Search Results

Search found 35663 results on 1427 pages for 'embedded java'.

Page 813/1427 | < Previous Page | 809 810 811 812 813 814 815 816 817 818 819 820  | Next Page >

  • Modelling a manyToMany relationship with attributes

    - by Javi
    Hello, I have a ManyToMany relationship between two classes, for instance class Customer and class Item. A customer can buy several items and an item can be bought by different customers. I need to store extra information in this relationship, for example the day when the item was bought. I wonder how is this usually modelled in JPA, cause I'm not sure how to express this in code. Do I have to create a new class to model all the attributes of the relationship and make a manyToMany relationship between the other classes or is a better way to do this? Thanks

    Read the article

  • 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:

    Read the article

  • Using a JMS Session from different threads

    - by Evan
    From the javadoc for Session it states: A Session object is a single-threaded context for producing and consuming messages. So I understand that you shouldn't use a Session object from two different threads at the same time. What I'm unclear on is if you could use the Session object (or children such as a Queue) from a different thread than the one it created. In the case I'm working on, I'm considering putting my Session objects into a pool of available sessions that any thread could borrow from, use, and return to the pool when it is finished with it. Is this kosher? (Using ActiveMQ BTW, if that impacts the answer at all.)

    Read the article

  • How do I subtract a binding using a Guice module override?

    - by Jimmy Yuen Ho Wong
    So according to my testing, If you have something like: Module modA = new AbstractModule() { public void configure() { bind(A.class).to(AImpl.class); bind(C.class).to(ACImpl.class); bind(E.class).to(EImpl.class); } } Module modB = New AbstractModule() { public void configure() { bind(A.class).to(C.class); bind(D.class).to(DImpl.class); } } Guice.createInjector(Modules.overrides(modA, modB)); // gives me binding for A, C, E AND D with A overridden to A->C. But what if you want to remove the binding for E in modB? I can't seem to find a way to do this without having to break the bind for E into a separate module. Is there a way?

    Read the article

  • Spring hibernate ehcache setup

    - by Johan Sjöberg
    I have some problems getting the hibernate second level cache to work for caching domain objects. According to the ehcache documentation it shouldn't be too complicated to add caching to my existing working application. I have the following setup (only relevant snippets are outlined): @Entity @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE public void Entity { // ... } ehcache-entity.xml <cache name="com.company.Entity" eternal="false" maxElementsInMemory="10000" overflowToDisk="true" diskPersistent="false" timeToIdleSeconds="0" timeToLiveSeconds="300" memoryStoreEvictionPolicy="LRU" /> ApplicationContext.xml <bean class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="dataSource" ref="ds" /> <property name="annotatedClasses"> <list> <value>com.company.Entity</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.generate_statistics">true</prop> <prop key="hibernate.cache.use_second_level_cache">true</prop> <prop key="net.sf.ehcache.configurationResourceName">/ehcache-entity.xml</prop> <prop key="hibernate.cache.region.factory_class">net.sf.ehcache.hibernate.SingletonEhCacheRegionFactory</prop> .... </property> </bean> Maven dependencies <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-annotations</artifactId> <version>3.4.0.GA</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-hibernate3</artifactId> <version>2.0.8</version> <exclusions> <exclusion> <artifactId>hibernate</artifactId> <groupId>org.hibernate</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>net.sf.ehcache</groupId> <artifactId>ehcache-core</artifactId> <version>2.3.2</version> </dependency> A test class is used which enables cache statistics: Cache cache = cacheManager.getCache("com.company.Entity"); cache.setStatisticsAccuracy(Statistics.STATISTICS_ACCURACY_GUARANTEED); cache.setStatisticsEnabled(true); // store, read etc ... cache.getStatistics().getMemoryStoreObjectCount(); // returns 0 No operation seems to trigger any cache changes. What am I missing? Currently I'm using HibernateTemplate in the DAO, perhaps that has some impact. [EDIT] The only ehcache log output when set to DEBUG is: SettingsFactory: Cache region factory : net.sf.ehcache.hibernate.SingletonEhCacheRegionFactory

    Read the article

  • Do you have examples of un-helpful/Obscure error messages

    - by Wiretap
    Yesterday I got this error The processing instruction target matching "[xX][mM][lL]" is not allowed when I investigated, it was caused by whitespace at the very start of my XML document. Not difficult to solve, but I was struck with how unhelpful that particular error message was to identifying the actual problem. So what other examples of obscure errors do people have, and are you willing to admit to some of your own making.

    Read the article

  • Generating a URL pattern when provided a set of 5 or so URLs

    - by ryan
    Provided with a set of URLs, I need to generate a pattern, For example: http://www.buy.com/prod/disney-s-star-struck/q/loc/109/213724402.html http://www.buy.com/prod/samsung-f2380-23-widescreen-1080p-lcd-monitor-150-000-1-dc-8ms-1920-x/q/loc/101/211249863.html http://www.buy.com/prod/panasonic-nnh765wf-microwave-oven-countertop-1-6-ft-1250w-panasonic/q/loc/66357/202045865.html http://www.buy.com/prod/escape-by-calvin-klein-for-women-3-4-oz-edp-spray/q/loc/66740/211210860.html http://www.buy.com/prod/v-touch-8gb-mp3-mp4-2-8-touch-screen-2mp-camera-expandable-minisd-w/q/loc/111/211402014.html Pattern is http://www.buy.com/prod/[^~]/q/loc/[^~].html

    Read the article

  • Why a variable is seen in the loop and is not seen outside the loop?

