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  • How to point to jdni.properties file to set properties in Java

    - by prosseek
    I can use System.getProperties() method to set properties in Java. System.getProperties().put("java.naming.factory.initial", "fr.dyade.aaa.jndi2.client.NamingContextFactory"); System.getProperties().put("java.naming.factory.host", "localhost"); System.getProperties().put("java.naming.factory.port", "16400"); How can I get the same effect by reading the properties stored in a file? When I have a jdni.properties with the following content: java.naming.factory.initial fr.dyade.aaa.jndi2.client.NamingContextFactory java.naming.factory.host localhost java.naming.factory.port 16400 How can I teach Java to read them as properties?

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  • How to determine Windows Java installation location

    - by Lance May
    I'm trying to dynamically run a .jar from a C# assembly (using Process.Start(info)). Now, from a console application I am able to just run: ProcessStartInfo info = new ProcessStartInfo("java", "-jar somerandom.jar"); In an assembly, however, I keep getting a Win32Exception of "The system cannot find the file specified" and have to change the line to the full path of Java like so: ProcessStartInfo info = new ProcessStartInfo("C:\\Program Files\\Java\\jre6\\bin\\java.exe", "-jar somerandom.jar"); This obviously won't do. I need a way to dynamically (but declaratively) determine the installed location of Java. I started thinking of looking to the registry, but when I go there I noticed that there were specific keys for the versions and that they could not even be guaranteed to be numeric (e.g. "HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.6" and "HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.6.0_20"). What would be the most reliable "long-haul" solution to finding the most up-to-date java.exe path from a C# application? Thanks much in advance.

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  • java code for capture the image by webcam

    - by Navneet
    I am using windows7 64 bit operating system. The source code is for capturing the image by webcam: import javax.swing.*; import javax.swing.event.*; import java.io.*; import javax.media.*; import javax.media.format.*; import javax.media.util.*; import javax.media.control.*; import javax.media.protocol.*; import java.util.*; import java.awt.*; import java.awt.image.*; import java.awt.event.*; import com.sun.image.codec.jpeg.*; public class SwingCapture extends Panel implements ActionListener { public static Player player = null; public CaptureDeviceInfo di = null; public MediaLocator ml = null; public JButton capture = null; public Buffer buf = null; public Image img = null; public VideoFormat vf = null; public BufferToImage btoi = null; public ImagePanel imgpanel = null; public SwingCapture() { setLayout(new BorderLayout()); setSize(320,550); imgpanel = new ImagePanel(); capture = new JButton("Capture"); capture.addActionListener(this); String str1 = "vfw:Logitech USB Video Camera:0"; String str2 = "vfw:Microsoft WDM Image Capture (Win32):0"; di = CaptureDeviceManager.getDevice(str2); ml = di.getLocator(); try { player = Manager.createRealizedPlayer(ml); player.start(); Component comp; if ((comp = player.getVisualComponent()) != null) { add(comp,BorderLayout.NORTH); } add(capture,BorderLayout.CENTER); add(imgpanel,BorderLayout.SOUTH); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { Frame f = new Frame("SwingCapture"); SwingCapture cf = new SwingCapture(); f.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { playerclose(); System.exit(0);}}); f.add("Center",cf); f.pack(); f.setSize(new Dimension(320,550)); f.setVisible(true); } public static void playerclose() { player.close(); player.deallocate(); } public void actionPerformed(ActionEvent e) { JComponent c = (JComponent) e.getSource(); if (c == capture) { // Grab a frame FrameGrabbingControl fgc = (FrameGrabbingControl) player.getControl("javax.media.control.FrameGrabbingControl"); buf = fgc.grabFrame(); // Convert it to an image btoi = new BufferToImage((VideoFormat)buf.getFormat()); img = btoi.createImage(buf); // show the image imgpanel.setImage(img); // save image saveJPG(img,"c:\\test.jpg"); } } class ImagePanel extends Panel { public Image myimg = null; public ImagePanel() { setLayout(null); setSize(320,240); } public void setImage(Image img) { this.myimg = img; repaint(); } public void paint(Graphics g) { if (myimg != null) { g.drawImage(myimg, 0, 0, this); } } } public static void saveJPG(Image img, String s) { BufferedImage bi = new BufferedImage(img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_RGB); Graphics2D g2 = bi.createGraphics(); g2.drawImage(img, null, null); FileOutputStream out = null; try { out = new FileOutputStream(s); } catch (java.io.FileNotFoundException io) { System.out.println("File Not Found"); } JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi); param.setQuality(0.5f,false); encoder.setJPEGEncodeParam(param); try { encoder.encode(bi); out.close(); } catch (java.io.IOException io) { System.out.println("IOException"); } } } This code is sucessfully compiled. On running the code, the following runtime error occurs: Exception in thread "VFW Request Thread" java.lang.UnsatisfiedLinkError:JMFSecurityManager: java.lang.UnsatisfiedLinkError:no jmvfw in java.library.path at com.sun.media.JMFSecurityManager.loadLibrary(JMFSecurityManager.java:206) at com.sun.media.protocol.vfw.VFWCapture.<clinit><VFWCapture.java:19> at com.sun.media.protocol.vfw.VFWSourceStream.doConnect(VFWSourceStream.java:241) at com.sun.media.protocol.vfw.VFWSourceStream.run(VFWSourceStream.java:763) at java.cdlang.Thread.run(Thread.java:619) Please send me solution of this problem/

