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  • JTable Insert row and refresh

    - by user269723
    Hi All, I am trying to create simple application where JTable gets updated and refreshed after data is changed.Structure is as follows. 1)Class Main which contains JFrame,JTable details. 2)SampleTableModel class which extends AbstractTableModel.I am overriding most of the methods.`import javax.swing.table.; import javax.swing.event.; import java.util.*; public class SampleTableModel extends AbstractTableModel { public SampleTableModel(){ // this.addTableModelListener( } String[] columnNames = {"A","B","C","D","E"}; int[][] data = {{1,2,3,4,5},{5,6,7,8,9},{12,13,14,15,16}}; Vector dataVector = new Vector(); public Object getValueAt(int rowIndex,int columnIndex) { return data[rowIndex][columnIndex]; } public int getColumnCount(){ return 5; } public int getRowCount(){ return 3; } public String getColumnName(int columnIndex){ return columnNames[columnIndex]; } public void setValueAt(Object value,int row,int column){ data[row][column] =99; } public void notifyTable(AEMessage message){ /* * This method will be called from another class to update JTable. * */ data[0][1]=999; data[0][2]=8838; data[1][1]=8883; fireTableRowsUpdated(0,3); } } ` As you can see, notifyTable will be called from another class(which is actually a thread-which calls this method frequently) Problem is I don't see data being changed in JTable.I see only the initialized data. In the Main class- I am setting like this- RVJDataTable.setModel(new SampleTableModel());

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  • Make JFace Window blink in taskbar or get users attention?

    - by Sophomore
    Hi folks I wonder someone has any idea how to solve this: In my Java Eclipse plugin there are some processes which take some time. Therefore the user might minimize the window and let the process run in the background. Now, when the process is finished, I can force the window to come to the top again, but that is a no-no in usability. I'd rather want the process to blink in the taskbar instead. Is there any way to achieve this? I had a look at the org.eclipse.jface.window but could'nt find anything like that, same goes for the SWT documentation... Another thing which came to my mind - as people are using this app on mac os x and linux as well, is there a platform independant solution, which will inform the user that the process has finished but without bringing the window to the top? Any ideas are highly welcome! Edit: I found out that on windows the user can adjust whether he would like to enable a force to foreground or not. If that option is disabled, the task will just blink in the taskbar... Here's a good read on that... If anyone maybe knows about some platform independant way of achieving this kind of behaviour, please share your knowledge with me!

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  • Having Issue with Bounded Wildcards in Generic

    - by Sanjiv
    I am new to Java Generics, and I'm currently experimenting with Generic Coding....final goal is to convert old Non-Generic legacy code to generic one... I have defined two Classes with IS-A i.e. one is sub-class of other. public class Parent { private String name; public Parent(String name) { super(); this.name = name; } } public class Child extends Parent{ private String address; public Child(String name, String address) { super(name); this.address = address; } } Now, I am trying to create a list with bounded Wildcard. and getting Compiler Error. List<? extends Parent> myList = new ArrayList<Child>(); myList.add(new Parent("name")); // compiler-error myList.add(new Child("name", "address")); // compiler-error myList.add(new Child("name", "address")); // compiler-error Bit confused. please help me on whats wrong with this ?

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  • ObjectOutputStream .writeObject

    - by bigbluedragon
    hey i have some problems with this code... This is a JDialogForm in which I have jTextField and button. I want to save data from this Jtextfield when i click button to use it in another window but i don't know why it doesn't work. I always get Exception ek and the message i have put there. private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { String sciezka = jTextField1.getText(); if (sciezka.length() > 0) { Zmienne_pomocnicze zp = new Zmienne_pomocnicze(); zp.setPrzechowaj(sciezka); try { ObjectOutputStream oos = new ObjectOutputStream (new FileOutputStream("danebaza")); oos.writeObject(zp); oos.close(); } catch(Exception ek) { JOptionPane.showMessageDialog(null, "Nie mozna pobrac nazwy_przedmiotu: " + ek); } } this.setVisible(false); } where class Zmienne_pomocnicze looks like this public class Zmienne_pomocnicze { public String n; public void setPrzechowaj (String neew){ n = neew; } public String getPrzechowaj () { return n; } } i guess the problem is with oos.writeObject(zp); but i don't know why.

