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• Correct use of WSDL-generated sources

  - by John K

  How can I easily convert between manually written classes and WSDL-generated equivalents? I have a Java SE 6 thick client that calls a web service to get and store data. The client has a DAO that works with my entity classes, calls <Entity.toDto() to convert them to DTOs, and sends/receives that data with the web service. My issue stems from the fact that the entity classes live on both sides of the service interface: client and server. Each entity has a constructor from the DTO and a toDto function: public class EntityClass { public EntityClass(EntityClassDto dto); public EntityClassDto toDto(); ... } This means I have a handwritten DTO class that the client and server both use. However, the service interface expects the WSDL-generated classes. I have tried writing conversion code between the hand-written DTO and the WSDL-generated DTO and it is tedious and error-prone. What is a reasonable alternative to this? Some back-story: The thick client should be able to have a configurable backend: either direct to the DB or through this web service. The aforementioned DAO is the web service based implementation and another imlpementation that is JPA-based exists.

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• Android HttpPost: how to get the result

  - by Sumit M Asok

  I have been trying long to send an HttpPost request and retrieve response but even though I was able to make a connection I don't yet get how to get the string message which is returned by the request-response HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost("http://www.myurl.com/app/page.php"); // Add your data List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(5); nameValuePairs.add(new BasicNameValuePair("type", "20")); nameValuePairs.add(new BasicNameValuePair("mob", "919895865899")); nameValuePairs.add(new BasicNameValuePair("pack", "0")); nameValuePairs.add(new BasicNameValuePair("exchk", "1")); try { httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); Log.d("myapp", "works till here. 2"); try { HttpResponse response = httpclient.execute(httppost); Log.d("myapp", "response " + response.getEntity()); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } catch (UnsupportedEncodingException e) { e.printStackTrace(); } I'm sorry, I sound very naive because I'm new to java. Please help me.

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• How to generate comments in hbm2java created POJO?

  - by jschoen

  My current setup using hibernate uses the hibernate.reveng.xml file to generate the various hbm.xml files. Which are then turned into POJOs using hbm2java. We spent some time while designing our schema, to place some pretty decent descriptions on the Tables and there columns. I am able to pull these descriptions into the hbm.xml files when generating them using hbm2jhbmxml. So I get something similar to this: <class name="test.Person" table="PERSONS"> <comment>The comment about the PERSONS table.</comment> <property name="firstName" type="string"> <column name="FIRST_NAME" length="100" not-null="true"> <comment>The first name of this person.</comment> </column> </property> <property name="middleInitial" type="string"> <column name="MIDDLE_INITIAL" length="1"> <comment>The middle initial of this person.</comment> </column> </property> <property name="lastName" type="string"> <column name="LAST_NAME" length="100"> <comment>The last name of this person.</comment> </column> </property> </class> So how do I tell hbm2java to pull and place these comments in the created Java files? I have read over this about editing the freemarker templates to change the way code is generated. I under stand the concept, but it was not to detailed about what else you could do with it beyond there example of pre and post conditions.

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• JAXB boolean handling oddities and JSF

  - by finrod

  There is a known bug in JAXB: https://jaxb.dev.java.net/issues/show_bug.cgi?id=733 JAXB does not properly generate boolean field getters and setters, this bug is left unfixed for backwards compatibility. A JAXB plugin exists and will ensure that the following getters and setters for boolean fields are generated: setXXX(Boolean value) is generated getXXX() is generated If the boolean attribute specifies default value in the XSD, then getXXX() returns boolean, If the boolean attribute does not specify default in the XSD, then getXXX() returns Boolean. Problem: trying to edit/view the XXX field in a JSF component (such as checkbox) does not work - the component is disabled. I have not traced this in depth but the assumption (backed by the workaround below) is that JSF EL resolver (or whathaveyou) looks for Boolean getXXX() method and since it does not find it, the component is disabled. Workaround: If I change the getXXX() method to always return Boolean, then everything goes. Questions: What are your ideas to address this problem? Have I missed some customization for the boolean-getter JAXB plugin? Is it possible (does it make sense) to alter JSF resolver (or whathaveyou) so that if Boolean getXXX() is not found, it will fall back to boolean getXXX()? I would prefer not to manually intervene and change all the generated getXXX() methods to return Boolean instead of boolean.

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• Disadvantage of OOP?