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  • Java programming accessing object variables

    - by Haxed
    Helo, there are 3 files, CustomerClient.java, CustomerServer.java and Customer.java PROBLEM: In the CustomerServer.java file, i get an error when I compile the CustomerServer.java at line : System.out.println(a[k].getName()); ERROR: init: deps-jar: Compiling 1 source file to C:\Documents and Settings\TLNA\My Documents\NetBeansProjects\Server\build\classes C:\Documents and Settings\TLNA\My Documents\NetBeansProjects\Server\src\CustomerServer.java:44: cannot find symbol symbol : method getName() location: class Customer System.out.println(a[k].getName()); 1 error BUILD FAILED (total time: 0 seconds) CustomerClient.java import java.io.*; import java.net.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.border.*; public class CustomerClient extends JApplet { private JTextField jtfName = new JTextField(32); private JTextField jtfSeatNo = new JTextField(32); // Button for sending a student to the server private JButton jbtRegister = new JButton("Register to the Server"); // Indicate if it runs as application private boolean isStandAlone = false; // Host name or ip String host = "localhost"; public void init() { JPanel p1 = new JPanel(); p1.setLayout(new GridLayout(2, 1)); p1.add(new JLabel("Name")); p1.add(jtfName); p1.add(new JLabel("Seat No.")); p1.add(jtfSeatNo); add(p1, BorderLayout.CENTER); add(jbtRegister, BorderLayout.SOUTH); // Register listener jbtRegister.addActionListener(new ButtonListener()); // Find the IP address of the Web server if (!isStandAlone) { host = getCodeBase().getHost(); } } /** Handle button action */ private class ButtonListener implements ActionListener { public void actionPerformed(ActionEvent e) { try { // Establish connection with the server Socket socket = new Socket(host, 8000); // Create an output stream to the server ObjectOutputStream toServer = new ObjectOutputStream(socket.getOutputStream()); // Get text field String name = jtfName.getText().trim(); String seatNo = jtfSeatNo.getText().trim(); // Create a Student object and send to the server Customer s = new Customer(name, seatNo); toServer.writeObject(s); } catch (IOException ex) { System.err.println(ex); } } } /** Run the applet as an application */ public static void main(String[] args) { // Create a frame JFrame frame = new JFrame("Register Student Client"); // Create an instance of the applet CustomerClient applet = new CustomerClient(); applet.isStandAlone = true; // Get host if (args.length == 1) { applet.host = args[0]; // Add the applet instance to the frame } frame.add(applet, BorderLayout.CENTER); // Invoke init() and start() applet.init(); applet.start(); // Display the frame frame.pack(); frame.setVisible(true); } } CustomerServer.java import java.io.*; import java.net.*; public class CustomerServer { private String name; private int i; private ObjectOutputStream outputToFile; private ObjectInputStream inputFromClient; public static void main(String[] args) { new CustomerServer(); } public CustomerServer() { Customer[] a = new Customer[30]; try { // Create a server socket ServerSocket serverSocket = new ServerSocket(8000); System.out.println("Server started "); // Create an object ouput stream outputToFile = new ObjectOutputStream( new FileOutputStream("student.dat", true)); while (true) { // Listen for a new connection request Socket socket = serverSocket.accept(); // Create an input stream from the socket inputFromClient = new ObjectInputStream(socket.getInputStream()); // Read from input //Object object = inputFromClient.readObject(); for (int k = 0; k <= 2; k++) { if (a[k] == null) { a[k] = (Customer) inputFromClient.readObject(); // Write to the file outputToFile.writeObject(a[k]); //System.out.println("A new student object is stored"); System.out.println(a[k].getName()); break; } if (k == 2) { //fully booked outputToFile.writeObject("All seats are booked"); break; } } } } catch (ClassNotFoundException ex) { ex.printStackTrace(); } catch (IOException ex) { ex.printStackTrace(); } finally { try { inputFromClient.close(); outputToFile.close(); } catch (Exception ex) { ex.printStackTrace(); } } } } Customer.java public class Customer implements java.io.Serializable { private String name; private String seatno; public Customer(String name, String seatno) { this.name = name; this.seatno = seatno; } public String getName() { return name; } public String getSeatNo() { return seatno; } }

