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  • Traceroute comparison and statistics

    - by ben-casey
    I have a number of traceroutes that i need to compare against each other but i dont know the best way to do it, ive been told that hash maps are a good technique but i dont know how to implement them on my code. so far i have: FileInputStream fstream = new FileInputStream("traceroute.log"); // Get the object of DataInputStream DataInputStream in = new DataInputStream(fstream); BufferedReader br = new BufferedReader(new InputStreamReader(in)); String strLine; // reads lines in while ((strLine = br.readLine()) != null) { System.out.println(strLine); } and the output looks like this: Wed Mar 31 01:00:03 BST 2010 traceroute to www.bbc.co.uk (212.58.251.195), 30 hops max, 40 byte packets 1 139.222.0.1 (139.222.0.1) 0.873 ms 1.074 ms 1.162 ms 2 core-from-cmp.uea.ac.uk (10.0.0.1) 0.312 ms 0.350 ms 0.463 ms 3 ueaha1btm-from-uea1 (172.16.0.34) 0.791 ms 0.772 ms 1.238 ms 4 bound-from-ueahatop.uea.ac.uk (193.62.92.71) 5.094 ms 4.451 ms 4.441 ms 5 gi0-3.norw-rbr1.eastnet.ja.net (193.60.0.21) 4.426 ms 5.014 ms 4.389 ms 6 gi3-0-2.chel-rbr1.eastnet.ja.net (193.63.107.114) 6.055 ms 6.039 ms * 7 lond-sbr1.ja.net (146.97.40.45) 6.994 ms 7.493 ms 7.457 ms 8 so-6-0-0.lond-sbr4.ja.net (146.97.33.154) 8.206 ms 8.187 ms 8.234 ms 9 po1.lond-ban4.ja.net (146.97.35.110) 8.673 ms 6.294 ms 7.668 ms 10 bbc.lond-sbr4.ja.net (193.62.157.178) 6.303 ms 8.118 ms 8.107 ms 11 212.58.238.153 (212.58.238.153) 6.245 ms 8.066 ms 6.541 ms 12 212.58.239.62 (212.58.239.62) 7.023 ms 8.419 ms 7.068 ms what i need to do is compare this trace against another one just like it and look for the changes and time differences etc, then print a stats page.

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  • Spring transactions not committing