  - by Bragaadeesh

  Typically i dont want to know the specifics of the cons of OOPs, but it felt kind of weird when I had an argument at an interview I attended recently. The question that was posted to me was to tell me one disadvantage of OOP (Object Oriented Programming). At that time, I felt OOP to be the most matured level of programming after the procedural/functional models. So I replied to him that I dont see any negatives at all. But the interviewer said there are few and I asked him to list one if he does not mind. He gave an example that I cant digest well, he said that OOP pattern does not strictly implement inheritance rules and cited the satellite/rocket example where the body parts will disintegrate periodically to remove weight during rocket launch and said that inheritance does not support this. His example kind of felt very weird to me the reason being the application of inheritance to this example. Then I left the example aside and I had this doubt - Can we unplug class hierarchies in such a manner (I am kind of confident in Java its not possible) in an ideal Object Oriented Design?

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• Make JAXWS-based webservice implement interface and unmarshall to known POJOs

  - by John K

  Given a Java SE 6 client, I would like to provide a configurable back-end: either directly to a database or through a web service which connects to a centralized DB. To that end, I've created some JPA- and JAXB-annotated entity classes and a DAO interface in a POJO library like the following: public interface MyDaoInterface { public MyEntity doSomething(); } @javax.persistence.Entity @javax.xml.bind.annotation.XmlRootElement public class MyEntity { private int a; .... } Now, I would like to have my auto-generated web service stubs implement that interface and interact with my defined entity classes, rather than the generated classes provided via the JAX-B unmarshaller. So, the client-side pseudo code would be something like MyDaoInterface dao; if (usingWebservice) dao = new WebserviceDao(); else dao = new JpaDao(); MyEntity e = dao.doSomething(); Is this possible with JPA, JAXB, JAXWS? Is this even advisable? Currently we achieve this through a slow manual process of massaging code, copying generating classes, and doing other things that seem just plain wrong to me.

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• Help matching fields between two classes

  - by Michael

  I'm not too experienced with Java yet, and I'm hoping someone can steer me in the right direction because right now I feel like I'm just beating my head against a wall... The first class is called MeasuredParams, and it's got 40+ numeric fields (height, weight, waistSize, wristSize - some int, but mostly double). The second class is a statistical classifier called Classifier. It's been trained on a subset of the MeasuredParams fields. The names of the fields that the Classifier has been trained on is stored, in order, in an array called reqdFields. What I need to do is load a new array, toClassify, with the values stored in the fields from MeasuredParams that match the field list (including order) found in reqdFields. I can make any changes necessary to the MeasuredParams class, but I'm stuck with Classifier as it is. My brute-force approach was to get rid of the fields in MeasuredParams and use an arrayList instead, and store the field names in an Enum object to act as an index pointer. Then loop through the reqdFields list, one element at a time, and find the matching name in the Enum object to find the correct position in the arrayList. Load the value stored at that positon into toClassify, and then continue on to the next element in reqdFields. I'm not sure how exactly I would search through the Enum object - it would be a lot easier if the field names were stored in a second arrayList. But then the index positions between the two would have to stay matched, and I'm back to using an Enum. I think. I've been running around in circles all afternoon, and I keep thinking there must be an easier way of doing it. I'm just stuck right now and can't see past what I've started. Any help would be GREATLY appreciated. Thanks so much! Michael

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• Graph colouring algorithm: typical scheduling problem

  - by newba

  Hi, I'm training code problems like UvA and I have this one in which I have to, given a set of n exams and k students enrolled in the exams, find whether it is possible to schedule all exams in two time slots. Input Several test cases. Each one starts with a line containing 1 < n < 200 of different examinations to be scheduled. The 2nd line has the number of cases k in which there exist at least 1 student enrolled in 2 examinations. Then, k lines will follow, each containing 2 numbers that specify the pair of examinations for each case above. (An input with n = 0 will means end of the input and is not to be processed). Output: You have to decide whether the examination plan is possible or not for 2 time slots. Example: Input: 3 3 0 1 1 2 2 0 9 8 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 Ouput: NOT POSSIBLE. POSSIBLE. I think the general approach is graph colouring, but I'm really a newb and I may confess that I had some trouble understanding the problem. Anyway, I'm trying to do it and then submit it. Could someone please help me doing some code for this problem? I will have to handle and understand this algo now in order to use it later, over and over. I prefer C or C++, but if you want, Java is fine to me ;) Thanks in advance

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• XMLBeans - xsi:type stripped using Axis2 and Tomcat?