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  • Makefile to compile both C and Java programs at the same time

    - by user342745
    I have three programs that need to be compiled at the same time, 2 written in C and 1 in java. I had all three working with the Makefile when they were in C, but then switched one of them to java... is there a way to compile all 3 at once with the same makefile? Here is my current Makefile: CC=gcc JC=javac JFLAGS= -g CFLAGS= -Wall -g -std=c99 LDFLAGS= -lm .SUFFIXES: .java .class .java.class: $(JC) $(JFLAGS) $*.java CLASSES = kasiski.java kentry.java ALL= ic ftable kasiski all: $(ALL) ic: ic.o kasiski: $(CLASSES:.java=.class) ftable: ftable.o ic.o: ic.c ic.h ftable.o: ftable.c ftable.h .PHONY: clean clean: rm -rf core* *.class *.o *.gch $(ALL)

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  • JAXB doesn't unmarshal list of interfaces

    - by Joker_vD
    It seems JAXB can't read what it writes. Consider the following code: interface IFoo { void jump(); } @XmlRootElement class Bar implements IFoo { @XmlElement public String y; public Bar() { y = ""; } public Bar(String y) { this.y = y; } @Override public void jump() { System.out.println(y); } } @XmlRootElement class Baz implements IFoo { @XmlElement public int x; public Baz() { x = 0; } public Baz(int x) { this.x = x; } @Override public void jump() { System.out.println(x); } } @XmlRootElement public class Holder { private List<IFoo> things; public Holder() { things = new ArrayList<>(); } @XmlElementWrapper @XmlAnyElement public List<IFoo> getThings() { return things; } public void addThing(IFoo thing) { things.add(thing); } } // ... try { JAXBContext context = JAXBContext.newInstance(Holder.class, Bar.class, Baz.class); Holder holder = new Holder(); holder.addThing(new Bar("1")); holder.addThing(new Baz(2)); holder.addThing(new Baz(3)); for (IFoo thing : holder.getThings()) { thing.jump(); } StringWriter s = new StringWriter(); context.createMarshaller().marshal(holder, s); String data = s.toString(); System.out.println(data); StringReader t = new StringReader(data); Holder holder2 = (Holder)context.createUnmarshaller().unmarshal(t); for (IFoo thing : holder2.getThings()) { thing.jump(); } } catch (Exception e) { System.err.println(e.getMessage()); } It's a simplified example, of course. The point is that I have to store two very differently implemented classes, Bar and Baz, in one collection. Well, I observed that they have pretty similar public interface, so I created an interface IFoo and made them two to implement it. Now, I want to have tools to save and load this collection to/from XML. Unfortunately, this code doesn't quite work: the collection is saved, but then it cannot be loaded! The intended output is 1 2 3 some xml 1 2 3 But unfortunately, the actual output is 1 2 3 some xml com.sun.org.apache.xerces.internal.dom.ElementNSImpl cannot be cast to testapplication1.IFoo Apparently, I need to use the annotations in a different way? Or to give up on JAXB and look for something else? I, well, can write "XMLNode toXML()" method for all classes I wan't to (de)marshal, but...

