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  • OptimisticLockException in inner transaction ruins outer transaction

    - by Pace
    I have the following code (OLE = OptimisticLockException)... public void outer() { try { middle() } catch (OLE) { updateEntities(); outer(); } } @Transactional public void middle() { try { inner() } catch (OLE) { updateEntities(); middle(); } @Transactional public void inner() { //Do DB operation } inner() is called by other non-transactional methods which is why both middle() and inner() are transactional. As you can see, I deal with OLEs by updating the entities and retrying the operation. The problem I'm having is that when I designed things this way I was assuming that the only time one could get an OLE was when a transaction closed. This is apparently not the case as the call to inner() is throwing an OLE even when the stack is outer()->middle()->inner(). Now, middle() is properly handling the OLE and the retry succeeds but when it comes time to close the transaction it has been marked rollbackOnly by Spring. When the middle() method call finally returns the closing aspect throws an exception because it can't commit a transaction marked rollbackOnly. I'm uncertain what to do here. I can't clear the rollbackOnly state. I don't want to force create a transaction on every call to inner because that kills my performance. Am I missing something or can anyone see a way I can structure this differently? EDIT: To clarify what I'm asking, let me explain my main question. Is it possible to catch and handle OLE if you are inside of an @Transactional method? FYI: The transaction manager is a JpaTransactionManager and the JPA provider is Hibernate.

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  • DDSteps date question.

    - by Srini
    DDStep Date Question: Currently trying to pass just the date from excel. But getting the below error while doing it. Failed to convert property value of type [java.lang.String] to required type [java.util.Date] for property ...no matching editors or conversion strategy found spring for date conversion I even tried to add customEditorConfigurer in the ddsteps-context file. Still getting error. But in their pet store example looks like it works fine. Any help is appreciated. <entry key="java.util.Date"> <bean class="org.springframework.beans.propertyeditors.CustomDateEditor"> <constructor-arg> <bean class="java.text.SimpleDateFormat"> <constructor-arg value="yyyy-MM-dd" /> </bean> </constructor-arg> <constructor-arg value="false" /> </bean> </entry>

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  • Long running method causing race condition

    - by keeleyt83
    Hi, I'm relatively new with hibernate so please be gentle. I'm having an issue with a long running method (~2 min long) and changing the value of a status field on an object stored in the DB. The pseudo-code below should help explain my issue. public foo(thing) { if (thing.getStatus() == "ready") { thing.setStatus("finished"); doSomethingAndTakeALongTime(); } else { // Thing already has a status of finished. Send the user back a message. } } The pseudo-code shouldn't take much explanation. I want doSomethingAndTakeALongTime() to run, but only if it has a status of "ready". My issue arises whenever it takes 2 minutes for doSomethingAndTakeALongTime() to finish and the change to thing's status field doesn't get persisted to the database until it leaves foo(). So another user can put in a request during those 2 minutes and the if statement will evaluate to true. I've already tried updating the field and flushing the session manually, but it didn't seem to work. I'm not sure what to do from here and would appreciate any help. PS: My hibernate session is managed by spring.

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  • (JBoss) Problem with .war project on production, while test works

    - by ikky
    Hello. I have a java project (using Spring mvc) which i have built and deployed on my local computer. It runs on a JBoss application server, and works fine on the local machine. The next step i do, is to copy the deployed project.war from the local machine to the server which has the same development environment as the local machine. I stop the JBoss server, delete the cache, and run the JBoss server again. When i now try to run one of the pages(xx.xxx.xxx:8080/webservice/test.htm), i get this exception: exception org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:583) root cause java.lang.NullPointerException com.project.db.DBCustomer.isCredentialsCorrect(DBCustomer.java:44) com.project.CreateHController.handleRequest(CreateHController.java:60) org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:807) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:571) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:501) javax.servlet.http.HttpServlet.service(HttpServlet.java:697) javax.servlet.http.HttpServlet.service(HttpServlet.java:810) org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:75) It seems like none of my classes are reachable. Does anyone have any idea of what is wrong? btw: as i said, the project works fine on the local machine.