    - by Clinton Bosch
    I am struggling to get my spring managed transactions to commit, could someone please spot what I have done wrong. All my tables are mysql InnonDB tables. My RemoteServiceServlet (GWT) is as follows: public class TrainTrackServiceImpl extends RemoteServiceServlet implements TrainTrackService { @Autowired private DAO dao; @Override public void init(ServletConfig config) throws ServletException { super.init(config); WebApplicationContext ctx = WebApplicationContextUtils.getRequiredWebApplicationContext(config.getServletContext()); AutowireCapableBeanFactory beanFactory = ctx.getAutowireCapableBeanFactory(); beanFactory.autowireBean(this); } @Transactional(propagation= Propagation.REQUIRED, rollbackFor=Exception.class) public UserDTO createUser(String firstName, String lastName, String idNumber, String cellPhone, String email, int merchantId) { User user = new User(); user.setFirstName(firstName); user.setLastName(lastName); user.setIdNumber(idNumber); user.setCellphone(cellPhone); user.setEmail(email); user.setDateCreated(new Date()); Merchant merchant = (Merchant) dao.find(Merchant.class, merchantId); if (merchant != null) { user.setMerchant(merchant); } // Save the user. dao.saveOrUpdate(user); UserDTO dto = new UserDTO(); dto.id = user.getId(); dto.firstName = user.getFirstName(); dto.lastName = user.getLastName(); return dto; } The DAO is as follows: public class DAO extends HibernateDaoSupport { private String adminUsername; private String adminPassword; private String godUsername; private String godPassword; public String getAdminUsername() { return adminUsername; } public void setAdminUsername(String adminUsername) { this.adminUsername = adminUsername; } public String getAdminPassword() { return adminPassword; } public void setAdminPassword(String adminPassword) { this.adminPassword = adminPassword; } public String getGodUsername() { return godUsername; } public void setGodUsername(String godUsername) { this.godUsername = godUsername; } public String getGodPassword() { return godPassword; } public void setGodPassword(String godPassword) { this.godPassword = godPassword; } public void saveOrUpdate(ModelObject obj) { getHibernateTemplate().saveOrUpdate(obj); } And my applicationContext.xml is as follows: <context:annotation-config/> <context:component-scan base-package="za.co.xxx.traintrack.server"/> <!-- Application properties --> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="locations"> <list> <value>file:${user.dir}/@propertiesFile@</value> </list> </property> </bean> <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">${connection.dialect}</prop> <prop key="hibernate.connection.username">${connection.username}</prop> <prop key="hibernate.connection.password">${connection.password}</prop> <prop key="hibernate.connection.url">${connection.url}</prop> <prop key="hibernate.connection.driver_class">${connection.driver.class}</prop> <prop key="hibernate.show_sql">${show.sql}</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> <prop key="hibernate.c3p0.min_size">5</prop> <prop key="hibernate.c3p0.max_size">20</prop> <prop key="hibernate.c3p0.timeout">300</prop> <prop key="hibernate.c3p0.max_statements">50</prop> <prop key="hibernate.c3p0.idle_test_period">60</prop> </props> </property> <property name="annotatedClasses"> <list> <value>za.co.xxx.traintrack.server.model.Answer</value> <value>za.co.xxx.traintrack.server.model.Company</value> <value>za.co.xxx.traintrack.server.model.CompanyRegion</value> <value>za.co.xxx.traintrack.server.model.Merchant</value> <value>za.co.xxx.traintrack.server.model.Module</value> <value>za.co.xxx.traintrack.server.model.Question</value> <value>za.co.xxx.traintrack.server.model.User</value> <value>za.co.xxx.traintrack.server.model.CompletedModule</value> </list> </property> </bean> <bean id="dao" class="za.co.xxx.traintrack.server.DAO"> <property name="sessionFactory" ref="sessionFactory"/> <property name="adminUsername" value="${admin.user.name}"/> <property name="adminPassword" value="${admin.user.password}"/> <property name="godUsername" value="${god.user.name}"/> <property name="godPassword" value="${god.user.password}"/> </bean> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory"> <ref local="sessionFactory"/> </property> </bean> <!-- enable the configuration of transactional behavior based on annotations --> <tx:annotation-driven transaction-manager="transactionManager"/> If I change the sessionFactory property to be autoCommit=true then my object does get persisited. <prop key="hibernate.connection.autocommit">true</prop>

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  • Arithmetic operator confusion

    - by Dusk
    Why I'm getting two different values while using the arithmetic operators for the same value of variables. I've just altered little bit my second program, which is resulted in giving me the different output. Could anyone please tell me why? int number=113; int rot=0; rot=number%10; rot*=100+number/10; System.out.println(rot);//333 int number=113; int rot=0; rot=number%10; rot=rot*100+number/10; System.out.println(rot);//311

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  • XML parsing by DOM

    - by blackpearl
    NodeList nList2 = doc.getElementsByTagName("dep"); Map<String, List<Map<String, String>>> depMap = new HashMap<String, List<Map<String, String>>>(); for (int temp = 0; temp < nList2.getLength(); temp++) { Element el = (Element)nList2.item(temp); String type=el.getAttribute("type"); Node nNode = nList2.item(temp); if (nNode.getNodeType() == Node.ELEMENT_NODE) { Element eElement = (Element) nNode; List<Map<String,String>> depList = new ArrayList<Map<String,String>>(); String governor = getTagValue("governor", eElement); String dependent = getTagValue("dependent", eElement); Map<String, String> govdepmap = new HashMap<String, String>(); govdepmap.put(governor, dependent); depList.add(govdepmap); List<Map<String,String>> flist = new ArrayList<Map<String,String>>(); flist.add(govdepmap); depMap.put(type, flist); } } I have the following structure in my XML file: going I Now i want to store the "idx" attribute of each "governor" and "dependent" tag. What code should I change or add?

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  • Application Server or Lightweight Container?

