Search Results

Search found 33640 results on 1346 pages for 'java generics'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 464/1346 | < Previous Page | 460 461 462 463 464 465 466 467 468 469 470 471  | Next Page >

  • How does a Java Arraylist contains() method evaluate objects?

    - by mvid
    Say i create one object and add it to my ArrayList. If I then create another object with exactly the same constructor input, will the contain() method evaluate the two objects to be the same? Assume the constructor doesn't do anything funny with the input, and the variables stored in both objects are identical. ArrayList<Thing> basket = new ArrayList<Thing>(); Thing thing = new Thing(100); basket.add(thing); Thing another = new Thing(100); basket.contains(another); // true or false?

    Read the article

  • Java Swing rendering bug on Windows 7 look-and-feel?

    - by John B.
    The knob on vertical JSlider's on my Windows 7 machine (with native look-and-feel) is really, really tiny in both directions. Not just skinny but short as well. Can anyone confirm this? Should I report it? If so, where? Thanks! Here is the code for the sample program (in the screen shot): import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JSlider; import javax.swing.SwingConstants; import javax.swing.UIManager; public class SliderTest { public static void main( String[] args ) { // Set the look and feel to that of the system try { UIManager.setLookAndFeel( UIManager.getSystemLookAndFeelClassName() ); } catch ( Exception e ) { System.err.println( e ); } // Launch the GUI from the event dispatch thread javax.swing.SwingUtilities.invokeLater( new Runnable() { public void run () { JFrame window = new JFrame(); window.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); JPanel contentPane = new JPanel(); contentPane.add( new JSlider(SwingConstants.HORIZONTAL) ); contentPane.add( new JSlider(SwingConstants.VERTICAL) ); window.setContentPane( contentPane ); window.pack(); window.setLocationRelativeTo( null ); // Center window window.setVisible( true ); } }); } }

    Read the article

  • Playing around with my Java project in Eclipse... what the crap did I just do?

    - by Daddy Warbox
    I don't even remember how, but somehow I managed to make all of my project's source files hidden in Eclipse's Package and Project Explorer panels. Go figure. 'Show Filtered Children (alt+click)' temporarily reveals the files, and only in Package Explorer can I double-click to reopen them from this view. They go back into hiding after I select another item, though. Plus, now I'm getting other annoyances, such as all of the folded non-hidden items altogether expanding when I click on an item, and the entire folder tree of my project now being shown in these panels (including my .svn subversion folders... which shouldn't be any of Eclipse's business, presently). Long story short, my Package/Project Explorers' just blew up on me, and I want to know how to fix this. Thanks in advance. P.S. What's a good guide I can use to learn my way around this silly contraption, anyway?

    Read the article

  • Does MultiThreading in Java takes much time for task completion?

    - by Geeta
    I have to search for a string in 10 large size files (in zip format 70 MB) and have to print the lines with the search string to corresponding 10 output files.(i.e. file 1 output should be in output_file1...file2--- output_file2). The same program takes 15 mins for a single file. But if use 10 threads to read 10 files and to write in 10 different files it should complete in 15 mins but its taking 40 mins. How can I solve this. Or multithreading will take this much time only?

    Read the article

  • Is there anything bad in declaring nested class inside interface in java?

    - by Roman
    I have an interface ProductService with method findByCriteria. This method had a long list of nullable parameters, like productName, maxCost, minCost, producer and so on. I refactored this method by introducing Parameter Object. I created class SearchCriteria and now method signature looks like this: findByCriteria (SearchCriteria criteria) I thought that instances of SearchCriteria are only created by method callers and are only used inside findByCriteria method, i.e.: void processRequest() { SearchCriteria criteria = new SearchCriteria () .withMaxCost (maxCost) ....... .withProducer (producer); List<Product> products = productService.findByCriteria (criteria); .... } and List<Product> findByCriteria(SearchCriteria criteria) { return doSmthAndReturnResult(criteria.getMaxCost(), criteria.getProducer()); } So I did not want to create a separate public class for SearchCriteria and put it inside ProductServiceInterface: public interface ProductService { List<Product> findByCriteria (SearchCriteria criteria); static class SearchCriteria { ... } } Is there anything bad with this interface? Where whould you place SearchCriteria class?

