How do I convert an arrayList to an array []

I want to create a generic method that I can pass a Collection ( An ArrayList if I have to be specific ) and also tell this method the underlying Object type the Collection contains and have it call the Collections.toArray method and create an array [] of the type I specify.
Part of the problem is how do I have the method resolve the return type at run time and how do I use the Class variable to tell it the type of objects the Collection holds.
Fo instance I load an ArrayList with 3 MyClass objects.
I want to pass this to the method and have it return me an array of Type MyClass containing 3 items.
I don't want to have to be tied to a method with the signature
public MyClass [] convert( ArrayList myList  ){ ... }Thanks ...

Since it is an "old system" I doubt that is feasible. Also I believe that this was intentionally left out of the API because specifying the array type is more natural than the Class object and using the normal approach you get back the same zero-length array that you passed in if the collection is of size zero. It does look nice from a "caller" perspective though.

Similar Messages

  • How can I convert  an ArrayList to a String[]

    Hi,
    How can I convert an ArrayList (only with strings) to a String[] ?
    I've tried this :
         public static String listToString(List l) {
              StringBuffer sb = new StringBuffer();
              Iterator iter = l.iterator();
              while (iter.hasNext()) {
                   sb.append(iter.next().toString());
                   if (iter.hasNext()) {
                        sb.append(',');
              return sb.toString();
    But what I get is an array of xxxxx@435634 (for example).
    Thanks a lot !

    Strings are Objects but not all Objects are Strings and at least one of the elements in your List is not a String.

  • How do I convert an Object into an Array?

    If I have an instance of type object that I know is really a DataGrid row that was cast into an object when passed to a function, how can I cast that Object to an array, such that each index of this array would correspond to the information in a given column of the row?

    @Sathyamoorthi
    Can you please explain what this function does? Essentially, what should be contained in the String?
    I printed out the string and it seems like I am getting a random row in the Object, as opposed to first or last. Why is that?
    UPDATE: I printed out the value of dataGrid0.columns[5].dataField but it just turned out to be the id of the column.

  • How can I convert four elements of an array of I8 to an I32?

    I am new to LabView I am trying to index through an array of bytes and pull out either 2 or 4 bytes and store the values in either words or longs. Is there any easy way to do this?
    Thanks
    David

    Hi,
    there is function Advansed\Data Manipulation\Join numbers.
    It get 2 numbers of 8\16 bits and join them to one 16\32 bits number.
    In your case you need to take 2 MSB 8-bits numbers and join to 16-bits number. Same thing do for 2 LSB numbers.
    After this join to 16-bits numbers to one 32-bits.
    I hope that help you.

  • Convert a string to an array/collection

    Hi,
    I have a string
    String s = "[ab,cd,ef,gh]";How can I convert this into a string array , arraylist or vector such that ab, cd, ef, gh are the elements of the array/collection.
    Please help.
    Any help in this regard will be well appreciated with dukes.
    Regards,
    Anees

    virusakos wrote:
    codingMonkey, the "^\\[|\\]$" regular expression will only work for [....,...,....] inputs and not for [...,[....],]...[,...] inputs.
    The OP should find the correct regular expression according to the requirements ;-)Meaning that any brackets which are part of the actual data will remain intact.

  • I need to convert PDF file to Word Document, so it can be edited. But the recognizing text options do not have the language that I need. How I can convert the file in the desired of me language?

    I need to convert PDF file to Word Document, so it can be edited. But the recognizing text options do not have the language that I need. How I can convert the file in the desired of me language?

    The application Acrobat provides no language translation capability.
    If you localize the language for OS, MS Office applications, Acrobat, etc to the desired language try again.
    Alternative: transfer a copy of content into a web based translation service (Bing or Google provides a free service).
    Transfer the output into a word processing program that is localized to the appropriate language.
    Do cleanup.
    Be well...

  • How can I move an ArrayList from one method to another?

    As the subject reveals, I want to know how I move an ArrayList. In one method, I fill my ArrayList with objects, and in the next I want to pick an arbitrary object out of the ArrayList.
    How do I make this work??

    You pass the same array list to both the method. Both method are getting the same thing.
    void main(){
    //create array list here
    ArrayList aList = new ArrayList();
    //pass it to a method to fill items
    fillArrayList(aList);
    //pass the same arraylist to another method
    printArrayList(aList);
    void fillArrayList(ArrayList list){
      list.add("A");
    void printArrayList(ArrayList list){
    //The array list will contain A added by the previos method
    System.out.println(list);
    FeedFeeds : http://www.feedfeeds.com                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

  • How can I convert an int to a string?

    Hi
    How can I convert an int to a string?
    /ad87geao

    Here is some the code:
    public class GUI
        extends Applet {
      public GUI() { 
        lastValue = 5;
        String temp = Integer.toString(lastValue);
        System.out.println(temp);
        showText(temp);
      private void showText(final String text) {
        SwingUtilities.invokeLater(new Runnable() {
          public void run() {
            tArea2.setText(text + "\n");
    }

  • How can I convert an InputStream to a FileInputStream ???

    How can I convert an InputStream to a FileInputStream ???

