Search Results

Search found 70043 results on 2802 pages for 'java lang class'.

Page 296/2802 | < Previous Page | 292 293 294 295 296 297 298 299 300 301 302 303  | Next Page >

• Can I add and remove elements of enumeration at runtime in Java

  - by Brabster

  It is possible to add and remove elements from an enum in Java at runtime? For example, could I read in the labels and constructor arguments of an enum from a file? @saua, it's just a question of whether it can be done out of interest really. I was hoping there'd be some neat way of altering the running bytecode, maybe using BCEL or something. I've also followed up with this question because I realised I wasn't totally sure when an enum should be used. I'm pretty convinced that the right answer would be to use a collection that ensured uniqueness instead of an enum if I want to be able to alter the contents safely at runtime.

  Read the article

• Copying files from one directory to another in Java

  - by user42155

  Hello, I want to copy files from one directory to another (subdirectory) using Java. I have a directory, dir, with text files. I iterate over the first 20 files in dir, and want to copy them to another directory in the dir directory, which I have created right before the iteration. In the code, I want to copy the review (which represents the ith text file or review) to trainingDir. How can I do this? There seems not to be such a function (or I couldn't find). Thank you. boolean success = false; File[] reviews = dir.listFiles(); String trainingDir = dir.getAbsolutePath() + "/trainingData"; File trDir = new File(trainingDir); success = trDir.mkdir(); for(int i = 1; i <= 20; i++) { File review = reviews[i]; }

  Read the article

• How to rate a connect four game situation in java

  - by MrPink

  Hey, I am trying to write a simple AI for a "Get four" game. The basic game principles are done, so I can throw in coins of different color, and they stack on each other and fill a 2D Array and so on and so forth. until now this is what the method looks like: public int insert(int x, int color) //0 = empty, 1=player1 2=player2" X is the horizontal coordinate, as the y coordinate is determined by how many stones are in the array already, I think the idea is obvious. Now the problem is I have to rate specific game situations, so find how many new pairs, triplets and possible 4 in a row I can get in a specific situation to then give each situation a specific value. With these values I can setup a "Game tree" to then decide which move would be best next (later on implementing Alpha-Beta-Pruning). My current problem is that I can't think of an efficient way to implement a rating of the current game situation in a java method. Any ideas would be greatly appreciated! greetings from Germany Mr. Pink

  Read the article

• Java Swing - Problem in JSpinner

  - by Yatendra Goel

  I am developing a Java Desktop Application and designing the GUI with the help of Netbeans Swing GUI builder. I want to use a JSpinner in my app. I have dragged and dropped it to a JPanel. Now, I want to set its two properties: First, It should display numbers in the range of 1 to 50. Neither less than 1 nor greater than 50. How can I set that range? Second, when I try to get the value of it by spinner.getValue() it returns an Object. As my spinner's data type is Integer, would it be better to downcast the Object into Integer or Is there any other way to get that numeric value?

  Read the article

• Sqlite + Java: table not updating

  - by Ben L

  I'm using a Java wrapper for SQLite called SQLiteJDBC - this may have some bearing on any answers... I have a table which I've displayed in a GUI, within that UI I have a button for the fields for an individual row of that table. When I save my changes I do this... Statement stmt = connection.createStatement(); stmt.execute("update 'tableName' set 'fieldName'=1 where userid=1"); int updateCount = stmt.getUpdateCount(); My connection is valid, I get no exceptions thrown and getUpdateCount() returns '1' indicating that one row has been updated. However my table is not updated. I've spent the last few hours trying to work out what's going on but I'm not having any luck. Help!!