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  • JUnit test failing - complaining of missing data that was just inserted

    - by Collin Peters
    I have an extremely odd problem in my JUnit tests that I just can't seem to nail down. I have a multi-module java webapp project with a fairly standard structure (DAO's, service clasess, etc...). Within this project I have a 'core' project which contains some abstracted setup code which inserts a test user along with the necessary items for a user (in this case an 'enterprise', so a user must belong to an enterprise and this is enforced at the database level) Fairly simple so far... but here is where the strangeness begins some tests fail to run and throw a database exception where it complains that a user cannot be inserted because an enterprise does not exist. But it just created the enterprise in the preceding line of code! And there was no errors in the insertion of the enterprise. Stranger yet, if this test class is run by itself everything works fine. It is only when the test is run as part of the project that it fails! And the exact same abstracted code was run by 10+ tests before the one that fails! f I have been banging my head against a wall with this for days and haven't really made any progress. I'm not even sure what information to offer up to help diagnose this. Using JUnit 4.4, Spring 2.5.6, iBatis 2.3.0, Postgresql 8.3 Switching to org.springframework.jdbc.datasource.DriverManagerDataSource from org.apache.commons.dbcp.BasicDataSource changed the problem. Using DriverManagerDataSource the tests work for the first time, but now all of a sudden a lot of data isn't rolled back in the database! It leaves everything behind. All with no errors Tests fail when run via Eclipse & Maven Please ask for any info which may help me solve my problem!

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  • Logic for family tree program

    - by david robers
    Hi All, I am creating a family tree program in Java, or at least trying to. I have developed several classes: Person - getters and setter for name gender age etc FamilyMember - extends Person getters and setters for setting arents and children Family - which consists of multiple family members and methods for adding removing members FamilyTree which is the main class for setting relationships. I have two main problems: 1) I need to set the relationships between people. Currently I am doing: FamilyMember A, FamilyMember B B.setMother(A); A.setChild(B); The example above is for setting a mother child relationship. This seems very clunky. Its getting very long winded to implement all relationships. Any ideas on how to implement multiple relationships in a less prodcedural way? 2) I have to be able to display the family tree. How can I do this? Are there any custom classes out there to make life easier? Thanks for your time...

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  • Serializing and deserializing a map with key as string

    - by Grace K
    Hi! I am intending to serialize and deserialize a hashmap whose key is a string. From Josh Bloch's Effective Java, I understand the following. P.222 "For example, consider the case of a harsh table. The physical representation is a sequence of hash buckets containing key-value entries. Which bucket an entry is placed in is a function of the hash code of the key, which is not, in general guaranteed to be the same from JVM implementation to JVM implementation. In fact, it isn't even guranteed to be the same from run to run on the same JVM implementation. Therefore accepting the default serialized form for a hash table would constitute a serious bug. Serializing and deserializing the hash table could yield an object whose invariants were seriously corrupt." My questions are: 1) In general, would overriding the equals and hashcode of the key class of the map resolve this issue and the map can be correctly restored? 2) If my key is a String and the String class is already overriding the hashCode() method, would I still have problem described above. (I am seeing a bug which makes me think this is probably still a problem even though the key is String with overriding hashCode.) 3)Previously, I get around this issue by serializing an array of entries (key, value) and when deserializing I would reconstruct the map. I am wondering if there is a better approach. 4) If the answers to question 1 and 2 are that I still can't be guaranteed. Could someone explain why? If the hashCodes are the same would they go to the same buckets across JVMs? Thanks, Grace

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  • Error creating Google Calendar