    - by Jeff Storey
    Let me preface this by saying this is not an actual situation of mine but I'm asking this question more for my own knowledge and to get other people's inputs here. I've used both Spring and EJB3/JBoss, and for the smaller types of applications I've built, Spring (+Tomcat when needed) has been much simpler to use. However, when scaling up to larger applications that require things like load balancing and clustering, is Spring still a viable solution? Or is it time to turn to a solution like EJB3/JBoss when you start to get big enough to need that? I'm not sure if I've scoped the problem well enough to get a good answer, so please let me know. Thanks, Jeff

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  • Delete files from blobstore using file serving URL

    - by Arturo
    In my app (GWT on GAE) we are storing on our database the serving URL that is stored on blobstore. When user selects one of these files and clicks "delete", we need to delete the file from blobstore. This is our code, but it is not deleting the file at all: public void remove(String fileURL) { BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService(); String key = getBlobKeyFromURL(box.getImageURL()); BlobKey blobKey = new BlobKey(key); blobstoreService.delete(blobKey); } Where fileURL looks like this: http://lh6.ggpht.com/d5VC0ywISACeJRiC3zkzaZug-tPsaI_LGt93-e_ATGTCwnGLao4yTWjLVppQ And getBlobKeyFromURL() would return what is after the last "/", in this example: d5VC0ywISACeJRiC3zkzaZug-tPsaI_LGt93-e_ATGTCwnGLao4yTWjLVppQ Could you please advice? Thanks

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  • How to detect a pending JDO transaction?

    - by Stevko
    I believe I am getting JDO commit Exceptions due to the transactions nesting although I'm not sure. Will this detect the situation where I am starting a transaction when another is pending? PersistenceManager pm = PersistenceManagerFactory.get().getPersistenceManager(); assert pm.currentTransaction().isActive() == false : "arrrgh"; pm.currentTransaction().begin(); Is there a better or more reliable way?

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  • How would I set up this enum to return the image I want?

    - by Justen
    I'm trying to set up this enum so that it has the ability to return the correct image, though I'm struggling with a way to incorporate the context since it is in a separate class. public enum CubeType { GREEN { public Drawable getImage() { return Context.getResources().getDrawable( R.drawable.cube_green ); } }; abstract public Drawable getImage(); } The error I'm getting is: Cannot make a static reference to the non-static method getResources() from the type Context

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  • Eclipse won't believe I have Maven 2.2.1

    - by Andrew Clegg
    I have a project (built from an AppFuse template) that requires Maven 2.2.1. So I upgraded to this (from 2.1.0) and set my path and my M2_HOME and MAVEN_HOME env variables. Then I ran mvn eclipse:eclipse and imported the project into Eclipse (Galileo). However, in the problems list for the project (and at the top of the pom.xml GUI editor) it says: Unable to build project '/export/people/clegg/data/GanymedeWorkspace/funcserve/pom.xml; it requires Maven version 2.2.1 (Please ignore 'GanymedeWorkspace', I really am using Galileo!) This persists whether I set Eclipse to use its Embedded Maven implementation, or the external 2.2.1 installation, in the Preferences - Maven - Installations dialog. I've tried closing and reopening the project, reindexing the repository, cleaning the project, restarting the IDE, logging out and back in again, everything I can think of! But Eclipse still won't believe I have Maven 2.2.1. I just did a plugin update so I have the latest version of Maven Integration for Eclipse -- 0.9.8.200905041414. Does anyone know how to convince Eclipse I really do have the right version of Maven? It's like it's recorded the previous version somewhere else and won't pay any attention to my changes :-( Many thanks! Andrew.

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  • Why does my JButton look differently of different computers?

    - by Roman
    I use JButtons in my application. They need to have different colors. First I used that btn.setBackground(col);. It works on my computer and on another computer my button just gray (not red, as it's supposed to be). Trying to solve this problem I decided to use images. I do it in the following way: tmp = new JButton(newIcon); Again, it works fine on my computer and on another computer I see just gray buttons. Does anybody have any ideas what can be the reason of the problem and how it can be solved? I heard it can be related to "look-and-feel of the native system". But I do not know what it means and what should I do if it is the case? Can anybody pleas, help me with that?