  Read the article

• while loop / string input not working java

  - by Mikeecb

  I have looked online and all of the tutorials / questions have pointed me to this. I can't see why this isn't working. Any help would be much appreciated. Thanks import java.util.*; public class test { static Scanner userInput = new Scanner(System.in); public static void main(String[] args) { String textEntered = userInput.next(); if (textEntered == "hello") { System.out.println("Hello to you too!"); } } } I enter "hello" but nothing is printed. Also I have tried next() and nextLine();

  Read the article

• Full stack framework for Java

  - by Jonathan Barbero

  Hello everyone, I'm looking for a full stack framework (from persistency to view generation (CRUD)) for Java. I don't have experience with Rails style frameworks, like Grails, but I worked a lot with Hibernate, Struts, Spring ... I prefer a framework that let you naturally modify the business domain design with the less effort ( i.e. writing the sql querys to modify the tables and constrains, change the view pages, etc ... ). I was looking a bit about this topic, I saw Naked Objects for example but its development has stopped. So, I want to hear about your experience. Thanks in advance.

  Read the article

• Global Exception Handlers in Java

  - by Samuh

  I am thinking of setting up a global, default Exception handler for my (Android) Mobile application(which uses Java syntax) using Thread.setDefaultUncaughtExceptionHandler(...) call. I am thinking of just displaying an Alert Dialog with appropriate message to the user. Are there any gotchas, caveats and rules that one needs to follow when setting DefaultExceptionHandlers? Any best practices like making sure that the process is killed, full stack trace is written to logs etc. ? Links to documentation, tutorials etc. that can throw some light on this are welcome. Thanks.

  Read the article

• Minimizing Java Thread Context Switching Overhead

  - by binil

  I have a Java application running on Sun 1.6 32-bit VM/Solaris 10 (x86)/Nahelem 8-core(2 threads per core). A specific usecase in the application is to respond to some external message. In my performance test environment, when I prepare and send the response in the same thread that receives the external input, I get about 50 us advantage than when I hand off the message to a separate thread to send the response. I use a ThreadPoolExecutor with a SynchronousQueue to do the handoff. In your experience what is the acceptable delay between scheduling a task to a thread pool and it getting picked up for execution? What ideas had worked for you in the past to try improve this?

  Read the article

• Forcibly clear memory in java

  - by MBennett

  I am writing an application in java that I care about being secure. After encrypting a byte array, I want to forcibly remove from memory anything potentially dangerous such as the key used. In the following snippet key is a byte[], as is data. SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec); byte[] encData = cipher.doFinal(data, 0, data.length); Arrays.fill(key, (byte)0); As far as I understand, the last line above overwrites the key with 0s so that it no longer contains any dangerous data, but I can't find a way to overwrite or evict secretKeySpec or cipher similarly. Is there any way to forcibly overwrite the memory held by secretKeySpec and cipher, so that if someone were to be able to view the current memory state (say, via a cold boot attack), they would not get access to this information?

  Read the article

• Network programming on java

  - by maks

  I have written a simple network program on java using sockets. Program has a client and a server. When user types a word on client side, server simply return this word to client. On server side I use Serversocket and bind it to port 4444. Why does not firewall block this connection on my server PC? I ask this question because earlier I wrote this program using corba technology, and firewall on my server PC was blocking the connection to this port; when I disabled the firewall the program worked fine.

  Read the article

• [java] how to parse XML document?

  - by user32167

  I have xml document in variable (not in file). How can i get data storaged in that? I don't have any additional file with that, i have it 'inside' my sourcecode. When i use DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = dbf.newDocumentBuilder(); Document doc = db.parse(XML); (XML is my xml variable), i get an error java.io.FileNotFoundException: C:\netbeans\app-s7013\<network ip_addr="10.0.0.0\8" save_ip="true"> File not found.

  Read the article

• Encoding problem in Java Server Side application.

  - by NikolayGS

  Hi! I have following problem - i`m running Java WS application. The server side (Axis2 WS Modules on Apache Tomcat) is running at Ubuntu server. The problem is when i get some information from client side in cyrilic and store in database it goes like "?????". If i add data in db directly(From Remote MYSQL Console - there is NO problem). Before move to ubuntu server side was at Windows XP and there was no problem? Sorry for bad explanation, but i have no idea where to start! Thanks in advance!

