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  • Java - Using Linear Coordinates to Check Against AI [closed]

    - by Oliver Jones
    I'm working on some artificial intelligence, and I want my AI not to run into given coordinates as these are references of a wall/boundary. To begin with, every time my AI hits a wall, it makes a reference to that position (x,y). When it hits the same wall three times, it uses linear check points to 'imagine' there is a wall going through these coordinates. I want to now prevent my AI from going into that wall again. To detect if my coordinates make a straight line, i use: private boolean collinear(double x1, double y1, double x2, double y2, double x3, double y3) { return (y1 - y2) * (x1 - x3) == (y1 - y3) * (x1 - x2); } This returns true is the given points are linear to one another. So my problems are: How do I determine whether my robot is approaching the wall from its current trajectory? Instead of Java 'imagining' theres a line from 1, to 3. But to 'imagine' a line all the way through these linear coordinantes, until infinity (or close). I have a feeling this is going to require some confusing trigonometry? (REPOST: http://stackoverflow.com/questions/13542592/java-using-linear-coordinates-to-check-against-ai)

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  • Is there a name for this use of the State design pattern?

    - by Chris C
    I'm looking to see if there is a particular name for this style of programming a certain kind of behavior into a program. Said program runs in real time, in an update loop, and the program uses the State design pattern to do some work, but it's the specific way it does the work that I want to know about. Here's how it's used. - Object Foo constructed, with concrete StateA object in it - First loop runs --- Foo.Run function calls StateA.Bar --- in StateA.Bar replace Foo's state to StateB - Second loop runs --- Foo.Run calls StateB.Bar - Third loop runs --- Foo.Run calls StateB.Bar - Fourth loop --- etc. So in short, Foo doesn't have an explicit Initialize function. It will just have Run, but Run will do something unique in the first frame to initialize something for Foo and then replace it with a different action that will repeat in all the frames following it- thus not needing to check if Foo's already initialized. It's just a "press start and go" action. What would you call implementing this type of behavior?

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  • Halloween: Season for Java Embedded Internet of Spooky Things (IoST) (Part 3)

    - by hinkmond
    So, let's now connect the parts together to make a Java Embedded ghost sensor using a Raspberry Pi. Grab your JFET transistor, LED light, wires, and breadboard and follow the connections on this diagram. The JFET transistor plugs into the breadboard with the flat part facing left. Then, plug in a wire to the same breadboard hole row as the top JFET lead (green in the diagram) and keep it unconnected to act as an antenna. Then, connect a wire (red) from the middle lead of the JFET transistor to Pin 1 on your RPi GPIO header. And, connect another wire (blue) from the lower lead of the JFET transistor to Pin 25 on your RPi GPIO header, then connect another (blue) wire from the lower lead of the JFET transistor to the long end of a common cathode LED, and finally connect the short end of the LED with a wire (black) to Pin 6 (ground) of the RPi GPIO header. That's it. Easy. Now test it. See: Ghost Sensor Testing Here's a video of me testing the Ghost Sensor circuit on my Raspberry Pi. We'll cover the Java SE app needed to record the ghost analytics in the next post. Hinkmond

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  • Maintaining C/C++/Java skills as a web developer

    - by wwwuser
    When I was in college I learned how to program in C, C++, and Java. Currently, I'm a web developer using front end and back end technologies (HTML/CSS/JS, PHP, MYSQL). While the sorting algorithms and OOP concepts that I learned in college can be applied to web development, I'm looking for ways to keep up my knowledge of all languages. I enjoy programming in C-Style (C/C++/Java) languages and front-end/back-end technologies. Unfortunately, there aren't many options to use C-style languages to build websites. However, I would like to keep up my knowledge and skills in the languages I learned in college as I know they will continue to help me with my growth. What resources are available to keep challenging myself in C-style languages that are relevant to web development? Would contract work for C-style languages be beneficial? Are there sites that offer algorithm challenges? Any help is appreciated. I'm also interested in how others that have asked themselves this have solved this problem.

