d1.getPage(); List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); nameValuePairs.add(new BasicNameValuePair("YearID", y)); nameValuePairs.add(new BasicNameValuePair("CircularNo", c)); nameValuePairs.add(new BasicNameValuePair("SearchText", d)); nameValuePairs.add(new BasicNameValuePair("pagenumber", p)); try { HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost(url); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); responseBody = EntityUtils.toString(entity); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } // return XML return responseBody; } public Document getDomElement(String xml) { Document doc = null; DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); try { DocumentBuilder db = dbf.newDocumentBuilder(); InputSource is = new InputSource(); is.setCharacterStream(new StringReader(xml)); doc = db.parse(is); } catch (ParserConfigurationException e) { Log.e("Error: ", e.getMessage()); return null; } catch (SAXException e) { Log.e("Error: ", e.getMessage()); // i m getting Exception here return null; } catch (IOException e) { Log.e("Error: ", e.getMessage()); return null; } return doc; } /** * Getting node value * * @param elem * element */ public final String getElementValue(Node elem) { Node child; if (elem != null) { if (elem.hasChildNodes()) { for (child = elem.getFirstChild(); child != null; child = child .getNextSibling()) { if (child.getNodeType() == Node.TEXT_NODE) { return child.getNodeValue(); } } } } return ""; } /** * Getting node value * * @param Element * node * @param key * string * */ public String getValue(Element item, String str) { NodeList n = item.getElementsByTagName(str); return this.getElementValue(n.item(0)); } } I am getting Exception in this class for parsing data. I want print this message in another class which extends from Activity. Can you please tell me how? I tried much but not able to do.. public class AndroidXMLParsingActivity extends Activity { public int currentPage = 1; public ListView lisView1; static final String KEY_ITEM = "docdetails"; static final String KEY_NAME = "heading"; public Button btnNext; public Button btnPre; public static String url = "http://dev.taxmann.com/TaxmannService/TaxmannService.asmx/GetNotificationList"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // listView1 lisView1 = (ListView) findViewById(R.id.listView1); // Next btnNext = (Button) findViewById(R.id.btnNext); // Perform action on click btnNext.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { currentPage = currentPage + 1; ShowData(); } }); // Previous btnPre = (Button) findViewById(R.id.btnPre); // Perform action on click btnPre.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { currentPage = currentPage - 1; ShowData(); } }); ShowData(); } public void ShowData() { XMLParser parser = new XMLParser(); String xml = parser.getXmlFromUrl(url); // getting XML Document doc = parser.getDomElement(xml); // getting DOM element NodeList nl = doc.getElementsByTagName(KEY_ITEM); int displayPerPage = 5; // Per Page int TotalRows = nl.getLength(); int indexRowStart = ((displayPerPage * currentPage) - displayPerPage); int TotalPage = 0; if (TotalRows <= displayPerPage) { TotalPage = 1; } else if ((TotalRows % displayPerPage) == 0) { TotalPage = (TotalRows / displayPerPage); } else { TotalPage = (TotalRows / displayPerPage) + 1; // 7 TotalPage = (int) TotalPage; // 7 } int indexRowEnd = displayPerPage * currentPage; // 5 if (indexRowEnd > TotalRows) { indexRowEnd = TotalRows; } // Disabled Button Next if (currentPage >= TotalPage) { btnNext.setEnabled(false); } else { btnNext.setEnabled(true); } // Disabled Button Previos if (currentPage <= 1) { btnPre.setEnabled(false); } else { btnPre.setEnabled(true); } // Load Data from Index int RowID = 1; ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>(); HashMap<String, String> map; // RowID if (currentPage > 1) { RowID = (displayPerPage * (currentPage - 1)) + 1; } for (int i = indexRowStart; i < indexRowEnd; i++) { Element e = (Element) nl.item(i); // adding each child node to HashMap key => value map = new HashMap<String, String>(); map.put("RowID", String.valueOf(RowID)); map.put(KEY_NAME, parser.getValue(e, KEY_NAME)); // adding HashList to ArrayList menuItems.add(map); RowID = RowID + 1; } SimpleAdapter sAdap; sAdap = new SimpleAdapter(AndroidXMLParsingActivity.this, menuItems, R.layout.list_item, new String[] { "RowID", KEY_NAME }, new int[] { R.id.ColRowID, R.id.ColName }); lisView1.setAdapter(sAdap); } } This my class where I want to Print that message

