Search Results

Search found 35513 results on 1421 pages for 'java interfaces'.

Page 329/1421 | < Previous Page | 325 326 327 328 329 330 331 332 333 334 335 336  | Next Page >

  • formatting and converting in java

    - by mike_hornbeck
    I have few small basic problems : How to format : int i = 456; to give output : ""00000456" ? I've tried %08d but it's not working. Next thing is a problem with conversion and then formatting. I have side and height of triangle, let's say int's 4,7, and 7 is the height. From formula for field we know that F=1/2(a*h). So how to get F as float, with precision up to 10 places ? float f = a*h; works fine, but multiplying it by 0.5 gives error and by 1/2 returns 0.

    Read the article

  • java oracle cusor is closed where cursor is not return to jdbc

    - by optimus
    I am executing a stored procedure which has 2 cusors within the stored procedure. The 1st cursor which is not return to the jdbc as a resultset is closed within the stored procedure. The 2nd cursor which returns the resultset to the jdbc is not closed within the stored procedure. Upon executing I encounter cursor is closed exception which is puzzling. Since the ResultSet will close all underlying cursor upon invoking the close() method

    Read the article

  • directory traversal in Java using different regular and enhanced for loops

    - by user3245621
    I have this code to print out all directories and files. I tried to use recursive method call in for loop. With enhanced for loop, the code prints out all the directories and files correctly. But with regular for loop, the code does not work. I am puzzled by the difference between regular and enhanced for loops. public class FileCopy { private File[] childFiles = null; public static void main(String[] args) { FileCopy fileCopy = new FileCopy(); File srcFile = new File("c:\\temp"); fileCopy.copyTree(srcFile); } public void copyTree(File file){ if(file.isDirectory()){ System.out.println(file + " is a directory. "); childFiles = file.listFiles(); /*for(int j=0; j<childFiles.length; j++){ copyTree(childFiles[j]); } This part is not working*/ for(File a: childFiles){ copyTree(a); } return; } else{ System.out.println(file + " is a file. "); return; } } }

    Read the article

  • Java How to find a value in a linked list iteratively and recursively

    - by Roxy
    Hi I have a method that has a reference to a linked list and a int value. So, this method would count and return how often the value happens in the linked list. So, I decided to make a class, public class ListNode{ public ListNode (int v, ListNode n) {value = v; next = n;) public int value; public ListNode next; } Then, the method would start with a public static int findValue(ListNode x, int valueToCount){ // so would I do it like this?? I don't know how to find the value, // like do I check it? for (int i =0; i< x.length ;i++){ valueToCount += valueToCount; } So, I CHANGED this part, If I did this recursively, then I would have public static int findValue(ListNode x, int valueToCount) { if (x.next != null && x.value == valueToCount { return 1 + findValue(x, valueToCount);} else return new findvalue(x, valueToCount); SO, is the recursive part correct now?

    Read the article

  • How to build our own java custom layout

    - by nguyendat
    Please help me how to creat own custom layout, container, component, layout manager... Example: Containers and Layout Managers Create a window frame. Nest panels within a frame for better layout control. Create and display buttons in a panel. List two component attributes that are controlled by a layout manager. Set the layout manager for a container. Place components in a panel using BorderLayout, GridLayout, and FlowLayout. Name one advantage of each of the layout managers. Create panels with titles. i was search on google but can't find any that match my requirement Thanks for your help

    Read the article

  • Java - How to pass a Generic parameter as Class<T> to a constructor

    - by Joe Almore
    I have a problem here that still cannot solve, the thing is I have this abstract class: public abstract class AbstractBean<T> { private Class<T> entityClass; public AbstractBean(Class<T> entityClass) { this.entityClass = entityClass; }... Now I have another class that inherits this abstract: @Stateless @LocalBean public class BasicUserBean<T extends BasicUser> extends AbstractBean<T> { private Class<T> user; public BasicUserBean() { super(user); // Error: cannot reference user before supertype contructor has been called. } My question is how can I make this to work?, I am trying to make the class BasicUserBean inheritable, so if I have class PersonBean which inherits BasicUserBean then I could set in the Generic the entity Person which also inherits the entity BasicUser. And it will end up being: @Stateless @LocalBean public class PersonBean extends BasicUserBean<Person> { public PersonBean() { super(Person.class); } ... I just want to inherit the basic functionality from BasicUserBean to all descendants, so I do not have to repeat the same code among all descendants. Thanks!.