  - by Matthew Gamble

  I’m new to XMLBeans and have been trying to use it to create an XML document as part of an axis2 web service. When I run my code as a standard Java application or as a standard servlet, the XML is correctly generated: <?xml version="1.0" encoding="UTF-8"?> <c:BroadsoftDocument protocol="OCI" xmlns:c="C"> <sessionId>000000001</sessionId> <command xsi:type="AuthenticationRequest" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <userId>admin</userId></command> </c:BroadsoftDocument> However, when the exact same code is run under Axis2 & Tomcat in a servlet I get: <?xml version="1.0" encoding="UTF-8"?> <c:BroadsoftDocument protocol="OCI" xmlns:c="C"> <sessionId>000000001</sessionId> <command> <userId>admin</userId></command> </c:BroadsoftDocument> This of course isn’t valid – the xsi:type of the “command” element is stripped when the code is run under Tomcat. Does anyone have any suggestions of what I could be doing wrong that would cause this type of issue only when running under Axis2? At first I thought it was a Tomcat issue, but after creating a generic servlet and running the exact same code I don't have any issues. I've tried playing with the XMLOptions for XMLBeans, but couldn't seem to resolve the problem. The options I'm currently using are: xmlOptions = new XmlOptions(); xmlOptions.setCharacterEncoding("UTF-8"); xmlOptions.setUseDefaultNamespace(); xmlOptions.setSaveAggressiveNamespaces(); xmlOptions.setSavePrettyPrint();

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• How to limit speed with BMW JSDK on 116i?

  - by lexicore

  I'm experimenting with the BMW Java SDK on the new BMW 116i Innovation Package. Basic things like turning the lights on and off, starting and stopping the motor work fine. What I'm trying to do now is that to write a carlet which would limit the speed to the maximum configured in the driver profile. Driver identity will be detected as usual via RFID reader. My problem is that though I can read the speed from the tachometer, I can't really limit the speed. Here's what I've got working so far: public class SpeenControllingCarlet extends GenericCarlet { public void start(final VehicleModel model) throws CarletException { RfidReader rfidReader = (RfidReader) model .getDevice(Devices.DRIVER_RFID_READER); Rfid rfid = rfidReader.getRfid(); DriverProfile driverProfile = model.getDriverProfileRegistry() .getDriverProfile(rfid.toString()); if (driverProfile == null) { return; } final Double maxAllowedSpeed = Double.valueOf(driverProfile .getCustomAttribute("maxAllowedSpeed", "190")); Tachometer tachometer = (Tachometer) mode.getDevice(Devices.TACHOMETER); tachometer.addSpeedListener(new SpeedListener() { public void onSpeedChanged(SpeedChangedEvent speedChangedEvent) { if (speedChangedEvent.getCurrentSpeed() > maxAllowedSpeed) { Horn horn = (Horn) mode.getDevice(Devices.HORN); horn.beep(440, 2000); } } }); } } This will just beep for two seconds if the driver goes faster than the driver profile allows. My question is - is there a possibility to actually limit the speed (not just silly beeping)?

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• Proof of library bug vs developer side application bug

  - by Paralife

  I have a problem with a specific java client library. I wont say here the problem or the name of the library because my question is a different one. Here is the situation: I have made a program that uses the library. The program is a class named 'WorkerThread' that extends Thread. To start it I have made a Main class that only contains a main() function that starts the thread and nothing else. The worker uses the library to perform comm with a server and get results. The problem appears when I want to run 2 WorkerThreads simultaneously. What I first did was to do this in the Main class: public class Main { public static void main(String args[]) { new WorkerThread().start(); // 1st thread. new WorkerThread().start(); // 2nd thread. } } When I run this, both threads produce irrational results and what is more , some results that should be received by 1st thread are received by the 2nd instead. If instead of the above, I just run 2 separate processes of one thread each, then everything works fine. Also: 1.There is no static class or method used inside WorkerThread that could cause the problem. My application consists of only the worker thread class and contains no static fields or methods 2.The library is supposed to be usable in a multithreaded environment. In my thread I just create a new instance of a library's class and then call methods on it. Nothing more. My question is this: Without knowing any details of my implementation, is the above situation and facts enough to prove that there is a bug in the library and not in my programm? Is it safe to assume that the library inside uses a static method or object that is indirectly shared by my 2 threads and this causes the problem? If no then in what hypothetical situation could the bug originate in the worker class code?