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  • J2ME TextField Exception

    - by Bob
    When I instantiate a textField, I have a number in it that I want to be the default text. The problem is, I can't seem to be able to place that value into the textfield without getting an error. The strange thing about it is that the same TextField is what I use to set the value of the variable containing the number. TextField myTF = new TextField("Number", value, 10, TextField.NUMERIC); When I run this code, I receive an exception stating that value doesn't match the constraints of TextField.NUMERIC. However, when I check the vale of the value of the variable, I get the following output: value = 1234567890 value.length() = 10 The value is set by the same TextField, saved to the phone that I am working on, and when loaded from the phone's settings, throws an exception.

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  • How to make a thread that runs at x:00 x:15 x:30 and x:45 do something different at 2:00.

    - by rmarimon
    I have a timer thread that needs to run at a particular moments of the day to do an incremental replication with a database. Right now it runs at the hour, 15 minutes past the hour, 30 minutes past the hour and 45 minutes past the hour. This is the code I have which is working ok: public class TimerRunner implements Runnable { private static final Semaphore lock = new Semaphore(1); private static final ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor(); public static void initialize() { long delay = getDelay(); executor.schedule(new TimerRunner(), delay, TimeUnit.SECONDS); } public static void destroy() { executor.shutdownNow(); } private static long getDelay() { Calendar now = Calendar.getInstance(); long p = 15 * 60; // run at 00, 15, 30 and 45 minutes past the hour long second = now.get(Calendar.MINUTE) * 60 + now.get(Calendar.SECOND); return p - (second % p); } public static void replicate() { if (lock.tryAcquire()) { try { Thread t = new Thread(new Runnable() { public void run() { try { // here is where the magic happens } finally { lock.release(); } } }); t.start(); } catch (Exception e) { lock.release(); } } else { throw new IllegalStateException("already running a replicator"); } } public void run() { try { TimerRunner.replicate(); } finally { long delay = getDelay(); executor.schedule(new TimerRunner(), delay, TimeUnit.SECONDS); } } } This process is started by calling TimerRunner.initialize() when a server starts and calling TimerRunner.destroy(). I have created a full replication process (as opposed to incremental) that I would like to run at a certain moment of the day, say 2:00am. How would change the above code to do this? I think that it should be very simple something like if it is now around 2:00am and it's been a long time since I did the full replication then do it now, but I can't get the if right. Beware that sometimes the replicate process takes way longer to complete. Sometimes beyond the 15 minutes, posing a problem in running at around 2:00am.

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  • Aiming Netbeans code snippets

    - by rwallace
    Not quite sure whether I'm using the right terminology here, but Netbeans has a very nice feature where e.g. if you start typing for it will offer to write a code fragment looping over an array or list, basing it on the name and type of an array or list variable actually in scope. If more than one such variable is in scope it will guess, sometimes correctly and sometimes not. Is there a way to aim this feature at the correct array/list variable?

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  • Add objects to Arraylist inside loop and get a list of them outside loops

    - by AgusDG
    Im already done with a method to do a shot on a board (bidimensional array). THe shot goes from the bottom to the top, and depending of the direction, it do bounces on the walls to get to the top. The thing is that I did the method to represent the trayectory with an 'x'. Now, I want to add the coordinates x and y of each position of the shot (b [x][y]) to and Arraylist of Objects Position. public Position(int row,int col) { this.row = row; this.col = col; } The thing is that the method uses a for loop and inside if loops, and I'll need to create the objects inside, and get them outside. I did that : public static ArrayList<Position> showTrayectory (char [][] b , int shotDirection, char bubble){ int row = 0, col = 0; ArrayList<Position> aListPos = new ArrayList<Position>(); Position positionsOfShot = new Position(row,col); START = ((RIGHT_WALL)/2) + shotDirection; boolean shotRight = false; if(shotDirection < 0) shotRight = false; else if(shotDirection > 0) shotRight = true; for(int y = BOTTOM,x = START ;y >= 0;y--) { if(!isOut(y,x) && !emptyCell(y,x)) break; if(x <= LEFT_WALL) shotRight = true; if(x >= RIGHT_WALL) shotRight = false; if(!isOut(y,x) && shotRight == true) { positionsOfShot = new Position(y,x); aListPos.add(positionsOfShot); b[y][x] = SHOT; ++x; } if(!isOut(y,x) && shotRight == false){ positionsOfShot = new Position(y,x); aListPos.add(positionsOfShot); b[y][x] = SHOT; --x; } } // The nested for loops below are for showing the positions // But I dont need it that way // I must get the trayectory from an ArrayList and print it from there for(int y=0;y < b.length;y++){ System.out.println(); for(int x=0;x < b[y].length;x++){ System.out.print(" "+b [y][x]+" "); } } System.out.println("\nTrayectory of the shot ["+shotDirection+"]"); System.out.println("Next bubble ["+bubble+"]"); for( Position ii : aListPos){ System.out.println("(" + positionsOfShot.getFila() + "," + positionsOfShot.getColumna()+")"); } return aListPos; } The sentence " b[y][x] = SHOT; " is still there, to see the proper trayectory of the shot (its not needed that way), but what I need, is getting the trayectory in an ArrayList, and print the trayectory from there. All that I get is a wrong position, and repeated during the number of positions the shot goes through. I need some help. I suppose the problem is that Im creating and adding Position Objects inside an ArrayList inside loops, but in a wrong way. I will need you to explain me how to do it properly ; ) Thanks in advance. I'll add the output for you see better what is that above haha *************************** y b y b g r b g o y g a a r y o y y r b y g r r o b o y y g b a r y r o a y y o o r r g r - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - x - - - - - - - x - - - - - - - x - - - Trayectory of the shot [1] Next bubble [y] (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) Action?