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  • Returnimng collection of interfaces

    - by apoorv020
    I have created the following interface public interface ISolutionSpace { public boolean isFeasible(); public boolean isSolution(); public Set<ISolutionSpace> generateChildren(); } However, in the implementation of ISolutionSpace in a class called EightQueenSolutionSpace, I am going to return a set of EightQueenSolutionSpace instances, like the following stub: @Override public Set<ISolutionSpace> generateChildren() { return new HashSet<EightQueenSolutionSpace>(); } However this stub wont compile. What changes do I need to make? EDIT: I tried 'HashSet' as well and had tried using the extends keyword. However since 'ISolutionSpace' is an interface and EightQueenSolutionSpace is an implementation(and not a subclass) of 'ISolutionSpace', it is still not working.

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  • java.lang.ClassNotFoundException: com.mysql.jdbc.Driver When run jar file

    - by user1024858
    Hi all, Connection conn = null; String url = "jdbc:mysql://localhost:3306/"; String dbName = "test"; String driver = "com.mysql.jdbc.Driver"; String userName = "root"; String password = "admin"; try { Class.forName(driver).newInstance(); conn = DriverManager.getConnection(url+dbName,userName,password); System.out.println("Connected to the database"); conn.close(); System.out.println("Disconnected from database"); } catch (Exception e) { e.printStackTrace();} I run in eclipse it's ok, but i built to jar file and run on command line java -jar Test.jar i get this error: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at java.net.URLClassLoader$1.run(Unknown Source) 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) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Unknown Source) Please help me how to fix it. Thanks!!!

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  • PHP and Java interoperablity

    - by Jack
    I am working on windows using tomcat 6 and PHP/Java Bridge. I know how to access a Java file from PHP but how do we do it the other way i.e accessing PHP from Java <?php require_once("java\Java.inc"); $systemInfo = new Java("java.lang.System"); print "Total seconds since January 1, 1970: ".$systemInfo->currentTimeMillis(); ?> Also how do I access Java classes that are created by me. Do I write a CLASSPATH env variable or change the php.ini config file?

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  • java version 1.6 applet requistes

    - by gautam
    Hi, I upgraded my java version 1.5 to 1.6. My applet is not working what are prequesties ? i have changed classid and MIME type to 1.6. Its giving exception: load: class com.timer.AppletGenerator.class not found. java.lang.ClassNotFoundException: com.timer.AppletGenerator.class at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source) at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source) at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: java.io.IOException: open HTTP connection failed:http://localhost:8080/Perfmonitoringgui-000.004.000/com/timer/AppletGenerator/class.class at sun.plugin2.applet.Applet2ClassLoader.getBytes(Unknown Source) at sun.plugin2.applet.Applet2ClassLoader.access$000(Unknown Source) at sun.plugin2.applet.Applet2ClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) ... 7 more Exception: java.lang.ClassNotFoundException: com.timer.AppletGenerator.class Thanks

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  • Can we build websites in Java

    - by Mirage
    IF some says to me to build webisite in java. What does that mean. That means building in core java, java servlets , jsp , java beans , j2ee or what. What thing i need to learn if some tells me to make webiste in java. Just like there are ready made login scripts in php , are those available in java as well thanks

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  • Constructors in Inner classes (implementing Interfaces)

    - by thepandaatemyface
    Hi, How would I go about writing a constructor for an inner class which is implementing an interface? I know I could make a whole new class, but I figure there's got to be a way to do something along the line of this: JButton b = new JButton(new AbstractAction() { public AbstractAction() { super("This is a button"); } public void actionPerformed(ActionEvent e) { System.out.println("button clicked"); } }); When I enter this it doesn't recognize the AbstractAction method as a constructor (compiler asks for return type). Anyone have an idea? Thanks

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  • regarding java programming language

    - by giri
    Hi I am java professional since last one year. I am pretty familier with core java and JSP and SERVLET technologies.Now I am hired by a telcom company where java is not used.The question I like to ask here is how to keep java enviornment around me so that I should not be unfamiler with java. As I come from company I get much time to work with java. I like to know any real time projects in java available so that I can work with java also. Please let me know... Thanks in advance

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  • Are Interfaces "Object"?