    Thanks for you reply, however, I am still stuck.
    I am trying to convert my application (which runs smoothly) to a signed applet. The following is the original (application) code:
    private void loadConfig() {
    String fileName = "resources/groupconfig";
    File name = new File(fileName);
    if(name.isFile()) {
    try {
         ObjectInputStream in = new ObjectInputStream(new FileInputStream(fileName));
         pAndGConfig = (PAGroupsConfig)in.readObject();
         in.close();
         return;
    } catch(ClassNotFoundException e) {
         System.err.println("++ERROR: "+e);
    } catch(IOException e) {
         System.err.println("++ERROR: "+e);
    System.out.println("Can't find file: " + fileName);
    Because all code and resources now reside in a Jar file (for the signed applet), I must use the following line to access the resources:
    InputStream is = this.getClass().getResourceAsStream(fileName);
    I then need to convert the 'InputStream' to 'ObjectInputStream' or 'FileInputStream' so that I can work with it.
    I would be very grateful if you could help shed some light on the matter - Cobram

  • How can I convert an audio file (speech) into a text?

    Hello everybody!
      Can someone explain how I can convert a garageband file (voice speech) into a text? My Mac is a Mac OS X 10.5.8 version, so I don't have programs such as mountain Lion. I thought to use googlevoice. Is this option available? If yes, how can I use it?
    Thanks.

    Hello, I only find google voice available for Abdroid!?
    http://www.ehow.com/info_10033225_google-voice-system-requirements-android.html
    Some possibilitities, not sure if they have 10.5.8 compatble versions anymore...
    http://atmac.org/speech-to-text-dictation-software-for-os-x
    Some reviews of later Dragon Speak...
    http://www.finetunedmac.com/forums/ubbthreads.php?ubb=showflat&Number=22962

  • How do I convert my existing iTunes account to a .mac account?

    I am trying to convert my existing iTunes account which uses an Earthlink address. The following is the INSTRUCTIONS from the Apple web site on how to do this.
    "I just signed up for .Mac. How do I convert my existing iTunes account to
    my new .Mac account?
    We'll be happy to convert your account for you. Please provide your old account name, your new .Mac account name and your billing address in your email. We will also need your explicit permission to reset your password to complete the conversion."
    This is the URL where I found those INSTRUCTIONS:
    http://www.apple.com/support/itunes/musicstore/email/
    I FOLLOWED THE INSTRUCTIONS ABOVE!
    I am now on my fifth exchange of emails with iTunes support.
    HAS ANYBODY SUCCESSFULLY EXECUTED THESE INSTRUCTIONS? I don't want to lose the ability to play my existing purchased music, but I want to close down Earthlink as my ISP.
    17" G4 Powerbook   Mac OS X (10.4.6)  
    17" G4 Powerbook   Mac OS X (10.4.6)  

    On any page in the iTunes Store, click the flag icon at the lower right.  This brings up a page saying "Choose your country or region."  Click Canada.
    Before you can buy anything, you will need to enter your Canadian credit card.

  • How can I convert an OVM vm (.img) to VDI (virtualbox)?

    Hi,
    how can I convert an OVM vm (.img) to VDI (virtualbox)?
    Is .img format a raw image? If yes can I use "VBoxManage convertdd" to convert from .img to vdi?
    tnx & regards,
    S.

    Hi,
    "VBoxManage convertdd" solved.
    Regards,
    S.

  • How can I convert an AUDIO MPEG-4 to an MPEG3 format? I need it for a Powerpoint Presentation

    How can I convert an AUDIO  MPEG-4 to another type of file, such as MPEG3  or mp3

    Use Handbrake.
    You can download it for free from this site:
    http://www.macupdate.com/info.php/id/12987/handbrake
    Good luck

  • How do I convert a pdf in Adobe Acrobat 9 to Microsoft Word document?

    How do I convert a pdf in Acrobat 9 to a Microsoft Word document?

    Hi fireatty,
    In Acrobat 9, you can use the Export command (File > Export) to export your PDF to Word format.
    Please let us know if you need additional assistance.
    Best,
    Sara

  • I changed from i iphone 5 back to a iphone 4.. now my itunes does not recognise that i have a iphone 4! how do i convert my last back up (on iphone 5) to my new iphone 4?

    i changed from i iphone 5 back to a iphone 4.. now my itunes does not recognise that i have a iphone 4! how do i convert my last back up (on iphone 5) to my new iphone 4?

    In your case you can only restore from a backup that has been created with the same iOS version. An iPhone 4 can only run 7.1.2, and, unless your iPhone 5 did not run the same version, you can't use a newer iOS backup of the 5 on the iPhone 4

Maybe you are looking for

  • ArrayList() problems

    Hi! I need a little help getting an ArrayList to work. I am refactoring some of the classes in one of the O'Reilly books for a class assignment. I believe that I cannot get my ArrayList to add elements into itself. I'm not quite sure what I'm doing w

  • Do I need to abandon Thunderbird because too slow.

    I have been using Thunderbird for many years under Windows XP Professional. There were no problems and there was a quick response from the programme. My bank forced me to abandon Window XP. I choose for Windows 8., which I installed on my old compute

  • How Can I connect to MS Access or DBASE using forms6i?

    Hello, I have installed Forms6i on my PC (No Oracle Database installed). I have Three Data source 1. MS access DB 2. Excel File 3. Dbase4 File. How can I connect to these databases using forms6i? I have created ODBC DSN for MS Access DB, in forms6i C

  • Removing Flash Gallery From Web Site

    I recently created and uploaded an LR flash gallery to my web site. Although I previewed it, once it was up I noticed something I didn't like and wanted to remove the whole gallery. When I go to the site I see my original file is gone and the gallery

  • Oracle biee presentation service is not starting

    hi All, Today i installed oracle biee on my machine(having windows vista) andreplaced all corresponding files (like .rpd file & catalog and modify the nqsconfig.ini & instanceconfig.xml files). but when i tried to start the oracle bi presentation ser