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  • Should I go with Java or Python for my next project, after using PHP for 5 years? [closed]

    - by vim
    I have a full-time PHP job and I've been working with PHP for 5 years. I'm not willing to stay within this technology stack any more. I also worked with Java for 2 year before, so for me it looks more obvious to switch back to Java. However during last 5 years I was thinking about starting my own project, and now I think I have a very good SAAS idea. I'm completely confused what technology should I use for my project. I don't want to do it in PHP, and after reading many articles about rapid prototype development it seems to me that Django is the best option. I will continue to work full time for my current employer because I need to pay my bills and will work on my project in my free time. The concern I have is should I do my project in Java or Python? To be realistic there is always a risk when you are doing your own project/start-up. If I do it in Java in the worst case scenario I believe I will be able to find a full time Java position because I already have some experience in Java + recent experience in my project. With regards to Python it looks like it is not very popular in my area and salaries are much more lower then for Java. On the other hand I have a feeling that if I chose Java it will take me a way longer to finish my project. Guys I'm completely confused and I need your advice. P.S. I have moved to London 2 years ago from another country, local guys are very welcome to share their thoughts about London's job market.

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  • Java or Python? Career/Start-up advice needed [closed]

    - by vim
    I have a full-time PHP job and I've been working with PHP for 5 years. As you can guess after spending 5 years I'm not willing to stay within this technology stack any more. I also worked with Java for 2 year before, so for me it looks more obvious to switch back to Java. However during last 5 years I was thinking about starting my own project, and now I think I have a very good SAAS idea. I'm completely confused what technology should I use for my project. I don't want to do it in PHP, and after reading many articles about rapid prototype development it seems to me that Django/Ruby is the best option. I will continue to work full time for my current employer because I need to pay my bills and will work on my project in my free time. The concern I have is should I do my project in Java or Python? To be realistic there is always a risk when you are doing your own project/start-up. If I do it in Java in the worst case scenario I believe I will be able to find a full time Java position because I already have some experience in Java + recent experience in my project. With regards to Python it looks like it is not very popular in my area and salaries are much more lower then for Java. On the other hand I have a feeling that if I chose Java it will take me a way longer to finish my project. Guys I'm completely confused and I need your advice. P.S. I have moved to London 2 years ago from another country, local guys are very welcome to share their thoughts about London's job market.

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  • Main class passes dbConn obj to all its services, I need to change the dbConn for one of its services. - suggestion for design pattern

    - by tech_learner
    There is this main class and there are several services ( which uses db connection to retrieve data ) These services are initialized in the main class db properties are obtained from the property file and then dbconnection is opened by calling a method dbOpen() written in the main class and the resultant connection object is set to the service objects by iterating through the list of services and by calling setConnection method on the service note: that the services are instantiated in the main class and the main class is not a superclass for services. I also need to mention that there is this recycle db connection scenario only main class is aware of. /** connects to DB, optionally recycling existing connection), * throws RuntimeException if unable to connect */ private void connectDb(boolean recycle) { try { if (recycle) { log.status( log.getSB().append("Recycling DB Connection") ); closeDb(); } openDb(); for ( int i = 0 ; i < service.length ; i++ ) { service[i].setConnection(db); } } One of the service needs to use a different database, what is the best design pattern to use?

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  • "Never do in code what you can get the SQL server to do well for you" - Is this a recipe for a bad design?

    - by PhonicUK
    It's an idea I've heard repeated in a handful of places. Some more or less acknowledging that once trying to solve a problem purely in SQL exceeds a certain level of complexity you should indeed be handling it in code. The logic behind the idea is that for the large majority of cases, the database engine will do a better job at finding the most efficient way of completing your task than you could in code. Especially when it comes to things like making the results conditional on operations performed on the data. Arguably with modern engines effectively JIT'ing + caching the compiled version of your query it'd make sense on the surface. The question is whether or not leveraging your database engine in this way is inherently bad design practice (and why). The lines become blurred further when all the logic exists inside the database and you're just hitting it via an ORM.

