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  • Problems with classes (super new)

    - by user260036
    Hi, I've problems to figure it out what's happening in the following exercise, I'm learning Smalltalk, so I'm newbie. Class Anew ^super new initialize. Ainitialize a:=0. Class Bnew: aParameter |instance| instance := super new. instance b: instance a + aParameter. ^instance Binitialize b:=0. The problem says what happen when the following code is executed: B new:10. But I can't not figure it out why instance variable does not belong to A class. Thanks

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  • How do you encode Algebraic Data Types in a C#- or Java-like language?

    - by Jörg W Mittag
    There are some problems which are easily solved by Algebraic Data Types, for example a List type can be very succinctly expressed as: data ConsList a = Empty | ConsCell a (ConsList a) consmap f Empty = Empty consmap f (ConsCell a b) = ConsCell (f a) (consmap f b) l = ConsCell 1 (ConsCell 2 (ConsCell 3 Empty)) consmap (+1) l This particular example is in Haskell, but it would be similar in other languages with native support for Algebraic Data Types. It turns out that there is an obvious mapping to OO-style subtyping: the datatype becomes an abstract base class and every data constructor becomes a concrete subclass. Here's an example in Scala: sealed abstract class ConsList[+T] { def map[U](f: T => U): ConsList[U] } object Empty extends ConsList[Nothing] { override def map[U](f: Nothing => U) = this } final class ConsCell[T](first: T, rest: ConsList[T]) extends ConsList[T] { override def map[U](f: T => U) = new ConsCell(f(first), rest.map(f)) } val l = (new ConsCell(1, new ConsCell(2, new ConsCell(3, Empty))) l.map(1+) The only thing needed beyond naive subclassing is a way to seal classes, i.e. a way to make it impossible to add subclasses to a hierarchy. How would you approach this problem in a language like C# or Java? The two stumbling blocks I found when trying to use Algebraic Data Types in C# were: I couldn't figure out what the bottom type is called in C# (i.e. I couldn't figure out what to put into class Empty : ConsList< ??? >) I couldn't figure out a way to seal ConsList so that no subclasses can be added to the hierarchy What would be the most idiomatic way to implement Algebraic Data Types in C# and/or Java? Or, if it isn't possible, what would be the idiomatic replacement?

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  • The C++ 'new' keyword and C

    - by Florian
    In a C header file of a library I'm using one of the variables is named 'new'. Unfortunately, I'm using this library in a C++ project and the occurence of 'new' as a variable names freaks out the compiler. I'm already using extern "C" { #include<... }, but that doesn't seem to help in this respect. Do I have to aks the library developer to change the name of that variable even though from his perspective, as a C developer, the code is absolutely fine, as 'new' is not a C keyword?

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  • proper way to creation multiple similiar buttons/panels

    - by JayAvon
    I have the below Code which i tried to do, but it only shows(the minus/plus button) on the last GirdLayout (Intelligence stat): JButton plusButton = new JButton("+"); JButton minusButton = new JButton("-"); statStrengthGridPanel = new JPanel(new GridLayout(1,3)); statStrengthGridPanel.add(minusButton); statStrengthGridPanel.add(new JLabel("10")); statStrengthGridPanel.add(plusButton); statConstitutionGridPanel = new JPanel(new GridLayout(1,3)); statConstitutionGridPanel.add(minusButton); statConstitutionGridPanel.add(new JLabel("10")); statConstitutionGridPanel.add(plusButton); statDexterityGridPanel = new JPanel(new GridLayout(1,3)); statDexterityGridPanel.add(minusButton); statDexterityGridPanel.add(new JLabel("10")); statDexterityGridPanel.add(plusButton); statIntelligenceGridPanel = new JPanel(new GridLayout(1,3)); statIntelligenceGridPanel.add(minusButton); statIntelligenceGridPanel.add(new JLabel("10")); statIntelligenceGridPanel.add(plusButton); I know I can do something like I did for the Panel names(have multiple ones), but I did not want to do that for the Panels in the first place. I am trying to use best practice and not have my code be repetitive. Any suggestions?? The goal is to have 4 stats, to assign points to, with decrement and increment buttons(I decided against sliders). Eventually I will have them have upper and lower limits, decrement the "unused" label, and all of that good stuff, but I just want to not be repetitive. Thanks for any help.

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  • while uploading image I get errors in logcat

    - by al0ne evenings
    I am uploading image and also sending some parameters with it. I am getting errors in my logcat while doing so. Here is my code public class Camera extends Activity { ImageView ivUserImage; Button bUpload; Intent i; int CameraResult = 0; Bitmap bmp; public String globalUID; UserFunctions userFunctions; String photoName; InputStream is; int serverResponseCode = 0; ProgressDialog dialog = null; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.camera); userFunctions = new UserFunctions(); globalUID = getIntent().getExtras().getString("globalUID"); Toast.makeText(getApplicationContext(), globalUID, Toast.LENGTH_LONG).show(); ivUserImage = (ImageView)findViewById(R.id.ivUserImage); bUpload = (Button)findViewById(R.id.bUpload); openCamera(); } private void openCamera() { i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE); startActivityForResult(i, CameraResult); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if(resultCode == RESULT_OK) { //set image taken from camera on ImageView Bundle extras = data.getExtras(); bmp = (Bitmap) extras.get("data"); ivUserImage.setImageBitmap(bmp); //Create new Cursor to obtain the file Path for the large image String[] largeFileProjection = { MediaStore.Images.ImageColumns._ID, MediaStore.Images.ImageColumns.DATA }; String largeFileSort = MediaStore.Images.ImageColumns._ID + " DESC"; //final String photoName = MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME; Cursor myCursor = this.managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, largeFileProjection, null, null, largeFileSort); try { myCursor.moveToFirst(); //This will actually give you the file path location of the image. final String largeImagePath = myCursor.getString(myCursor.getColumnIndexOrThrow(MediaStore.Images.ImageColumns.DATA)); //final String photoName = myCursor.getString(myCursor.getColumnIndexOrThrow(MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME)); //Log.e("URI", largeImagePath); File f = new File("" + largeImagePath); photoName = f.getName(); bUpload.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { dialog = ProgressDialog.show(Camera.this, "", "Uploading file...", true); new Thread(new Runnable() { public void run() { runOnUiThread(new Runnable() { public void run() { //tv.setText("uploading started....."); Toast.makeText(getBaseContext(), "File is uploading...", Toast.LENGTH_LONG).show(); } }); if(imageUpload(globalUID, largeImagePath)) { Toast.makeText(getApplicationContext(), "Image uploaded", Toast.LENGTH_LONG).show(); } else { Toast.makeText(getApplicationContext(), "Error uploading image", Toast.LENGTH_LONG).show(); } //Log.e("Response: ", response); //System.out.println("RES : " + response); } }).start(); } }); } finally { myCursor.close(); } //Uri uriLargeImage = Uri.withAppendedPath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, String.valueOf(imageId)); //String imageUrl = getRealPathFromURI(uriLargeImage); } } public boolean imageUpload(String uid, String imagepath) { boolean success = false; //Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher); Bitmap bitmapOrg = BitmapFactory.decodeFile(imagepath); ByteArrayOutputStream bao = new ByteArrayOutputStream(); bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 90, bao); byte [] ba = bao.toByteArray(); String ba1=Base64.encodeToString(ba, 0); ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); nameValuePairs.add(new BasicNameValuePair("image",ba1)); nameValuePairs.add(new BasicNameValuePair("uid", uid)); try { HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost("http://www.example.info/androidfileupload/index.php"); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); if(response != null) { success = true; } is = entity.getContent(); } catch(Exception e) { Log.e("log_tag", "Error in http connection "+e.toString()); } dialog.dismiss(); return success; } Here is my logcat 06-23 11:54:48.555: E/AndroidRuntime(30601): FATAL EXCEPTION: Thread-11 06-23 11:54:48.555: E/AndroidRuntime(30601): java.lang.OutOfMemoryError 06-23 11:54:48.555: E/AndroidRuntime(30601): at java.lang.String.<init>(String.java:513) 06-23 11:54:48.555: E/AndroidRuntime(30601): at java.lang.AbstractStringBuilder.toString(AbstractStringBuilder.java:650) 06-23 11:54:48.555: E/AndroidRuntime(30601): at java.lang.StringBuilder.toString(StringBuilder.java:664) 06-23 11:54:48.555: E/AndroidRuntime(30601): at org.apache.http.client.utils.URLEncodedUtils.format(URLEncodedUtils.java:170) 06-23 11:54:48.555: E/AndroidRuntime(30601): at org.apache.http.client.entity.UrlEncodedFormEntity.<init>(UrlEncodedFormEntity.java:71) 06-23 11:54:48.555: E/AndroidRuntime(30601): at com.zafar.login.Camera.imageUpload(Camera.java:155) 06-23 11:54:48.555: E/AndroidRuntime(30601): at com.zafar.login.Camera$1$1.run(Camera.java:119) 06-23 11:54:48.555: E/AndroidRuntime(30601): at java.lang.Thread.run(Thread.java:1019) 06-23 11:54:53.960: E/WindowManager(30601): Activity com.zafar.login.DashboardActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@405db540 that was originally added here 06-23 11:54:53.960: E/WindowManager(30601): android.view.WindowLeaked: Activity com.zafar.login.DashboardActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@405db540 that was originally added here 06-23 11:54:53.960: E/WindowManager(30601): at android.view.ViewRoot.<init>(ViewRoot.java:266) 06-23 11:54:53.960: E/WindowManager(30601): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:174) 06-23 11:54:53.960: E/WindowManager(30601): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:117) 06-23 11:54:53.960: E/WindowManager(30601): at android.view.Window$LocalWindowManager.addView(Window.java:424) 06-23 11:54:53.960: E/WindowManager(30601): at android.app.Dialog.show(Dialog.java:241) 06-23 11:54:53.960: E/WindowManager(30601): at android.app.ProgressDialog.show(ProgressDialog.java:107) 06-23 11:54:53.960: E/WindowManager(30601): at android.app.ProgressDialog.show(ProgressDialog.java:90) 06-23 11:54:53.960: E/WindowManager(30601): at com.zafar.login.Camera$1.onClick(Camera.java:110) 06-23 11:54:53.960: E/WindowManager(30601): at android.view.View.performClick(View.java:2538) 06-23 11:54:53.960: E/WindowManager(30601): at android.view.View$PerformClick.run(View.java:9152) 06-23 11:54:53.960: E/WindowManager(30601): at android.os.Handler.handleCallback(Handler.java:587) 06-23 11:54:53.960: E/WindowManager(30601): at android.os.Handler.dispatchMessage(Handler.java:92) 06-23 11:54:53.960: E/WindowManager(30601): at android.os.Looper.loop(Looper.java:130) 06-23 11:54:53.960: E/WindowManager(30601): at android.app.ActivityThread.main(ActivityThread.java:3691) 06-23 11:54:53.960: E/WindowManager(30601): at java.lang.reflect.Method.invokeNative(Native Method) 06-23 11:54:53.960: E/WindowManager(30601): at java.lang.reflect.Method.invoke(Method.java:507) 06-23 11:54:53.960: E/WindowManager(30601): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907) 06-23 11:54:53.960: E/WindowManager(30601): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665) 06-23 11:54:53.960: E/WindowManager(30601): at dalvik.system.NativeStart.main(Native Method) 06-23 11:54:55.190: I/Process(30601): Sending signal. PID: 30601 SIG: 9

