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  • Restore previously serialized JFrame-object, how?

    - by elementz
    Hi all. I have managed to serialize my very basic GUI-object containing a JTextArea and a few buttons to a file 'test.ser'. Now, I would like to completely restore the previously saved state from 'test.ser', but seem to have a misconception of how to properly deserialize an objects state. The class MyFrame creates the JFrame and serializes it. public class MyFrame extends JFrame implements ActionListener { // Fields JTextArea textArea; String title; static MyFrame gui = new MyFrame(); private static final long serialVersionUID = 1125762532137824262L; /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub gui.run(); } // parameterless default contructor public MyFrame() { } // constructor with title public MyFrame(String title) { } // creates Frame and its Layout public void run() { JFrame frame = new JFrame(title); JPanel panel_01 = new JPanel(); JPanel panel_02 = new JPanel(); JTextArea textArea = new JTextArea(20, 22); textArea.setLineWrap(true); JScrollPane scrollPane = new JScrollPane(textArea); scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED); panel_01.add(scrollPane); // Buttons JButton saveButton = new JButton("Save"); saveButton.addActionListener(this); JButton loadButton = new JButton("Load"); loadButton.addActionListener(this); panel_02.add(loadButton); panel_02.add(saveButton); // Layout frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.getContentPane().add(BorderLayout.CENTER, panel_01); frame.getContentPane().add(BorderLayout.SOUTH, panel_02); frame.setSize(300, 400); frame.setVisible(true); } /* * */ public void serialize() { try { ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("test.ser")); oos.writeObject(gui); oos.close(); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } } public void actionPerformed(ActionEvent ev) { System.out.println("Action received!"); gui.serialize(); } } Here I try to do the deserialization: public class Deserialize { static Deserialize ds; static MyFrame frame; public static void main(String[] args) { try { ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.ser")); frame = (MyFrame) ois.readObject(); ois.close(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } Maybe somebody could point me into the direction where my misconception is? Thx in advance!

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  • Looking to eventually build a smartphone app...

    - by Brian L
    Hi all- I'm a young, inexperienced programmer (I've had a year of Java, some MATLAB, and HTML/CSS in school) but I've decided that to get better, I'm making it my goal to produce a simple smartphone app of some kind this year- probably either webOS or Android since I'm on a PC and can't afford a Mac just to write an iPhone app. So my question is, where do I start? I've read the threads about How to Write for Android and such, but I'm not sure I have enough Java experience to just jump right in. And then there's webOS which is based on JavaScript, correct? I guess I'd just like some input from more experienced folks. I have some Barnes and Noble book credit I'm looking to get rid of too, so if there's a guide you think would be useful, feel free to request. tl;dr: Programming newbie ultimately wants to build a simple smartphone app. Where do I start?

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  • Efficiently generate a 16-character, alphanumeric string

    - by ensnare
    I'm looking for a very quick way to generate an alphanumeric unique id for a primary key in a table. Would something like this work? def genKey(): hash = hashlib.md5(RANDOM_NUMBER).digest().encode("base64") alnum_hash = re.sub(r'[^a-zA-Z0-9]', "", hash) return alnum_hash[:16] What would be a good way to generate random numbers? If I base it on microtime, I have to account for the possibility of several calls of genKey() at the same time from different instances. Or is there a better way to do all this? Thanks.

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  • How do i get the screen to pause?

    - by Dakota
    So im learning c++ and i was given this example and i wanted to run it. But i cannot get it to stay up, unless i change it. How do i get Microsoft visual 2010 to keep up the screen when it gets to the end of the program after I release it? include using namespace std; int area(int length, int width); /* function declaration */ /* MAIN PROGRAM: */ int main() { int this_length, this_width; cout << "Enter the length: "; /* <--- line 9 */ cin >> this_length; cout << "Enter the width: "; cin >> this_width; cout << "\n"; /* <--- line 13 */ cout << "The area of a " << this_length << "x" << this_width; cout << " rectangle is " << area(this_length, this_width); return 0; } /* END OF MAIN PROGRAM */ /* FUNCTION TO CALCULATE AREA: */ int area(int length, int width) /* start of function definition */ { int number; number = length * width; return number; } /* end of function definition */ /* END OF FUNCTION */

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  • magento - webserver question

    - by WANNABE
    I've uploaded the Magento installation file to my hosting and I've been told to go to the URL you uploaded it to using you browser, then the installation wizard will run you through the processes. I uploaded to /home/domain/public_html/magneto What URL should I use to access it? Thanks in advance

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  • Tutorial/resource for implementing VM

    - by zaharpopov
    Hello, I want self-education purpose implement a simple virtual machine for a dynamic language, prefer in C language. Something like the Lua VM, or Parrot, or Python VM, but simpler. Are there any good resources/tutorials on achieving this, apart from looking at code and design documentations of the existing VMs? Thanks in advance for your answers and ideas Edit: why close vote? I don't understand - is this not programming. Please comment if there is specific problem with my question.

