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

  • 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

  • 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

  • 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

  • Easiest way to get Enum in to Key Value pair.

    - by vijay.shad
    Hi, I have defined my Enums like this. public enum UserType { RESELLER("Reseller"), SERVICE_MANAGER("Manager"), HOST("Host"); private String name; private UserType(String name) { this.name = name; } public String getName() { return name; } } What should be the easiest way to get a key-value pair form the enum values?

    Read the article

  • android listview loadmore button with xml parsing

    - by user1780331
    Hi i have to developed listview with load more button using xml parsing in android application. Here i have faced some problem. my xml feed is empty means how can hide the load more button on last page. i have used below code here. public class CustomizedListView extends Activity { // All static variables private String URL = "http://dev.mmm.com/xctesting/xcart444pro/retrieve.php?page=1"; // XML node keys static final String KEY_SONG = "Order"; static final String KEY_TITLE = "orderid"; static final String KEY_DATE = "date"; static final String KEY_ARTIST = "payment_method"; int current_page = 1; ListView lv; LazyAdapter adapter; ProgressDialog pDialog; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); lv = (ListView) findViewById(R.id.list); ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>(); XMLParser parser = new XMLParser(); String xml = parser.getXmlFromUrl(URL); // getting XML from URL Document doc = parser.getDomElement(xml); // getting DOM element NodeList nl = doc.getElementsByTagName(KEY_SONG); // looping through all song nodes <song> for (int i = 0; i < nl.getLength(); i++) { // creating new HashMap HashMap<String, String> map = new HashMap<String, String>(); Element e = (Element) nl.item(i); // adding each child node to HashMap key => value map.put(KEY_ID, parser.getValue(e, KEY_ID)); map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE)); map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST)); songsList.add(map); } Button btnLoadMore = new Button(this); btnLoadMore.setText("Load More"); btnLoadMore.setBackgroundResource(R.drawable.lgnbttn); // Adding Load More button to lisview at bottom lv.addFooterView(btnLoadMore); // Getting adapter adapter = new LazyAdapter(this, songsList); lv.setAdapter(adapter); btnLoadMore.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { // Starting a new async task new loadMoreListView().execute(); } }); } private class loadMoreListView extends AsyncTask<Void, Void, Void> { @Override protected void onPreExecute() { // Showing progress dialog before sending http request pDialog = new ProgressDialog( CustomizedListView.this); pDialog.setMessage("Please wait.."); //pDialog.setIndeterminateDrawable(getResources().getDrawable(R.drawable.my_progress_indeterminate)); pDialog.setIndeterminate(true); pDialog.setCancelable(false); pDialog.show(); pDialog.setContentView(R.layout.custom_dialog); } protected Void doInBackground(Void... unused) { current_page += 1; // Next page request URL = "http://dev.mmm.com/xctesting/xcart444pro/retrieve.php?page=" + current_page; ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>(); XMLParser parser = new XMLParser(); String xml = parser.getXmlFromUrl(URL); // getting XML from URL Document doc = parser.getDomElement(xml); // getting DOM element NodeList nl = doc.getElementsByTagName(KEY_SONG); NodeList nl = doc.getElementsByTagName(KEY_SONG); if (nl.getLength() == 0) { btnLoadMore.setVisibility(View.GONE); pDialog.dismiss(); } else // looping through all item nodes <item> for (int i = 0; i < nl.getLength(); i++) { // creating new HashMap HashMap<String, String> map = new HashMap<String, String>(); Element e = (Element) nl.item(i); // adding each child node to HashMap key => value map.put(KEY_ID, parser.getValue(e, KEY_ID)); map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE)); map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST)); songsList.add(map); } // get listview current position - used to maintain scroll position int currentPosition = lv.getFirstVisiblePosition(); // Appending new data to menuItems ArrayList adapter = new LazyAdapter( CustomizedListView.this, songsList); lv.setAdapter(adapter); lv.setSelectionFromTop(currentPosition + 1, 0); } }); return (null); } protected void onPostExecute(Void unused) { // closing progress dialog pDialog.dismiss(); } } } EDIT: Here i have to run the app means the listview is displayed on perpage 4 items.my last page having 1 item.please refer this screenshot:http://screencast.com/t/fTl4FETd In last page i have to click the load more button means have to go next activity and successfully hide the button on empty page..please refer this screenshot:http://screencast.com/t/wyG5zdp3r i have to check the condition for empty page: if (nl.getLength() == 0) { btnLoadMore.setVisibility(View.GONE); pDialog.dismiss(); } How can i write the conditon fot last page?????pleas ehelp me Here i wish to need the o/p is hide the button on last page. Please help me.how can i check the condition.give me some code programmatically.