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  • IOException during blocking network NIO in JDK 1.7

    - by Bass
    I'm just learning NIO, and here's the short example I've written to test how a blocking NIO can be interrupted: class TestBlockingNio { private static final boolean INTERRUPT_VIA_THREAD_INTERRUPT = true; /** * Prevent the socket from being GC'ed */ static Socket socket; private static SocketChannel connect(final int port) { while (true) { try { final SocketChannel channel = SocketChannel.open(new InetSocketAddress(port)); channel.configureBlocking(true); return channel; } catch (final IOException ioe) { try { Thread.sleep(1000); } catch (final InterruptedException ie) { } continue; } } } private static byte[] newBuffer(final int length) { final byte buffer[] = new byte[length]; for (int i = 0; i < length; i++) { buffer[i] = (byte) 'A'; } return buffer; } public static void main(final String args[]) throws IOException, InterruptedException { final int portNumber = 10000; new Thread("Reader") { public void run() { try { final ServerSocket serverSocket = new ServerSocket(portNumber); socket = serverSocket.accept(); /* * Fully ignore any input from the socket */ } catch (final IOException ioe) { ioe.printStackTrace(); } } }.start(); final SocketChannel channel = connect(portNumber); final Thread main = Thread.currentThread(); final Thread interruptor = new Thread("Inerruptor") { public void run() { System.out.println("Press Enter to interrupt I/O "); while (true) { try { System.in.read(); } catch (final IOException ioe) { ioe.printStackTrace(); } System.out.println("Interrupting..."); if (INTERRUPT_VIA_THREAD_INTERRUPT) { main.interrupt(); } else { try { channel.close(); } catch (final IOException ioe) { System.out.println(ioe.getMessage()); } } } } }; interruptor.setDaemon(true); interruptor.start(); final ByteBuffer buffer = ByteBuffer.allocate(32768); int i = 0; try { while (true) { buffer.clear(); buffer.put(newBuffer(buffer.capacity())); buffer.flip(); channel.write(buffer); System.out.print('X'); if (++i % 80 == 0) { System.out.println(); Thread.sleep(100); } } } catch (final ClosedByInterruptException cbie) { System.out.println("Closed via Thread.interrupt()"); } catch (final AsynchronousCloseException ace) { System.out.println("Closed via Channel.close()"); } } } In the above example, I'm writing to a SocketChannel, but noone is reading from the other side, so eventually the write operation hangs. This example works great when run by JDK-1.6, with the following output: Press Enter to interrupt I/O XXXX Interrupting... Closed via Thread.interrupt() — meaning that only 128k of data was written to the TCP socket's buffer. When run by JDK-1.7 (1.7.0_25-b15 and 1.7.0-u40-b37), however, the very same code bails out with an IOException: Press Enter to interrupt I/O XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXX Exception in thread "main" java.io.IOException: Broken pipe at sun.nio.ch.FileDispatcherImpl.write0(Native Method) at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47) at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93) at sun.nio.ch.IOUtil.write(IOUtil.java:65) at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:487) at com.example.TestBlockingNio.main(TestBlockingNio.java:109) Can anyone explain this different behaviour?

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  • Calendar issue in simple java form using swing package?

    - by Rand Mate
    I have created a form using java swing package, For the purpose of adding Date of Birth in the form I have used the following code particularly to add in java Frame via Swing Package. Is there any alternative way to simplify the code. JLabel l2 = new JLabel("Date of Birth"); l2.setBounds(200,160,100,20); String day[] ={"1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20","21","22","23","24","25","26","27","28","29","30"}; String month[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; String year[] = {"2012","2011","2010","2009","2008","2007","2006","2005","2004","2003","2002","2001","2000","1999","1998","1997","1996","1995","1994","1993","1992","1991","1990","1989","1988","1987","1986","1985","1984","1983","1982","1981","1980","1979","1976","1975"}; JComboBox cb1 = new JComboBox(day); cb1.setBounds(450,160,50,20); JComboBox cb2 = new JComboBox(month); cb2.setBounds(500,160,50,20); JComboBox cb3 = new JComboBox(year); cb3.setBounds(550,160,60,20);

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  • Java 7 New Features

    - by John W.
    I have done some good reading on the new java.util.concurrent features being introduced with the java 7 release. For instance, Phaser, TransferQueue and the more exciting Fork Join Framework. I recently saw a power point made by Josh Bloch about even more features that are going to be introduced however that link has been lost. For example I remember one change is being able to build a Map the same way you can build an array for: Map myMap = {"1,Dog","2,Cat"}; and so forth (this may not be 100% correct but the idea is there) Does anyone know of a list or just can name some new things to look forward to? Note: I did see a question asked http://stackoverflow.com/questions/213958/new-features-in-java-7 however it was asked ~2 years ago and I am sure the list of updates are more concrete. Thanks!

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  • How can i pass an object to a new thread generated anonymously in a button listener

    - by WaterBoy
    I would like to pass an object (docket for printing) to a new thread which will print the docket. My code is: private final Button.OnClickListener cmdPrintOnClickListener = new Button.OnClickListener() { public void onClick(View v) { new Thread(new Runnable() { public void run() { enableTestButton(false); Looper.prepare(); doConnectionTest(); Looper.loop(); Looper.myLooper().quit(); } }).start(); } }; How do I pass the object to it? Also - I need to generate the object in the UI thread, just before starting the new thread so where could I put this method (e.g. getDocketObject()) in relation to my code below thanks, anton

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  • Open a new panel via a button Java Swing

    - by abuteau
    I saw a lot of post on StackOverflow relating to this, but unable to solve my problem. I want to open a new Panel by clicking a button. Here is how i try to do it parameterButton = new JButton("Parametres"); parameterButton.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e){ createParameterPanel = new DisplayParameterPanel(); createParameterPanel.setVisible(true); add(createParameterPanel); }; }); add(parameterButton); When I click the parameterButton it doesn't open. How can I open a new panel. Thanks,

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  • Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException

    - by Dheeraj kumar
    Hi, I have to read xls file in java.I used poi-3.6 to read xls file in Eclipse.But i m getting this ERROR"Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException at ReadExcel2.main(ReadExcel2.java:38)". I have added following jars 1)poi-3.6-20091214.jar 2)poi-contrib-3.6-20091214.jar 3)poi-examples-3.6-20091214.jar 4)poi-ooxml-3.6-20091214.jar 5)poi-ooxml-schemas-3.6-20091214.jar 6)poi-scratchpad-3.6-20091214.jar Below is the code which i m using: import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import org.apache.poi.xssf.usermodel.XSSFCell; import org.apache.poi.xssf.usermodel.XSSFRow; import java.io.FileInputStream; import java.io.IOException; import java.util.Iterator; import java.util.List; import java.util.ArrayList; public class ReadExcel { public static void main(String[] args) throws Exception { // // An excel file name. You can create a file name with a full path // information. // String filename = "C:\\myExcel.xl"; // // Create an ArrayList to store the data read from excel sheet. // List sheetData = new ArrayList(); FileInputStream fis = null; try { // // Create a FileInputStream that will be use to read the excel file. // fis = new FileInputStream(filename); // // Create an excel workbook from the file system. // // HSSFWorkbook workbook = new HSSFWorkbook(fis); Workbook workbook = new XSSFWorkbook(fis); // // Get the first sheet on the workbook. // Sheet sheet = workbook.getSheetAt(0); // // When we have a sheet object in hand we can iterator on each // sheet's rows and on each row's cells. We store the data read // on an ArrayList so that we can printed the content of the excel // to the console. // Iterator rows = sheet.rowIterator(); while (rows.hasNext()) { Row row = (XSSFRow) rows.next(); Iterator cells = row.cellIterator(); List data = new ArrayList(); while (cells.hasNext()) { Cell cell = (XSSFCell) cells.next(); data.add(cell); } sheetData.add(data); } } catch (IOException e) { e.printStackTrace(); } finally { if (fis != null) { fis.close(); } } showExelData(sheetData); } private static void showExelData(List sheetData) { // // Iterates the data and print it out to the console. // for (int i = 0; i < sheetData.size(); i++) { List list = (List) sheetData.get(i); for (int j = 0; j < list.size(); j++) { Cell cell = (XSSFCell) list.get(j); System.out.print(cell.getRichStringCellValue().getString()); if (j < list.size() - 1) { System.out.print(", "); } } System.out.println(""); } } } Please help. thanks in anticipation, Regards, Dheeraj!

