Search Results

Search found 33297 results on 1332 pages for 'java java ee'.

Page 914/1332 | < Previous Page | 910 911 912 913 914 915 916 917 918 919 920 921  | Next Page >

  • Explicit constructor still has default values even though a default constructor is not invoked.

    - by Phoenix
    According to my understanding a default constructor initializes the state of the object to default values, so if i provide an explicit no-arg public constructor like this then how are the values of d and e still getting initialized to zero because in this case the default constructor is not invoked. public class B extends A{ private int d; private int e; public B() { System.out.println(d); System.out.println(e); } } EDIT:: The only thing default constructor does is call to super() then how come if i have a explicitly mentioned a constructor here and A has a protected variable say c which is initialized to 17 in its constructor. Should I not be explicitly calling super() to be able to see that change since I'm using my own constructor ? Why is B still getting the value of 17 through inheritance ?

    Read the article

  • Design pattern: Polymorphism for list of objects

    - by ziang
    Suppose I have a class A, and A1, A2 inherits from A. There are 2 functions: List<A1> getListA1(){...} List<A2> getListA2(){...} Now I want to do something similar to both A1 and A2 in another function public void process(List<A>){...} If I want to pass the instance of either ListA1 or ListA2, of course the types doesn't match because the compiler doesn't allow the coercion from List< A1 to List< A. I can't do something like this: List<A1> listA1 = getListA1(); List<A> newList = (List<A>)listA1; //this is not allowed. So what is the best approach to the process()? Is there any way to do it in a universal way rather than write the similar code to both List and List?

    Read the article

  • Convert an array of primitive longs into a List of Longs

    - by CaptainAwesomePants
    This may be a bit of an easy, headesk sort of question, but my first attempt surprisingly completely failed to work. I wanted to take an array of primitive longs and turn it into a list, which I attempted to do like this: long[] input = someAPI.getSomeLongs(); List<Long> = Arrays.asList(input); //Total failure to even compile! What's the right way to do this?

    Read the article

  • Alternatives to FastDateFormat for efficient date parsing?

    - by Tom Tucker
    Well aware of performance and thread issues with SimpleDateFormat, I decided to go with FastDateFormat, until I realized that FastDateFormat is for formatting only, no parsing! Is there an alternative to FastDateFormat, that is ready to use out of the box and much faster than SimpleDateFormat? I believe FastDateFormat is one of the faster ones, so anything that is about as fast would do. Just curious , any idea why FastDateFormat does not support parsing? Doesn't it seriously limit its use? Thanks! EDIT Holy crap, I just left a comment and that literally REMOVED a good answer! This appears a serious bug on stackoverflow!

    Read the article

  • javax.activation.DataSource size question

    - by folone
    How do I get the amount of physical memory, consumed by the DataSource (specifically — ByteArrayDataSource)? I use ByteArrayDataSource (byte[] bytes, String type) constructor, where I get bytes like this: String str = "test"; byte[] bytes = str.getBytes(); Would that be str.length() in bytes? Any other ideas?

    Read the article

  • why isn't the input text file being read into the ArrayList<String>, diary?

    - by hmg
    Here's my code: public void readFile() throws IOException { System.out.println("Input file name: "); Scanner in = new Scanner(System.in); String readName = in.nextLine(); Scanner reader = new Scanner(new File(readName)); System.out.println("Reading file..."); while (reader.hasNextLine()) { System.out.println(reader.nextLine()); } System.out.println("File read."); Scanner inAgain = new Scanner(System.in); System.out.println("Would you like to read this into the current Diary?"); System.out.println("Warning: This will overwrite your current Diary!"); String readFileConfirm = inAgain.nextLine(); ArrayList<String> readData = new ArrayList<String>(); if (readFileConfirm.equalsIgnoreCase("yes")) { for (int i = 0; i < readData.size(); i++) { readData.add(reader.nextLine()); } System.out.println("Data added to extra array..."); System.out.println("Here are the contents."); for (int i = 0; i < readData.size(); i++) { System.out.println(readData.get(i)); } System.out.println("Contents read."); System.out.println("Now overwriting current Diary with read file..."); diary.clear(); for (int i = 0; i < diary.size(); i++) { diary.add(readData.get(i)); } System.out.println("New Diary created!"); System.out.println("Use 'recall' to see your new Diary!"); } else { System.out.println("Very well, returning to first command entry."); } } Thanks in advance! -h

    Read the article

  • Installer for web application

    - by Xinus
    We have developed a web application which is to be deployed by nontechnical person. Therefor I want to create an installer for it. Installer has functions of installing JVM, Apache Tomcat, and the web application war file depending on whether they are installed or not. Is there any installation suit which I can use to achieve this?