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  • Which web framework or technologies would suit me?

    - by Suraj Chandran
    Hi, I had been working on desktop apps and server side(non web) for some time and now I am diving in to web first time. I plan to write a scalable enterprise level app. I have worked with Java, Javascript, Jquery etc. but I absolutely hate jsp. So is there any framework that focuses on developing enterprise level web apps without jsp. I liked Wicket's approach, but I think there is a little lack of support of dynamic html in it and jquery(yes i looked at wiquery). Also I feel making wicket apps scalable would take some sweat. Can Spring MVC, Struts2 etc. help me make with this with just using say Java, JavaScript, and JQuery. Or are there any other options for me like Wicket. Please do forgive if anything above looks insane, I am still working on my understanding with enterprise web apps. NOTE: If you think that I should take a different direction or approach, please do suggest!

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  • How to get around LazyInitializationException in scheduled jobs?

    - by Shreerang
    I am working on a J2EE server application which is deployed on Tomcat. I use Spring source as MVC framework and Hibernate as ORM provider. My object model has lot of Lazy relationships (dependent objects are fetched on request). The high level design is like Service level methods call a few DAO methods to perform database operation. The service method is called either from the Flex UI or as a scheduled job. When it is called from Flex UI, the service method works fine i.e. it fetches some objects using DAO methods and even Lazy loading works. This is possible by the use of OpenSessionInViewFilter configured with the UI servlet. But when the same service method is called as scheduled Job, it gives LazyInitializationException. I can not configure OpenSessionInViewFilter because there is no servlet or UI request associated with that. I tried configuring Transaction around the scheduled job method so that service method starts a transaction and all the DAO methods participate in that same transaction, hoping that the transaction will remain active and hibernate session will be available. But it does not work. Please suggest if anyone has ever been able to get such a configuration working. If needed, I can post the Hibernate configuration and log messages. Thanks a lot for help! Shreerang

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  • JPA returning null for deleted items from a set

    - by Jon
    This may be related to my question from a few days ago, but I'm not even sure how to explain this part. (It's an entirely different parent-child relationship.) In my interface, I have a set of attributes (Attribute) and valid values (ValidValue) for each one in a one-to-many relationship. In the Spring MVC frontend, I have a page for an administrator to edit these values. Once it's submitted, if any of these fields (as <input> tags) are blank, I remove the ValidValue object like so: Set<ValidValue> existingValues = new HashSet<ValidValue>(attribute.getValidValues()); Set<ValidValue> finalValues = new HashSet<ValidValue>(); for(ValidValue validValue : attribute.getValidValues()) { if(!validValue.getValue().isEmpty()) { finalValues.add(validValue); } } existingValues.removeAll(finalValues); for(ValidValue removedValue : existingValues) { getApplicationDataService().removeValidValue(removedValue); } attribute.setValidValues(finalValues); getApplicationDataService().modifyAttribute(attribute); The problem is that while the database is updated appropriately, the next time I query for the Attribute objects, they're returned with an extra entry in their ValidValue set -- a null, and thus, the next time I iterate through the values to display, it shows an extra blank value in the middle. I've confirmed that this happens at the point of a merge or find, at the point of "Execute query ReadObjectQuery(entity.Attribute). Here's the code I'm using to modify the database (in the ApplicationDataService): public void modifyAttribute(Attribute attribute) { getJpaTemplate().merge(attribute); } public void removeValidValue(ValidValue removedValue) { ValidValue merged = getJpaTemplate().merge(removedValue); getJpaTemplate().remove(merged); } Here are the relevant parts of the entity classes: Entity @Table(name = "attribute") public class Attribute { @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "attribute") private Set<ValidValue> validValues = new HashSet<ValidValue>(0); } @Entity @Table(name = "valid_value") public class ValidValue { @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "attr_id", nullable = false) private Attribute attribute; }

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  • "Detecting" and loading of "plugins" in GAE