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  • Modern Java alternatives

    - by Ralph
    I'm not sure if stackoverflow is the best forum for this discussion. I have been a Java developer for 14 years and have written an enterprise-level (~500,000 line) Swing application that uses most of the standard library APIs. Recently, I have become disappointed with the progress that the language has made to "modernize" itself, and am looking for an alternative for ongoing development. I have considered moving to the .NET platform, but I have issues with using something the only runs well in Windows (I know about Mono, but that is still far behind Microsoft). I also plan on buying a new Macbook Pro as soon as Apple releases their new rumored Arrandale-based machines and want to develop in an environment that will feel "at home" in Unix/Linux. I have considered using Python or Ruby, but the standard Java library is arguably the largest of any modern language. In JVM-based languages, I looked at Groovy, but am disappointed with its performance. Rumor has it that with the soon-to-be released JDK7, with its InvokeDynamic instruction, this will improve, but I don't know how much. Groovy is also not truly a functional language, although it provides closures and some of the "functional" features on collections. It does not embrace immutability. I have narrowed my search down to two JVM-based alternatives: Scala and Clojure. Each has its strengths and weaknesses. I am looking for the stackoverflow readerships' opinions. I am not an expert at either of these languages; I have read 2 1/2 books on Scala and am currently reading Stu Halloway's book on Clojure. Scala is strongly statically typed. I know the dynamic language folks claim that static typing is a crutch for not doing unit testing, but it does provide a mechanism for compile-time location of a whole class of errors. Scala is more concise than Java, but not as much as Clojure. Scala's inter-operation with Java seems to be better than Clojure's, in that most Java operations are easier to do in Scala than in Clojure. For example, I can find no way in Clojure to create a non-static initialization block in a class derived from a Java superclass. For example, I like the Apache commons CLI library for command line argument parsing. In Java and Scala, I can create a new Options object and add Option items to it in an initialization block as follows (Java code): final Options options = new Options() { { addOption(new Option("?", "help", false, "Show this usage information"); // other options } }; I can't figure out how to the same thing in Clojure (except by using (doit...)), although that may reflect my lack of knowledge of the language. Clojure's collections are optimized for immutability. They rarely require copy-on-write semantics. I don't know if Scala's immutable collections are implemented using similar algorithms, but Rich Hickey (Clojure's inventor) goes out of his way to explain how that language's data structures are efficient. Clojure was designed from the beginning for concurrency (as was Scala) and with modern multi-core processors, concurrency takes on more importance, but I occasionally need to write simple non-concurrent utilities, and Scala code probably runs a little faster for these applications since it discourages, but does not prohibit, "simple" mutability. One could argue that one-off utilities do not have to be super-fast, but sometimes they do tasks that take hours or days to complete. I know that there is no right answer to this "question", but I thought I would open it up for discussion. If anyone has a suggestion for another JVM-based language that can be used for enterprise level development, please list it. Also, it is not my intent to start a flame war. Thanks, Ralph

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  • [Java] Cannot draw pixels

    - by Wilhelm
    Hello everyone. I want to print each digit of pi number as a colored pixel, so, I get na input, with the pi number, then parse it into a list, each node containing a digit (I know, I'll use an array later), but I never get this painted to screen... Can someone help me to see where I'm wrong? package edu.pi.view; import java.awt.Graphics; import java.awt.Image; import java.awt.image.MemoryImageSource; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.util.ArrayList; import java.util.List; import javax.swing.JFrame; import javax.swing.JPanel; public class Main extends JPanel { private static final long serialVersionUID = 6416932054834995251L; private static int pixels[]; private static List<Integer> pi; public static void readFile(String name) { File file = new File(name); BufferedReader reader = null; pi = new ArrayList<Integer>(); char[] digits; try { reader = new BufferedReader(new FileReader(file)); String text = null; while((text = reader.readLine()) != null) { digits = text.toCharArray(); for(char el : digits) if(el != ' ') pi.add(Character.getNumericValue(el)); } } catch (Exception e) { e.printStackTrace(); } } public void paint(Graphics gg) { readFile("c:\\pi.txt"); int h = 5; int w = 2; int color = 0xffffff; int digit; int i = 0; pixels = new int[w * h]; for (int y = 0; y < h; y++) { for (int x = 0; x < h; x++) { digit = pi.get(i); if(digit == 0) color = 0x000000; else if(digit == 1) color = 0x787878; else if(digit == 2) color = 0x008B00; else if(digit == 3) color = 0x00008B; else if(digit == 4) color = 0x008B8B; else if(digit == 5) color = 0x008B00; else if(digit == 6) color = 0xCDCD00; else if(digit == 7) color = 0xFF4500; else if(digit == 8) color = 0x8B0000; else if(digit == 9) color = 0xFF0000; pixels[i] = color; i++; } } Image art = createImage(new MemoryImageSource(w, h, pixels, 0, w)); gg.drawImage(art, 0, 0, this); } public static void main(String[] args) { JFrame frame = new JFrame(); frame.getContentPane().add(new Main()); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300,300); frame.setVisible(true); } }