    Read the article

  • JAVA. Writing a matrix in a file using column information.

    - by Dmitry
    Hello, everybody! I have a file in which a matrix is stored. This file has a RandomAccessFile type. This matrix is stored by columns. I mean that in an i-th row of this matrix an i-th column (of a real matrix) is stored. There is an example: i-th row: 1 2 3 4 (in the file). That means that the real matrix has an i-th column: (1 2 3 4)(transpose). I need to save this matrix in natural way (by rows) in a new file, which I will then open with FileReader and display with TestArea. DO you know, how to do that? If so, please help =)

    Read the article

  • I'm new to Java most basic question about arrays!

    - by ambidextorous
    Hey I have not been able to find a proper answer on any forums about this but how exactly do I pass an array to a class? public class TestArray { String name; String[] array; public TestArray(String name, String[] anArray){ this.name = name; int len = anArray.length; this.array = new String[len]; for (int i = 0; i < len; i++){ this.array[i] = new String(anArray[i]); } } } public static void main(String[] args){ String[] anArray = new String[2]; anArray[0] = new String("Test"); anArray[1] = new String("Test2"); TestArray work = new TestArray("Jordan", anArray?); } }

    Read the article

  • Does Java have something like C#'s ref and out keywords?

    - by devoured elysium
    Something like the following: ref example: void changeString(ref String str) { str = "def"; } void main() { String abc = "abc"; changeString(ref abc); System.out.println(abc); //prints "def" } out example: void setString(out String str) { str = "def"; } void main() { String abc; changeString(out abc); System.out.println(abc); //prints "def" }

    Read the article

  • how to get http responses continuously to a java application?

    - by senrulz
    I have the coding shown below where I have sheduled to get a http response from a php web server page. public static void stopPHPDataChecker() { canStop=true; } public static void main (String args[]) { // http request to the php page and get the response PHPDataChecker pdc = new PHPDataChecker(); ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1); final ScheduledFuture<?> pdcHandle = scheduler.scheduleAtFixedRate(pdc, 0L, 10L, TimeUnit.MILLISECONDS);// Start schedule scheduler.schedule(new Runnable() { public void run() { System.out.println(">> TRY TO STOP!!!"); pdcHandle.cancel(true); Sheduler.stopPHPDataChecker(); System.out.println("DONE"); } }, 1L, TimeUnit.MILLISECONDS); do { if (canStop) { scheduler.shutdown(); } } while (!canStop); System.out.println("END"); } this coding only returns one response but I want it to get responses continuously so i can do different tasks according to the returned value. how can i do it? Thank you in advance :)

    Read the article

  • How is this statement making sense? (Sun's naming convention for Java variables)

    - by polygenelubricants
    I've been quoting this segment from Sun's document for the past few days, and only now do I stop and think about what it's saying, and I can't make sense out of it. Please keep in mind that English is not my first language. Naming conventions Variables: Except for variables, all instance, class, and class constants are in mixed case with a lowercase first letter. How is this making sense? Isn't this saying that class names are in mixed case with a lowercase first letter? Like I should name it class myClass? And class constants are also in mixed case with a lowercase first letter? Like I should name it Integer.maxValue? And is it really saying anything about how variables themselves should be named? Am I not parsing this properly or is this actually a blatant error?

    Read the article

  • What is the explanation of this results in Java ?

    - by M.H
    I have the following code : public class Main { private int i = j; //1 private int j = 10; public static void main(String[] args) { System.out.println((new Main()).i); } } and there is a compiler error in line 1 because an illegal forward reference. But when I am trying the following code : public class Main { int i = getJ(); //1 int getJ(){ return j; } int j=10; public static void main(String[] args) { System.out.println(new Main().i); } } it works fine and the result is 0.Why there is no illegal forward reference in line 1 here?.The two codes look similar to me.