    - by Don
    Hi, I'm trying to use the Google Calendar Java API to create a secondary calendar for a Google apps user. The relevant code is: // Initialise the API client CalendarService googleCalendar = new GCalendarService("canimo.ca"); googleCalendar.setUserCredentials("[email protected]", "secret"); // Create the calendar CalendarEntry cal = new CalendarEntry(); cal.title = new PlainTextConstruct(user.email); cal.summary = new PlainTextConstruct("Collection calendar"); cal.timeZone = new TimeZoneProperty("America/Montreal"); cal.hidden = HiddenProperty.FALSE; googleCalendar.insert(CALENDAR_URL, calendar); The call to insert() above results in com.google.gdata.util.ServiceException: Internal Server Error and no calendar is created. If I try and perform the same operation through the Google calendar website, it also fails with the error message: We could not save changes. Please try again in a few minutes. An obvious conclusion is that there's some problem on Google's side, but this has been going on for several days now. Strangely, if I create a new user, everything works fine for a while. I can create calendars via the website, and download them via the API. But as soon as I try and create a new calendar using the API, I get the exception above, and thereafter can't create new calendars using either the website or the API. Thanks, Don

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  • Broken console in Maven project using Netbeans

    - by Maciek Sawicki
    Hi, I have strange problem with my Neatens+Maven installation. This is the shortest code to reproduce the problem: public class App { public static void main( String[] args ) { // Create a scanner to read from keyboard Scanner scanner = new Scanner (System.in); Scanner s= new Scanner(System.in); String param= s.next(); System.out.println(param); } } When I'm running it as Maven Project inside Netbeans console seems to be broken. It just ignores my input. It's look like infinitive loop in System.out.println(param);. However this project works fine when it's compiled as "Java Aplication" project. It also works O.K. if I build and run it from cmd. System info: Os: Vista IDE: Netbeans 6.8 Maven: apache-maven-2.2.1 //edit Built program (using mavean from Netbeans) works fine. I just can't test it using Net beans. And I think I forgot to ask the question ;). So of course my first question is: how can I fix this problem? And second is: Is it any workaround for this? For example configuring Netbeans to run external commend line app instead of using built in console.

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  • JDBC transaction dead-lock solution required?

    - by user49767
    It's a scenario described my friend and challenged to find solution. He is using Oracle database and JDBC connection with read committed as transaction isolation level. In one of the transaction, he updates a record and executes selects statement and commits the transaction. when everything happening within single thread, things are fine. But when multiple requests are handled, dead-lock happens. Thread-A updates a record. Thread B updates another record. Thread-A issues select statement and waits for Thread-B's transaction to complete the commit operation. Thread-B issues select statement and waits for Thread-A's transaction to complete the commit operation. Now above causes dead-lock. Since they use command pattern, the base framework allows to issue commit only once (at the end of all the db operation), so they are unable to issue commit immediately after select statement. My argument was Thread-A supposed to select all the records which are committed and hence should not be issue. But he said that Thread-A will surely wait till Thread-B commits the record. is that true? What are all the ways, to avoid the above issue? is it possible to change isolation-level? (without changing underlying java framework) Little information about base framework, it is something similar to Struts action, their each and every request handled by one action, transaction begins before execution and commits after execution.

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  • Problem in inferring instances that have integer cardinality constraint

    - by Mikae Combarado
    Hello, I have created an RDF/OWL file using Protege 4.1 alpha. I also created a defined class in Protege called CheapPhone. This class has a restriction which is shown below : (hasPrice some integer[< 350]) Whenever, a price of a phone is below 350, it is inferred as CheapPhone. There is no problem for inferring this in Protege 4.1 alpha. However, I cannot infer this using Jena. I also created a defined class called SmartPhone. This class also has a restriction which is shown below : (has3G value true) and (hasInternet value true) Whenever, a phone has 3G and Internet, it is inferred as SmartPhone. In this situation, there is no problem inferring this in both Protege and Jena. I have started to think that there is a problem in default inference engine of Jena. The code that I use in Java is below : Reasoner reasoner = ReasonerRegistry.getOWLReasoner(); reasoner = reasoner.bindSchema(ontModel); OntModelSpec ontModelSpec = OntModelSpec.OWL_MEM_MINI_RULE_INF; ontModelSpec.setReasoner(reasoner); // Create ontology model with reasoner support // ontModel was created and read before, so I don't share the code in order // not to create garbage here OntModel model = ModelFactory.createOntologyModel(ontModelSpec, ontModel); OntClass sPhone = model.getOntClass(ns + "SmartPhone"); ExtendedIterator s = sPhone.listInstances(); while(s.hasNext()) { OntResource mp = (OntResource)s.next(); System.out.println(mp.getURI()); } This code works perfectly and returns me the instances, but when I change the code below and make it appropriate for CheapPhone, it doesn't return anything. OntClass sPhone = model.getOntClass(ns + "CheapPhone"); Am I doing something wrong ?

