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  • How to read a password encrypted key with java?

    - by Denis
    Hi, This is very simple question. I have private key stored in file in PKCS8 DER format and protected by password. What is the easiest way to read it? Here is the code I use to load unencrypted one: InputStream in = new FileInputStream(privateKeyFilename); byte[] privateKeydata = new byte[in.available()]; in.read(privateKeydata); in.close(); KeyFactory privateKeyFactory = KeyFactory.getInstance("RSA"); PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(privateKeydata); PrivateKey privateKey = privateKeyFactory.generatePrivate(encodedKeySpec); Please, Help!!!

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  • Dealing with ArrayLists in java...all members of the arraylist updating themselves?

    - by Charlie
    I have a function that shrinks the size of a "Food bank" (represented by a rectangle in my GUI) once some of the food has been taken. I have the following function check for this: public boolean tryToPickUpFood(Ant a) { int xCoord = a.getLocation().x; int yCoord = a.getLocation().y; for (int i = 0; i < foodPiles.size(); i++) { if (foodPiles.get(i).containsPoint(xCoord, yCoord)) { foodPiles.get(i).decreaseFood(); return true; } } return false; } Where decreaseFood shrinks the rectangle.. public void decreaseFood() { foodAmount -= 1; shrinkPile(); } private void shrinkPile() { WIDTH -=1; HEIGHT = WIDTH; } However, whenever one rectangle shrinks, ALL of the rectangles shrink. Why would this be?

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  • A simple free MIDI implementation in Java besides javax.sound.midi: Are there any?

    - by Peterdk
    The problem is: Android doesn't implement javax.sound.midi. I need a simple free library that allows me to create simple 1-track midi files. I searched the net for it, but can't really find anything, since everything uses javax.sound.midi . The license needs to be one where I don't need to opensource my linked app. Any ideas? I also looked into the fileformat itself. However, I am totally not familiar with working with bytes, hexidecimal stuff etc. So, other option is: are there any simple midi implementations that I can use as reference?

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  • State pattern: Why doesn't the context class implement or inherit the State abstract interface/class

    - by Ricket
    I'm reading about the State pattern. I have only just begun, so of course I begin by reading the entire Wikipedia article on it. I noticed that both of the examples in the article have some base abstract class or Java interface for a generic State's methods/functions. Then there are some states which inherit from the base and implement those methods/functions in different ways. Then there's a Context class which has a private member of type State and which, at any time, can be equal to an instance of one of the implementations. That context class also implements the same methods, and passes them onto the current state instance, and then has an additional method to change the state (or depending on design I understand the change of state could be a reaction to one of the implemented methods). Why doesn't this context class specifically "extend" or "implement" the generic State base class/interface?

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  • Java InputReader. Detect if file being read is binary?

    - by Trizicus
    I had posted a question in regards to this code. I found that JTextArea does not support the binary type data that is loaded. So my new question is how can I go about detecting the 'bad' file and canceling the file I/O and telling the user that they need to select a new file? class Open extends SwingWorker<Void, String> { File file; JTextArea jta; Open(File file, JTextArea jta) { this.file = file; this.jta = jta; } @Override protected Void doInBackground() throws Exception { BufferedReader br = null; try { br = new BufferedReader(new FileReader(file)); String line = br.readLine(); while(line != null) { publish(line); line = br.readLine(); } } finally { try { br.close(); } catch (IOException e) { } } return null; } @Override protected void process(List<String> chunks) { for(String s : chunks) jta.append(s + "\n"); } }

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  • Spring-MVC Problem using @Controller on controller implementing an interface