    - by PrashantGupta
    package inheritance; class A{ public String display(){ return "This is A!"; } } interface Workable{ public String work(); } class B extends A implements Workable{ public String work(){ return "B is working!"; } } public class TestInterfaceObject{ public static void main(String... args){ B obj=new B(); Workable w=obj; //System.out.println(w.work()); //invoking work method on Workable type reference System.out.println(w.display()); //invoking display method on Workable type reference //System.out.println(w.hashCode()); // invoking Object's hashCode method on Workable type reference } } As we know that methods which can be invoked depend upon the type of the reference variable on which we are going to invoke. Here, in the code, work() method was invoked on "w" reference (which is Workable type) so method invoking will compile successfully. Then, display() method is invoked on "w" which yields a compilation error which says display method was not found, quite obvious as Workable doesn't know about it. Then we try to invoke the Object class's method i.e. hashCode() which yields a successful compilation and execution. How is it possible? Any logical explanation?

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  • Eclipse NullPointerException at getFontList

    - by Jan Fabry
    Eclipse doesn't start anymore. I get a dialog box that points me to a log file with the following entry: !SESSION 2009-12-08 08:49:16.263 ----------------------------------------------- eclipse.buildId=M20090917-0800 java.version=1.6.0_17 java.vendor=Apple Inc. BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US Framework arguments: -product org.eclipse.epp.package.php.product -keyring /Users/cheezy/.eclipse_keyring -showlocation Command-line arguments: -os macosx -ws cocoa -arch x86_64 -product org.eclipse.epp.package.php.product -keyring /Users/cheezy/.eclipse_keyring -showlocation !ENTRY org.eclipse.osgi 4 0 2009-12-08 08:49:19.993 !MESSAGE Application error !STACK 1 java.lang.NullPointerException at org.eclipse.swt.graphics.Device.getFontList(Device.java:369) at org.eclipse.jface.resource.FontRegistry.filterData(FontRegistry.java:465) at org.eclipse.jface.resource.FontRegistry.createFont(FontRegistry.java:499) at org.eclipse.jface.resource.FontRegistry.defaultFontRecord(FontRegistry.java:563) at org.eclipse.jface.resource.FontRegistry.getFontRecord(FontRegistry.java:673) at org.eclipse.jface.resource.FontRegistry.get(FontRegistry.java:613) at org.eclipse.jface.resource.JFaceResources.getDialogFont(JFaceResources.java:273) at org.eclipse.jface.dialogs.Dialog.initializeDialogUnits(Dialog.java:925) at org.eclipse.jface.dialogs.TitleAreaDialog.createContents(TitleAreaDialog.java:131) at org.eclipse.jface.window.Window.create(Window.java:431) at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089) at org.eclipse.jface.window.Window.open(Window.java:790) at org.eclipse.ui.internal.ide.ChooseWorkspaceDialog.prompt(ChooseWorkspaceDialog.java:91) at org.eclipse.ui.internal.ide.application.IDEApplication.promptForWorkspace(IDEApplication.java:275) at org.eclipse.ui.internal.ide.application.IDEApplication.checkInstanceLocation(IDEApplication.java:223) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:103) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:368) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514) at org.eclipse.equinox.launcher.Main.run(Main.java:1311) I did clean up my font list in Font Book by disabling duplicate fonts. I also upgraded to Mac OS X 10.6.2.

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  • installing jdk1.7.0 on Ubuntu 11.04 machine

    - by Yogesh
    I am facing a problem while trying to install Java 7 on Ubuntu. The following are the steps that I performed for installing: I installed the setup file from the link given below: wget http://download.oracle.com/otn-pub/java/jdk/7u1-b08/jdk-7u1-linux-x64.tar.gz I have a file: jdk-7u1-linux-x64.tar.gz I Untared it: tar -xvf jdk-7u1-linux-x64.tar.gz sudo mv ./jdk1.7.0_01 /usr/lib/jvm/jdk1.7.0_01 sudo update-alternatives –config java Here it gave me the following output: There is only one alternative in link group java: /usr/lib/jvm/java-6-sun/jre/bin/java Nothing to configure. sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_01/jre/bin/java 1(I entered 1 here.) sudo update-alternatives --config java java -version. It showed the following output java version "1.6.0_26" Java(TM) SE Runtime Environment (build 1.6.0_26-b03) Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode) I am not sure if jdk1.7.0 is installed as its showing the version as 1.6.0_26.