    Read the article

  • How do I manipulate a tree of immutable objects?

    - by Frederik
    I'm building an entire application out of immutable objects so that multi-threading and undo become easier to implement. I'm using the Google Collections Library which provides immutable versions of Map, List, and Set. My application model looks like a tree: Scene is a top-level object that contains a reference to a root Node. Each Node can contain child Nodes and Ports. An object graph might look like this: Scene | +-- Node | +-- Node | +- Port +-- Node | +- Port +- Port If all of these objects are immutable, controlled by a top-level SceneController object: What is the best way to construct this hierarchy? How would I replace an object that is arbitrarily deep in the object tree? Is there a way to support back-links, e.g. a Node having a "parent" attribute?

    Read the article

  • capture text, including tags from string, and then reorder tags with text

    - by Brian
    I have the following text: abcdef<CONVERSION>abcabcabcabc<2007-01-12><name1><2007-01-12>abcabcabcabc<name2><2007-01-11>abcabcabcabc<name3><2007-02-12>abcabcabcabc<name4>abcabcabcabc<2007-03-12><name5><date>abcabcabcabc<name6> I need to use regular expressions in order to clean the above text: The basic extraction rule is: <2007-01-12>abcabcabcabc<name2> I have no problem extracting this pattern. My issue is that within th text I have malformed sequences: If the text doesn't start with a date, and end with a name my extraction fails. For example, the text above may have several mal formed sequences, such as: abcabcabcabc<2007-01-12><name1> Should be: <2007-01-12>abcabcabcabc<name1> Is it possible to have a regular expression that would clean the above, prior to extracting my consistent pattern. In short, i need to find all mal formed patterns, and then take the date tag and put it in front of it, as provided in the example above. Thanks.

    Read the article

  • Twitter friends timeline not returning full history

    - by twofivesevenzero
    I am using twitter4J to get a user's friends timeline, but it is not returning the full available history. I know there are pagination limits (200 per request and 3200 total as per http://bit.ly/ck8ysq) and I am well within those. I make a request like so: private static final int MAX_COUNT = 200; private List<Status> getAllStatuses(long sinceID) throws TwitterException { Twitter twitter = new Twitter(username, password); List<Status> friendsTimelineList = new ArrayList<Status>(); List<Status> tempList; int page = 0; do { page++; tempList = twitter.getFriendsTimeline( new Paging(page, MAX_COUNT, sinceID)); if(tempList == null ) break; friendsTimelineList.addAll(tempList); } while(true); return friendsTimelineList; } This results in only 423 statuses being returned across 3 pages. Any idea why this might be happening?

    Read the article

  • Linked List. Insert integers in order

    - by user69514
    I have a linked list of integers. When I insert a new Node I need to insert it not at the end, but in oder... i.e. 2, 4, 5, 8, 11, 12, 33, 55, 58, 102, etc. I don't think I am inserting it in the correct position. Do see what Im doing wrong? Node newNode = new Node(someInt); Node current = head; for(int i=0; i<count; i++){ if(current == tail && tail.data < someInt){ tail.next = newNode; } if(current.data < someInt && current.next.data >= someInt){ newNode.next = current.next; current.next = newNode; } }