    Read the article

  • problem in deleting record

    - by akshay
    I have a entity manager em1 .em1 starts a transcation tx on db1 table1.Now inside tx i call a API getdata().This API creastes a new entitymanger em2 and return 1 record.Now if entity manger em1 tries to delete the record returned by em1 , it hangs.Code times out.Is the record locked by em1.How can ii solve this problem? create em1 //em1 start transcation tx1 tx1.start Object r = getData(); em1 tried to delete r //code hangs here tx1.commit Object getData(){ create em2 return data found using em2 }

    Read the article

  • How do I reload servlet classes without restarting my web application?

    - by Ramon
    I want to reload just my web layer classes without reloading my service layer classes (which take longer to initialize and change less frequently). There are no references from my service layer into the web layer and I can create a whole new instance of the web layer without problems. I can conceive of a solution involving complicated class-loader tricks to isolate the web layer in its own class-loader and I think this is probably the only way to do this so what I'm asking is, is there a library out there which does this? I know about JavaRebel - I don't need that much power and I'm really looking for a more lightweight free solution.

    Read the article

  • Guice child injector override binding

    - by Roman
    Hi All I am trying to to override a binding in a child injector that was already configured in a base injector. like that : public class PersistenceModule extends Abstract{ @Override protected void configure() { bind(IProductPersistenceHelper.class).to(ProductPersistenceHelper.class); } } then : Injector injector = Guice.createInjector(new PersistenceModule()); injector.createChildInjector(new AbstractModule(){ @Override protected void configure() { bind(IProductPersistenceHelper.class).to(MockProductPersistenceHelper.class); } }) Guice is complaining that it has already a binding for that. Are there any patterns or best practices for that problem ?

    Read the article

  • MySQL connection timeout

    - by NikolayGS
    I'm running program at apache tomcat server, that should be on permanently, but every morning(the client part isn't accessible at night) i receive error message (in apache tomcat console) that MySQL server is off. So is there any way to prevent this? Thanks in advance!

    Read the article

  • create jar file with images and database

    - by Samurai
    Hi I am using NetBeans IDE and I have my images (what I am using in my project) in a folder named Images. When I am building jar it doesn't take that images. The code I am using to set image is, buttonObj.setIcon(new ImageIcon("\Images\a.jpg") any help please.

    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

  • Is catching NumberFormatException a bad practice?

    - by integeruser
    I have to parse a String that can assume hex values or other non-hex values 0xff, 0x31 or A, PC, label, and so on. I use this code to divide the two cases: String input = readInput(); try { int hex = Integer.decode(input); // use hex ... } catch (NumberFormatException e) { // input is not a hex, continue parsing } Can this code be considered "ugly" or difficult to read? Are there other (maybe more elegant) solutions? EDIT : I want to clarify that (in my case) a wrong input doesn't exist: i just need to distinguish if it is a hex number, or not. And just for completeness, i'm making a simple assebler for DCPU-16.

    Read the article

  • Any way to make a generic List where I can add a type AND a subtype?

    - by user383178
    I understand why I cannot do the following: private class Parent { }; private class Child extends Parent { }; private class GrandChild extends Child { }; public void wontCompile(List<? extends Parent> genericList, Child itemToAdd) { genericList.add(itemToAdd); } My question is there ANY practical way to have a typesafe List where you can call add(E) where E is known to be only a Parent or a Child? I vaguely remember some use of the "|" operator as used for wildcard bounds, but I cannot find it in the spec... Thanks!

    Read the article

  • Should I put actors in the Domain-Model/Class-Diagram?

    - by devoured elysium
    When designing both the domain-model and class-diagrams I am having some trouble understanding what to put in them. I'll give an example of what I mean: I am doing a vacations scheduler program, that has an Administrator and End-Users. The Administrator does a couple of things like registering End-Users in the program, changing their previleges, etc. The End-User can choose his vacations days, etc. I initially defined an Administrator and End-User as concepts in the domain-model, and later as classes in the class-diagram. In the class-diagram, both classes ended up having a couple of methods like Administrator.RegisterNewUser(); Administrator.UnregisterUser(int id); etc. Only after some time I realised that actually both Administrator and End-User are actors, and maybe I got this design totally wrong. Instead of filling Administrator and End-User classes with methods to do what my Use-Cases request, I could define other classes from the domain to do them, and have controllers handle the Use-Cases(actually, I decided to do one for each Use-Case). I could have a UserDatabase.RegisterNewUser() and UserDatabase.UnregisterUser(int id);, for example, instead of having those methods on the Administrator class. The idea would be to try to think of the whole vacation-scheduler as a "closed-program" that has a set of features and doesn't bother with things such as authentication, that should be internal/protected, being that the only public things I'd let the outside world see would be its controllers. Is this the right approach? Or am I getting this totally wrong? Is it generally bad idea to put Actors in the domain-model/class-diagrams? What are good rules of thumb for this? My lecturer is following Applying UML and Patterns, which I find awful, so I'd like to know where I could look up more info on this described actor-models situation. I'm still a bit confused about all of this, as this new approach is radically different from anything I've done before.