    Read the article

  • Android Java error handling XML file

    - by Paul
    I'm using SAX and XML reader to read XML weather info from the web and it works fine if the page exists. But if for instance the user inputs an invalid city, zip etc the XML page that gets read from is empty and the app force closes with nullpointerexception. The area that generates the error is here right at open inputstream. Any suggestions?: SAXParserFactory spf = SAXParserFactory.newInstance(); SAXParser sp = null; try { sp = spf.newSAXParser(); } catch (ParserConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); } /* Get the XMLReader of the SAXParser we created. */ XMLReader xr = null; try { xr = sp.getXMLReader(); } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); } /* Create a new ContentHandler and apply it to the XML-Reader*/ WeatherHandler myExampleHandler = new WeatherHandler(); xr.setContentHandler(myExampleHandler); /* Parse the xml-data from our URL. */ try { xr.parse(new InputSource(url.openStream())); parsedWeatherDataSet = myExampleHandler.getParsedData(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); } return parsedWeatherDataSet.toString();

    Read the article

  • Java split is eating my characters.

    - by Fenris_uy
    Hi, I have a string like this String str = "la$le\$li$lo". I want to split it to get the following output "la","le\$li","lo". The \$ is a $ escaped so it should be left in the output. But when I do str.split("[^\\\\]\\$") y get "l","le\$l","lo". From what I get my regex is matching a$ and i$ and removing then. Any idea of how to get my characters back? Thanks

    Read the article

  • Big-Oh running time of code in Java (are my answers accurate

    - by Terry Frederick
    the Method hasTwoTrueValues returns true if at least two values in an array of booleans are true. Provide the Big-Oh running time for all three implementations proposed. // Version 1 public boolean has TwoTrueValues( boolean [ ] arr ) { int count = 0; for( int i = 0; i < arr. length; i++ ) if( arr[ i ] ) count++; return count >= 2; } // Version 2 public boolean hasTwoTrueValues( boolean [ ] arr ) { for( int i = 0; i < arr.length; i++ ) for( int j = i + 1; j < arr.length; j++ ) if( arr[ i ] && arr[ j ] ) return true; } // Version 3 public boolean hasTwoTrueValues( boolean [ ] arr ) { for( int i = 0; i < arr.length; i++ if( arr[ i ] ) for( int j = i + 1; j < arr.length; j++ ) if( arr[ j ] ) return true; return false; } For Version 1 I say the running time is O(n) Version 2 I say O(n^2) Version 3 I say O(n^2) I am really new to this Big Oh Notation so if my answers are incorrect could you please explain and help.

    Read the article

  • Java : Count even values in a Binary Search Tree recursively

    - by user307682
    Hi, I need to find out how many even values are contained in a binary tree. this is my code. private int countEven(BSTNode root){ if ((root == null)|| (root.value%2==1)) return 0; return 1+ countEven(root.left) + countEven(root.right); } this i just coded as i do not have a way to test this out. I'm not able to test it out at the moment but need an answer so badly. any help is deeply appreciated.

    Read the article

  • Java print binary number using bit-wise operator

    - by user69514
    Hi I am creating a method that will take a number and print it along with its binary representation. The problems is that my method prints all 0's for any positive number, and all 1's for any negative number private static void display( int number ){ System.out.print(number + "\t"); int mask = 1 << 31; for(int i=1; i<=32; i++) { if( (mask & number) != 0 ) System.out.print(1); else System.out.print(0); if( (i % 4) == 0 ) System.out.print(" "); } }

    Read the article

  • Rotation in a Vector2d class in Java

    - by wanstein
    I've been working on this for one hour, just can't get it. I have a Vector2d class: public class Vector2d { public double x = 0.0; public double y = 0.0; .... } This vector class has a rotate() method which is causing me trouble. The first snippet seems to make the x and y values smaller and smaller. The second one works just fine! Am I missing something simple here? public void rotate(double n) { this.x = (this.x * Math.cos(n)) - (this.y * Math.sin(n)); this.y = (this.x * Math.sin(n)) + (this.y * Math.cos(n)); } This works: public void rotate(double n) { rx = (this.x * Math.cos(n)) - (this.y * Math.sin(n)); ry = (this.x * Math.sin(n)) + (this.y * Math.cos(n)); x = rx; y = ry; } I just can't spot any difference there