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  • Sent Item code in java

    - by Farhan Khan
    I need urgent help, if any one can resolve my issue it will be very highly appriciated. I have create a SMS composer on jAVA netbians its on urdu language. the probelm is its not saving sent sms on Sent items.. i have tried my best to make the code but failed. Tomorrow is my last day to present the code on university please help me please below is the code that i have made till now. Please any one.... /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package newSms; import javax.microedition.io.Connector; import javax.microedition.midlet.*; import javax.microedition.lcdui.*; import javax.wireless.messaging.MessageConnection; import javax.wireless.messaging.TextMessage; import org.netbeans.microedition.util.SimpleCancellableTask; /** * @author AHTISHAM */ public class composeurdu extends MIDlet implements CommandListener, ItemCommandListener, ItemStateListener { private boolean midletPaused = false; private boolean isUrdu; String numb=" "; Alert alert; //<editor-fold defaultstate="collapsed" desc=" Generated Fields ">//GEN-BEGIN:|fields|0| private Form form; private TextField number; private TextField textUrdu; private StringItem stringItem; private StringItem send; private Command exit; private Command sendMesg; private Command add; private Command urdu; private Command select; private SimpleCancellableTask task; //</editor-fold>//GEN-END:|fields|0| MessageConnection clientConn; private Display display; public composeurdu() { display = Display.getDisplay(this); } private void showMessage(){ display=Display.getDisplay(this); //numb=number.getString(); if(number.getString().length()==0 || textUrdu.getString().length()==0){ Alert alert=new Alert("error "); alert.setString(" Enter phone number"); alert.setTimeout(5000); display.setCurrent(alert); } else if(number.getString().length()>11){ Alert alert=new Alert("error "); alert.setString("invalid number"); alert.setTimeout(5000); display.setCurrent(alert); } else{ Alert alert=new Alert("error "); alert.setString("success"); alert.setTimeout(5000); display.setCurrent(alert); } } void showMessage(String message, Displayable displayable) { Alert alert = new Alert(""); alert.setTitle("Error"); alert.setString(message); alert.setType(AlertType.ERROR); alert.setTimeout(5000); display.setCurrent(alert, displayable); } //<editor-fold defaultstate="collapsed" desc=" Generated Methods ">//GEN-BEGIN:|methods|0| //</editor-fold>//GEN-END:|methods|0| //<editor-fold defaultstate="collapsed" desc=" Generated Method: initialize ">//GEN-BEGIN:|0-initialize|0|0-preInitialize /** * Initializes the application. It is called only once when the MIDlet is * started. The method is called before the * <code>startMIDlet</code> method. */ private void initialize() {//GEN-END:|0-initialize|0|0-preInitialize // write pre-initialize user code here //GEN-LINE:|0-initialize|1|0-postInitialize // write post-initialize user code here }//GEN-BEGIN:|0-initialize|2| //</editor-fold>//GEN-END:|0-initialize|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: startMIDlet ">//GEN-BEGIN:|3-startMIDlet|0|3-preAction /** * Performs an action assigned to the Mobile Device - MIDlet Started point. */ public void startMIDlet() {//GEN-END:|3-startMIDlet|0|3-preAction // write pre-action user code here switchDisplayable(null, getForm());//GEN-LINE:|3-startMIDlet|1|3-postAction // write post-action user code here form.setCommandListener(this); form.setItemStateListener(this); }//GEN-BEGIN:|3-startMIDlet|2| //</editor-fold>//GEN-END:|3-startMIDlet|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: resumeMIDlet ">//GEN-BEGIN:|4-resumeMIDlet|0|4-preAction /** * Performs an action assigned to the Mobile Device - MIDlet Resumed point. */ public void resumeMIDlet() {//GEN-END:|4-resumeMIDlet|0|4-preAction // write pre-action user code here //GEN-LINE:|4-resumeMIDlet|1|4-postAction // write post-action user code here }//GEN-BEGIN:|4-resumeMIDlet|2| //</editor-fold>//GEN-END:|4-resumeMIDlet|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: switchDisplayable ">//GEN-BEGIN:|5-switchDisplayable|0|5-preSwitch /** * Switches a current displayable in a display. The * <code>display</code> instance is taken from * <code>getDisplay</code> method. This method is used by all actions in the * design for switching displayable. * * @param alert the Alert which is temporarily set to the display; if * <code>null</code>, then * <code>nextDisplayable</code> is set immediately * @param nextDisplayable the Displayable to be set */ public void switchDisplayable(Alert alert, Displayable nextDisplayable) {//GEN-END:|5-switchDisplayable|0|5-preSwitch // write pre-switch user code here Display display = getDisplay();//GEN-BEGIN:|5-switchDisplayable|1|5-postSwitch if (alert == null) { display.setCurrent(nextDisplayable); } else { display.setCurrent(alert, nextDisplayable); }//GEN-END:|5-switchDisplayable|1|5-postSwitch // write post-switch user code here }//GEN-BEGIN:|5-switchDisplayable|2| //</editor-fold>//GEN-END:|5-switchDisplayable|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Displayables ">//GEN-BEGIN:|7-commandAction|0|7-preCommandAction /** * Called by a system to indicated that a command has been invoked on a * particular displayable. * * @param command the Command that was invoked * @param displayable the Displayable where the command was invoked */ public void commandAction(Command command, Displayable displayable) {//GEN-END:|7-commandAction|0|7-preCommandAction // write pre-action user code here if (displayable == form) {//GEN-BEGIN:|7-commandAction|1|16-preAction if (command == exit) {//GEN-END:|7-commandAction|1|16-preAction // write pre-action user code here exitMIDlet();//GEN-LINE:|7-commandAction|2|16-postAction // write post-action user code here } else if (command == sendMesg) {//GEN-LINE:|7-commandAction|3|18-preAction // write pre-action user code here String mno=number.getString(); String msg=textUrdu.getString(); if(mno.equals("")) { alert = new Alert("Alert"); alert.setString("Enter Mobile Number!!!"); alert.setTimeout(2000); display.setCurrent(alert); } else { try { clientConn=(MessageConnection)Connector.open("sms://"+mno); } catch(Exception e) { alert = new Alert("Alert"); alert.setString("Unable to connect to Station because of network problem"); alert.setTimeout(2000); display.setCurrent(alert); } try { TextMessage textmessage = (TextMessage) clientConn.newMessage(MessageConnection.TEXT_MESSAGE); textmessage.setAddress("sms://"+mno); textmessage.setPayloadText(msg); clientConn.send(textmessage); } catch(Exception e) { Alert alert=new Alert("Alert","",null,AlertType.INFO); alert.setTimeout(Alert.FOREVER); alert.setString("Unable to send"); display.setCurrent(alert); } } //GEN-LINE:|7-commandAction|4|18-postAction // write post-action user code here }//GEN-BEGIN:|7-commandAction|5|7-postCommandAction }//GEN-END:|7-commandAction|5|7-postCommandAction // write post-action user code here }//GEN-BEGIN:|7-commandAction|6| //</editor-fold>//GEN-END:|7-commandAction|6| //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Items ">//GEN-BEGIN:|8-itemCommandAction|0|8-preItemCommandAction /** * Called by a system to indicated that a command has been invoked on a * particular item. * * @param command the Command that was invoked * @param displayable the Item where the command was invoked */ public void commandAction(Command command, Item item) {//GEN-END:|8-itemCommandAction|0|8-preItemCommandAction // write pre-action user code here if (item == number) {//GEN-BEGIN:|8-itemCommandAction|1|21-preAction if (command == add) {//GEN-END:|8-itemCommandAction|1|21-preAction // write pre-action user code here //GEN-LINE:|8-itemCommandAction|2|21-postAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|3|28-preAction } else if (item == send) { if (command == select) {//GEN-END:|8-itemCommandAction|3|28-preAction // write pre-action user code here //GEN-LINE:|8-itemCommandAction|4|28-postAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|5|24-preAction } else if (item == textUrdu) { if (command == urdu) {//GEN-END:|8-itemCommandAction|5|24-preAction // write pre-action user code here if (isUrdu) isUrdu = false; else { isUrdu = true; TextField tf = (TextField)item; } //GEN-LINE:|8-itemCommandAction|6|24-postAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|7|8-postItemCommandAction }//GEN-END:|8-itemCommandAction|7|8-postItemCommandAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|8| //</editor-fold>//GEN-END:|8-itemCommandAction|8| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: form ">//GEN-BEGIN:|14-getter|0|14-preInit /** * Returns an initialized instance of form component. * * @return the initialized component instance */ public Form getForm() { if (form == null) {//GEN-END:|14-getter|0|14-preInit // write pre-init user code here form = new Form("form", new Item[]{getNumber(), getTextUrdu(), getStringItem(), getSend()});//GEN-BEGIN:|14-getter|1|14-postInit form.addCommand(getExit()); form.addCommand(getSendMesg()); form.setCommandListener(this);//GEN-END:|14-getter|1|14-postInit // write post-init user code here form.setItemStateListener(this); // form.setCommandListener(this); }//GEN-BEGIN:|14-getter|2| return form; } //</editor-fold>//GEN-END:|14-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: number ">//GEN-BEGIN:|19-getter|0|19-preInit /** * Returns an initialized instance of number component. * * @return the initialized component instance */ public TextField getNumber() { if (number == null) {//GEN-END:|19-getter|0|19-preInit // write pre-init user code here number = new TextField("Number ", null, 11, TextField.PHONENUMBER);//GEN-BEGIN:|19-getter|1|19-postInit number.addCommand(getAdd()); number.setItemCommandListener(this); number.setDefaultCommand(getAdd());//GEN-END:|19-getter|1|19-postInit // write post-init user code here }//GEN-BEGIN:|19-getter|2| return number; } //</editor-fold>//GEN-END:|19-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: textUrdu ">//GEN-BEGIN:|22-getter|0|22-preInit /** * Returns an initialized instance of textUrdu component. * * @return the initialized component instance */ public TextField getTextUrdu() { if (textUrdu == null) {//GEN-END:|22-getter|0|22-preInit // write pre-init user code here textUrdu = new TextField("Message", null, 2000, TextField.ANY);//GEN-BEGIN:|22-getter|1|22-postInit textUrdu.addCommand(getUrdu()); textUrdu.setItemCommandListener(this);//GEN-END:|22-getter|1|22-postInit // write post-init user code here }//GEN-BEGIN:|22-getter|2| return textUrdu; } //</editor-fold>//GEN-END:|22-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: exit ">//GEN-BEGIN:|15-getter|0|15-preInit /** * Returns an initialized instance of exit component. * * @return the initialized component instance */ public Command getExit() { if (exit == null) {//GEN-END:|15-getter|0|15-preInit // write pre-init user code here exit = new Command("Exit", Command.EXIT, 0);//GEN-LINE:|15-getter|1|15-postInit // write post-init user code here }//GEN-BEGIN:|15-getter|2| return exit; } //</editor-fold>//GEN-END:|15-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: sendMesg ">//GEN-BEGIN:|17-getter|0|17-preInit /** * Returns an initialized instance of sendMesg component. * * @return the initialized component instance */ public Command getSendMesg() { if (sendMesg == null) {//GEN-END:|17-getter|0|17-preInit // write pre-init user code here sendMesg = new Command("send", Command.OK, 0);//GEN-LINE:|17-getter|1|17-postInit // write post-init user code here }//GEN-BEGIN:|17-getter|2| return sendMesg; } //</editor-fold>//GEN-END:|17-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: add ">//GEN-BEGIN:|20-getter|0|20-preInit /** * Returns an initialized instance of add component. * * @return the initialized component instance */ public Command getAdd() { if (add == null) {//GEN-END:|20-getter|0|20-preInit // write pre-init user code here add = new Command("add", Command.OK, 0);//GEN-LINE:|20-getter|1|20-postInit // write post-init user code here }//GEN-BEGIN:|20-getter|2| return add; } //</editor-fold>//GEN-END:|20-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: urdu ">//GEN-BEGIN:|23-getter|0|23-preInit /** * Returns an initialized instance of urdu component. * * @return the initialized component instance */ public Command getUrdu() { if (urdu == null) {//GEN-END:|23-getter|0|23-preInit // write pre-init user code here urdu = new Command("urdu", Command.OK, 0);//GEN-LINE:|23-getter|1|23-postInit // write post-init user code here }//GEN-BEGIN:|23-getter|2| return urdu; } //</editor-fold>//GEN-END:|23-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: stringItem ">//GEN-BEGIN:|25-getter|0|25-preInit /** * Returns an initialized instance of stringItem component. * * @return the initialized component instance */ public StringItem getStringItem() { if (stringItem == null) {//GEN-END:|25-getter|0|25-preInit // write pre-init user code here stringItem = new StringItem("string", null);//GEN-LINE:|25-getter|1|25-postInit // write post-init user code here }//GEN-BEGIN:|25-getter|2| return stringItem; } //</editor-fold>//GEN-END:|25-getter|2| //</editor-fold> //<editor-fold defaultstate="collapsed" desc=" Generated Getter: send ">//GEN-BEGIN:|26-getter|0|26-preInit /** * Returns an initialized instance of send component. * * @return the initialized component instance */ public StringItem getSend() { if (send == null) {//GEN-END:|26-getter|0|26-preInit // write pre-init user code here send = new StringItem("", "send", Item.BUTTON);//GEN-BEGIN:|26-getter|1|26-postInit send.addCommand(getSelect()); send.setItemCommandListener(this); send.setDefaultCommand(getSelect());//GEN-END:|26-getter|1|26-postInit // write post-init user code here }//GEN-BEGIN:|26-getter|2| return send; } //</editor-fold>//GEN-END:|26-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: select ">//GEN-BEGIN:|27-getter|0|27-preInit /** * Returns an initialized instance of select component. * * @return the initialized component instance */ public Command getSelect() { if (select == null) {//GEN-END:|27-getter|0|27-preInit // write pre-init user code here select = new Command("select", Command.OK, 0);//GEN-LINE:|27-getter|1|27-postInit // write post-init user code here }//GEN-BEGIN:|27-getter|2| return select; } //</editor-fold>//GEN-END:|27-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: task ">//GEN-BEGIN:|40-getter|0|40-preInit /** * Returns an initialized instance of task component. * * @return the initialized component instance */ public SimpleCancellableTask getTask() { if (task == null) {//GEN-END:|40-getter|0|40-preInit // write pre-init user code here task = new SimpleCancellableTask();//GEN-BEGIN:|40-getter|1|40-execute task.setExecutable(new org.netbeans.microedition.util.Executable() { public void execute() throws Exception {//GEN-END:|40-getter|1|40-execute // write task-execution user code here }//GEN-BEGIN:|40-getter|2|40-postInit });//GEN-END:|40-getter|2|40-postInit // write post-init user code here }//GEN-BEGIN:|40-getter|3| return task; } //</editor-fold>//GEN-END:|40-getter|3| /** * Returns a display instance. * @return the display instance. */ public Display getDisplay () { return Display.getDisplay(this); } /** * Exits MIDlet. */ public void exitMIDlet() { switchDisplayable (null, null); destroyApp(true); notifyDestroyed(); } /** * Called when MIDlet is started. * Checks whether the MIDlet have been already started and initialize/starts or resumes the MIDlet. */ public void startApp() { startMIDlet(); display.setCurrent(form); } /** * Called when MIDlet is paused. */ public void pauseApp() { midletPaused = true; } /** * Called to signal the MIDlet to terminate. * @param unconditional if true, then the MIDlet has to be unconditionally terminated and all resources has to be released. */ public void destroyApp(boolean unconditional) { } public void itemStateChanged(Item item) { if (item == textUrdu) { if (isUrdu) { stringItem.setText("urdu"); TextField tf = (TextField)item; String s = tf.getString(); char ch = s.charAt(s.length() - 1); s = s.substring(0, s.length() - 1); ch = Urdu.ToUrdu(ch); s = s + String.valueOf(ch); tf.setString(""); tf.setString(s); }//end if throw new UnsupportedOperationException("Not supported yet."); } } }