    - by layne
    I'm using spring 2.5 and annotations to configure my spring-mvc web context. Unfortunately, I am unable to get the following to work. I'm not sure if this is a bug (seems like it) or if there is a basic misunderstanding on how the annotations and interface implementation subclassing works. For example, @Controller @RequestMapping("url-mapping-here") public class Foo { @RequestMapping(method=RequestMethod.GET) public void showForm() { ... } @RequestMapping(method=RequestMethod.POST) public String processForm() { ... } } works fine. When the context starts up, the urls this handler deals with are discovered, and everything works great. This however does not: @Controller @RequestMapping("url-mapping-here") public class Foo implements Bar { @RequestMapping(method=RequestMethod.GET) public void showForm() { ... } @RequestMapping(method=RequestMethod.POST) public String processForm() { ... } } When I try to pull up the url, I get the following nasty stack trace: javax.servlet.ServletException: No adapter for handler [com.shaneleopard.web.controller.RegistrationController@e973e3]: Does your handler implement a supported interface like Controller? org.springframework.web.servlet.DispatcherServlet.getHandlerAdapter(DispatcherServlet.java:1091) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:874) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:501) javax.servlet.http.HttpServlet.service(HttpServlet.java:627) However, if I change Bar to be an abstract superclass and have Foo extend it, then it works again. @Controller @RequestMapping("url-mapping-here") public class Foo extends Bar { @RequestMapping(method=RequestMethod.GET) public void showForm() { ... } @RequestMapping(method=RequestMethod.POST) public String processForm() { ... } } This seems like a bug. The @Controller annotation should be sufficient to mark this as a controller, and I should be able to implement one or more interfaces in my controller without having to do anything else. Any ideas?

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  • Where to store a DataSource resource in a Java web app?

    - by Slavko
    This is a rookie question. What's the best place to put @Resource private DataSource ds; in a web application? Do I put it in a servlet, context listener or maybe there's a better place for it? Also, do I create a new Connection object in my doGet()/doPost() or should I do it somewhere else? What's the best practice for stuff like this? Thank you!

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  • Am I doing getters/setters the right way in Java?

    - by Sergio Tapia
    public class Persona { int Codigo; String Nombre; public Persona(int Codigo, String Nombre){ this.Codigo = Codigo; this.Nombre = Nombre; } public void setCodigo(int Codigo){ this.Codigo = Codigo; } public int getCodigo(){ return this.Codigo; } public void setNombre(String Nombre){ this.Nombre = Nombre; } public String getNombre(){ return this.Nombre; } } Or is there a much shorter (realiable) way to do it?

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  • How does a Java Arraylist contains() method evalute objects?

    - by mvid
    Say i create one object and add it to my ArrayList. If I then create another object with exactly the same constructor input, will the contain() method evaluate the two objects to be the same? Assume the constructor doesn't do anything funny with the input, and the variables stored in both objects are identical. ArrayList<Thing> basket = new ArrayList<Thing>(); Thing thing = new Thing(100); basket.add(thing); Thing another = new Thing(100); basket.contains(another); // true or false?

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  • How to authenticate my own provider( only for testing purposes)

    - by user308806
    Dear all Now, I wrote a new provider (ESMJCE provider), and I also write a simple application to test it, but I have some exceptions like that java.lang.SecurityException: JCE cannot authenticate the provider ESMJCE at javax.crypto.Cipher.getInstance(DashoA13*..) at javax.crypto.Cipher.getInstance(DashoA13*..) at testprovider.main(testprovider.java:27) Caused by: java.util.jar.JarException: Cannot parse file:/C:/Program%20Files/Java/jre1.6.0_02/lib/ext/abc.jar at javax.crypto.SunJCE_c.a(DashoA13*..) at javax.crypto.SunJCE_b.b(DashoA13*..) at javax.crypto.SunJCE_b.a(DashoA13*..) ... 3 more And here is my source code import java.security.Provider; import java.security.Security; import javax.crypto.Cipher; import esm.jce.provider.ESMProvider; public class testprovider { / @param args / public static void main(String[] args) { // TODO Auto-generated method stub ESMProvider esmprovider = new esm.jce.provider.ESMProvider(); Security.insertProviderAt(esmprovider,2); Provider[] temp = Security.getProviders(); for (int i= 0; i<temp.length; i++){ System.out.println("Providers: " temp[i].getName()); } try{ Cipher cipher = Cipher.getInstance("DES", "ESMJCE"); System.out.println("Cipher: " cipher); int blockSize= cipher.getBlockSize(); System.out.println("blockSize= " + blockSize); }catch (Exception e){ e.printStackTrace(); } } } Please help me solve this issue Thanks

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  • Java: how to tell if a line in a text file was supposed to be blank?