    Read the article

  • Java code compression and decompression of a string

    - by user1822710
    I am having a problem figuring how to check a string for the same characters in a row then count that same character in a row then printing it out then giving the location of the last occorance of that character count then printing it out then moving to the next character in the string that is different then the previous character and the program is case sensitive. So the input could be: aaaaAAAbbbddccc How would I compress this string to: a4A3b3d2c3 ? and then decompress it?

    Read the article

  • Convert any object to pretty HTML in java

    - by ripper234
    How can I convert a given object (in a generic way with reflection) to pretty printable HTML? What ready made library do you recommend that does this? I need support for simple nested objects (as long as they don't create loops in the object graph). I tried to convert it to JSON, but DefaultPrettyPrinter is not HTML friendly.

    Read the article

  • removing the first value in an array c# or java

    - by MrCode
    hey there i was working on a program and was thinking is it possible was to remove the value from the first element in an array. Has anyone any ideas on how this could be done ? thanks for all input is much appreciated. i have only tried removing from the last element wasnt sure on how i would remove the first this is how i done the last element try { if (isEmpty()) { throw new Exception("list is empty"); } size = size -1; return values[size]; } catch(Exception e) { System.out.println(e); return -1; }

    Read the article

  • Replace <Unknown Source> in Java Rhino (JSR223) with actual file name

    - by Lord.Quackstar
    Hello everyone, In my code, all of the scripts are contained in .js files. Whenever one of the scripts contains an error, I get this: javax.script.ScriptException: sun.org.mozilla.javascript.internal.EcmaError: ReferenceError: "nonexistant" is not defined. (<Unknown source>#5) in <Unknown source> at line number 5 What bugs me is the <Unknown Source>. Multiple files are in one ScriptContext, and it can be hard to track down an error. It also looks horrible. Is there a way to replace <Unknown Source> with the actual file name? None of the methods I see support passing a File object, so I'm really confused here.

    Read the article

  • 2 bucks for !! java basic question

    - 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

  • Improving performance for WRITE operation on Oracle DB in Java

    - by Lucky
    I've a typical scenario & need to understand best possible way to handle this, so here it goes - I'm developing a solution that will retrieve data from a remote SOAP based web service & will then push this data to an Oracle database on network. Also, this will be a scheduled task that will execute every 15 minutes. I've event queues on remote service that contains the INSERT/UPDATE/DELETE operations that have been done since last retrieval, & once I retrieve the events for last 15 minutes, it again add events for next retrieval. Now, its just pushing data to Oracle so all my interactions are INSERT & UPDATE statements. There are around 60 tables on Oracle with some of them having 100+ columns. Moreover, for every 15 minutes cycle there would be around 60-70 Inserts, 100+ Updates & 10-20 Deletes. This will be an executable jar file that will terminate after operation & will again start on next 15 minutes cycle. So, I need to understand how should I handle WRITE operations (best practices) to improve performance for this application as whole ? Current Test Code (on every cycle) - Connects to remote service to get events. Creates a connection with DB (single connection object). Identifies the type of operation (INSERT/UPDATE/DELETE) & table on which it is done. After above, calls the respective method based on type of operation & table. Uses Preparedstatement with positional parameters, & retrieves each column value from remote service & assigns that to statement parameters. Commits the statement & returns to get event class to process next event. Above is repeated till all the retrieved events are processed after which program closes & then starts on next cycle & everything repeats again. Thanks for help !

    Read the article

  • Java: Do something on event in SQL Database?

    - by wretrOvian
    Hello I'm building an application with distributed parts. Meaning, while one part (writer) maybe inserting, updating information to a database, the other part (reader) is reading off and acting on that information. Now, i wish to trigger an action event in the reader and reload information from the DB whenever i insert something from the writer. Is there a simple way about this? Would this be a good idea? : // READER while(true) { connect(); // reload info from DB executeQuery("select * from foo"); disconnect(); }

    Read the article

< Previous Page | 325 326 327 328 329 330 331 332 333 334 335 336  | Next Page >