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  • Getting started with microcontroller programming

    - by Trix
    I'm a fairly good programmer, knowledgeable in C, C++, Python, Ruby and PHP. I'd like to get started with microcontroller programming. I do know nothing about this topic. Microcontrollers are minimal computers on little circuit boards, right? I'm pretty new to electronics too, do I need to be an expert in it to do stuff with microcontrollers? What can I do with them? Would e.g.: A Pacman or Tetris game on an LCD be possible and not too hard? Where should I start? Basically I want to program something really small I can then take with me. This is my only real goal. Are microcontrollers the right thing for this, or are there better solutions? I'd like to do this for fun and as a hobby, I don't want to become a professional in it.

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  • error with string list in C#

    - by Chelsea_cole
    Same namespace: 2 forms. public class Account //frm1 { public string Username; public string Password; } public class ListAcc { public static List<Account> UserList; } private void button1_Click(object sender, EventArgs e) { List<Account> UserList = new List<Account>(); Account acc = new Account(); acc.Username = textBox1.Text; acc.Password = textBox2.Text; UserList.Add(acc); } private void button2_Click(object sender, EventArgs e) //frm2 { string p = frmDangky.ListAcc.UserList[0].Username; // null ->error string p = frmDangky.ListAcc.UserList[0].Password; // null ->error } Someone help me? :( why my string is NULL???????? The textBox is not empty... Thanks!

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  • XML and HTML = need help using HTML code

    - by whitstone86
    I'm converting my static HTML site to a dynamic PHP/XML-driven one. This is my current code: <div class="divider"></div> <div class="main" style="width: 552px;"> <div class="time">00:00</div> <div class="show"><h3><b>Radio Show</b></h3> <p>Description</p></div> <div class="footer"></div> </div> and my XML file: <?xml version="1.0"?> <show> <showdesc> <divider1></divider1> <divmain></divmain> <airtime></airtime> <presenter></presenter> <showinfo></showinfo> <divfooter></divfooter> </showdesc> which is the above HTML, that I'm trying to get into the XML file. I don't know how to get it to get the info in, I can display a simple XML page, as suggested here: http://www.kirupa.com/web/xml_php_parse_intermediate.htm but I am trying to in PHP get this to display what's in the XML pages or display this output: "Sorry. No schedule page is available" if the XML is blank, as above. Anyone able to help me fix this? I've tried and tried but it's baffling me... Thanks.

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  • C# Using singleton instead of a global static instance

    - by Farstucker
    I ran into a problem today and a friend recommended I use a global static instance or more elegantly a singleton pattern. I spent a few hours reading about singletons but a few things still escape me. Background: What Im trying to accomplish is creating an instance of an API and use this one instance in all my classes (as opposed to making a new connection, etc). There seems to be about 100 ways of creating a singleton but with some help from yoda I found some thread safe examples. ..so given the following code: public sealed class Singleton { public static Singleton Instance { get; private set; } static Singleton() { Instance = new Singleton(); } } How/Where would you instantiate the this new class and how should it be called from a separate class? Thanks for your help.

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  • Why do I get "mysql_query(): supplied argument is not a valid"

    - by Brian Ojeda
    Why do I get a "mysql_query(): supplied argument is not a valid" for the first... $r = mysql_query($q, $connection); In the following code... $bId = trim($_POST['bId']); $title = trim($_POST['title']); $story = trim($_POST['story']); $q = "SELECT * "; $q .= "FROM " . DB_NAME . ".`blog` "; $q .= "WHERE `blog`.`id` = {$bId}"; $r = mysql_query($q, $connection); //confirm_query($r); if (mysql_num_rows($r) == 1) { $q = "UPDATE " . DB_NAME . ".`blog` SET `title` = '{$title}', `story` = '{$story}' WHERE `id` = {$bId}"; $r = mysql_query($q, $connection); if (mysql_affected_rows() == 1) { //Successful $data['success'] = true; $date['errors'] = false; $date['message'] = "You are the Greatest!"; } else { //Fail $data['success'] = false; $data['error'] = true; $date['message'] = "You can't do it fool!"; } } I also get an "mysql_num_rows(): supplied argument is not a valid MySQL result resource" error too. Side notes: I am using 1&1 Hosting (worst hosting ever), custom .htaccess file with one line text to enable PHP 5.2 (only why with 1&1 Hosting).

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  • Avoiding string copying in Lua

    - by Matt Sheppard
    Say I have a C program which wants to call a very simple Lua function with two strings (let's say two comma separated lists, returning true if the lists intersect at all, false if not). The obvious way to do this is to push them onto the stack with lua_pushstring, which works fine, however, from the doc it looks like lua_pushstring but makes a copy of the string for Lua to work with. That means that to cross over to the Lua function is going to require two string copies which I could avoid by rewriting the Lua function in C. Is there any way to arrange things so that the existing C strings could be reused on the Lua side for the sake of performance (or would the strcpy cost pale into insignificance anyway)? From my investigation so far (my first couple of hours looking seriously at Lua), lite userdata seems like the sort of thing I want, but in the form of a string.