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• JFreeChart - change SeriesStroke of chart lines from solid to dashed in one line

  - by MisterMichaelK

  The answer accepted here (JFreechart(Java) - How to draw lines that is partially dashed lines and partially solid lines?) helped me start down the path of changing my seriesstroke lines on my chart. After stepping through my code and watching the changes, I see that my seriesstroke does in fact change to "dashedStroke" when it is supposed to (after a certain date "dai"), but when the chart is rendered the entire series line is dashed. How can I get a series line to be drawn solid at first and dashed after a set date? /* series line modifications */ final Number dashedAfter = timeNowDate.getTime(); final int dai = Integer.parseInt(ndf.format(timeNowDate)); XYLineAndShapeRenderer render = new XYLineAndShapeRenderer() { Stroke regularStroke = new BasicStroke(); Stroke dashedStroke = new BasicStroke( 1.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND, 1.0f, new float[] {10.0f, 6.0f}, 0.0f ); @Override public Stroke getItemStroke(int row, int column) { Number xVal = cd.getXValue(row, column); int xiv = xVal.intValue(); if (xVal.doubleValue() > dashedAfter.doubleValue()) { return dashedStroke; } else { return regularStroke; } } }; plot.setRenderer(render);

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• Parse Pdf File and write content in word file using java

  - by kedar kamthe

  how to Parse a PDF file and write the content in word file using Java?

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• How to convert an InputStream to a DataHandler?

  - by pcorey

  I'm working on a java web application in which files will be stored in a database. Originally we retrieved files already in the DB by simply calling getBytes on our result set: byte[] bytes = resultSet.getBytes(1); ... This byte array was then converted into a DataHandler using the obvious constructor: dataHandler=new DataHandler(bytes,"application/octet-stream"); This worked great until we started trying to store and retrieve larger files. Dumping the entire file contents into a byte array and then building a DataHandler out of that simply requires too much memory. My immediate idea is to retrieve a stream of the data in the database with getBinaryStream and somehow convert that InputStream into a DataHandler in a memory-efficient way. Unfortunately it doesn't seem like there's a direct way to convert an InputStream into a DataHandler. Another idea I've been playing with is reading chunks of data from the InputStream and writing them to the OutputStream of the DataHandler. But... I can't find a way to create an "empty" DataHandler that returns a non-null OutputStream when I call getOutputStream... Has anyone done this? I'd appreciate any help you can give me or leads in the right direction.

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• Difference in performance between Stax and DOM parsing

  - by Fazal

  I have been using DOM for a long time and as such DOM parsing performance wise has been pretty good. Even when dealing with XML of about 4-7 MB the parsing has been fast. The issue we face with DOM is the memory footprint which become huge as soon as we start dealing with large XMLs. Lately I tried moving to Stax (Streaming parsers for XML) which are supposed top be second generation parsers (reading about Stax it said its the fastest parser now). When I tried stax parser for large XML for about 4MB memory footprint definitely reduced drastically but time take to parse entire XML and create java object out of it increased almost by 5 times over DOM. I used sjsxp.jar implementation of Stax. I can deuce to some extent logically that performance may not be extremely good due to streaming nature of the parser but a reduction of 5 time (e.g. DOM takes about 8 seconds to build object for this XML, whereas Stax parsing took about 40 seconds on average) is definitely not going to be acceptable. Am I missing some point here completely as I am not able to come to terms with these performance numbers

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• How do I check if output stream of a socket is closed?

  - by Roman

  I have this code: public void post(String message) { output.close(); final String mess = message; (new Thread() { public void run() { while (true) { try { output.println(mess); System.out.println("The following message was successfully sent:"); System.out.println(mess); break; } catch (NullPointerException e) { try {Thread.sleep(1000);} catch (InterruptedException ie) {} } } } }).start(); } As you can see I close the socket in the very beginning of the code and then try to use it to send some information to another computer. The program writes me "The following message was successfully sent". It means that the NullPointerException was not thrown. So, does Java throw no exception if it tries to use a closed output stream of a socket? Is there a way to check if a socket is closed or opened? ADDED I initialize the socket in the following way: clientSideSocket = new Socket(hostname,port); PrintWriter out = new PrintWriter(clientSideSocket.getOutputStream(), true); browser.output = out;