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  • preverification error in netbeans and eclipse while including j2ssh maverick

    - by user568651
    problem-- Preverification errors: Error preverifying class com.maverick.ssh.components.ComponentFactory java/lang/NoClassDefFoundError: java/lang/Cloneable j2ssh Unknown Java Problem this error comes while j2ssh is added as a library in my application. console-- Uncaught exception: java.lang.NoClassDefFoundError: com/maverick/ssh/LicenseManager - mobilessh.MobileSSH.run(), bci=2 - java.lang.Thread.run(), bci=11 this error shows both in eclipse and netbeans ide 6.9.1 jdk 1.6 installed.. wtk 3.0 and 2.5.2.

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  • Break a class in twain, or impose an interface for restricted access?

    - by bedwyr
    What's the best way of partitioning a class when its functionality needs to be externally accessed in different ways by different classes? Hopefully the following example will make the question clear :) I have a Java class which accesses a single location in a directory allowing external classes to perform read/write operations to it. Read operations return usage stats on the directory (e.g. available disk space, number of writes, etc.); write operations, obviously, allow external classes to write data to the disk. These methods always work on the same location, and receive their configuration (e.g. which directory to use, min disk space, etc.) from an external source (passed to the constructor). This class looks something like this: public class DiskHandler { public DiskHandler(String dir, int minSpace) { ... } public void writeToDisk(String contents, String filename) { int space = getAvailableSpace(); ... } public void getAvailableSpace() { ... } } There's quite a bit more going on, but this will do to suffice. This class needs to be accessed differently by two external classes. One class needs access to the read operations; the other needs access to both read and write operations. public class DiskWriter { DiskHandler diskHandler; public DiskWriter() { diskHandler = new DiskHandler(...); } public void doSomething() { diskHandler.writeToDisk(...); } } public class DiskReader { DiskHandler diskHandler; public DiskReader() { diskHandler = new DiskHandler(...); } public void doSomething() { int space = diskHandler.getAvailableSpace(...); } } At this point, both classes share the same class, but the class which should only read has access to the write methods. Solution 1 I could break this class into two. One class would handle read operations, and the other would handle writes: // NEW "UTILITY" CLASSES public class WriterUtil { private ReaderUtil diskReader; public WriterUtil(String dir, int minSpace) { ... diskReader = new ReaderUtil(dir, minSpace); } public void writeToDisk(String contents, String filename) { int = diskReader.getAvailableSpace(); ... } } public class ReaderUtil { public ReaderUtil(String dir, int minSpace) { ... } public void getAvailableSpace() { ... } } // MODIFIED EXTERNALLY-ACCESSING CLASSES public class DiskWriter { WriterUtil diskWriter; public DiskWriter() { diskWriter = new WriterUtil(...); } public void doSomething() { diskWriter.writeToDisk(...); } } public class DiskReader { ReaderUtil diskReader; public DiskReader() { diskReader = new ReaderUtil(...); } public void doSomething() { int space = diskReader.getAvailableSpace(...); } } This solution prevents classes from having access to methods they should not, but it also breaks encapsulation. The original DiskHandler class was completely self-contained and only needed config parameters via a single constructor. By breaking apart the functionality into read/write classes, they both are concerned with the directory and both need to be instantiated with their respective values. In essence, I don't really care to duplicate the concerns. Solution 2 I could implement an interface which only provisions read operations, and use this when a class only needs access to those methods. The interface might look something like this: public interface Readable { int getAvailableSpace(); } The Reader class would instantiate the object like this: Readable diskReader; public DiskReader() { diskReader = new DiskHandler(...); } This solution seems brittle, and prone to confusion in the future. It doesn't guarantee developers will use the correct interface in the future. Any changes to the implementation of the DiskHandler could also need to update the interface as well as the accessing classes. I like it better than the previous solution, but not by much. Frankly, neither of these solutions seems perfect, but I'm not sure if one should be preferred over the other. I really don't want to break the original class up, but I also don't know if the interface buys me much in the long run. Are there other solutions I'm missing?