  Read the article

• How do I calculate someone's age in Java?

  - by nojevive

  I want to return an age in years as an int in a Java method. What I have now is the following where getBirthDate() returns a Date object (with the birth date ;-)): public int getAge() { long ageInMillis = new Date().getTime() - getBirthDate().getTime(); Date age = new Date(ageInMillis); return age.getYear(); } But since getYear() is deprecated I'm wondering if there is a better way to do this? I'm not even sure this works correctly, since I have no unit tests in place (yet).

  Read the article

• How to stop Interruptible Threads in Java

  - by Dr.Lesh

  I have a Java application that I CAN'T EDIT that starts a Thread wich has this run method: public void run(){ while(true){ System.out.println("Something"); } } And at a certain moment I wanna stop it, but if I use thread.interrupt(); it won't work. If I use thread.stop(); it works, but this method is deprecated and its use is discouraged because soon it will be removed from JVM. Does anyone knows how to do it? Thank you.

  Read the article

• generating function arguments in java

  - by aloishis89

  I'm very new to java and am working on my first Android app. I am using the webview demo as a template. I am trying to generate a random integer between 1 and 12 and then call a certain javascript function based on the result. Here's what I have: int number = 1 + (int)(Math.random() * ((12 - 1) + 1)); number = (int) Math.floor(number); String nextQuote = "javascript:wave" + number + "()"; mWebView.loadUrl(nextQuote); So mWebView.loadUrl(nextQuote) will be the same as something like mWebView.loadUrl("javascript:wave1()") I just want to know if what I have here is correct and will work the way I think it will. The application isn't responding as expected and I suspect this bit of code is the culprit.

  Read the article

• Fast way to pass a simple java object from one thread to another

  - by Adal

  I have a callback which receives an object. I make a copy of this object, and I must pass it on to another thread for further processing. It's very important for the callback to return as fast as possible. Ideally, the callback will write the copy to some sort of lock-free container. I only have the callback called from a single thread and one processing thread. I only need to pass a bunch of doubles to the other thread, and I know the maximum number of doubles (around 40). Any ideas? I'm not very familiar with Java, so I don't know the usual ways to pass stuff between threads.

  Read the article

• Java Sql Udate error, data type missmatch

  - by codo

  I have created a table in ms access. I have set the data type of ID to Auto Number in MS-access. In java when I try to update a record. the netBeans IDE gives me the error of " data type missmatch in criteria expression". But when I changed the ID number that was not in the table already it works well. The code is below. String sql = "Update table1 set price ='" + txtPrice.getText() + "', quantity='" + txtQuantity.getText() + "', description='" + txtDescription.getText() + "' where id= " + txtid.getText() + ""; try { pst = conn.prepareStatement(sql); pst.executeUpdate(); JOptionPane.showMessageDialog(null, "Updated"); UpdateJTable(); } catch (Exception e) { JOptionPane.showMessageDialog(null, e); }

  Read the article

• How do I access abstract private data from derived class without friend or 'getter' functions in C++?

  - by John

  So, I am caught up in a dilemma right now. How am I suppose to access a pure abstract base class private member variable from a derived class? I have heard from a friend that it is possible to access it through the base constructor, but he didn't explain. How is it possible? There are some inherited classes from base class. Is there any way to gain access to the private variables ? class Base_button { private: bool is_vis; Rect rButton; public: // Constructors Base_button(); Base_button( const Point &corner, double height, double width ); // Destructor virtual ~ Base_button(); // Accessors virtual void draw() const = 0; bool clicked( const Point &click ) const; bool is_visible() const; // Mutators virtual void show(); virtual void hide(); void move( const Point &loc ); }; class Button : public Base_button { private: Message mButton; public: // Constructors Button(); Button( const Point &corner, const string &label ); // Acessors virtual void draw() const; // Mutators virtual void show(); virtual void hide(); }; I want to be able access Rect and bool in the base class from the subclass