    - by Patrick Cornelissen
    Hi! I have a "plugin like" architecture and I want to create one instance of each class that implements a dedicated interface and put these in a cache. (To have a singleton-ish effect). The plugins will be provided as jars and put into the app engine war file before the app is uploaded. I have tried to use the ClassPathScanningCandidateComponentProvider as I'm using spring anyway, but this didn't work. The provider complained that it was not able to find the HttpServletResponse class file while scanning the classpath. I can't get around this, when I add the servlet jar, then I'll get of course problems, because the same jar is also provided by the GAE. If I don't, I'm getting the error above... So I tried to add a static initialization code, but of course this doesn't work, because the class is initialized when it's instantiated for the first time. (Well I knew that but it was worth a try) The last chance I currently see is that I create a properties file with all plugin classes when the package is created, but this requires writing of a maven plugin etc. and I'd like to avoid that. Is there something that I am missing?

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  • Locking database edit by key name

    - by Will Glass
    I need to prevent simultaneous edits to a database field. Users are executing a push operation on a structured data field, so I want to sequence the operations, not simply ignore one edit and take the second. Essentially I want to do synchronized(key name) { push value onto the database field } and set up the synchronized item so that only one operation on "key name" will occur at a time. (note: I'm simplifying, it's not always a simple push). A crude way to do this would be a global synchronization, but that bottlenecks the entire app. All I need to do is sequence two simultaneous writes with the same key, which is rare but annoying occurrence. This is a web-based java app, written with Spring (and using JPA/MySQL). The operation is triggered by a user web service call. (the root cause is when a user sends two simultaneous http requests with the same key). I've glanced through the Doug Lea/Josh Bloch/et al Concurrency in Action, but don't see an obvious solution. Still, this seems simple enough I feel there must be an elegant way to do this.

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  • SpringMvc java.lang.NullPointerException When Posting Form To Server

    - by dev_darin
    I have a form with a user name field on it when i tab out of the field i use a RESTFUL Web Service that makes a call to a handler method in the controller. The method makes a call to a DAO class that checks the database if the user name exists. This works fine, however when the form is posted to the server i call the same exact function i would call in the handler method however i get a java.lang.NullPointerException when it accesses the class that makes a call to the DAO object. So it does not even access the DAO object the second time. I have exception handlers around the calls in all my classes that makes calls. Any ideas as to whats happening here why i would get the java.lang.NullPointerException the second time the function is called.Does this have anything to do with Spring instantiating DAO classes using a Singleton method or something to that effect? What can be done to resolve this? This is what happens the First Time The Method is called using the Web Service(this is suppose to happen): 13011 [http-8084-2] INFO com.crimetrack.jdbc.JdbcOfficersDAO - Inside jdbcOfficersDAO 13031 [http-8084-2] DEBUG org.springframework.jdbc.core.JdbcTemplate - Executing prepared SQL query 13034 [http-8084-2] DEBUG org.springframework.jdbc.core.JdbcTemplate - Executing prepared SQL statement [SELECT userName FROM crimetrack.tblofficers WHERE userName = ?] 13071 [http-8084-2] DEBUG org.springframework.jdbc.datasource.DataSourceUtils - Fetching JDBC Connection from DataSource 13496 [http-8084-2] DEBUG org.springframework.jdbc.core.StatementCreatorUtils - Setting SQL statement parameter value: column index 1, parameter value [adminz], value class [java.lang.String], SQL type unknown 13534 [http-8084-2] DEBUG org.springframework.jdbc.datasource.DataSourceUtils - Returning JDBC Connection to DataSource 13537 [http-8084-2] INFO com.crimetrack.jdbc.JdbcOfficersDAO - No username was found in exception 13537 [http-8084-2] INFO com.crimetrack.service.ValidateUserNameManager - UserName :adminz does NOT exist The Second time When The Form Is 'Post' and a validation method handles the form and calls the same method the web service would call: 17199 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - UserName is not null so going to check if its valid for :adminz 17199 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - User Name in try.....catch block is adminz 17199 [http-8084-2] INFO com.crimetrack.service.ValidateUserNameManager - Inside Do UserNameExist about to validate with username : adminz 17199 [http-8084-2] INFO com.crimetrack.service.ValidateUserNameManager - UserName :adminz EXCEPTION OCCURED java.lang.NullPointerException