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  • Which field of programming is known as the best practice for Java? [closed]

    - by user1276509
    I'm a CS student and I have some programming background such as PHP, JavaScript and Pascal. Since Java is so popular among local companies and Java is known as market skill, I'm going to learn it. But I don't know in which field I can use it. So I wonder, what can I do with Java? I heard that Java is not good for web development, although there is Play! Framework. I know a lot of people who prefer to use Python, Ruby and PHP for web development instead of Java and its Play. I also heard that Java is not good to write destkop applications, although it's cross-platform. Many programmers prefer C# for destkop. So I see there's only one field which I can use Java for it - is Android development. But I'm not interested in mobile application development. So my question is which field of programming is known as the best practice for Java? Thanks in advance.

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  • ?????????????????????????/???????????Java EE??????????????????????????????????JavaOne Tokyo 2012?????|WebLogic Channel|??????

    - by ???02
    ??????·???????????????????·???????????????????/????????????????????????????――?????6?????????????????????WebLogic Server?????????????????????????????????????????????????????????2012?4???????JavaOne Tokyo 2012????????????????????·????????????????Java EE???????????????????????????????(???)?????????????????????????? ?????????????NTT??????????????????????????·???????????????????????2005???????1??????????·?????????2006??????????????????????Java EE??????????????????????????????????????????????????????????????????????????????????????????????????????????? DU ?????? ???????????????? ???????????? ?? ????????????????????????????????31????????????????????????????·???????????????????????????30?????????????20??????????????3?????????????????????????????????????????????2??????????????????????????????????????????????????????????????????????????????????????????? ????????????????????????????????????????????????????????????2??????????????????????:??/???????????????????????????????????2??????????/???????:????????????????????????????????2??~1????????????/???????????????·??????????? ?????????????????????????????2?????????????????????????·????(B2C????????????????)?????????????????????????????????????????????????????????????????????????????/?????????????????????? ?????????????????????????????????????(???)?????????(??/???????)???????????????????????????????????????????????????????????????????????????????????????????????·?????WebLogic Server????????·?????Informix???????????? ?????????????????????????????????????????B2C??????????C2C???????????????????????????C2C????????????????????????????????????????????????????????????????????????????????????????????????????????????·????????????????????????????????1???????????????????????????????????????????????? ????????????????????????????????????????????????????????????????????????????????Java EE????????????????????????????????????????????????????????????????????????????????????????????????????????????? ??????????????????3???????????????????(Inexpensive):????????????????????????????????(Agile):???????????????????????????(Simple):???????????????????????? ??????????2006???5????????????????????????????????????????Java EE?????????????????????????????????Java?????????????(???)???????????·??????????????????????????????????????????????????????????????????????Java???????????????????????????????????WebLogic Server??????????????????????????????????????(???)???????????????????????????????? ????????????????????????????????????????????WebLogic Server?????????????????????????/???????????????????GlassFish????????????GlassFish????Java EE?????????????????????????????????????????WebLogic Server??????????????????Tomcat???????????????(???)?????????????????????????????????? ????????????????????????????WebLogic Server?????????????WebLogic Server?????????????????????????????????????JRockit Mission Control???????????????(???)??????WebLogic Server?GlassFish????? ???????????????????????????????????C2C??????????????????????????????????????2006???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????RDB?????/????·???(KVS)???????NoSQL?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ?????????????/??????????API???????????????????????????????????????KVS?????????????????GlassFish?????KVS??????????API?GlassFish??????????????????????????JAX-RS???????????????(REST API)???????????????????????????????????????????????????????????????? ?KVS??????????API?????????????????????????????????????????????????????????????????????????????????????????????????(???)?????????? ????API?????????????????????????????????????????????170?????????? ??????????Ruby on Rails??????????????????????????????(???)?????????????????????????????????????(???)??????????????????????????????????????????????????????????????????????Maven 2??????????????????????????????????????????????????????????????????????????????????????????????? GlassFish??????????????????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????????????????????????????????????????????????/?????????????????????????????????????????????????/????????????????????????????