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  • Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException

    - by Dheeraj kumar
    I have to read xls file in java.I used poi-3.6 to read xls file in Eclipse.But i m getting this ERROR"Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException at ReadExcel2.main(ReadExcel2.java:38)". I have added following jars 1)poi-3.6-20091214.jar 2)poi-contrib-3.6-20091214.jar 3)poi-examples-3.6-20091214.jar 4)poi-ooxml-3.6-20091214.jar 5)poi-ooxml-schemas-3.6-20091214.jar 6)poi-scratchpad-3.6-20091214.jar Below is the code which i m using: import org.apache.poi.ss.usermodel.Workbook; import org.apache.poi.ss.usermodel.Sheet; import org.apache.poi.ss.usermodel.Row; import org.apache.poi.ss.usermodel.Cell; import org.apache.poi.xssf.usermodel.XSSFWorkbook; import org.apache.poi.xssf.usermodel.XSSFCell; import org.apache.poi.xssf.usermodel.XSSFRow; import java.io.FileInputStream; import java.io.IOException; import java.util.Iterator; import java.util.List; import java.util.ArrayList; public class ReadExcel { public static void main(String[] args) throws Exception { // // An excel file name. You can create a file name with a full path // information. // String filename = "C:\\myExcel.xl"; // // Create an ArrayList to store the data read from excel sheet. // List sheetData = new ArrayList(); FileInputStream fis = null; try { // // Create a FileInputStream that will be use to read the excel file. // fis = new FileInputStream(filename); // // Create an excel workbook from the file system. // // HSSFWorkbook workbook = new HSSFWorkbook(fis); Workbook workbook = new XSSFWorkbook(fis); // // Get the first sheet on the workbook. // Sheet sheet = workbook.getSheetAt(0); // // When we have a sheet object in hand we can iterator on each // sheet's rows and on each row's cells. We store the data read // on an ArrayList so that we can printed the content of the excel // to the console. // Iterator rows = sheet.rowIterator(); while (rows.hasNext()) { Row row = (XSSFRow) rows.next(); Iterator cells = row.cellIterator(); List data = new ArrayList(); while (cells.hasNext()) { Cell cell = (XSSFCell) cells.next(); data.add(cell); } sheetData.add(data); } } catch (IOException e) { e.printStackTrace(); } finally { if (fis != null) { fis.close(); } } showExelData(sheetData); } private static void showExelData(List sheetData) { // // Iterates the data and print it out to the console. // for (int i = 0; i < sheetData.size(); i++) { List list = (List) sheetData.get(i); for (int j = 0; j < list.size(); j++) { Cell cell = (XSSFCell) list.get(j); System.out.print(cell.getRichStringCellValue().getString()); if (j < list.size() - 1) { System.out.print(", "); } } System.out.println(""); } } } Please help. thanks in anticipation, Regards, Dheeraj!

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  • Modern alternatives to Java

    - by Ralph
    I have been a Java developer for 14 years and have written an enterprise-level (~500 kloc) Swing application that uses most of the standard library APIs. Recently, I have become disappointed with the progress that the language has made to "modernize" itself, and am looking for an alternative for ongoing development. I have considered moving to the .NET platform, but I have issues with using something the only runs well in Windows (I know about Mono, but that is still far behind Microsoft). I also plan on buying a new Macbook Pro as soon as Apple releases their new rumored Arrandale-based machines and want to develop in an environment that will feel "at home" in Unix/Linux. I have considered using Python or Ruby, but the standard Java library is arguably the largest of any modern language. In JVM-based languages, I looked at Groovy, but am disappointed with its performance. Rumor has it that with the soon-to-be released JDK7, with its InvokeDynamic instruction, this will improve, but I don't know how much. Groovy is also not truly a functional language, although it provides closures and some of the "functional" features on collections. It does not embrace immutability. I have narrowed my search down to two JVM-based alternatives: Scala and Clojure. Each has its strengths and weaknesses. I am looking for opinions. I am not an expert at either of these languages; I have read 2 1/2 books on Scala and am currently reading Stu Halloway's book on Clojure. Scala is strongly statically typed. I know the dynamic language folks claim that static typing is a crutch for not doing unit testing, but it does provide a mechanism for compile-time location of a whole class of errors. Scala is more concise than Java, but not as much as Clojure. Scala's inter-operation with Java seems to be better than Clojure's, in that most Java operations are easier to do in Scala than in Clojure. For example, I can find no way in Clojure to create a non-static initialization block in a class derived from a Java superclass. For example, I like the Apache commons CLI library for command line argument parsing. In Java and Scala, I can create a new Options object and add Option items to it in an initialization block as follows (Java code): final Options options = new Options() { { addOption(new Option("?", "help", false, "Show this usage information"); // other options } }; I can't figure out how to the same thing in Clojure (except by using (doit...)), although that may reflect my lack of knowledge of the language. Clojure's collections are optimized for immutability. They rarely require copy-on-write semantics. I don't know if Scala's immutable collections are implemented using similar algorithms, but Rich Hickey (Clojure's inventor) goes out of his way to explain how that language's data structures are efficient. Clojure was designed from the beginning for concurrency (as was Scala) and with modern multi-core processors, concurrency takes on more importance, but I occasionally need to write simple non-concurrent utilities, and Scala code probably runs a little faster for these applications since it discourages, but does not prohibit, "simple" mutability. One could argue that one-off utilities do not have to be super-fast, but sometimes they do tasks that take hours or days to complete. I know that there is no right answer to this "question", but I thought I would open it up for discussion. Are there other JVM-based languages that can be used for enterprise level development?

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  • ask help: I need to create a demo application in Java to test my new designed Java Api

    - by Christophe
    A new programmer needs yourhelp. I'm working on a porject of re-developement of Java driver for the company's PIN pad terminals. the Java Api (CPXApplicationUpdate) will allow the applications in pinpads to be updated and to be downloaded at different speed (Baud rate). the Java Api was created. i followed the protocolto build the message. the message is to send to a RS-232 port. i'm trying to use setter and getter to let the code work as an API. import java.io.InputStream; import java.io.OutputStream; import java.util.Properties; public class CPXApplicationUpdate extends CPXCommand { private int speed; // TODO: temporary variable for baud rate test stub. // speed: baud rate of the maintenance application performing DL /** Creates a new instance of CPXApplicationUpdate */ public CPXApplicationUpdate() { speed = 9600; // no baud rate change CPXProcessor.logger.fine("-------CPXApplicationUpdate constructor"); // setParam("timeout", _cmdInfo.getDefaultParValue("timeout")); } public CPXApplicationUpdate(int speedinit) { speed = speedinit; // TODO: where to get the speed? wait for user input. CPXProcessor.logger.fine("-------CPXApplicationUpdate constructor"); // setParam("timeout", _cmdInfo.getDefaultParValue("timeout")); } public void setSpeed(int speed){ this.speed = speed; } protected void buildRequest() throws ElitePortException { String trans = ""; // build the full-qualified message trans = addToRequest(trans, (char) 0); trans = addToRequest(trans, (char) 5); trans = addToRequest(trans, (char) 6); trans = addToRequest(trans, (char) 0); trans = addToRequest(trans, (char) 0); trans = addToRequest(trans, (char) 2); switch (speed) { case 9600: trans = addToRequest(trans, (char) 0x09); break; case 19200: trans = addToRequest(trans, (char) 0x0A); break; case 115200: trans = addToRequest(trans, (char) 0x0E); break; default: // TODO: unexpected baud rate. throw(); break; } trans = EncryptBinary(trans); trans = "F0." + trans; wrapRequest(trans); } protected String addToRequest(String req, char c) { CPXProcessor.logger.fine("adding char to request: I-" + (int) c + " C-" + c + " H-" + Integer.toHexString((int) c)); return req + c; } protected String addToRequest(String req, String s) { CPXProcessor.logger.fine("adding String to request: S-" + s); return req + s; } protected String addToRequest(String req) { return req; } public void analyzeResponse() { String response_transaction, response; int absLen = _response.length(); if (absLen < 4) return; response = _response.substring(3); CPXProcessor.logger.fine("stripped response=[" + response + "]"); for (int i = 0; i < response.length(); i++) { char c = response.charAt(i); CPXProcessor.logger.fine("[" + i + "] = " + c + " <> " + Integer.toHexString((int) c)); } int status = (short) response.charAt(3); CPXProcessor.logger.fine("status = " + status); _outputValues.put("status", "" + status); } please help me to correct the code. Now, i need to create a demo application to test if this java driver (Java Api) works. the value of the speed can be input by users (command line), or creat property files. how can i do that?