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  • How to create a separate thread to do some operation periodically and update UI in WPF?I'm stack

    - by black sensei
    Hello Experts! I'm trying to do a periodic separated thread operation let's say check for internet connection or check for user's info via web service and update the user interface. i've tried with quartz.net to implement that.So i created an inner class for the window i need to update.That inner class does what is meant for but the problem is that i don't know how to access parent's(window class) members form the child(inner class). for example public partial class Window2 : Window { private int i; public Window2() { InitializeComponent(); } public string doMyOperation() { //code here return result; } public class Myclass :IJob { public void Execute(JobExecutionContext context) { string result = doMyOperation(); //Now here i could be able to call a label of name lblNotif //lblNotif.Content = result; } } } Well the whole idea works but i'm stacked at here i need to access a controls of Window2 Since i'm stacked i tried Spring.Net way of implementing Quartz hoping that i could use MethodInvokingJobDetailFactoryObject and rather have the Operation done on Window2 itself.But for some reason i'm having an exception Cannot resolve type [System.Windows.Window2,System.Windows];, could not load type from string value System.Windows.Window2,System.Windows and the wiring is done so <object name="UpdateLabelJob" type="System.Windows.Window2,System.Windows"/> What i'm i doing wrong here?Is that a way round? thanks for reading and for helping out

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  • PropertyPlaceholderConfigurer works from Maven command line, but not from Eclipse?

    - by HDave
    I have Eclipse configured to use an external maven instance. Nonetheless I have an integration test that runs fine from the command line, but fails from within Eclipse. The error is a class Spring application context bean error: Cannot convert value of type [java.lang.String] to required type The culprit it a bean that sets property values using a PropertyPlaceholderConfigurer. <!-- property settings for non-JNDI database connections --> <bean id="placeholderConfigUuid" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" /> <property name="location" value="classpath:database.properties" /> <property name="placeholderPrefix" value="$DS{" /> </bean> I know which bean is failing because it appears in the stack trace and because when I replace the $DS{hibernate.dialect} with a static value it works. I have two questions: 1) Since M2Eclipse is using the same Maven setup as the command line, why does one work and the other fail? 2) How to fix this? I really like the ability to run a single jUnit test from within Eclipse on demand.

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  • Testing Hibernate DAO, without building the universe around it.

    - by Varun Mehta
    We have an application built using spring/Hibernate/MySQL, now we want to test the DAO layer, but here are a few shortcomings we face. Consider the use case of multiple objects connected to one another, eg: Book has Pages. The Page object cannot exist without the Book as book_id is mandatory FK in Page. For testing a Page I have to create a Book. This simple usecase is easy to manage, but if you start building a Library, till you don't create the whole universe surrounding the Book and Page, you cannot test it! So to test Page; Create Library Create Section Create Genre Create Author Create Book Create Page Now test Page. Is there an easy way to by pass this "universe creation" and just test he page object in isolation. I also want to be able to test HQLs related to Page. eg: SELECT new com.test.BookPage (book.id, page.name) FROM Book book, Page page. JUnit is supposed to run in isolation, so I have to write the whole test case to create the Page. Any tips will be useful.

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  • What is the right way to process inconsistent data files?