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  • Accelerometer Values from Android/iPhone device

    - by mrlinx
    I'm trying to map my movements with a android device into an OpenGL scene. I've recorded accelerometer values for a simples movement: Moving the phone (lies flat on a table) 10cm forward (+x), and then 10cm backward (-x). The problem is that this values when used to calculate velocity and position, makes only the opengl cube go forward. Seems like the negative acceleration recorded was not enough to reduce the speed and invert its movement. What can be the problem? This is my function that updates the velocity and position every time new data comes in: void updatePosition(double T2) { double T = 0.005; Vec3 old_pos = position.clone(), old_vel = velocity.clone(); velocity = old_vel.plus(acceleration.times(T)); position = old_pos.plus(old_vel.times(T).plus(acceleration.times(0.5 * Math.pow(T, 2)))); } This is the X,Y,Z accelerometer values over the entire captured time:

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  • pluto or jetspeed on google app engine?

    - by Patrick Cornelissen
    I am trying to build something "portlet server"-ish on the google app engine. (as open source) I'd like to use the JSR168/286 standards, but I think that the restrictions of the app engine will make it somewhere between tricky and impossible. Has anyone tried to run jetspeed or an application that uses pluto internally on the google app engine? Based on my current knowledge of portlets and the google app engine I'm anticipating these problems: A war file with portlets is from the deployment standpoint more or less a complete webapp (yes, I know that it doesn't really work without a portal server). The war file may contain it's own web.xml etc. This makes deployment on the app engine rather difficult, because the apps are not visible to each other, so all portlet containing archives need to be included in the war file of the deployed "app engine based portal server". The "portlets" are (at least in liferay) started as permanent servlet processes, based on their portlet.xmls and web.xmls which is located in the same spot for every portlet archive that is loaded. I think this may be problematic in the app engine, because everything is in one big "web app", so it may be tricky to access the portlet.xmls from each archive. This prevents a 100% compatibility in my opinion. Is here anyone who has any experience with the combination of portlets and the app engine? Do you think it's feasible to modify jetspeed, pluto or any other portlet container to be able to run it on the app engine?

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  • NoSuchMessageException: No message found