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  • Unable to persist objects in GAE JDO

    - by Basil Dsouza
    Hello Guys, I am completely fresh to both JDO and GAE, and have been struggling to get my data layer to persist any code at all! The issues I am facing may be very simple, but I just cant seem to find any a way no matter what solution I try. Firstly the problem: (Slightly simplified, but still contains all the info necessary) My data model is as such: User: (primary key) String emailID String firstName Car: (primary key) User user (primary key) String registration String model This was the initial datamodel. I implemented a CarPK object to get a composite primary key of the User and the registration. However that ran into a variety of issues. (Which i will save for another time/question) I then changed the design as such: User: (Unchanged) Car: (primary key) String fauxPK (here fauxPK = user.getEmailID() + SEP + registration) User user String registration String model This works fine for the user, and it can insert and retrieve user objects. However when i try to insert a Car Object, i get the following error: "Cannot have a java.lang.String primary key and be a child object" Found the following helpful link about it: http://stackoverflow.com/questions/2063467/persist-list-of-objects Went to the link suggested there, that explains how to create Keys, however they keep talking about "Entity Groups" and "Entity Group Parents". But I cant seem to find any articles or sites that explain what are "Entity Group"s or an "Entity Group Parents" I could try fiddling around some more to figure out if i can store an object somehow, But I am running sort on patience and also would rather understand and implement than vice versa. So i would appreciate any docs (even if its huge) that covers all these points, and preferably has some examples that go beyond the very basic data modeling. And thanks for reading such a long post :)

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  • Why SetMinimumSize sets the minimal heights but not width?

    - by Roman
    Here is my code: import javax.swing.*; import java.awt.*; public class PanelModel { public static void main(String[] args) { JFrame frame = new JFrame("Colored Trails"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JPanel mainPanel = new JPanel(); mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS)); JPanel firstPanel = new JPanel(); firstPanel.setLayout(new GridLayout(4, 4)); firstPanel.setMaximumSize(new Dimension(4*100, 4*100)); firstPanel.setMinimumSize(new Dimension(4*100, 4*100)); JButton btn; for (int i=1; i<=4; i++) { for (int j=1; j<=4; j++) { btn = new JButton(); btn.setPreferredSize(new Dimension(100, 100)); firstPanel.add(btn); } } mainPanel.add(firstPanel); frame.add(mainPanel); frame.setSize(520,600); //frame.setMinimumSize(new Dimension(520,600)); frame.setVisible(true); } } When I increase the size of the window (by mouse) I see that my panel does not increase its size. It is the expected behavior (because I set the maximal size of the panel). However, when I decrease the size of the window, I see that width of the panel is decreased too (while the height is constant). So, the setMinimumSize works only partially. Why is that?

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  • Third party multipart request in playframework

    - by Brian
    I'm making an application to post photos to yfrog and twitpic and I am having a little trouble figuring out how to set the parameters. Here is my code: public static Result index() { HttpClient httpclient = new DefaultHttpClient(); WSRequestHolder holder = WS.url("http://api.twitpic.com/2/upload.json"); holder.setHeader("Authorization", ""); return async(holder.post("").map(new Function<WS.Response, Result>() { public Result apply(WS.Response response) { return ok(response.getBody()); } })); } Now, I don't expect this to actually get an ok response from the server, as I am just testing the responses that I get back from the server, and that is one that says I need to provide the api key. I figured as much, but I'm not sure of the syntax for providing that parameter, as I need to also give the name of the file and the file. I tried setting holder.post("key=somekey"), with the hope that I would get a different error message (like the key you provided is invalid) but I just get the same error. I'm assuming that I probably need to send it in the for of a multipart request, but I am not very experienced with this kind of request and can't find any play documentation on how to create a multipart request, other than in an html form. Any suggestions and help will be much appreciated. And fyi, I do know that there are yfrog and twitpic java classes to handle this kind of stuff, but I want to do it myself, more so for learning how to do this kind of stuff. Thanks in advance!