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  • Problems with HMAC when switching to Java 6

    - by Pablo Fernandez
    We have recently switched to java6 and it's mandatory in the project. One of our apps that used to work is failing, with this stacktrace (relevant part) java.lang.NoClassDefFoundError: Could not initialize class com.apple.crypto.provider.HmacSHA1 sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) java.lang.reflect.Constructor.newInstance(Constructor.java:513) java.lang.Class.newInstance0(Class.java:355) java.lang.Class.newInstance(Class.java:308) java.security.Provider$Service.newInstance(Provider.java:1221) javax.crypto.Mac.a(DashoA13*..) javax.crypto.Mac.init(DashoA13*..) Has anyone had this problem before? Thanks a lot

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  • on Google App Engine 500 Error, it should be 200 instead of 500

    - by Faisal Amjad
    requestToken = function() { var getTokenURI = '/gettoken?userid=' + userid; var httpRequest = makeRequest(getTokenURI, true); httpRequest.onreadystatechange = function() { if (httpRequest.readyState == 4) { if (httpRequest.status == 200) { openChannel(httpRequest.responseText); } else { alert('ERROR: AJAX request status = ' + httpRequest.status); } } } }; function makeRequest(url, async) { var httpRequest; if (window.XMLHttpRequest) { httpRequest = new XMLHttpRequest(); } else if (window.ActiveXObject) { // IE try { httpRequest = new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { try { httpRequest = new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) { } } } if (!httpRequest) { return false; } httpRequest.open('POST', url, async); httpRequest.send(); return httpRequest; } it is running excellent on localhost...but on google app engine it httpRequest.status equals 500 and goes in else statement. WHY? LOG on google app engine: /getFriendList?userid=d 500 253ms 0kb Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11 175.110.179.86 - - [17/Dec/2012:08:35:33 -0800] "POST /getFriendList?userid=d HTTP/1.1" 500 0 "http://faisalimmsngr.appspot.com/" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.97 Safari/537.11" "faisalimmsngr.appspot.com" ms=254 cpu_ms=110 instance=00c61b117caf2d11ca57d2a2296ccd0b902b038a W 2012-12-17 08:35:33.272 Failed startup of context com.google.apphosting.utils.jetty.RuntimeAppEngineWebAppContext@10ff62a{/,/base/data/home/apps/s~faisalimmsngr/1.363934467542140431} org.mortbay.util.MultiException[java.lang.UnsupportedClassVersionError: adv/web/mid/exam/FriendServlet : Unsupported major.minor version 51.0, java.lang.UnsupportedClassVersionError: adv/web/mid/exam/MessageServlet : Unsupported major.minor version 51.0, java.lang.UnsupportedClassVersionError: adv/web/mid/exam/TokenServlet : Unsupported major.minor version 51.0] at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:656) at org.mortbay.jetty.servlet.Context.startContext(Context.java:140) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.createHandler(AppVersionHandlerMap.java:219) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.getHandler(AppVersionHandlerMap.java:194) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:134) at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:447) at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454) at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461) at com.google.tracing.TraceContext.runInContext(TraceContext.java:703) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:338) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:330) at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458) at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251) at java.lang.Thread.run(Thread.java:679) java.lang.UnsupportedClassVersionError: adv/web/mid/exam/FriendServlet : Unsupported major.minor version 51.0 at com.google.appengine.runtime.Request.process-c04431eac3a1f275(Request.java) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:634) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:277) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at java.lang.ClassLoader.loadClass(ClassLoader.java:266) at org.mortbay.util.Loader.loadClass(Loader.java:91) at org.mortbay.util.Loader.loadClass(Loader.java:71) at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:73) at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685) at org.mortbay.jetty.servlet.Context.startContext(Context.java:140) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454) at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461) at com.google.tracing.TraceContext.runInContext(TraceContext.java:703) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:338) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:330) at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458) at java.lang.Thread.run(Thread.java:679)

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  • Copying a java text file into a String.

    - by Deepak Konidena
    Hi, I run into the following errors when i try to store a large file into a string. Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at java.util.Arrays.copyOf(Arrays.java:2882) at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:100) at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:515) at java.lang.StringBuffer.append(StringBuffer.java:306) at rdr2str.ReaderToString.main(ReaderToString.java:52) As is evident, i am running out of heap space. Basically my pgm looks like something like this. FileReader fr = new FileReader(<filepath>); sb = new StringBuffer(); char[] b = new char[BLKSIZ]; while ((n = fr.read(b)) > 0) sb.append(b, 0, n); fileString = sb.toString(); Can someone suggest me why i am running into heap space error? Thanks.