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  • JSF - Random Number using Beans (JAVA)

    - by Alex Encore Tr
    I am trying to create a jsf application which, upon page refresh increments the hit counter and generates two random numbers. What should be displayed on the window may look something like this: On your On your roll x you have thrown x and x For this program I decided to create two Beans, one to hold the page refresh counter and one to generate a random number. Those look like this for the moment: CounterBean.java package diceroll; public class CounterBean { int count=0; public CounterBean() { } public void setCount(int count) { this.count=count; } public int getCount() { count++; return count; } } RandomNumberBean.java package diceroll; import java.util.Random; public class RandomNumberBean { int rand=0; Random r = new Random(); public RandomNumberBean() { rand = r.nextInt(6); } public void setNextInt(int rand) { this.rand=rand; } public int getNextInt() { return rand; } } I have then created an index.jsp to display the above message. <html> <%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%> <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%> <f:view> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Roll the Dice</title> </head> <body> <h:form> <p> On your roll # <h:outputText value="#{CounterBean.count} " /> you have thrown <h:outputText value="#{RandomNumberBean.rand}" />and <h:outputText value="#{RandomNumberBean.rand} " /> </p> </h:form> </body> </f:view> </html> However, when I run the application, I get the following message: org.apache.jasper.el.JspPropertyNotFoundException: /index.jsp(14,20) '#{RandomNumberBean.rand}' Property 'rand' not found on type diceroll.RandomNumberBean Caused by: org.apache.jasper.el.JspPropertyNotFoundException - /index.jsp(14,20) '#{RandomNumberBean.rand}' Property 'rand' not found on type diceroll.RandomNumberBean I suppose there's a mistake with my faces-config.xml file, so I will post this here as well, see if somebody can provide some help: faces-config.xml <?xml version="1.0" encoding="UTF-8"?> <faces-config xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd" version="2.0"> <managed-bean> <managed-bean-name>CounterBean</managed-bean-name> <managed-bean-class>diceroll.CounterBean</managed-bean-class> <managed-bean-scope>session</managed-bean-scope> </managed-bean> <managed-bean> <managed-bean-name>RandomNumberBean</managed-bean-name> <managed-bean-class>diceroll.RandomNumberBean</managed-bean-class> <managed-bean-scope>session</managed-bean-scope> </managed-bean> </faces-config>

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  • Only Execute Code on Certain Requests Java

    - by BillPull
    I am building a little API for class and the teacher supplied us with a link to a tutorial that provided a simple webserver that implements Runnable. I have already written some code that will parse arguments the arguments ( or at least get me the request string ) and some code that will return some simple xml. however I think certain requests like the one for the favicon are sent I think it is messing up my code. I wrapped that in an if else but it does not seem to be working. package server; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.Socket; import java.util.*; import java.io.*; import java.net.*; import parkinglots.*; public class WorkerRunnable implements Runnable{ protected Socket clientSocket = null; protected String serverText = null; public WorkerRunnable(Socket clientSocket, String serverText) { this.clientSocket = clientSocket; this.serverText = serverText; } public Boolean authenticateAPI(String key){ //Authenticate Key against Stored Keys //TODO: Create Stored Keys and Compare return true; } public void run() { try { InputStream input = clientSocket.getInputStream(); OutputStream output = clientSocket.getOutputStream(); long time = System.currentTimeMillis(); //TODO: Parse args and output different formats and Authentication //Parse URL Arguments BufferedReader in = new BufferedReader( new InputStreamReader(clientSocket.getInputStream(), "8859_1")); String request = in.readLine(); //Server gets Favicon Request so skip that and goto args System.out.println(request); if ( request != "GET /favicon.ico HTTP/1.1" && request != "GET / HTTP/1.1" && request != null ){ String format = "", apikey =""; System.out.println("I am Here"); String request_location = request.split(" ")[1]; String request_args = request_location.replace("/",""); request_args = request_args.replace("?",""); String[] queries = request_args.split("&"); System.out.println(queries[0]); for ( int i = 0; i < queries.length; i++ ){ if( queries[i] == "format" ){ format = queries[i].split("=")[1]; } else if( queries[i] == "apikey" ){ apikey = queries[i].split("=")[1]; } } if( apikey == "" ){ apikey = "None"; } if( format == "" ){ format = "xml"; } Boolean auth = authenticateAPI(apikey); if ( auth ){ if ( format == "xml"){ // Retrieve XML Document String xml = LotFromDB.getParkingLotXML(); output.write((xml).getBytes()); }else{ //Retrieve JSON String json = LotFromDB.getParkingLotJSON(); output.write((json).getBytes()); } }else{ output.write(("Access Denied - User is Not Authenticated").getBytes()); } }else{ output.write(("Access Denied Must Pass API Key").getBytes()); } output.close(); input.close(); System.out.println("Request processed: " + time); } catch (IOException e) { //report exceptions e.printStackTrace(); } } } Console output I get I am Here format=json Request processed: 1333516648331 GET /favicon.ico HTTP/1.1 I am Here favicon.ico Request processed: 1333516648332 It always returns the XML as well. This is my first exposure to writing a web server and dealing with networking in Java, which frustrates me a lot in general, So any suggestions here are very appreciated.

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  • Small adventure game

    - by Nick Rosencrantz
    I'm making a small adventure game where the player can walk through Dungeons and meet scary characters: The whole thing is 20 java classes and I'm making this a standalone frame while it could very well be an applet I don't want to make another applet since I might want to recode this in C/C++ if the game or game engine turns out a success. The engine is the most interesting part of the game, it controls players and computer-controlled characters such as Zombies, Reptile Warriors, Trolls, Necromancers, and other Persons. These persons can sleep or walk around in the game and also pick up and move things. I didn't add many things so I suppose that is the next thing to do is to add things that can get used now that I already added many different types of walking persons. What do you think I should add and do with things in the game? The things I have so far is: package adventure; /** * The data type for things. Subclasses will be create that takes part of the story */ public class Thing { /** * The name of the Thing. */ public String name; /** * @param name The name of the Thing. */ Thing( String name ) { this.name = name; } } public class Scroll extends Thing { Scroll (String name) { super(name); } } class Key extends Thing { Key (String name) { super(name); } } The key is the way to win the game if you figure our that you should give it to a certain person and the scroll can protect you from necromancers and trolls. If I make this game more Dungeons and Dragons-inspired, do you think will be any good? Any other ideas that you think I could use here? The Threadwhich steps time forward and wakes up persons is called simulation. Do you think I could do something more advanced with this class? package adventure; class Simulation extends Thread { private PriorityQueue Eventqueue; Simulation() { Eventqueue = new PriorityQueue(); start(); } public void wakeMeAfter(Wakeable SleepingObject, double time) { Eventqueue.enqueue(SleepingObject, System.currentTimeMillis()+time); } public void run() { while(true) { try { sleep(5); //Sov i en halv sekund if (Eventqueue.getFirstTime() <= System.currentTimeMillis()) { ((Wakeable)Eventqueue.getFirst()).wakeup(); Eventqueue.dequeue(); } } catch (InterruptedException e ) { } } } } And here is the class that makes up the actual world: package adventure; import java.awt.*; import java.net.URL; /** * Subklass to World that builds up the Dungeon World. */ public class DungeonWorld extends World { /** * * @param a Reference to adventure game. * */ public DungeonWorld(Adventure a) { super ( a ); // Create all places createPlace( "Himlen" ); createPlace( "Stairs3" ); createPlace( "IPLab" ); createPlace( "Dungeon3" ); createPlace( "Stairs5" ); createPlace( "C2M2" ); createPlace( "SANS" ); createPlace( "Macsal" ); createPlace( "Stairs4" ); createPlace( "Dungeon2" ); createPlace( "Datorsalen" ); createPlace( "Dungeon");//, "Ljushallen.gif" ); createPlace( "Cola-automaten", "ColaAutomat.gif" ); createPlace( "Stairs2" ); createPlace( "Fable1" ); createPlace( "Dungeon1" ); createPlace( "Kulverten" ); // Create all connections between places connect( "Stairs3", "Stairs5", "Down", "Up" ); connect( "Dungeon3", "SANS", "Down", "Up" ); connect( "Dungeon3", "IPLab", "West", "East" ); connect( "IPLab", "Stairs3", "West", "East" ); connect( "Stairs5", "Stairs4", "Down", "Up" ); connect( "Macsal", "Stairs5", "South", "Norr" ); connect( "C2M2", "Stairs5", "West", "East" ); connect( "SANS", "C2M2", "West", "East" ); connect( "Stairs4", "Dungeon", "Down", "Up" ); connect( "Datorsalen", "Stairs4", "South", "Noth" ); connect( "Dungeon2", "Stairs4", "West", "East" ); connect( "Dungeon", "Stairs2", "Down", "Up" ); connect( "Dungeon", "Cola-automaten", "South", "North" ); connect( "Stairs2", "Kulverten", "Down", "Up" ); connect( "Stairs2", "Fable1", "East", "West" ); connect( "Fable1", "Dungeon1", "South", "North" ); // Add things // --- Add new things here --- getPlace("Cola-automaten").addThing(new CocaCola("Ljummen cola")); getPlace("Cola-automaten").addThing(new CocaCola("Avslagen Cola")); getPlace("Cola-automaten").addThing(new CocaCola("Iskall Cola")); getPlace("Cola-automaten").addThing(new CocaCola("Cola Light")); getPlace("Cola-automaten").addThing(new CocaCola("Cuba Cola")); getPlace("Stairs4").addThing(new Scroll("Scroll")); getPlace("Dungeon3").addThing(new Key("Key")); Simulation sim = new Simulation(); // Load images to be used as appearance-parameter for persons Image studAppearance = owner.loadPicture( "Person.gif" ); Image asseAppearance = owner.loadPicture( "Asse.gif" ); Image trollAppearance = owner.loadPicture( "Loke.gif" ); Image necromancerAppearance = owner.loadPicture( "Necromancer.gif" ); Image skeletonAppearance = owner.loadPicture( "Reptilewarrior.gif" ); Image reptileAppearance = owner.loadPicture( "Skeleton.gif" ); Image zombieAppearance = owner.loadPicture( "Zombie.gif" ); // --- Add new persons here --- new WalkingPerson(sim, this, "Peter", studAppearance); new WalkingPerson(sim, this, "Zombie", zombieAppearance ); new WalkingPerson(sim, this, "Zombie", zombieAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "John", studAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Sean", studAppearance ); new WalkingPerson(sim, this, "Reptile", reptileAppearance ); new LabAssistant(sim, this, "Kate", asseAppearance); new LabAssistant(sim, this, "Jenna", asseAppearance); new Troll(sim, this, "Troll", trollAppearance); new Necromancer(sim, this, "Necromancer", necromancerAppearance); } /** * * The place where persons are placed by default * *@return The default place. * */ public Place defaultPlace() { return getPlace( "Datorsalen" ); } private void connect( String p1, String p2, String door1, String door2) { Place place1 = getPlace( p1 ); Place place2 = getPlace( p2 ); place1.addExit( door1, place2 ); place2.addExit( door2, place1 ); } } Thanks