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  • why the main method are not covered? urgent, please help me

    - by Mike.Huang
    main method: public static void main(String[] args) throws Exception { if (args.length != EXPECTED_NUMBER_OF_ARGUMENTS) { System.err.println("Usage - java XFRCompiler ConfigXML PackageXML XFR"); } String configXML = args[0]; String packageXML = args[1]; String xfr = args[2]; AutoConfigCompiler compiler = new AutoConfigCompiler(); compiler.setConfigDocument(loadDocument(configXML)); compiler.setPackageInfoDoc(loadDocument(packageXML)); // compiler.setVisiblityDoc(loadDocument("VisibilityFilter.xml")); compiler.compileModel(xfr); } private static Document loadDocument(String fileName) throws Exception { TXDOMParser parser = (TXDOMParser) ParserFactory.makeParser(TXDOMParser.class.getName()); InputSource source = new InputSource(new FileInputStream(fileName)); parser.parse(source); return parser.getDocument(); } testcase: @Test public void testCompileModel() throws Exception { // construct parameters URL configFile = Thread.currentThread().getContextClassLoader().getResource("Ford_2008_Mustang_Config.xml"); URL packageFile = Thread.currentThread().getContextClassLoader().getResource("Ford_2008_Mustang_Package.xml"); File tmpFile = new File("Ford_2008_Mustang_tmp.xfr"); if(!tmpFile.exists()) { tmpFile.createNewFile(); } String[] args = new String[]{configFile.getPath(),packageFile.getPath(),tmpFile.getPath()}; try { // test main method XFRCompiler.main(args); } catch (Exception e) { assertTrue(true); } try { // test args length is less than 3 XFRCompiler.main(new String[]{"",""}); } catch (Exception e) { assertTrue(true); } tmpFile.delete(); } coverage outputs displayed as the lines from “String configXML = args[0];" in main method are not covered

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  • Unable to create a breakpoint in Eclipse and Tomcat

    - by Traroth
    Since yesterday, I get a strange error message when I start my Tomcat (6.0.35) under Eclipse Juno (build 20120614-1722): Among the things I tried in order to get rid of the error: Check in Preferences - Java - Compiler if all "Classfile Generation" checkboxes where checked. I did that for both general preferences and project preference Uncheck them, build, check them build again (found on another question) Add org.eclipse.jdt.core.compiler.debug.lineNumber=generate to my .settings/org.eclipse.jdt.core.prefs file Use a new CVS checkout (same symptoms) And now, I don't know what to do anymore. The problem is really stopping me from get anything done. I can't work anymore. Crazy is: the problem doesn't happen on every class, only on some of them. Neither does it happen on my other Eclipse projects. And it didn't happen before yesterday, even if I can't remeber having done anything weird. Actually, I have never seen a problem like this in almost 10 years I'm using Eclipse... If you have any idea, I would be really grateful... Edit: I also tried to ignore the message and go on with my tests: If I create another breakpoint upstream from my problematic class, when I enter this problematic class, it tries to open a $Proxy132 class, which means it actually opens an empty page, with a source not found message

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  • Using maven to distribute a swing application that can have each dependency individually tracked

    - by tms
    I'm moving my project to Maven and eventually OSGi. I currently distribute the project is a large Zip file with all the dependencies. Although my projects code is only 20% of the total package I have to redistribute all the dependency. With smaller independent modules this may be even less. Looking here on stack overflow it seems that to keep my current plan the maven-assembly-plugin should do the trick. I was considering having a base installer that would look at a XML manifest, then collect all the libraries that needed to be updated. This would mean that libraries that change occasionally would be downloaded less often. This also makes since for something like OSGi plugins (which could have independent release schedules). In essence I want my software to look and manage individual libraries, and download on demand (based on the manifest). I was wondering if there is a "maven way" of generating this Manifest and publishing all the libraries to a website? I believe the deploy life-cycle would do the second step. As an alternative, is there a OpenSource Java library that does this type of deployment? I don't want to embed Maven or something larger with the distributed code. The application is not for coders, the simpler the better, and the smaller the installer the better.