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• Running custom JAXB2 plugins using Maven JAXB 2.x Plugin

  - by nadouani

  I would like to generate JAXB Java classes using the Maven JAXB 2.x plugin http://static.highsource.org/mjiip/maven-jaxb2-plugin/generate-mojo.html To declare the custom JAXB plugins I would execute during the generate process, I used the "args" element like below: <plugin> <groupId>org.jvnet.jaxb2.maven2</groupId> <artifactId>maven-jaxb2-plugin</artifactId> <version>0.7.4</version> <executions> <execution> <goals> <goal>generate</goal> </goals> </execution> </executions> <configuration> <extension>true</extension> <args> <arg>-Xinheritance</arg> <arg>-XtoString</arg> </args> ... </configuration> ... </plugin> The issue is that the maven generate process is failing with the following error: Failed to execute goal org.jvnet.jaxb2.maven2:maven-jaxb2-plugin:0.7.4:generate (default) on project was: Error parsing the command line [[Ljava.lang.String;@1ad4a1ae] Any idea on how to specify the args values? Thanks

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• Loading a javascript library in javax.script?

  - by Shane

  I want to run Protovis javascript from Java and get the evaluated SVG code. I am using javax.script.* to run the Javascript: public static void EvalScript() throws Exception { ScriptEngineManager factory = new ScriptEngineManager(); ScriptEngine engine = factory.getEngineByName("JavaScript"); Object result = engine.eval("var vis = new pv.Panel().width(300).height(300) .add (pv.Line).data ([1,0.5, 0.1, 0.01, 0.001, 0.3, 0.2,0.1,1]) .left (function () { return this.index * 30; }) .bottom (function (d) { return d * 250; }); vis.root.render(); vis.scene[0].canvas.innerHTML;"); System.out.println(result); } This would complain because I never loaded Protovis itself, as would ordinarily be done with <script type="text/javascript" src="../protovis-r3.1.0.js"></script> Is there a good way, short of sourcing in the full Javascript into the eval() command, of loading a library when running Javascript through javax.script? (Incidentally, I know of examples that use Rhino to do this from the Google discussion group.)

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• Does GC guarantee that cleared References are enqueued to ReferenceQueue in topological order?

  - by Dimitris Andreou

  Say there are two objects, A and B, and there is a pointer A.x --> B, and we create, say, WeakReferences to both A and B, with an associated ReferenceQueue. Assume that both A and B become unreachable. Intuitively B cannot be considered unreachable before A is. In such a case, do we somehow get a guarantee that the respective references will be enqueued in the intuitive (topological when there are no cycles) order in the ReferenceQueue? I.e. ref(A) before ref(B). I don't know - what if the GC marked a bunch of objects as unreachable, and then enqueued them in no particular order? I was reviewing Finalizer.java of guava, seeing this snippet: private void cleanUp(Reference<?> reference) throws ShutDown { ... if (reference == frqReference) { /* * The client no longer has a reference to the * FinalizableReferenceQueue. We can stop. */ throw new ShutDown(); } frqReference is a PhantomReference to the used ReferenceQueue, so if this is GC'ed, no Finalizable{Weak, Soft, Phantom}References can be alive, since they reference the queue. So they have to be GC'ed before the queue itself can be GC'ed - but still, do we get the guarantee that these references will be enqueued to the ReferenceQueue at the order they get "garbage collected" (as if they get GC'ed one by one)? The code implies that there is some kind of guarantee, otherwise unprocessed references could theoretically remain in the queue. Thanks

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• How do i write this jpql query?