    Read the article

  • Web and stand-alone apps development tendency

    - by Narek
    There is a strong tendency of making web apps and even seems that very soon a lot of features will be available online so that for every day use people will have all necessary software free online and they will not need to install any software locally. Only specific (professional) tools that usually people don’t use at home will not be available as a web app. So my question, how do you imagine selling software that was necessary for everyday use and was not free (seems they can't make money any more by selling their product – no need of those products). And what disadvantages have web apps, that is to say, what is bad to use software online compared with having the same software locally (please list)? Please do not consider this question not connected with programming, as I really would like to have a little statistics from professional programmers who are aware from nowday’s tendency of software and programming. Thanks.

    Read the article

  • Looking for advice on how to do some bit-twiddling [closed]

    - by davit-datuashvili
    hi everybody fisrt of all this is not homework and now question is like this suppose i have array int a[]=new int[]{0xBCDA,0xABFE,0xBCAD,0xEFCA,0xFFCA} i know that there is always some hexadecimal number which occurs in all number or in this case A is repeat in array everywhere so my aim is print only repeat number and other numbers should be zero so my new array should be like this 0x000A, 0xA000,0x00A0 0x000A,0x000A any idea please help me? p.s please nobody say that this is homework

    Read the article

  • Problem loading a contents URL into a string

    - by bebeTech
    I've been using this method for a few weeks now as suggested on my previous question and the app now keeps crashing with a Protocol 443 error - something about unable to resolve the address. Worked fine when first installed and then just stopped. The same with on the device itself, worked fine until this morning and now the same issue?? Nothing wrong with the URL as I can still load in a browser. If I leave it for a couple of days it starts working again?? Is there a more effecient way of using the Http POST and GET functions? All I am trying to do is perform a login and save the resulting page to a string. Is there a more Android friendly way?

    Read the article

  • Is there a simpliest way of doing this?

    - by Tom Brito
    Is there a simpler way of implement this? Or a implemented method in JDK or other lib? /** * Convert a byte array to 2-byte-size hexadecimal String. */ public static String to2DigitsHex(byte[] bytes) { String hexData = ""; for (int i = 0; i < bytes.length; i++) { int intV = bytes[i] & 0xFF; // positive int String hexV = Integer.toHexString(intV); if (hexV.length() < 2) { hexV = "0" + hexV; } hexData += hexV; } return hexData; } public static void main(String[] args) { System.out.println(to2DigitsHex(new byte[] {8, 10, 12})); } the output is: "08 0C 0A" (without the spaces)

    Read the article

  • Is there a way to force JUnit to fail on ANY unchecked exception, even if swallowed

    - by Uri
    I am using JUnit to write some higher level tests for legacy code that does not have unit tests. Much of this code "swallows" a variety of unchecked exceptions like NullPointerExceptions (e.g., by just printing stack trace and returning null). Therefore the unit test can pass even through there is a cascade of disasters at various points in the lower level code. Is there any way to have a test fail on the first unchecked exception even if they are swallowed? The only alternative I can think of is to write a custom JUnit wrapper that redirects System.err and then analyzes the output for exceptions.

    Read the article

  • Identifying a class which is extending an abstract class

    - by Simon A. Eugster
    Good Evening, I'm doing a major refactoring of http://wiki2xhtml.sourceforge.net/ to finally get better overview and maintainability. (I started the project when I decided to start programming, so – you get it, right? ;)) At the moment I wonder how to solve the problem I'll describe now: Every file will be put through several parsers (like one for links, one for tables, one for images, etc.): public class WikiLinks extends WikiTask { ... } public class WikiTables extends WikiTask { ... } The files will then be parsed about this way: public void parse() { if (!parse) return; WikiTask task = new WikiLinks(); do { task.parse(this); } while ((task = task.nextTask()) != null); } Sometimes I may want to use no parser at all (for files that only need to be copied), or only a chosen one (e.g. for testing purposes). So before running task.parse() I need to check whether this certain parser is actually necessary/desired. (Perhaps via Blacklist or Whitelist.) What would you suggest for comparing? An ID for each WikiTask (how to do?)? Comparing the task Object itself against a new instance of a WikiTask (overhead)?