    Read the article

  • Clone a 'link' in SWT

    - by Steve
    I have a table of information that includes a username, an ip address, and a timestamp. What I wanted to do was to have the ip address contained within a link object that when the link is clicked it utilizes bgp.he.net to get information about the host/IP address. I have tried creating threads to resolve the IP addresses but it is often a large amount of IP addresses and I read that InetAddress#getByName isn't non-blocking, so I figured having links that go to this site is the next best thing. Question is: Is it possible to have links for each of my IP addresses in the table without creating a new link object for each row? I don't know how bad that would be on memory usage which is why I'm inquiring about cloning an instance of an IP and having the link open bgp.he.net/link.getText()

    Read the article

  • using Hibernate to loading 20K products, modifying the entity and updating to db

    - by Blankman
    I am using hibernate to update 20K products in my database. As of now I am pulling in the 20K products, looping through them and modifying some properties and then updating the database. so: load products foreach products session begintransaction productDao.MakePersistant(p); session commit(); As of now things are pretty slow compared to your standard jdbc, what can I do to speed things up? I am sure I am doing something wrong here.

    Read the article

  • How do I use a custom select statement in Hibernate using the HibernateDaoSupport class

    - by Bill Leeper
    I am trying to write a custom select statement in Hibernate using the getHibernateTemplate() method. I am having problems with the resulting mapping. Example Code: List<User> users = getHibernateTemplate().find("Select user, sysdate as latestPost from User as user"); for (User user : users) { assertNotNull(users.name); } The goal of the above line is to eventually have a join where I get the max(date) of posts made by the user. The problem I am having is that the resulting users list is not a list of User objects and I get a class cast exception. Hopefully that is enough code. It is a greatly simplified version of my problem and a combination of snippets from various parts of my application.

    Read the article

  • How to get stream to "in-memory" database created via H2DB?

    - by Reynevan
    I have to create such a mechanism: Create in-memory (H2DB) database; Create tables and fill them using some data; Get stream to that database; Send that stream via WebDAV or something else; I know everything except that "How to get stream to "in-memory" database created via H2DB"? And some explanations: I can't create file because of some server restrictions; I need that stream to create a file;

    Read the article

  • calling a service layer method to my presentation layer

    - by Josepth Vodary
    Ok I feel really dumb asking this but I seem to be missing something really simple here. I have the following code in a class in my service layer - public Items getItems(String category, float amount, String color, String type) The code reads from a database and returns the results - I plan on placing it in a jframe. Nice and simple. But no matter how I call it from the jframe I get errors in eclipse that the code is wrong - either that their are illegal modifiers or such. So obviously I am calling it completely wrong, so my stupid question is how do you call that method into a jframe? For example - if I try to call it this way: public Items getItems(); I get told that getItems is an illegal parameter. If I call this.. Items getItems(); I am told its undefined

    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

  • Should we or should we not check in the classes folder in WEB-INF directory into SVN?

    - by Vatsala
    I use SVN, and am learning how to use it along with eclipse IDE. The first time I add classes to my package, there is no problem, the generated class files get into SVN smoothly. The moment I edit them, I get this message - "WEB-INF/classes" is obstructed. I try the "clean-up" command and the clean up command says "WEB-INF/classes" folder is locked. I use TortoiseSVN as my SVN client. I know why this is happening. It probably because the Eclipse overwrites all the files while generating classes and then causes this - Is it inappropriate to commit the class files into SVN? If not, what should I do to commit these class files smoothly?

    Read the article

  • Can an applet communicate with an instance of a servlet

    - by mithun1538
    Hello everyone, I have an applet that communicates with a servlet using Http (Not sockets). Currently, each instance of the applet (i.e. when each applet is run by a different client on a different computer), all the instances communicate with the same servlet. What I want is that each instance of the applet communicate with different instances of the same servlet. Is this possible?

    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

  • Click Listener not invoked within ListFragment

    - by membersound
    I'm extending a SherlockListFragment, but it should not matter as my question seems to be more general related to Fragments. Now, I implement a simple click listener for my list, but it does not get called. public class MyListFragment extends SherlockListFragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.list, container, false); v.setOnClickListener(new OnClickListener() { public void onClick(View view) { Log.i("debug", "single click"); } }); return v; } } Is anything wrong with this? //Solution: listView.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Log.i("debug", "single click"); } });

    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

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