  - by Nitesh Panchal

  Hello, Say i have 5 tables, tblBlogs tblBlogPosts tblBlogPostComment tblUser tblBlogMember BlogId BlogPostsId BlogPostCommentId UserId BlogMemberId BlogTitle BlogId CommentText FirstName UserId PostTitle BlogPostsId BlogId BlogMemberId Now i want to retrieve only those blogs and posts for which blogMember has actually commented. So in short, how do i write this plain old sql :- Select b.BlogTitle, bp.PostTitle, bpc.CommentText from tblBlogs b Inner join tblBlogPosts bp on b.BlogId = bp.BlogId Inner Join tblBlogPostComment bpc on bp.BlogPostsId = bpc.BlogPostsId Inner Join tblBlogMember bm On bpc.BlogMemberId = bm.BlogMemberId Where bm.UserId = 1; As you can see, everything is Inner join, so only that row will be retrieved for which the user has commented on some post of some blog. So, suppose he has joined 3 blogs whose ids are 1,2,3 (The blogs which user has joined are in tblBlogMembers) but the user has only commented in blog 2 (of say BlogPostId = 1). So that row will be retrieved and 1,3 won't as it is Inner Join. How do i write this kind of query in jpql? In jpql, we can only write simple queries like say :- Select bm.blogId from tblBlogMember Where bm.UserId = objUser; Where objUser is supplied using :- em.find(User.class,1); Thus once we get all blogs(Here blogId represents a blog object) which user has joined, we can loop through and do all fancy things. But i don't want to fall in this looping business and write all this things in my java code. Instead, i want to leave that for database engine to do. So, how do i write the above plain sql into jpql? and what type of object the jpql query will return? because i am only selecting few fields from all table. In which class should i typecast the result to? I think i posted my requirement correctly, if i am not clear please let me know. Thanks in advance :).

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• ForeignSecurityPrincipals with LDAP connection on Active Directory servers with trusted forest

  - by Killerwhile

  The context is the following : Two domains mutually trusted dc=dom1 dc=dom2 a group cn=group1,ou=someou,dc=dom1 with users inside : cn=user11,ou=anotherou,dc=dom1 cn=user12,ou=anotherou,dc=dom1 cn=user13,ou=anotherou,dc=dom1 cn=user21,ou=anotherou,dc=dom2 cn=user22,ou=anotherou,dc=dom2 cn=user23,ou=anotherou,dc=dom2 The questions : 1. Test user's credentials How can I do a ldap bind to test credentials for users of dom2 ? I tried to bind as usual but I cannot authenticate users of dom2, even if I connect in ldaps. Is there any trick ? Special permissions to set ? 2. Search and display users from the group. How can I retrieve the detailed informations about the users of dom1 and dom2 using LDAP(s) connection on the AD of dom1 ? I have an technical user which has right to browse both domain. I'm able to see 6 entries in the group with the following filter : (&(memberOf=cn=group1,ou=someou,dc=dom1)(|(objectClass=user)(objectClass=foreignSecurityPrincipal))) but the users from the other domain are seen as cn=...(some key)...,cn=foreignSecurityPrincipal,dc=dom1 Java hints would be better. Thanks a lot !

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• Which knowledge base/rule-based inference engine to choose for real time Runway incursion prevention

  - by Piligrim

  Hello, we are designing a project that would listen to dialog between airport controllers and pilots to prevent runway incursions (eg. one airplane is taking off while other is crossing the runway). Our professor wants us to use Jena for knowledge base (or anything else but it should be some sort of rule-based engine). Inference is not the main thing in Jena and there's not much documentation and examples of this. So we need an engine that would get messages from pilots as input and output possible risks of incursion or any other error in message protocol. It should be easy to write rules, and should be easy to provide engine with real time data. I image it something like this: A pilot sends a message that he lands on some runway, the system remembers that the runway is busy and no one should cross it If someone is given an instruction to cross this runway, the engine should fire a rule that something is wrong When the pilot sends a message that he left the runway and goes to the gate, the system clears the runway and lets other planes to use it. So is Jena, or prolog or any other rules engine suitable for this? I mean it is suitable, but do we really need to use it? I asked the prof. if we could just keep state of the runway and use some simple checks based on messages we receive and he said that it is not scalable and we need the knowledge base. Can someone give me any advise on which approach to use for this system? If you recommend k.b., then which one should we use? The project is written in java. Thank you.

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• Project Euler: Programmatic Optimization for Problem 7?