    Read the article

  • Can I user a layout on the android to render just part of an image at a time?

    - by gamernb
    I have an image file that has all the character sprites that I will be using in a game, and I want to make a layout that will allow the user to cycle through each image to be able to pick which one they want. So, I have one large image, and I need to render just a small (32 x 32) section of it at a time. Is that possible with the layouts or will I have to use a canvas, and manually do most of this?

    Read the article

  • Android getSelectedItem, how to use?

    - by user1881184
    Im trying use the spinner control result in order to point it to another screen that would be on the app. For example in the spinner control if the user chose chevy it would then take you to another screen which is coded in chevy.xml and Chevy.class. This is what i have thus far and need some help, as our book only used getSelectedItem and the example was only for an output statement. Please help. import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemSelectedListener; import android.widget.Spinner; public class Mainpage extends Activity implements OnItemSelectedListener { String carChoice, chevy, ford, dodge, toyota; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); /* carChoice = group.getSelectedItem().toString(); } if (carChoice.compareTo(chevy)==0) { startActivity(new Intent(Mainpage.this, Chevy.class)); */ } public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { final Spinner group = (Spinner) findViewById(R.id.carGroup); group.setOnItemSelectedListener(this); // TODO Auto-generated method stub String selected = group.getItemAtPosition(1).toString(); } public void onNothingSelected(AdapterView<?> arg0) { // TODO Auto-generated method stub } }

    Read the article

  • How to map a search object to a class with more fields with JPA annotations

    - by Moli
    Hi all, I'm a newbie with JPA. I need to map a search object to a table. The search object has only and id, name. The big object has more fileds id, name, adress and more. I use this as big object view plaincopy to clipboardprint? I use this as big object @Entity @Table(name="users") public class User { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; private String name; private String adress; private String keywords; } //this is my search object @XXX public class UserSearch { @Id @GeneratedValue(strategy = GenerationType.AUTO) private long id; private String name; } What annotations I need to use to map the search object to the table users? I'm using spring+struts2+hibernate+JPA. Help is appreciated! Thanks!

    Read the article

  • How to close IOs?

    - by blackdog
    when i managed IO, i found a problem. i used to close it like this: try { // my code } catch (Exception e) { // my code } finally{ if (is != null) { is.close(); } } but the close method also would throw exception. if i have more than one IO, i have to close all of them. so the code maybe like this: try { // my code } catch (Exception e) { // my code } finally{ if (is1 != null) { is1.close(); } if(is2 != null{ is2.close(); } // many IOs } if is1.close() throws an exception, is2, is3 would not close itself. So i have to type many try-catch-finally to control them. is there other way to solve the problem?

    Read the article

  • Does allocation speed depend on the garbage collector being used?

    - by jkff
    My app is allocating a ton of objects (1mln per second; most objects are byte arrays of size ~80-100 and strings of the same size) and I think it might be the source of its poor performance. The app's working set is only tens of megabytes. Profiling the app shows that GC time is negligibly small. However, I suspect that perhaps the allocation procedure depends on which GC is being used, and some settings might make allocation faster or perhaps make a positive influence on cache hit rate, etc. Is that so? Or is allocation performance independent on GC settings under the assumption that garbage collection itself takes little time?

    Read the article

  • Determining if an offset is in between line numbers?

    - by Sophomore
    hi I need to determine if a given selection is in between a start line and an end line. I have an ILineRange and a given offset within the viewport of eclipse. (I need to know, if the selection (from a remote party) was made within the current viewport of the local user. Unfortunately, I cannot get an LineRange from the selection. I must rely on getOffset() and getLength()... Anyone has an idea? I think there is not a clean solution for this, as the offset (or the characters per line vary (new line lines or a big block of comment).

    Read the article

< Previous Page | 910 911 912 913 914 915 916 917 918 919 920 921  | Next Page >