    - by Tahabi
    I'm working at a company that uses Excel files to store product data, specifically, test results from products before they are shipped out. There are a few thousand spreadsheets with anywhere from 50-100 relevant data points per file. Over the years, the schema for the spreadsheets has changed significantly, but not unidirectionally - in the sense that, changes often get reverted and then re-added in the space of a few dozen to few hundred files. My project is to convert about 8000 of these spreadsheets into a database that can be queried. I'm using MongoDB to deal with the inconsistency in the data, and Python. My question is, what is the "right" or canonical way to deal with the huge variance in my source files? I've written a data structure which stores the data I want for the latest template, which will be the final template used going forward, but that only helps for a few hundred files historically. Brute-forcing a solution would mean writing similar data structures for each version/template - which means potentially writing hundreds of schemas with dozens of fields each. This seems very inefficient, especially when sometimes a change in the template is as little as moving a single line of data one row down or splitting what used to be one data field into two data fields. A slightly more elegant solution I have in mind would be writing schemas for all the variants I can find for pre-defined groups in the source files, and then writing a function to match a particular series of files with a series of variants that matches that set of files. This is because, more often that not, most of the file will remain consistent over a long period, only marred by one or two errant sections, but inside the period, which section is inconsistent, is inconsistent. For example, say a file has four sections with three data fields, which is represented by four Python dictionaries with three keys each. For files 7000-7250, sections 1-3 will be consistent, but section 4 will be shifted one row down. For files 7251-7500, 1-3 are consistent, section 4 is one row down, but a section five appears. For files 7501-7635, sections 1 and 3 will be consistent, but section 2 will have five data fields instead of three, section five disappears, and section 4 is still shifted down one row. For files 7636-7800, section 1 is consistent, section 4 gets shifted back up, section 2 returns to three cells, but section 3 is removed entirely. Files 7800-8000 have everything in order. The proposed function would take the file number and match it to a dictionary representing the data mappings for different variants of each section. For example, a section_four_variants dictionary might have two members, one for the shifted-down version, and one for the normal version, a section_two_variants might have three and five field members, etc. The script would then read the matchings, load the correct mapping, extract the data, and insert it into the database. Is this an accepted/right way to go about solving this problem? Should I structure things differently? I don't know what to search Google for either to see what other solutions might be, though I believe the problem lies in the domain of ETL processing. I also have no formal CS training aside from what I've taught myself over the years. If this is not the right forum for this question, please tell me where to move it, if at all. Any help is most appreciated. Thank you.

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  • jstree dynamic JSON data from django

    - by danspants
    I'm trying to set up jsTree to dynamically accept JSON data from django. This is the test data i have django returning to jstree: result=[{ "data" : "A node", "children" : [ { "data" : "Only child", "state" : "closed" } ], "state" : "open" },"Ajax node"] response=HttpResponse(content=result,mimetype="application/json") this is the jstree code I'm using: jQuery("#demo1").jstree({ "json_data" : { "ajax" : { "url" : "/dirlist", "data" : function (n) { return { id : n.attr ? n.attr("id") : 0 }; }, error: function(e){alert(e);} } }, "plugins" : [ "themes","json_data"] }); All I get is the ajax loading symbol, the ajax error response is also triggered and it alerts "undefined". I've also tried simpleJson encoding in django but with the same result. If I change the url so that it is receiving a JSON file with identical data, it works as expected. Any ideas on what the issue might be?

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  • How to filter the jqGrid data NOT using the built in search/filter box

    - by Jimbo
    I want users to be able to filter grid data without using the intrinsic search box. I have created two input fields for date (from and to) and now need to tell the grid to adopt this as its filter and then to request new data. Forging a server request for grid data (bypassing the grid) and setting the grid's data to be the response data wont work - because as soon as the user tries to re-order the results or change the page etc. the grid will request new data from the server using a blank filter. I cant seem to find grid API to achieve this - does anyone have any ideas? Thanks.

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  • Machine learning challenge: diagnosing program in java/groovy (datamining, machine learning)

    - by Registered User
    Hi All! I'm planning to develop program in Java which will provide diagnosis. The data set is divided into two parts one for training and the other for testing. My program should learn to classify from the training data (BTW which contain answer for 30 questions each in new column, each record in new line the last column will be diagnosis 0 or 1, in the testing part of data diagnosis column will be empty - data set contain about 1000 records) and then make predictions in testing part of data :/ I've never done anything similar so I'll appreciate any advice or information about solution to similar problem. I was thinking about Java Machine Learning Library or Java Data Mining Package but I'm not sure if it's right direction... ? and I'm still not sure how to tackle this challenge... Please advise. All the best!