    - by adisembiring
    Hi .... I try to learn Spring MVC 3.0 validation. but I got NoSuchMessageException: No message found under code 'name.required' for locale 'en_US' error message when form submted. I have create message.properties in src/message.properties and the content of that file is: name.required = User Name is required password.required = Password is required gender.required = Gender is required I have set ResourceBundleMessageSource in my app-servlet.xml <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource" p:basename="messages" /> My validator code is: @Component("registrationValidator") public class RegistrationValidator implements Validator { @Override public boolean supports(Class<?> clazz) { return RegistrationCommand.class.isAssignableFrom(clazz); } @Override public void validate(Object target, Errors errors) { RegistrationCommand registrationCommand = (RegistrationCommand) target; ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "name.required"); ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "password.required"); ValidationUtils.rejectIfEmpty(errors, "gender", "gender.required"); ValidationUtils.rejectIfEmpty(errors, "country", "country.required"); //ValidationUtils.rejectIfEmpty(errors, "community", "community.required"); ValidationUtils.rejectIfEmptyOrWhitespace(errors, "description", "description.required"); if (registrationCommand.getCommunity().length == 0) { errors.rejectValue("community", "community.required"); } } } and JSP Page is: <form:form commandName="registrationCommand"> <p class="name"> <label for="name">Name</label> <form:input path="name" /> <form:errors path="name" cssClass="error"></form:errors> </p> <p class="password"> <label for="password">Password</label> <form:password path="password" /> <form:errors path="password" cssClass="error"></form:errors> </p> <p class="gender"> <label>Gender</label> <form:radiobutton path="gender" value="M" label="M" /> <form:radiobutton path="gender" value="F" label="F" /> <form:errors path="gender" cssClass="error"></form:errors> </p> <p class="submit"> <input type="submit" value="Submit" /> </p> </form:form>

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  • What design pattern will you choose ?

    - by MemoryLeak
    I want to design a class, which contains a procedure to achieve a goal. And it must follow some order to make sure the last method, let's say "ExecuteIt", to behave correctly. in such a case, what design patter will you use ? which can make sure that the user must call the public method according some ordering. If you really don't know what I am saying, then can you share me some concept of choosing a design patter, or what will you consider while design a class?

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  • Security when using GWT RPC

    - by gerdemb
    I have an POJO in Google Web Toolkit like this that I can retrieve from the server. class Person implements Serializable { String name; Date creationDate; } When the client makes changes, I save it back to the server using the GWT RemoteServiceServlet like this: rpcService.saveObject(myPerson,...) The problem is that the user shouldn't be able to change the creationDate. Since the RPC method is really just a HTTP POST to the server, it would be possible to modify the creationDate by changing the POST request. A simple solution would be to create a series of RPC functions like changeName(String newName), etc., but with a class with many fields would require many methods for each field, and would be inefficient to change many fields at once. I like the simplicity of having a single POJO that I can use on both the server and GWT client, but need a way to do it securely. Any ideas?

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  • JPA getSingleResult() or null

    - by Eugene Ramirez
    Hi. I have an insertOrUpdate method which inserts an Entity when it doesn't exist or update it if it does. To enable this, I have to findByIdAndForeignKey, if it returned null insert if not then update. The problem is how do I check if it exists? So I tried getSingleResult. But it throws an exception if the public Profile findByUserNameAndPropertyName(String userName, String propertyName) { String namedQuery = Profile.class.getSimpleName() + ".findByUserNameAndPropertyName"; Query query = entityManager.createNamedQuery(namedQuery); query.setParameter("name", userName); query.setParameter("propName", propertyName); Object result = query.getSingleResult(); if(result==null)return null; return (Profile)result; } but "getSingleResult" throws an exception. Thanks

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  • How do JVM's implicit memory barriers behave when chaining constructors

    - by Joonas Pulakka
    Referring to my earlier question on incompletely constructed objects, I have a second question. As Jon Skeet pointed out, there's an implicit memory barrier in the end of a constructor that makes sure that final fields are visible to all threads. But what if a constructor calls another constructor; is there such a memory barrier in the end of each of them, or only in one being called from outside? That is, when the "wrong" solution is: public class ThisEscape { public ThisEscape(EventSource source) { source.registerListener( new EventListener() { public void onEvent(Event e) { doSomething(e); } }); } } And the correct one would be a factory method version: public class SafeListener { private final EventListener listener; private SafeListener() { listener = new EventListener() { public void onEvent(Event e) { doSomething(e); } } } public static SafeListener newInstance(EventSource source) { SafeListener safe = new SafeListener(); source.registerListener(safe.listener); return safe; } } Would the following work too, or not? public class MyListener { private final EventListener Listener; private MyListener() { listener = new EventListener() { public void onEvent(Event e) { doSomething(e); } } } public MyListener(EventSource source) { this(); source.register(listener); } }

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