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  • I am not able launch JNLP aaplications using "Java Web Start"?

    - by akjain
    Up until recently, I was able to launch/open JNLP files in Firefox using Java web start. Don't know what happened all of a sudden JNLP files stopped launching, a splash screen appears saying Java Starting... and then nothing happens. Even the Java Console in the browser and javacpl.cpl applet doesn't open. Tried all possibilities: removed all older version and installed the latest JRE (java version "1.6.0_17"), still it doesn't work. Done some googling for this problem, people suggested to start javaws.exe with -viewer option but same behavior (a splash screen appears saying "Java Starting..." and then disappears) The problem is that I don't know any place (logs etc.) to look for to see what is causing the problem. I am using WinXP SP3, and some of the screenshots below shows further info about my system. I can provide any other detail if required but please help me solve this problem. Update: Although this question is bit old, Following solution fixed above issue for me (indeed this was the actual cause)

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  • Java URL("file://") doesn't work on Windows XP

    - by Soumya Simanta
    For some reason the following code doesn't work on Windows XP. new URL("file://" + tempfile.getAbsolutePath()); I'm using Java 1.6. Java(TM) SE Runtime Environment (build 1.6.0_31-b05) Java HotSpot(TM) Client VM (build 20.6-b01, mixed mode, sharing) However, the same code just works fine in OS X (Lion) and Java 1.6 java version "1.6.0_29" Java(TM) SE Runtime Environment (build 1.6.0_29-b11-402-11M3527) Java HotSpot(TM) 64-Bit Server VM (build 20.4-b02-402, mixed mode) Linux (Linux 2.6.32-38-generic #83-Ubuntu x86_64 GNU/Linux) with Java 1.6 java version "1.6.0_26" Java(TM) SE Runtime Environment (build 1.6.0_26-b03) Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode) Based on this the above code should work.

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  • Are there any well known anti-patterns in the field of system administration?

    - by ojblass
    I know a few common patterns that seem to bedevil nearly every project at some point in its life cycle: Inability to take outages Third party components locking out upgrades Non uniform environments Lack of monitoring and alerting Missing redundancy Lack of Capacity Poor Change Management Too liberal or tight access policies Organizational changes adversely blur infrastructure ownership I was hoping there is some well articulated library of these anti-patterns summarized in a book or web site. I am almost positive that many organizations are learning through trial by fire methods. If not let's start one.

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  • Persistance JDO - How to query a property of a collection with JDOQL?