    - by defn
    I'm working on a project in which I have to read in a Grammar file (breaking it up into my data structure), with the goal of being able to generate a random "DearJohnLetter". My problem is that when reading in the .txt file, I don't know how find out whether the file was supposed to be a completely blank line or not, which is detrimental to the program. Here is an example of part of the file, How do i tell if the next line was supposed to be a blank line? (btw I'm just using a buffered reader) Thanks! <start> I have to break up with you because <reason> . But let's still <disclaimer> . <reason> <dubious-excuse> <dubious-excuse> , and also because <reason> <dubious-excuse> my <person> doesn't like you I'm in love with <another> I haven't told you this before but <harsh> I didn't have the heart to tell you this when we were going out, but <harsh> you never <romantic-with-me> with me any more you don't <romantic> any more my <someone> said you were bad news

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  • Separate functionality depending on Role in ASP.NET MVC

    - by Andrew Bullock
    I'm looking for an elegant pattern to solve this problem: I have several user roles in my system, and for many of my controller actions, I need to deal with slightly different data. For example, take /Users/Edit/1 This allows a Moderator to edit a users email address, but Administrators to edit a user's email address and password. I'd like a design for separating the two different bits of action code for the GET and the POST. Solutions I've come up with so far are: Switch inside each method, however this doesn't really help when i want different model arguments on the POST :( Custom controller factory which chooses a UsersController_ForModerators and UsersController_ForAdmins instead of just UsersController from the controller name and current user role Custom action invoker which choose the Edit_ForModerators method in a similar way to above Have an IUsersController and register a different implementation of it in my IoC container as a named instance based on Role Build an implementation of the controller at runtime using Castle DynamicProxy and manipulate the methods to those from role-based implementations Im preferring the named IoC instance route atm as it means all my urls/routing will work seamlessly. Ideas? Suggestions?

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  • Read from one large file and write to many (tens, hundreds, or thousands) files in Java?

    - by Rudiger
    I have a large-ish file (4-5 GB compressed) of small messages that I wish to parse into approximately 6,000 files by message type. Messages are small; anywhere from 5 to 50 bytes depending on the type. Each message starts with a fixed-size type field (a 6-byte key). If I read a message of type '000001', I want to write append its payload to 000001.dat, etc. The input file contains a mixture of messages; I want N homogeneous output files, where each output file contains only the messages of a given type. What's an efficient a fast way of writing these messages to so many individual files? I'd like to use as much memory and processing power to get it done as fast as possible. I can write compressed or uncompressed files to the disk. I'm thinking of using a hashmap with a message type key and an outputstream value, but I'm sure there's a better way to do it. Thanks!

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  • How to make video in Java captured from webcam through lti-Civil CaptureDeviceStream ?

    - by i.Psi
    Can I do it only with the lti-Civil classes or I need FMJ or JMF ? do I use the actual Stream or set of captured Images from CaptureObserver? Thanks. captureStream = system.openCaptureDeviceStream(info.getDeviceID()); captureStream.setObserver(new CaptureObserver(){ public void onError(CaptureStream arg0, CaptureException arg1) { } public void onNewImage(CaptureStream streamSource, Image image) { try { imageFrame.setImage(AWTImageConverter.toBufferedImage(image)); bufferedImage = AWTImageConverter.toBufferedImage(image); } catch (Throwable t) { t.printStackTrace(); } } }); captureStream.start();

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  • Java Swing: How to make the JComboxBox drop down list taller?

    - by NoozNooz42
    How to make the "dropdown" (or "popup", I don't know how it's called) of a JComboBox taller on the screen? By default, when I open my JComboBox I see, say, 7 out of 29 items, then I need to scroll. What should I do so that I can see, say, 15 out of these 32 items? (or if the dropdown is, say, 150 pixels tall, how can I make it 300 pixels tall?) I've read the Sun tutorial on JComboBox and the JavaDoc but I must have overlooked the method(s) to call.

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  • Java encryption : with method can get me a shorter message ?

    - by Frank
    I don't know too much about encryption, I just want to ask, which method can get me the shortest result message ? For instance, the message looks like this : "This is the secret input message", I wonder if the encrypted message can be shorter then the above 32 characters long ? Maybe something like "dfkfjkvf12". Frank

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