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  • qT quncompress gzip data

    - by talei
    Hello, I stumble upon a problem, and can't find a solution. So what I want to do is uncompress data in qt, using qUncompress(QByteArray), send from www in gzip format. I used wireshark to determine that this is valid gzip stream, also tested with zip/rar and both can uncompress it. Code so far, is like this: static const char dat[40] = { 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0xaa, 0x2e, 0x2e, 0x49, 0x2c, 0x29, 0x2d, 0xb6, 0x4a, 0x4b, 0xcc, 0x29, 0x4e, 0xad, 0x05, 0x00, 0x00, 0x00, 0xff, 0xff, 0x03, 0x00, 0x2a, 0x63, 0x18, 0xc5, 0x0e, 0x00, 0x00, 0x00 }; //this data contains string: {status:false}, in gzip format QByteArray data; data.append( dat, sizeof(dat) ); unsigned int size = 14; //expected uncompresed size, reconstruct it BigEndianes //prepand expected uncompressed size, last 4 byte in dat 0x0e = 14 QByteArray dataPlusSize; dataPlusSize.append( (unsigned int)((size >> 24) & 0xFF)); dataPlusSize.append( (unsigned int)((size >> 16) & 0xFF)); dataPlusSize.append( (unsigned int)((size >> 8) & 0xFF)); dataPlusSize.append( (unsigned int)((size >> 0) & 0xFF)); QByteArray uncomp = qUncompress( dataPlusSize ); qDebug() << uncomp; And uncompression fails with: qUncompress: Z_DATA_ERROR: Input data is corrupted. AFAIK gzip consist of 10 byte header, DEFLATE peyload, 12 byte trailer ( 8 byte CRC32 + 4 byte ISIZE - uncompresed data size ). Striping header and trailer should leave me with DEFLATE data stream, qUncompress yields same error. I checked with data string compressed in PHP, like this: $stringData = gzcompress( "{status:false}", 1); and qUncompress uncompress that data.(I didn't see and gzip header though i.e. ID1 = 0x1f, ID2 = 0x8b ) I checked above code with debug, and error occurs at: if ( #endif ((BITS(8) << 8) + (hold >> 8)) % 31) { //here is error, WHY? long unsigned int hold = 35615 strm->msg = (char *)"incorrect header check"; state->mode = BAD; break; } inflate.c line 610. I know that qUncompress is simply a wrapper to zlib, so I suppose it should handle gzip without any problem. Any comments are more then welcome. Best regards

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  • RDLC - Adding a Data Source in VS2010

    - by Kezzer
    Greetings. I have an RDLC file and am wanting to add a data source to it, although without any luck so far. The data source is a custom class written by myself (just to add, we do this all the time). We recently converted over to the VS2010 RDLC format which caused some problems, but we've made some changes to our implementation that workaround the more major issues. So, back to the issue at hand, when I attempt to add my data source to the DummyDataSource list in the RDLC view in VS2010 it just does nothing, however it does add the data source to the list of data sources, but you can't select it from the drop-down list in the RDLC view which means I can't add the data source at all. Has anyone come across this problem? Is there anything I need to check? I've searched with fervour and had no luck.

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  • Best Practices - Data Annotations vs OnChanging in Entity Framework 4

    - by jptacek
    I was wondering what the general recommendation is for Entity Framework in terms of data validation. I am relatively new to EF, but it appears there are two main approaches to data validation. The first is to create a partial class for the model, and then perform data validations and update a rule violation collection of some sort. This is outlined at http://msdn.microsoft.com/en-us/library/cc716747.aspx The other is to use data annotations and then have the annotations perform data validation. Scott Guthrie explains this on his blog at http://weblogs.asp.net/scottgu/archive/2010/01/15/asp-net-mvc-2-model-validation.aspx. I was wondering what the benefits are of one over the other. It seems the data annotations would be the preferred mechanism, especially as you move to RIA Services, but I want to ensure I am not missing something. Of course, nothing precludes using both of them together. Thanks John

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  • Database design for very large amount of data