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  • Open Source AI Bot interfaces

    - by David Young
    What are some open source AI Bot interfaces? Similar to Pogamut 3 GameBots2004 for custom Unreal Tournament bots or Brood Wars API for Starcraft bots etc. If you could please post one AI bot interface per answer (make sure to provide a link) and give a brief summary as to the content of the blog posts. Please include what type of bot interface structure it is, client/server, server/server, etc e.g. BWAPI is client/server which emulates a real player

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  • Héritage multiple en C++: Pourquoi l'héritage d'interfaces est insuffisant, Par Loïc Joly

    Bonjour à tous ! Je viens de mettre en ligne un article, intitulé : Héritage multiple en C++ : Pourquoi l'héritage d'interfaces est insuffisant N'hésitez pas à faire donner votre avis, faire des remarques. L'article compare aussi des fonctionnalités de différents langages orientés objet, principalement C++, C# et Java. En tant que tel, j'espère qu'il pourra susciter des discussions intéressantes, sans sombrer dans le troll inter-langages. Bonne lecture !...

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  • Getting output parameter(SYS_REFCURSOR) from Oracle stored procedure in iBATIS 3(by using annotation

    - by yjacket
    I got an example how to call oracle SP in iBATIS 3 without a map file. And now I understand how to call it. But I got another problem that how to get a result from output parameter(Oracle cursor). A part of exception messages is "There is no setter for property named 'rs' in 'class java.lang.Class". Below is my code. Does anyone can help me? Oracle Stored Procedure: CREATE OR REPLACE PROCEDURE getProducts ( rs OUT SYS_REFCURSOR ) IS BEGIN OPEN rs FOR SELECT * FROM Products; END getProducts; Interface: public interface ProductMapper { @Select("call getProducts(#{rs,mode=OUT,jdbcType=CURSOR})") @Options(statementType = StatementType.CALLABLE) List<Product> getProducts(); } DAO: public class ProductDAO { public List<Product> getProducts() { return mapper.getProducts(); // mapper is ProductMapper } } Full Error Message: Exception in thread "main" org.apache.ibatis.exceptions.IbatisException: ### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' ### The error may involve defaultParameterMap ### The error occurred while setting parameters ### Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:61) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:53) at org.apache.ibatis.binding.MapperMethod.executeForList(MapperMethod.java:82) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:63) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:35) at $Proxy8.getList(Unknown Source) at com.dao.ProductDAO.getList(ProductDAO.java:42) at com.Ibatis3Test.main(Ibatis3Test.java:30) Caused by: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:154) at org.apache.ibatis.reflection.wrapper.BeanWrapper.set(BeanWrapper.java:36) at org.apache.ibatis.reflection.MetaObject.setValue(MetaObject.java:120) at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleOutputParameters(FastResultSetHandler.java:69) at org.apache.ibatis.executor.statement.CallableStatementHandler.query(CallableStatementHandler.java:44) at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:55) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:41) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:94) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:72) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:59) ... 7 more Caused by: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.Reflector.getSetInvoker(Reflector.java:300) at org.apache.ibatis.reflection.MetaClass.getSetInvoker(MetaClass.java:97) at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:146) ... 16 more

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  • How to get a result from output parameter(SYS_REFCURSOR) of Oracle stored procedure in iBATIS 3(by u

    - by yjacket
    I got an example how to call oracle SP in iBATIS 3 without a map file. And now I understand how to call it. But I got another problem that how to get a result from output parameter(Oracle cursor). A part of exception messages is "There is no setter for property named 'rs' in 'class java.lang.Class". Below is my code. Does anyone can help me? Oracle Stored Procedure: CREATE OR REPLACE PROCEDURE getProducts ( rs OUT SYS_REFCURSOR ) IS BEGIN OPEN rs FOR SELECT * FROM Products; END getProducts; Interface: public interface ProductMapper { @Select("call getProducts(#{rs,mode=OUT,jdbcType=CURSOR})") @Options(statementType = StatementType.CALLABLE) List<Product> getProducts(); } DAO: public class ProductDAO { public List<Product> getProducts() { return mapper.getProducts(); // mapper is ProductMapper } } Full Error Message: Exception in thread "main" org.apache.ibatis.exceptions.IbatisException: ### Error querying database. Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' ### The error may involve defaultParameterMap ### The error occurred while setting parameters ### Cause: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:61) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:53) at org.apache.ibatis.binding.MapperMethod.executeForList(MapperMethod.java:82) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:63) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:35) at $Proxy8.getList(Unknown Source) at com.dao.ProductDAO.getList(ProductDAO.java:42) at com.Ibatis3Test.main(Ibatis3Test.java:30) Caused by: org.apache.ibatis.reflection.ReflectionException: Could not set property 'rs' of 'class org.apache.ibatis.reflection.MetaObject$NullObject' with value 'oracle.jdbc.driver.OracleResultSetImpl@1a001ff' Cause: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:154) at org.apache.ibatis.reflection.wrapper.BeanWrapper.set(BeanWrapper.java:36) at org.apache.ibatis.reflection.MetaObject.setValue(MetaObject.java:120) at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleOutputParameters(FastResultSetHandler.java:69) at org.apache.ibatis.executor.statement.CallableStatementHandler.query(CallableStatementHandler.java:44) at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:55) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:41) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:94) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:72) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:59) ... 7 more Caused by: org.apache.ibatis.reflection.ReflectionException: There is no setter for property named 'rs' in 'class java.lang.Class' at org.apache.ibatis.reflection.Reflector.getSetInvoker(Reflector.java:300) at org.apache.ibatis.reflection.MetaClass.getSetInvoker(MetaClass.java:97) at org.apache.ibatis.reflection.wrapper.BeanWrapper.setBeanProperty(BeanWrapper.java:146) ... 16 more