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  • Navigating Libgdx Menu with arrow keys or controller

    - by Phil Royer
    I'm attempting to make my menu navigable with the arrow keys or via the d-pad on a controller. So Far I've had no luck. The question is: Can someone walk me through how to make my current menu or any libgdx menu keyboard accessible? I'm a bit noobish with some stuff and I come from a Javascript background. Here's an example of what I'm trying to do: http://dl.dropboxusercontent.com/u/39448/webgl/qb/qb.html For a simple menu that you can just add a few buttons to and it run out of the box use this: http://www.sadafnoor.com/blog/how-to-create-simple-menu-in-libgdx/ Or you can use my code but I use a lot of custom styles. And here's an example of my code: import aurelienribon.tweenengine.Timeline; import aurelienribon.tweenengine.Tween; import aurelienribon.tweenengine.TweenManager; import com.badlogic.gdx.Game; import com.badlogic.gdx.Gdx; import com.badlogic.gdx.Screen; import com.badlogic.gdx.graphics.GL20; import com.badlogic.gdx.graphics.Texture; import com.badlogic.gdx.graphics.g2d.Sprite; import com.badlogic.gdx.graphics.g2d.SpriteBatch; import com.badlogic.gdx.graphics.g2d.TextureAtlas; import com.badlogic.gdx.math.Vector2; import com.badlogic.gdx.scenes.scene2d.Actor; import com.badlogic.gdx.scenes.scene2d.InputEvent; import com.badlogic.gdx.scenes.scene2d.InputListener; import com.badlogic.gdx.scenes.scene2d.Stage; import com.badlogic.gdx.scenes.scene2d.ui.Skin; import com.badlogic.gdx.scenes.scene2d.ui.Table; import com.badlogic.gdx.scenes.scene2d.ui.TextButton; import com.badlogic.gdx.scenes.scene2d.utils.Align; import com.badlogic.gdx.scenes.scene2d.utils.ClickListener; import com.project.game.tween.ActorAccessor; public class MainMenu implements Screen { private SpriteBatch batch; private Sprite menuBG; private Stage stage; private TextureAtlas atlas; private Skin skin; private Table table; private TweenManager tweenManager; @Override public void render(float delta) { Gdx.gl.glClearColor(0, 0, 0, 1); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); batch.begin(); menuBG.draw(batch); batch.end(); //table.debug(); stage.act(delta); stage.draw(); //Table.drawDebug(stage); tweenManager.update(delta); } @Override public void resize(int width, int height) { menuBG.setSize(width, height); stage.setViewport(width, height, false); table.invalidateHierarchy(); } @Override public void resume() { } @Override public void show() { stage = new Stage(); Gdx.input.setInputProcessor(stage); batch = new SpriteBatch(); atlas = new TextureAtlas("ui/atlas.pack"); skin = new Skin(Gdx.files.internal("ui/menuSkin.json"), atlas); table = new Table(skin); table.setBounds(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); // Set Background Texture menuBackgroundTexture = new Texture("images/mainMenuBackground.png"); menuBG = new Sprite(menuBackgroundTexture); menuBG.setSize(Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); // Create Main Menu Buttons // Button Play TextButton buttonPlay = new TextButton("START", skin, "inactive"); buttonPlay.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new LevelMenu()); } }); buttonPlay.addListener(new InputListener() { public boolean keyDown (InputEvent event, int keycode) { System.out.println("down"); return true; } }); buttonPlay.padBottom(12); buttonPlay.padLeft(20); buttonPlay.getLabel().setAlignment(Align.left); // Button EXTRAS TextButton buttonExtras = new TextButton("EXTRAS", skin, "inactive"); buttonExtras.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new ExtrasMenu()); } }); buttonExtras.padBottom(12); buttonExtras.padLeft(20); buttonExtras.getLabel().setAlignment(Align.left); // Button Credits TextButton buttonCredits = new TextButton("CREDITS", skin, "inactive"); buttonCredits.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new Credits()); } }); buttonCredits.padBottom(12); buttonCredits.padLeft(20); buttonCredits.getLabel().setAlignment(Align.left); // Button Settings TextButton buttonSettings = new TextButton("SETTINGS", skin, "inactive"); buttonSettings.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { ((Game) Gdx.app.getApplicationListener()).setScreen(new Settings()); } }); buttonSettings.padBottom(12); buttonSettings.padLeft(20); buttonSettings.getLabel().setAlignment(Align.left); // Button Exit TextButton buttonExit = new TextButton("EXIT", skin, "inactive"); buttonExit.addListener(new ClickListener() { @Override public void clicked(InputEvent event, float x, float y) { Gdx.app.exit(); } }); buttonExit.padBottom(12); buttonExit.padLeft(20); buttonExit.getLabel().setAlignment(Align.left); // Adding Heading-Buttons to the cue table.add().width(190); table.add().width((table.getWidth() / 10) * 3); table.add().width((table.getWidth() / 10) * 5).height(140).spaceBottom(50); table.add().width(190).row(); table.add().width(190); table.add(buttonPlay).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonExtras).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonCredits).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonSettings).spaceBottom(20).width(460).height(110); table.add().row(); table.add().width(190); table.add(buttonExit).width(460).height(110); table.add().row(); stage.addActor(table); // Animation Settings tweenManager = new TweenManager(); Tween.registerAccessor(Actor.class, new ActorAccessor()); // Heading and Buttons Fade In Timeline.createSequence().beginSequence() .push(Tween.set(buttonPlay, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonExtras, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonCredits, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonSettings, ActorAccessor.ALPHA).target(0)) .push(Tween.set(buttonExit, ActorAccessor.ALPHA).target(0)) .push(Tween.to(buttonPlay, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonExtras, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonCredits, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonSettings, ActorAccessor.ALPHA, .5f).target(1)) .push(Tween.to(buttonExit, ActorAccessor.ALPHA, .5f).target(1)) .end().start(tweenManager); tweenManager.update(Gdx.graphics.getDeltaTime()); } public static Vector2 getStageLocation(Actor actor) { return actor.localToStageCoordinates(new Vector2(0, 0)); } @Override public void dispose() { stage.dispose(); atlas.dispose(); skin.dispose(); menuBG.getTexture().dispose(); } @Override public void hide() { dispose(); } @Override public void pause() { } }

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  • Help with MVC design pattern?

    - by user3681240
    I am trying to build a java program for user login but I am not sure if my MVC design is accurate. I have the following classes: LoginControl - servlet LoginBean - data holder java class with private variables getters and setters LoginDAO - concrete java class where I am running my SQL queries and doing rest of the logical work. Connection class - java class just to connect to the database view - jsp to display the results html - used for form Is this how you design a java program based on MVC design pattern? Please provide some suggestions?

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  • HttpPost works in Java project, not in Android

    - by dave.c
    I've written some code for my Android device to login to a web site over https and parse some data out of the resulting pages. An HttpGet happens first to get some info needed for login, then an HttpPost to do the actual login process. The code below works great in a Java project within Eclipse which has the following Jar files on the build path: httpcore-4.1-beta2.jar, httpclient-4.1-alpha2.jar, httpmime-4.1-alpha2.jar, commons-logging-1.1.1.jar. public static MyBean gatherData(String username, String password) { MyBean myBean = new MyBean(); try { HttpResponse response = doHttpGet(URL_PAGE_LOGIN, null, null); System.out.println("Got login page"); String content = EntityUtils.toString(response.getEntity()); String token = ContentParser.getToken(content); String cookie = getCookie(response); System.out.println("Performing login"); System.out.println("token = "+token +" || cookie = "+cookie); response = doLoginPost(username,password,cookie, token); int respCode = response.getStatusLine().getStatusCode(); if (respCode != 302) { System.out.println("ERROR: not a 302 redirect!: code is \""+ respCode+"\""); if (respCode == 200) { System.out.println(getHeaders(response)); System.out.println(EntityUtils.toString(response.getEntity()).substring(0, 500)); } } else { System.out.println("Logged in OK, loading account home"); // redirect handler and rest of parse removed } }catch (Exception e) { System.out.println("ERROR in gatherdata: "+e.toString()); e.printStackTrace(); } return myBean; } private static HttpResponse doHttpGet(String url, String cookie, String referrer) { try { HttpClient client = new DefaultHttpClient(); client.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1); client.getParams().setParameter(CoreProtocolPNames.HTTP_CONTENT_CHARSET, "UTF-8"); HttpGet httpGet = new HttpGet(url); httpGet.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1); httpGet.setHeader(HEADER_USER_AGENT,HEADER_USER_AGENT_VALUE); if (referrer != null && !referrer.equals("")) httpGet.setHeader(HEADER_REFERER,referrer); if (cookie != null && !cookie.equals("")) httpGet.setHeader(HEADER_COOKIE,cookie); return client.execute(httpGet); } catch (Exception e) { e.printStackTrace(); throw new ConnectException("Failed to read content from response"); } } private static HttpResponse doLoginPost(String username, String password, String cookie, String token) throws ClientProtocolException, IOException { try { HttpClient client = new DefaultHttpClient(); client.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1); client.getParams().setParameter(CoreProtocolPNames.HTTP_CONTENT_CHARSET, "UTF-8"); HttpPost post = new HttpPost(URL_LOGIN_SUBMIT); post.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1); post.setHeader(HEADER_USER_AGENT,HEADER_USER_AGENT_VALUE); post.setHeader(HEADER_REFERER, URL_PAGE_LOGIN); post.setHeader(HEADER_COOKIE, cookie); post.setHeader("Content-Type","application/x-www-form-urlencoded"); List<NameValuePair> formParams = new ArrayList<NameValuePair>(); formParams.add(new BasicNameValuePair("org.apache.struts.taglib.html.TOKEN", token)); formParams.add(new BasicNameValuePair("showLogin", "true")); formParams.add(new BasicNameValuePair("upgrade", "")); formParams.add(new BasicNameValuePair("username", username)); formParams.add(new BasicNameValuePair("password", password)); formParams.add(new BasicNameValuePair("submit", "Secure+Log+in")); UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams,HTTP.UTF_8); post.setEntity(entity); return client.execute(post); } catch (Exception e) { e.printStackTrace(); throw new ConnectException("ERROR in doLoginPost(): "+e.getMessage()); } } The server (which is not under my control) returns a 302 redirect when the login was successful, and 200 if it fails and re-loads the login page. When run with the above Jar files I get the 302 redirect, however if I run the exact same code from an Android project with the 1.6 Android Jar file on the build path I get the 200 response from the server. I get the same 200 response when running the code on my 2.2 device. My android application has internet permissions, and the HttpGet works fine. I'm assuming that the problem lies in the fact that HttpPost (or some other class) is different in some significant way between the Android Jar version and the newer Apache versions. I've tried adding the Apache libraries to the build path of the Android project, but due to the duplicate classes I get messages like: INFO/dalvikvm(390): DexOpt: not resolving ambiguous class 'Lorg/apache/http/impl/client/DefaultHttpClient;' in the log. I've also tried using a MultipartEntity instead of the UrlEncodedFormEntity but I get the same 200 result. So, I have a few questions: - Can I force the code running under android to use the newer Apache libraries in preference to the Android versions? - If not, does anyone have any ideas how can I alter my code so that it works with the Android Jar? - Are there any other, totally different approaches to doing an HttpPost in Android? - Any other ideas? I've read a lot of posts and code but I'm not getting anywhere. I've been stuck on this for a couple of days and I'm at a loss how to get the thing to work, so I'll try anything at this point. Thanks in advance.