  - by bmucklow

  So I would call myself a fairly novice programmer as I focused mostly on hardware in my schooling and not a lot of Computer Science courses. So I solved Problem 7 of Project Euler: By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the 10001st prime number? I managed to solve this without problem in Java, but when I ran my solution it took 8 and change seconds to run. I was wondering how this could be optimized from a programming standpoint, not a mathematical standpoint. Is the array looping and while statements the main things eating up processing time? And how could this be optimized? Again not looking for a fancy mathematical equation..there are plenty of those in the solution thread. SPOILER My solution is listed below. public class PrimeNumberList { private ArrayList<BigInteger> primesList = new ArrayList<BigInteger>(); public void fillList(int numberOfPrimes) { primesList.add(new BigInteger("2")); primesList.add(new BigInteger("3")); while (primesList.size() < numberOfPrimes){ getNextPrime(); } } private void getNextPrime() { BigInteger lastPrime = primesList.get(primesList.size()-1); BigInteger currentTestNumber = lastPrime; BigInteger modulusResult; boolean prime = false; while(!prime){ prime = true; currentTestNumber = currentTestNumber.add(new BigInteger("2")); for (BigInteger bi : primesList){ modulusResult = currentTestNumber.mod(bi); if (modulusResult.equals(BigInteger.ZERO)){ prime = false; break; } } if(prime){ primesList.add(currentTestNumber); } } } public BigInteger get(int primeTerm) { return primesList.get(primeTerm - 1); } }

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• web service - client classes

  - by Noona

  The web service that I implemented is up and running, when I try to run the client I get the following error with regard to the classes that were generated using wsimport, Caused by: java.security.PrivilegedActionException: com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 4 counts of IllegalAnnotationExceptions Two classes have the same XML type name "{http://server.agency.hw2/}userJoined". Use @XmlType.name and @XmlType.namespace to assign different names to them. this problem is related to the following location: at hw2.chat.backend.main.generatedfromserver.UserJoined at public javax.xml.bind.JAXBElement hw2.chat.backend.main.generatedfromserver.ObjectFactory.createUserJoined(hw2.chat.backend.main.generatedfromserver.UserJoined) at hw2.chat.backend.main.generatedfromserver.ObjectFactory this problem is related to the following location: at ChatCompany.BackendChatServer.hw2.chat.backend.main.generatedfromserver.UserJoined Two classes have the same XML type name "{http://server.agency.hw2/}userJoinedResponse". Use @XmlType.name and @XmlType.namespace to assign different names to them. this problem is related to the following location: at hw2.chat.backend.main.generatedfromserver.UserJoinedResponse at public javax.xml.bind.JAXBElement hw2.chat.backend.main.generatedfromserver.ObjectFactory.createUserJoinedResponse(hw2.chat.backend.main.generatedfromserver.UserJoinedResponse) But I can't figure out what exactly is meant by the error. I am assuming I need to change something in annotations in this class as pointed out by the compiler: @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "userJoinedResponse") public class UserJoinedResponse { } could someone please point out why there's a name collision and what annotations I need to change? thanks

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• SSL HandShakeException: No_Certificate. Using IBM's J9 JVM and Apache Tomcat

  - by DaveJohnston

  I am developing a mobile application that is to run on a Windows Mobile PDA. The application is written in Java and to run it we are using the J9 JVM from IBM. The application communicates with an Apache Tomcat server over HTTP and we are trying to set it up now to use SSL. I have generated public/private keys for both the client and the server, exported their self signed certificates and imported them into the respective keystores. Initially I tried to just get it working using only server side authentication and that was successful. But I am now trying to get mutual authentication by setting clientAuth="true" in the server.xml file in the apache conf directory. I have enabled the SSL logging on the server and when the client connects the server reports an SSLProtocolException: handshake alert: no_certificate. The client logs also show an exception: javax.net.ssl.SSLHandshakeException: unexpected_message at com.ibm.j9.jsse.SSLSocketImpl.completeHandshake(Unknown Source) at com.ibm.j9.jsse.SSLSocketImpl.startHandshake(Unknown Source) at com.ibm.oti.net.www.protocol.https.HttpsURLConnection.openSocket(Unknown Source) at com.ibm.oti.net.www.protocol.https.HttpsURLConnection.connect(Unknown Source) at com.ibm.oti.net.www.protocol.https.HttpsURLConnection.sendRequest(Unknown Source) at com.ibm.oti.net.www.protocol.https.HttpsURLConnection.doRequest(Unknown Source) at com.ibm.oti.net.www.protocol.https.HttpsURLConnection.getInputStream(Unknown Source) The client keystore and truststore is configured by setting the following System Properties: javax.net.ssl.trustStore javax.net.ssl.trustStorePassword javax.net.ssl.keyStore javax.net.ssl.keyStorePassword Does anyone have any ideas how I can set up client authentication on the J9 JVM?

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