    Read the article

  • Transparently storing class state without exposing implementation

    - by RoToRa
    I have a model (MVC) class whose internal state (which basically contains of private int fields) I want to store. The program is running on Android (for now) so I need to store the in a Bundle, but I'll be using the same class later in a desktop application where I'll have to store the state some other way, so I can't reference Bundle directly in my class. So my question is: What is the best way to store (and retrieve) the state of a class without exposing it's implementation? The best I could think of removing the private access modifier so that the fields become package accessible and create read/write helper classes in the same package, but that somehow seems wrong.

    Read the article

  • Require help with program for edutainment game

    - by Ender
    I am working on a factorisation problem and for small numbers it is working well. I've been able to calculate the factors (getting the answers from Wolfram Alpha) for small numbers, like the one on the Wikipedia page (5959). Along with the Wikipedia page I have been following this guide. Once again, as my Math knowledge is pretty poor I cannot follow what I need to do next. EDIT: It finally works! I'll post the working code up here once I've got it fully working so that others in my predicament can learn from it.

    Read the article

  • sqlite database help

    - by mamila
    Hi all i have some questions regarding database in android. 1. in my project, I would like to create a database with single table. i would also like to insert data on this table from word or excel document. is it possible? if so please how can i do it? some code snippets would be of great help. 2. i have four different activities which i would like them to interact with this single table. the first is the main activity and its purpose is just to launch the other three activities according to user choice. so it has no interaction with the db. but the other three activities will read from the table whenever called. can you please tell me how to call the dbhelper on these activities. am kind of unable to do this.and am currently creating one db per each activity which is not the optimal way. any help is really appreciated and would be better if very soon tahnks

    Read the article

  • How to deal with the test data in Junit?

    - by user351637
    In TDD(Test Driven Development) development process, how to deal with the test data? Assumption that a scenario, parse a log file to get the needed column. For a strong test, How do I prepare the test data? And is it properly for me locate such files to the test class files?

    Read the article

  • Android - Access to online Database SQlite

    - by Oneiros
    I need to open, read and insert items into an online SQLite database from an Android app. I know url, username and password. In JavaSE i would do the following: Class.forName("com.mysql.jdbc.Driver"); Connection dbConnection = DriverManager.getConnection(URL, USER, PASSWORD); I read that I can't do this in Android because there is not a JDBC Driver (there is a "SQLite.JDBCDriver" but it is not documented and not recommended). So which is the easiest way? I asked to Google but it looks like he either doesn't know.

    Read the article

  • Why junit ComparisonFailure is not used by assertEquals(Object, Object) ?

    - by Philippe Blayo
    In Junit 4, do you see any drawback to throw a ComparisonFailure instead of an AssertionError when assertEquals(Object, Object) fails ? assertEquals(Object, Object) throws a ComparisonFailure if both expected and actual are String an AssertionError if either is not a String @Test(expected=ComparisonFailure.class ) public void twoString() { assertEquals("a String", "another String"); } @Test(expected=AssertionError.class ) public void oneString() { assertEquals("a String", new Object()); } The two reasons why I ask the question: ComparisonFailure provide far more readable way to spot the differences in dialog box of eclipse or Intellij IDEA (FEST-Assert throws this exception) Junit 4 already use String.valueOf(Object) to build message "expected ... but was ..." (format method invoqued by Assert.assertEquals(message, Object, Object) in junit-4.8.2): static String format(String message, Object expected, Object actual) { ... String expectedString= String.valueOf(expected); String actualString= String.valueOf(actual); if (expectedString.equals(actualString)) return formatted + "expected: " + formatClassAndValue(expected, expectedString) +" but was: " + formatClassAndValue(actual, actualString); else return formatted +"expected:<"+ expectedString +"> but was:<"+ actualString +">"; Isn't it possible in assertEquals(message, Object, Object) to replace fail(format(message, expected, actual)); by throw new ComparisonFailure(message, formatClassAndValue(expectedObject, expectedString), formatClassAndValue(actualObject, actualString)); Do you see any compatibility issue with other tool, any algorithmic problem with that... ?

    Read the article

< Previous Page | 915 916 917 918 919 920 921 922 923 924 925 926  | Next Page >