  Read the article

• Sort Java List/Map by order in which items are in an XML File

  - by Brandon Smith

  Hello everyone, What I'm looking to do is to sorta a Java List or Map in the order the items are in a XML File. For Example I have a list of function names as so: functionOne functionThree functionTwo The XML File looks like this: <xml> <function>functionOne</function> <function>functionTwo</function> <function>functionThree</function> </xml> So I would like to sort the list so the function names are as so: functionOne functionTwo functionThree Now Im trying to do this for Variables as well, so there are around 500+ unique 'items'. Does anyone have any idea how I can go about doing this? Now for the file that determines that sort order doesn't have to be XML it just what I use the most, it can be anything that can get the job done. Thanks in advance for your time.

  Read the article

• Java Synchronized Write Block

  - by ikurtz

  im new to java and i have a question regarding Synchronized. i have the following code for writing to network (simple implementation for now): public void networkSendData(byte[] data){ try { out.write(data); out.flush(); } catch (IOException e) { } } i was wondering if there is a need for block level Synchronized here as im am writing the whole data at once. or is there a chance for race condition? i ask because the data to write is coming for multiple sources. thank you.

  Read the article

• How to get the field name of a java (weak) reference pointing to an object in an other class?

  - by Tom

  Imagine I have the following situation: Test1.java import java.lang.ref.WeakReference; public class Test1 { public WeakReference fieldName; public init() { fieldName = new WeakReference(this); Test2.setWeakRef(fieldName); } } Test2.java import java.lang.ref.WeakReference; public class Test2 { public static setWeakRef(WeakReference weakRef) { //at this point I got weakRef in an other class.. now, how do I get the field name this reference was created with? So that it returns exactly "fieldName", because that's the name I gave it in Test1.java? } } At the location of the comment I received the weak reference created in an other class. How would I retreive the field name that this weak reference was created with, in this case "fieldName"? Thanks in advance.

  Read the article

• java decmail string to AS 3.0 conversion procedure

  - by Jack Smith

  Hello, I have a problem with conversion java code to action script 3. Anyone can help with code translation? Thanks. public static short[] decmail_str_to_binary_data(String s) { short[] data = new short[s.length()/2]; for (int i = 0; i < s.length(); i += 2) { char c1 = s.charAt(i); char c2 = s.charAt(i + 1); int comb = Character.digit(c1, 16) & 0xff; comb <<= 4; comb += Character.digit(c2, 16) & 0xff; data[i/2] = (short)comb; } return data; }

  Read the article

• having problems in running my java program..

  - by Tarun

  I'm a beginner in java so this question might seem a little stupid, my jdk and jre are installed in C:\program files, I write my program and save it in in my folder G:\start, now my program compiles without any error(the .class file is also generated), but when i run my program it says "unable to locate G:\lib\amd64\jvm.cfg", so i copy the 'lib' folder from my jdk folder and paste it in G:, again program compiles without any error, but when i run it,it gives my a new error saying "unable to locate G:\bin\server\jvm.dll",so i copy the 'bin' folder to g:, but now when i run, it gives me the same error again "unable to locate G:\bin\server\jvm.dll",where am I going wrong?

  Read the article

• Authenticating a SOAP service in Java (password security)

  - by user1686448

  I am writing an application, in Java, which needs to log in to a remote SOAP service (JIRA) prior to calling methods on that service. I have looked at examples of how to do this, for example http://www.j-tricks.com/1/post/2010/8/jira-soap-client.html, however I am concerned that I need to put the password in memory at some point. I've read that I should store the password as a char[] but still, I'm concerned about storing the password in the clear at all. How should I store the password used by my client to log into the SOAP service? And how should I read it and pass it to JIRA?

  Read the article

< Previous Page | 292 293 294 295 296 297 298 299 300 301 302 303  | Next Page >