    Read the article

  • How to test whether a char is NOT in a string? (java, junit)

    - by JB
    As title says, im having trouble with my junit tests passing for checking if a character is not in a string and how to check if an empty string doesnt have a character. here is the method i have: public static boolean isThere(String s, char value){ for(int x = 0; x <= s.length(); x++){ if(s.charAt(x) == value){ return true; } else if(s.length() == 0){ return false; } } return false; And here is the junit test: public void testIsThere() { { String sVal = "Jeff George"; boolean hasA = StringMethods.isThere(sVal,'e'); assertTrue(hasA); boolean hasE = StringMethods.isThere(sVal, 'o'); assertTrue(hasE); boolean notIn = StringMethods.isThere(sVal,'b'); assertTrue(notIn); } { String sVal = ""; boolean nothingIn = StringMethods.isThere(sVal,'a'); assertFalse(nothingIn); boolean notIn = StringMethods.isThere(sVal,'b'); assertFalse(notIn); } } Thank you very much, appreciated

    Read the article

  • My java program seems to be skipping over the try{}, executing the catch{} and then throwing a NullPointerException. What should I do?

    - by Matt Bolopue
    I am writing a program that calculates the number of words, syllables, and sentences in any given text file. I don't need help finding those numbers, however my program (which currently should only find the number of words in the text file) will not import the text file even when I type in the name of the file correctly. The text file is in the same folder as the source code. Instead it tells me every time that what I typed in has the wrong file extension (see my catch{}) and then proceeds to throw a null pointer. I am at a loss for what could be causing it. Any suggestions? import java.io.*; import java.util.*; public class Reading_Lvl_Calc { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int words = 0; String fileName; Scanner scan; Scanner keyread = new Scanner(System.in); System.out.println("Please enter a file name (or QUIT to exit)"); fileName = keyread.nextLine(); File doc = new File(fileName); //while(scan.equals(null)){ try { scan = new Scanner(doc); } catch(Exception e) { if(fileName.substring(fileName.indexOf(".")) != ".txt") System.out.println("I'm sorry, the file \"" + fileName + "\" has an invalid file extension."); else System.out.println("I am sorry, the file \"" + fileName + " \" cannot be found.\n The file must be in the same directory as this program"); scan = null; } // } while(scan.hasNext()){ words++; scan.next(); } System.out.println(words); } }

    Read the article

  • Java- Copy file to either new file or existing file.

    - by jared
    Hi- I would like to write a function copy(File f1, File f2) f1 is always a file. f2 is either a file or a directory. If f2 is a directory I would like to copy f1 to this directory (the file name should stay the same). If f2 is a file I would like to copy the contents of f1 to the end of the file f2. So for example if F2 has the contents: 2222222222222 And F1 has the contents 1111111111111 And I do copy(f1,f2) then f2 should become 2222222222222 1111111111111 Thanks!

    Read the article

  • Java long task - Did it stop writing to file?

    - by rockit
    I am writing a lot of data to a file, and while keeping my eye on the file it eventually stopped growing in size. Essentially my task is getting information from a database, and printing out all non-unique values in column A. Since there are many rows to the database table, and the database table is across my network, this is taking days to complete. Thus I'm concerned that since the file isn't growing, that it isn't actually writing to the file anymore. Which is odd, I have no "catch"'s in my code, so if there was a problem writing to file, wouldn't it have thrown an error?! Should I let the task complete (estimate 2-3 days from today), or is there something else that I don't know going on here making my application not write to the file?! my algorithm goes something like this Declare file Create new file Open file for writing get database connection get resultset from database for each row in the resultset - write column "A" to file - if row# % 100000 then write to screen "completed " + row# + " rows" when no more rows exist close file write to screen - "completed"

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 460 461 462 463 464 465 466 467 468 469 470 471  | Next Page >