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  • Implementing union of Set using basic java array

    - by lupindeterd
    Note: This is an assignment. Hi, Continuing with my Set implementation using Java basic array, I'm now struggling with the 3 to last function namely the union. import java.io.*; class Set { private int numberOfElements = 0; private String[] setElements = new String[5]; private int maxNumberOfElements = 5; // constructor for our Set class public Set(int numberOfE, int setE, int maxNumberOfE) { int numberOfElements = numberOfE; String[] setElements = new String[setE]; int maxNumberOfElements = maxNumberOfE; } // Helper method to shorten/remove element of array since we're using basic array instead of ArrayList or HashSet from collection interface :( static String[] removeAt(int k, String[] arr) { final int L = arr.length; String[] ret = new String[L - 1]; System.arraycopy(arr, 0, ret, 0, k); System.arraycopy(arr, k + 1, ret, k, L - k - 1); return ret; } int findElement(String element) { int retval = 0; for ( int i = 0; i < setElements.length; i++) { if ( setElements[i] != null && setElements[i].equals(element) ) { return retval = i; } retval = -1; } return retval; } void add(String newValue) { int elem = findElement(newValue); if( numberOfElements < maxNumberOfElements && elem == -1 ) { setElements[numberOfElements] = newValue; numberOfElements++; } } int getLength() { if ( setElements != null ) { return setElements.length; } else { return 0; } } String[] emptySet() { setElements = new String[0]; return setElements; } Boolean isFull() { Boolean True = new Boolean(true); Boolean False = new Boolean(false); if ( setElements.length == maxNumberOfElements ){ return True; } else { return False; } } Boolean isEmpty() { Boolean True = new Boolean(true); Boolean False = new Boolean(false); if ( setElements.length == 0 ) { return True; } else { return False; } } void remove(String newValue) { for ( int i = 0; i < setElements.length; i++) { if ( setElements[i].equals(newValue) ) { setElements = removeAt(i,setElements); } } } int isAMember(String element) { int retval = -1; for ( int i = 0; i < setElements.length; i++ ) { if (setElements[i] != null && setElements[i].equals(element)) { return retval = i; } } return retval; } void printSet() { for ( int i = 0; i < setElements.length; i++) { System.out.println("Member elements on index: "+ i +" " + setElements[i]); } } String[] getMember() { String[] tempArray = new String[setElements.length]; for ( int i = 0; i < setElements.length; i++) { if(setElements[i] != null) { tempArray[i] = setElements[i]; } } return tempArray; } Set union(Set x, Set y) { String[] newtemparray = new String[x.getLength]; newtemparray = x.getMember; return x; } } // This is the SetDemo class that will make use of our Set class class SetDemo { public static void main(String[] args) { //get input from keyboard BufferedReader keyboard; InputStreamReader reader; String temp = ""; reader = new InputStreamReader(System.in); keyboard = new BufferedReader(reader); try { System.out.println("Enter string element to be added" ); temp = keyboard.readLine( ); System.out.println("You entered " + temp ); } catch (IOException IOerr) { System.out.println("There was an error during input"); } /* ************************************************************************** * Test cases for our new created Set class. * ************************************************************************** */ Set setA = new Set(1,10,10); setA.add(temp); setA.add("b"); setA.add("b"); setA.add("hello"); setA.add("world"); setA.add("six"); setA.add("seven"); setA.add("b"); int size = setA.getLength(); System.out.println("Set size is: " + size ); Boolean isempty = setA.isEmpty(); System.out.println("Set is empty? " + isempty ); int ismember = setA.isAMember("sixb"); System.out.println("Element six is member of setA? " + ismember ); Boolean output = setA.isFull(); System.out.println("Set is full? " + output ); setA.printSet(); int index = setA.findElement("world"); System.out.println("Element b located on index: " + index ); setA.remove("b"); setA.emptySet(); int resize = setA.getLength(); System.out.println("Set size is: " + resize ); setA.printSet(); Set setB = new Set(0,10,10); Set SetA = setA.union(setB,setA); } } Ok the method in question will be the implementation of union. As such this: Set union(Set x, Set y) { String[] newtemparray = new String[x.getLength]; newtemparray = x.getMember; return x; } I got this error: symbol : variable getLength location: class Set String[] newtemparray = new String[x.getLength]; ^ d:\javaprojects\Set.java:122: cannot find symbol symbol : variable getMember location: class Set newtemparray = x.getMember; ^ 2 errors My approach for union would be: *) create temporary array of string with size of the object x length. *) store object x members to temporary array by looping the object and calling the getMember *) loop object y members and check if element exist against temporary array. *) discard if it exist/add if it is not there *) return obj x with the union array. thanks, lupin

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  • Java: Switch statements with methods involving arrays

    - by Shane
    Hi guys I'm currently creating a program that allows the user to create an array, search an array and delete an element from an array. Looking at the LibraryMenu Method, the first case where you create an array in the switch statement works fine, however the other ones create a "cannot find symbol error" when I try to compile. My question is I want the search and delete functions to refer to the first switch case - the create Library array. Any help is appreciated, even if its likely from a simple mistake. import java.util.*; public class EnterLibrary { public static void LibraryMenu() { java.util.Scanner scannerObject =new java.util.Scanner(System.in); LibraryMenu Menu = new LibraryMenu(); Menu.displayMenu(); switch (scannerObject.nextInt() ) { case '1': { System.out.println ("1 - Add Videos"); Library[] newLibrary; newLibrary = createLibrary(); } break; case '2': System.out.println ("2 - Search Videos"); searchLibrary(newLibrary); break; case '3': { System.out.println ("3 - Change Videos"); //Change video method TBA } break; case '4': System.out.println ("4 - Delete Videos"); deleteVideo(newLibrary); break; default: System.out.println ("Unrecognized option - please select options 1-3 "); break; } } public static Library[] createLibrary() { Library[] videos = new Library[4]; java.util.Scanner scannerObject =new java.util.Scanner(System.in); for (int i = 0; i < videos.length; i++) { //User enters values into set methods in Library class System.out.print("Enter video number: " + (i+1) + "\n"); String number = scannerObject.nextLine(); System.out.print("Enter video title: " + (i+1) + "\n"); String title = scannerObject.nextLine(); System.out.print("Enter video publisher: " + (i+1) + "\n"); String publisher = scannerObject.nextLine(); System.out.print("Enter video duration: " + (i+1) + "\n"); String duration = scannerObject.nextLine(); System.out.print("Enter video date: " + (i+1) + "\n"); String date= scannerObject.nextLine(); System.out.print("VIDEO " + (i+1) + " ENTRY ADDED " + "\n \n"); //Initialize arrays videos[i] = new Library (); videos[i].setVideo( number, title, publisher, duration, date ); } return videos; } public static void printVidLibrary( Library[] videos) { //Get methods to print results System.out.print("\n======VIDEO CATALOGUE====== \n"); for (int i = 0; i < videos.length; i++) { System.out.print("Video number " + (i+1) + ": \n" + videos[i].getNumber() + "\n "); System.out.print("Video title " + (i+1) + ": \n" + videos[i].getTitle() + "\n "); System.out.print("Video publisher " + (i+1) + ": \n" + videos[i].getPublisher() + "\n "); System.out.print("Video duration " + (i+1) + ": \n" + videos[i].getDuration() + "\n "); System.out.print("Video date " + (i+1) + ": \n" + videos[i].getDate() + "\n "); } } public static Library searchLibrary( Library[] videos) { //User enters values to setSearch Library titleResult = new Library(); java.util.Scanner scannerObject =new java.util.Scanner(System.in); for (int n = 0; n < videos.length; n++) { System.out.println("Search for video number:\n"); String newSearch = scannerObject.nextLine(); titleResult.getSearch( videos, newSearch); if (!titleResult.equals(-1)) { System.out.print("Match found!\n" + newSearch + "\n"); } else if (titleResult.equals(-1)) { System.out.print("Sorry, no matches found!\n"); } } return titleResult; } public static void deleteVideo( Library[] videos) { Library titleResult = new Library(); java.util.Scanner scannerObject =new java.util.Scanner(System.in); for (int n = 0; n < videos.length; n++) { System.out.println("Search for video number:\n"); String deleteSearch = scannerObject.nextLine(); titleResult.deleteVideo(videos, deleteSearch); System.out.print("Video deleted\n"); } } public static void main(String[] args) { Library[] newLibrary; new LibraryMenu(); } }

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