    - by Hossein
    Hi, I am working on a project, involving large amount of data from the delicious website.The data available is at files are "Date,UserId,Url,Tags" (for each bookmark). I normalized my database to a 3NF, and because of the nature of the queries that we wanted to use In combination I came down to 6 tables....The design looks fine, however, now a large amount of data is in the database, most of the queries needs to "join" at least 2 tables together to get the answer, sometimes 3 or 4. At first, we didn't have any performance issues, because for testing matters we haven't had added too much data in the database. No that we have a lot of data, simply joining extremely large tables does take a lot of time and for our project which has to be real-time is a disaster.I was wondering how big companies solve these issues.Looks like normalizing tables just adds complexity, but how does the big company handle large amounts of data in their databases, don't they do the normalization? thanks

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  • Invalid XML in persistence.xml : Init method

    - by James.Elsey
    I'm getting the following error when I try to startup my application on google app engine: Failed startup of context com.google.apphosting.utils.jetty.RuntimeAppEngineWebAppContext@8fcc7b{/,/base/data/home/apps/sales-tracker/3.340980411948080671} org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'clientDao' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Cannot resolve reference to bean 'entityManagerFactory' while setting bean property 'entityManagerFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Invalid XML in persistence unit from URL [file:/base/data/home/apps/sales-tracker/3.340980411948080671/WEB-INF/classes/META-INF/persistence.xml] at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:275) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:104) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1245) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1010) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:472) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:380) at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:255) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:45) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548) at org.mortbay.jetty.servlet.Context.startContext(Context.java:136) 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:191) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.getHandler(AppVersionHandlerMap.java:168) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:123) at com.google.apphosting.runtime.JavaRuntime.handleRequest(JavaRuntime.java:243) at com.google.apphosting.base.RuntimePb$EvaluationRuntime$6.handleBlockingRequest(RuntimePb.java:5485) at com.google.apphosting.base.RuntimePb$EvaluationRuntime$6.handleBlockingRequest(RuntimePb.java:5483) at com.google.net.rpc.impl.BlockingApplicationHandler.handleRequest(BlockingApplicationHandler.java:24) at com.google.net.rpc.impl.RpcUtil.runRpcInApplication(RpcUtil.java:398) at com.google.net.rpc.impl.Server$2.run(Server.java:852) at com.google.tracing.LocalTraceSpanRunnable.run(LocalTraceSpanRunnable.java:56) at com.google.tracing.LocalTraceSpanBuilder.internalContinueSpan(LocalTraceSpanBuilder.java:536) at com.google.net.rpc.impl.Server.startRpc(Server.java:807) at com.google.net.rpc.impl.Server.processRequest(Server.java:369) at com.google.net.rpc.impl.ServerConnection.messageReceived(ServerConnection.java:442) at com.google.net.rpc.impl.RpcConnection.parseMessages(RpcConnection.java:319) at com.google.net.rpc.impl.RpcConnection.dataReceived(RpcConnection.java:290) at com.google.net.async.Connection.handleReadEvent(Connection.java:474) at com.google.net.async.EventDispatcher.processNetworkEvents(EventDispatcher.java:831) at com.google.net.async.EventDispatcher.internalLoop(EventDispatcher.java:207) at com.google.net.async.EventDispatcher.loop(EventDispatcher.java:103) at com.google.net.rpc.RpcService.runUntilServerShutdown(RpcService.java:251) at com.google.apphosting.runtime.JavaRuntime$RpcRunnable.run(JavaRuntime.java:404) at java.lang.Thread.run(Unknown Source) Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Invalid XML in persistence unit from URL [file:/base/data/home/apps/sales-tracker/3.340980411948080671/WEB-INF/classes/META-INF/persistence.xml] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1338) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:269) ... 47 more Caused by: java.lang.IllegalArgumentException: Invalid XML in persistence unit from URL [file:/base/data/home/apps/sales-tracker/3.340980411948080671/WEB-INF/classes/META-INF/persistence.xml] at org.springframework.orm.jpa.persistenceunit.PersistenceUnitReader.readPersistenceUnitInfos(PersistenceUnitReader.java:151) at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.readPersistenceUnitInfos(DefaultPersistenceUnitManager.java:303) at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:275) at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.afterPropertiesSet(DefaultPersistenceUnitManager.java:260) at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:192) at org.springframework.orm.jpa.AbstractEnti My persistence.xml looks as follows, as taken from the GAE documentation <?xml version="1.0" encoding="UTF-8" ?> <persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"version="1.0"> <persistence-unit name="transactions-optional"> <provider>org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider</provider> <properties> <property name="datanucleus.NontransactionalRead" value="true" /> <property name="datanucleus.NontransactionalWrite" value="true" /> <property name="datanucleus.ConnectionURL" value="appengine" /> </properties> </persistence-unit> </persistence> Is there something wrong with my persistence file? Or could my errors be caused elsewhere? Can someone please give me some pointers thanks