    - by Sergio del Amo
    I want to build an application where a user identified by an email address can have several application accounts. Each account can have one o more users. I am trying to use the JDO Storage capabilities with Google App Engine Java. Here is my attempt: @PersistenceCapable @Inheritance(strategy = InheritanceStrategy.NEW_TABLE) public class AppAccount { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Long id; @Persistent private String companyName; @Persistent List<Invoices> invoices = new ArrayList<Invoices>(); @Persistent List<AppUser> users = new ArrayList<AppUser>(); // Getter Setters and Other Fields } @PersistenceCapable @EmbeddedOnly public class AppUser { @Persistent private String username; @Persistent private String firstName; @Persistent private String lastName; // Getter Setters and Other Fields } When a user logs in, I want to check how many accounts does he belongs to. If he belongs to more than one he will be presented with a dashboard where he can click which account he wants to load. This is my code to retrieve a list of app accounts where he is registered. public static List<AppAccount> getUserAppAccounts(String username) { PersistenceManager pm = JdoUtil.getPm(); Query q = pm.newQuery(AppAccount.class); q.setFilter("users.username == usernameParam"); q.declareParameters("String usernameParam"); return (List<AppAccount>) q.execute(username); } But I get the next error: SELECT FROM invoices.server.AppAccount WHERE users.username == usernameParam PARAMETERS String usernameParam: Encountered a variable expression that isn't part of a join. Maybe you're referencing a non-existent field of an embedded class. org.datanucleus.store.appengine.FatalNucleusUserException: SELECT FROM com.softamo.pelicamo.invoices.server.AppAccount WHERE users.username == usernameParam PARAMETERS String usernameParam: Encountered a variable expression that isn't part of a join. Maybe you're referencing a non-existent field of an embedded class. at org.datanucleus.store.appengine.query.DatastoreQuery.getJoinClassMetaData(DatastoreQuery.java:1154) at org.datanucleus.store.appengine.query.DatastoreQuery.addLeftPrimaryExpression(DatastoreQuery.java:1066) at org.datanucleus.store.appengine.query.DatastoreQuery.addExpression(DatastoreQuery.java:846) at org.datanucleus.store.appengine.query.DatastoreQuery.addFilters(DatastoreQuery.java:807) at org.datanucleus.store.appengine.query.DatastoreQuery.performExecute(DatastoreQuery.java:226) at org.datanucleus.store.appengine.query.JDOQLQuery.performExecute(JDOQLQuery.java:85) at org.datanucleus.store.query.Query.executeQuery(Query.java:1489) at org.datanucleus.store.query.Query.executeWithArray(Query.java:1371) at org.datanucleus.jdo.JDOQuery.execute(JDOQuery.java:243) at com.softamo.pelicamo.invoices.server.Store.getUserAppAccounts(Store.java:82) at com.softamo.pelicamo.invoices.test.server.StoreTest.testgetUserAppAccounts(StoreTest.java:39) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28) at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184) at org.junit.runners.ParentRunner.run(ParentRunner.java:236) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Any idea? I am getting JDO persistance totally wrong?

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  • Updating and deleting java (red hat / centos)

    - by JochemTheSchoolKid
    I am a total noob with linux. So please explain clearly if you have a solution for me. I have an VPS and I want to update JAVA. I found a guide on the Java site which says: rpm -e < package_name I searched for the packages: [root@srv1 ~]# rpm -qa | grep java java_cup-0.10k-5.el6.x86_64 java-1.5.0-gcj-1.5.0.0-29.1.el6.x86_64 Than I tried to do the delete command [root@srv1 ~]# rpm -e java-1.5.0-gcj-1.5.0.0-29.1.el6.x86_64 error: Failed dependencies: java-gcj-compat is needed by (installed) java_cup-1:0.10k-5.el6.x86_64 java-gcj-compat >= 1.0.70 is needed by (installed) sinjdoc-0.5-9.1.el6.x86_64 What should I do now?

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  • Java DnD - Java Component to .Net Component

    - by JT703
    I'm trying to use Java drag and drop to drag an object from a JTree into a native .NET component that is embedded in my app. This .NET component only accepts File objects, so I'm having trouble with the DnD's Transferable object. Anyone know how I can make this Transferable "look" like a file to this .Net component? p.s. I need this answer as Quickly as possible. Thanks!

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  • Vim & Java: add java import statements automatically

    - by HH
    The tip. The errors are "E349: No identifier unders cursor", "E433: No tags file" and "E426: tag not found: public". I feel them unrelated or I cannot understand their message. I have the code in "~/.vimrc" and pressed "F1", "F9" and "ESC". A related tip but more advanced. so how can I add Java import statements automatically in Vim?

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  • Java - simple division in Java ---> bug/feature?!

    - by msr
    Hello, Im astonished. Im trying this simple calculation in a Java application: System.out.println("b=" + (1 - 7/10)); Obviously Im wainting for "b=0.3" in the output but here's what I get: b=1 What?! Why this happens? If I make: System.out.println("b=" + (1-0.7)); I get the right result which is "b=0.3". What's going wrong here? Thanks!

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  • Java constructor with large arguments or Java bean getter/setter approach

    - by deelo55
    Hi, I can't decide which approach is better for creating objects with a large number of fields (10+) (all mandatory) the constructor approach of the getter/setter. Constructor at least you enforce that all the fields are set. Java Beans easier to see which variables are being set instead of a huge list. The builder pattern DOES NOT seem suitable here as all the fields are mandatory and the builder requires you put all mandatory parameters in the builder constructor. Thanks, D

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