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  • Need help implementing this algorithm with map Hadoop MapReduce

    - by Julia
    Hi all! i have algorithm that will go through a large data set read some text files and search for specific terms in those lines. I have it implemented in Java, but I didnt want to post code so that it doesnt look i am searching for someone to implement it for me, but it is true i really need a lot of help!!! This was not planned for my project, but data set turned out to be huge, so teacher told me I have to do it like this. EDIT(i did not clarified i previos version)The data set I have is on a Hadoop cluster, and I should make its MapReduce implementation I was reading about MapReduce and thaught that i first do the standard implementation and then it will be more/less easier to do it with mapreduce. But didnt happen, since algorithm is quite stupid and nothing special, and map reduce...i cant wrap my mind around it. So here is shortly pseudo code of my algorithm LIST termList (there is method that creates this list from lucene index) FOLDER topFolder INPUT topFolder IF it is folder and not empty list files (there are 30 sub folders inside) FOR EACH sub folder GET file "CheckedFile.txt" analyze(CheckedFile) ENDFOR END IF Method ANALYZE(CheckedFile) read CheckedFile WHILE CheckedFile has next line GET line FOR(loops through termList) GET third word from line IF third word = term from list append whole line to string buffer ENDIF ENDFOR END WHILE OUTPUT string buffer to file Also, as you can see, each time when "analyze" is called, new file has to be created, i understood that map reduce is difficult to write to many outputs??? I understand mapreduce intuition, and my example seems perfectly suited for mapreduce, but when it comes to do this, obviously I do not know enough and i am STUCK! Please please help.

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  • Remotely connecting two non-local computers with sockets

    - by Velizar Hristov
    This question seems like something very obvious to ask, and yet I spent more than an hour trying to find an answer. First I host and wait for someone to connect. Then, from another instance of the application, I try to connect with a socket - for the constructor, I use InetAddress, port. The port is always right, and everything works if I use "localhost" for the address. However, if I type my IP, I get an IOException. I even sent the application to someone else, gave him my IP, and it didn't work. The aim of the application is to connect two computers. It's in Java. Here is the relevant code. Server: ServerSocket serverSocket = new ServerSocket(port); Socket clientSocket = serverSocket.accept(); Client: InetAddress a = InetAddress.getByName(ip); Socket s = new Socket(a, port); I don't get past that. Obviously, the values of int port and String ip are taken from text fields. Edit: the purpose of my application is to connect two non-local computers.

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  • How to Connect to a web service (SSL enabled and proxy interface)

    - by blgnklc
    There is a web service running on tomcat on a server. It is built on Java Servlet. It is listening others to call itself on a SSL enabled http port. so its web service adreess looks like: https://172.29.12.12/axis/services/XYZClient?wsdl On the other hand I want to connect the web service above from a windows application which is built on .NET frame work. Finally, when I want to connect the web service from my computer; I get some specific erros; Firstly I get; Proxy authentication error; then I added some new line to my code; Dim cr As System.Net.NetworkCredential = New System.Net.NetworkCredential("xname", "xsurname", "xdomainname") Dim myProxy As New WebProxy("http://mar.xxxyyy.com", True) myProxy.Credentials = cr Secondly, after this modifications It says that bad request. I did not get over this error. Moreover I did try to connect the web server on the same computer. I copied my executable program to the computer where the web service runs. The error was like; The underlying connection was closed: Could not establish trust relationship for SSL/TLS secure channel PS: When I try to connect to web service by using Internet Explorer; I see firstly some warnings about accepting an unknown certificate and I click take me to web service an I get there clearly. I want to know what are the basic elements to connect a web service, could you please tell me the requirements that I have to use on my windows project. regards bk

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  • C# to Java: What is a [DefaultProperty("value")]?