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  • What's an efficient way of calculating the nearest point?

    - by Griffo
    I have objects with location data stored in Core Data, I would like to be able to fetch and display just the nearest point to the current location. I'm aware there are formulas which will calculate the distance from current lat/long to a stored lat/long, but I'm curious about the best way to perform this for a set of 1000+ points stored in Core Data. I know I could just return the points from Core Data to an array and then loop through that looking for the min value for distance between the points but I'd imagine there's a more efficient method, possibly leveraging Core Data in some way. Any insight would be appreciated. EDIT: I don't know how I missed this on my initial search but this SO question suggests just iterating through an array of Core Data objects but limiting the array size with a bounding box based on the current location. Is this the best I can do?

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  • Need help receiving ByteArray data

    - by k80sg
    Hi folks, I am trying to receive byte array data from a machine. It sends out 3 different types of data structure each with different number of fields which consist of mostly int and a few floats, and byte sizes, the first being 320 bytes, 420 for the second type and 560 for the third. When the sending program is launched, it fires all 3 types of data simultaneouly with an interval of 1 sec. Example: Sending order: Pack1 - 320 bytes 1 sec later Pack2 - 420 bytes 1 sec later Pack3 - 560 bytes 1 sec later Pack1 - 320 bytes ... .. . How do I check the incoming byte size before passing it to: byte[] handsize = new byte[bytesize]; as the data I receive are all out of order, for instance using the following the read all int: System.out.println("Reading data in int format:" + " " + datainput.readInt()); I get many different sets of values whenever I run my prog although with some valid field data but they are all over the place. I am not too sure how exactly should I do it but I tried the following and apparently my data fields are not receiving in correct sequence: BufferedInputStream bais = new BufferedInputStream(requestSocket.getInputStream()); DataInputStream datainput = new DataInputStream(bais); byte[] handsize = new byte[560]; datainput.readFully(handsize); int n = 0; int intByte[] = new int[140]; for (int i = 0; i < 140 ; i++) { System.out.println("Reading data in int format:" + " " + datainput.readInt()); intByte[n] = datainput.readInt(); n = n + 1; System.out.println("The value in array is:" + intByte[0]); System.out.println("The value in array is:" + intByte[1]); System.out.println("The value in array is:" + intByte[2]); System.out.println("The value in array is:" + intByte[3]); Also from the above code, the order of the values printed out with System.out.println("Reading data in int format:" + " " + datainput.readInt()); and System.out.println("The value in array is:" + intByte[0]); System.out.println("The value in array is:" + intByte[1]); are different. Any help will be appreciated. Thanks

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  • C# Winforms ADO.NET - DataGridView INSERT starting with null data

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    I have a C# Winforms app that is connecting to a SQL Server 2005 database. The form I am currently working on allows a user to enter a large amount of different types of data into various textboxes, comboboxes, and a DataGridView to insert into the database. It all represents one particular type of machine, and the data is spread out over about nine tables. The problem I have is that my DataGridView represents a type of data that may or may not be added to the database. Thus, when the DataGridView is created, it is empty and not databound, and so data cannot be entered. My question is, should I create the table with hard-coded field names representing the way that the data looks in the database, or is there a way to simply have the column names populate with no data so that the user can enter it if they like? I don't like the idea of hard-coding them in case there is a change in the database schema, but I'm not sure how else to deal with this problem.

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