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  • Active Record like functionality on array instance variable

    - by rube_noob
    I would like to write a module that provides active record like functionality on an array instance variable. Examples of its use would be x = Container.new x.include(ContainerModule) x.elements << Element.new x.elements.find id module ContainerModule def initialize(*args) @elements = [] class << @elements def <<(element) #do something with the Container... super(element) end def find(id) #find an element using the Container's id self #=> #<Array..> but I need #<Container..> end end super(*args) end end The problem is that I need the Container object within these methods. Any reference to self will return the Array, not the Container object. Is there any way to do this? Thanks!

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  • How to learn a language that has very little coverage?

    - by bennybdbc
    I recently came across the Kogut language, and was interested by it. However, the only website to gain information from is the sourceforge page that hosts the project. I had no idea how to even attempt to look at the language in more depth. So what I'm asking is, has anyone here learnt a language that doesn't have the thousands of resources that Ruby, Python etc. have? What would be the best method to do so?

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  • taking integer input in java

    - by ruchir patwa
    I am actually new to java programming and am finding it difficult to take integer input and storing it in variables...i would like it if someone could tell me how to do it or provide with an example like adding two numbers given by the user..

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  • How to use SQLite3 with Java

    - by Bruce
    I am trying to build a simple java program which creates a db file, then a table and inserts dummy values in the table. I found this page http://www.zentus.com/sqlitejdbc/index.html and tried out the example given on the page but I am getting the following error - Exception in thread "main" java.lang.NoClassDefFoundError: Test Caused by: java.lang.ClassNotFoundException: Test at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) Could not find the main class: Test. Program will exit.

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  • Java: how to have try-catch as conditional in for-loop?

    - by HH
    I know how to solve the problem by comparing size to an upper bound but I want a conditional that look for an exception. If an exception occur in conditinal, I want to exit. import java.io.*; import java.util.*; public class listTest{ public static void main(String[] args){ Stack<Integer> numbs=new Stack<Integer>(); numbs.push(1); numbs.push(2); for(int count=0,j=0;try{((j=numbs.pop())<999)}catch(Exception e){break;}&& !numbs.isEmpty(); ){ System.out.println(j); } // I waited for 1 to be printed, not 2. } } Some Errors javac listTest.java listTest.java:10: illegal start of expression for(int count=0,j=0;try{((j=numbs.pop())<999)}catch(Exception e){break;}&& ^ listTest.java:10: illegal start of expression for(int count=0,j=0;try{((j=numbs.pop())<999)}catch(Exception e){break;}&& ^

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  • Choosing a Java IDE for homework assignments

    - by Andrew
    Can anyone recommend a light Java IDE that doesn't require you to make new projects each time you want to compile and run a program? I just want to be able to open java files and compile and run them. I have already tried Eclipse and NetBeans but both require you to make a new project each time you want to compile and run a program. Making a new project is fine for large scale projects but for small school assignments this just makes the process more tedious. Thanks

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  • Java newbie problem: package with private access

    - by HH
    Pack.java imports pack.TestPack; but it cannot access it. I cannot understand why it cannot access the class despite the import. Error Pack.java:7: TestPack() is not public in pack.TestPack; cannot be accessed from outside package System.out.println(new TestPack().getHello()); ^ 1 error Pack.java import pack.TestPack; import java.io.*; public class Pack { public static void main(String[] args){ System.out.println(new TestPack().getHello()); } } TestPack.java package pack; import java.util.*; import java.io.*; public class TestPack { private String hello="if you see me, you ar inside class TestPack"; public String getHello(){return hello;} TestPack(){} }

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  • feeding input to a java process from a batch file

    - by YGL
    If I have a simple java program that processes lines of text from standard input, then I can run it with the following script: @Echo off java Test < file.txt pause exit The script redirects lines of input from a separate file. Is there a way that I can avoid having to use an extra file? Or is this the easiest way? Thanks.

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  • How do I keep from running out of memory on graphics for an Android app?

    - by user279112
    I've been working on an Android app in Eclipse, and so far, my program hasn't really grown past midget size. However I've already run into an issue with an Out of Memory error. You see, I've been using graphics comprised solely of bitmaps and PNGs in this program, and recently, when I tried to add a little bit more functionality to the program (mainly including a few more bitmaps and causing an extra sprite to be created), it started crashing in the graphics thread's constructor - sprite's constructor. When I tracked the problem down, it turned out to be an Out of Memory error that is seemingly caused by adding too many picture files to the program and creating Drawables out of them. This would be a problem, as I really don't have that many picture resources worked into that program...maybe 20 or so. I haven't even started to include sound yet. These images aren't all that fancy. My questions are this: 1) Are programs for the Android phone really that limited on how much memory they can employ, or is it probably something other than the 20-30 resource pictures causing that error? 2) If the memory for Android apps is so awful it can't even handle 20-30 picture resources being loaded into Drawables that exist at the same time, then how in the world are you supposed to make decent graphics and sound for that thing? Thanks.

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