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  • Glassfish v3 / JNDI entry cannot be found problems!

    - by REMP
    I've been having problems trying to call an EJB's method from a Java Application Client. Here is the code. EJB Remote Interface package com.test; import javax.ejb.Remote; @Remote public interface HelloBeanRemote { public String sayHello(); } EJB package com.test; import javax.ejb.Stateless; @Stateless (name="HelloBeanExample" , mappedName="ejb/HelloBean") public class HelloBean implements HelloBeanRemote { @Override public String sayHello(){ return "hola"; } } Main class (another project) import com.test.HelloBeanRemote; import javax.naming.Context; import javax.naming.InitialContext; public class Main { public void runTest()throws Exception{ Context ctx = new InitialContext(); HelloBeanRemote bean = (HelloBeanRemote)ctx.lookup("java:global/Test/HelloBeanExample!com.test.HelloBeanRemote"); System.out.println(bean.sayHello()); } public static void main(String[] args)throws Exception { Main main = new Main(); main.runTest(); } } Well, what is my problem? JNDI entry for this EJB cannot be found! java.lang.NullPointerException at com.sun.enterprise.naming.impl.SerialContext.getRemoteProvider(SerialContext.java:297) at com.sun.enterprise.naming.impl.SerialContext.getProvider(SerialContext.java:271) at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:430) at javax.naming.InitialContext.lookup(InitialContext.java:392) at testdesktop.Main.runTest(Main.java:22) at testdesktop.Main.main(Main.java:31) Exception in thread "main" javax.naming.NamingException: Lookup failed for 'java:global/Test/HelloBeanExample!com.test.HelloBeanRemote' in SerialContext [Root exception is javax.naming.NamingException: Unable to acquire SerialContextProvider for SerialContext [Root exception is java.lang.NullPointerException]] at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:442) at javax.naming.InitialContext.lookup(InitialContext.java:392) at testdesktop.Main.runTest(Main.java:22) at testdesktop.Main.main(Main.java:31) Caused by: javax.naming.NamingException: Unable to acquire SerialContextProvider for SerialContext [Root exception is java.lang.NullPointerException] at com.sun.enterprise.naming.impl.SerialContext.getProvider(SerialContext.java:276) at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:430) ... 3 more Caused by: java.lang.NullPointerException at com.sun.enterprise.naming.impl.SerialContext.getRemoteProvider(SerialContext.java:297) at com.sun.enterprise.naming.impl.SerialContext.getProvider(SerialContext.java:271) ... 4 more Java Result: 1 I've trying with different JNDI entries but nothing works (I got this entries from NetBeans console): INFO: Portable JNDI names for EJB HelloBeanExample : [java:global/Test/HelloBeanExample, java:global/Test/HelloBeanExample!com.test.HelloBeanRemote] INFO: Glassfish-specific (Non-portable) JNDI names for EJB HelloBeanExample : [ejb/HelloBean, ejb/HelloBean#com.test.HelloBeanRemote] So I tried with the following entries but I got the same exception : java:global/Test/HelloBeanExample java:global/Test/HelloBeanExample!com.test.HelloBeanRemote ejb/HelloBean ejb/HelloBean#com.test.HelloBeanRemote I'm using Netbeans 6.8 and Glassfish v3!

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