    - by Shiftbit
    I do not understand how the DefaultProperty Metadata tag work or what it signifies. I've read the MSDN and went through the sample but I find it confusing. DefaultPropertyAttribute Class I've read a few blogs and they seem to refer to the indexers. I'm not sure why you would want metadata for your properties? I am coming from a Java background, perhaps a Java analogy would help. [DefaultProperty("Value")] public abstract class FOO<T> : ANY, IBAR<T> { public FOO() { } public FOO(T value) { this.Value = value; } public virtual T Value { get; set; } } Follow up: Property Grid

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  • SCJP Book, IO section: Is this a typo or is there a reason it would look like this?

    - by iamchuckb
    My question is about line 4, where the new PrintWriter is created with the constructor taking the FileWriter fw as a parameter. I don't understand the use of chaining the BufferedWriter bw to FileWriter if it isn't used later on in the actual writing. Can Java apply chaining in a way that bw still somehow affects the rest of the program? 16. try { 17. FileWriter fw = new FileWriter(test); 18. BufferedWriter bw = new BufferedWriter(fw, 1024); 19. PrintWriter out = new PrintWriter(fw); 20. out.println("<html><body><h1>"); 21. out.println(args[0]); 22. out.println("</h1></body></html>"); 23. out.close(); 24. bw.close(); 25. fw.close(); 26. }catch(IOException e) { 27. e.printStackTrace(); 28. } I think it is probably a typo and they meant to use bw as the parameter for PrintWriter out but like the title says, I'm new to this. Thanks to all in advance.

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  • Set size of JTable in JScrollPane and in JPanel with the size of the JFrame

    - by user1761818
    I want the table with the same width as the frame and also when I resize the frame the table need to be resized too. I think setSize() of JTable doesn't work correctly. Can you help me? import java.awt.Color; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.SwingUtilities; public class Main extends JFrame { public Main() { setSize(400, 600); String[] columnNames = {"A", "B", "C"}; Object[][] data = { {"Moni", "adsad", 2}, {"Jhon", "ewrewr", 4}, {"Max", "zxczxc", 6} }; JTable table = new JTable(data, columnNames); JScrollPane tableSP = new JScrollPane(table); int A = this.getWidth(); int B = this.getHeight(); table.setSize(A, B); JPanel tablePanel = new JPanel(); tablePanel.add(tableSP); tablePanel.setBackground(Color.red); add(tablePanel); setTitle("Marks"); setLocationRelativeTo(null); setDefaultCloseOperation(EXIT_ON_CLOSE); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { Main ex = new Main(); ex.setVisible(true); } }); } }

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  • How to organize and manage multiple database credentials in application?

    - by Polaris878
    Okay, so I'm designing a stand-alone web service (using RestLET as my framework). My application is divided in to 3 layers: Data Layer (just above the database, provides APIs for connecting to/querying database, and a database object) Object layer (responsible for serialization from the data layer... provides objects which the client layer can use without worrying about database) Client layer (This layer is the RestLET web service... basically just creates objects from the object layer and fulfills webservice request) Now, for each object I create in the object layer, I want to use different credentials (so I can sandbox each object...). The object layer should not know the exact credentials (IE the login/pw/DB URL etc). What would be the best way to manage this? I'm thinking that I should have a super class Database object in my data layer... and each subclass will contain the required log-in information... this way my object layer can just go Database db = new SubDatabase(); and then continue using that database. On the client level, they would just be able to go ItemCollection items = new ItemCollection(); and have no idea/control over the database that gets connected. I'm asking this because I am trying to make my platform extensible, so that others can easily create services off of my platform. If anyone has any experience with these architectural problems or how to manage this sort of thing I'd appreciate any insight or advice... Feel free to ask questions if this is confusing. Thanks! My platform is Java, the REST framework I'm using is RestLET, my database is MySQL.

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