    - by Roman
    I have the following code: String serviceType; ServiceBrowser tmpBrowser; for (String playerName: players) { serviceType = "_" + playerName + "._tcp"; tmpBrowser = BrowsersGenerator.getBrowser(serviceType); tmpBrowser.browse(); System.out.println(tmpBrowser.getStatus()); } System.out.println(tmpBrowser.getStatus()); The compiler complains about the last line. It writes "variable tmpBrowser might not been initialized". If I comment the last line the compile does not complain.

    Read the article

  • Using ControllerClassNameHandlerMapping with @Controller and extending AbstractController

    - by whiskerz
    Hey there, actually I thought I was trying something really simple. ControllerClassNameHandlerMapping sounded great to produce a small spring webapp using a very lean configuration. Just annotate the Controller with @Controller, have it extend AbstractController and the configuration shouldn't need more than this <context:component-scan base-package="test.mypackage.controller" /> <bean id="urlMapping" class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" /> to resolve my requests and map them to my controllers. I've mapped the servlet to "*.spring", and calling <approot>/hello.spring All I ever get is an error stating that no mapping was found. If however I extend the MultiActionController, and do something like <approot>/hello/hello.spring it works. Which somehow irritates me, as I would have thought that if that is working, why didn't my first try? Does anyone have any idea? The two controllers I used looked like this @Controller public class HelloController extends AbstractController { @Override protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView modelAndView = new ModelAndView("hello"); modelAndView.addObject("message", "Hello World!"); return modelAndView; } } and @Controller public class HelloController extends MultiActionController { public ModelAndView hello(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView modelAndView = new ModelAndView("hello"); modelAndView.addObject("message", "Hello World!"); return modelAndView; } }

    Read the article

  • How do I add a library in Eclipse?

    - by jul
    hi, I downloaded the Gson library from http://code.google.com/p/google-gson/. The archive contains the following jar files: google-gson-1.3/gson-1.3-javadoc.jar google-gson-1.3/gson-1.3.jar google-gson-1.3/gson-1.3-sources.jar How do I set my Eclipse to be able to use the package in my projects? Where do I put the documentation? Thanks jul

    Read the article

  • How to read attachment messages without using scriptlets in JSP?

    - by Stardust
    Hi, I want to know how can I read attachment messages without using scriplets in JSP? After getting Message object as an attribute by using request object from servlets, how can I confirm whether Message content is an instance of Multipart or not without using scriplets like: if(message.getContent() instanceOf Multipart) How can I read the content of any file by using EL in JSP? As I can't see any getRead method in inputStream subclass.

    Read the article

  • Possible to split one JAX-WS service across multiple source files?

    - by Rob S.
    Hi everyone, Is it possible to split a web service in to multiple classes and still provide a single path to the web service? I know this isn't possible because of the duplicate url-pattern values. It sort of illustrates where we're wanting to go :) <endpoint name="OneBigService" implementation="SmallImpl1" url-pattern="/OneBigService"/> <endpoint name="OneBigService" implementation="SmallImpl2" url-pattern="/OneBigService"/> Basically, how do avoid having one monolithic @WebService class? Thanks! Rob

    Read the article

  • Running server-program from a .jar file

    - by skiwi
    I have created and am working on a server-application that monitors for specific folders and takes appropriate actions whenever files are being added. Now I come to the point where I want to be able to shutdown the program, for example for applying a patch. The server runs simply in a command prompt, how can I signal that I want to perform maintenance on it? I do not think reading System.In is feasible as I am also outputting text in the prompt. Regards.

    Read the article

  • 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?

    Read the article

  • What is design principle behind Servlets being Singleton

    - by Sandeep Jindal
    A servlet container "generally" create one instance of a servlet and different threads of the same instance to serve multiple requests. (I know this can be changed using deprecated SingleThreadModel and other features, but this is the usual way). I thought, the simple reason behind this is performance gain, as creating threads is better than creating instances. But it seems this is not the reason. On the other hand, creating instances have little advantage that developers never have to worry about thread safety. I am trying to understand the reason for this decision over the trade-off of thread-safety.

    Read the article

  • What does this do and why does it require a transaction?

    - by S. Palin
    What does the following code example do and why does it require a transaction? // PersistenceManager pm = ...; Transaction tx = pm.currentTransaction(); User user = userService.currentUser(); List<Account> accounts = new ArrayList<Account>(); try { tx.begin(); Query query = pm.newQuery("select from Customer " + "where user == userParam " + "parameters User userParam"); List<Customer> customers = (List<Customer>) query.execute(user); query = pm.newQuery("select from Account " + "where parent-pk == keyParam " + "parameters Key keyParam"); for (Customer customer : customers) { accounts.addAll((List<Account>) query.execute(customer.key)); } } finally { if (tx.isActive()) { tx.rollback(); } }

    Read the article

  • Using Hibernate with Dynamic Eclipse Plug-ins

    - by AlbertoPL
    I have classes that are named exactly the same across different plug-ins that I use for my application, and I'd like to be able to configure them properly with Hibernate. The problem is that it looks like Hibernate dynamically generates a class' package name when trying to find a class when it's doing its mapping. With one plug-in this scheme works, but across multiple plug-ins it's not working. It looks like Hibernate gets confused when dealing with Hibernate configuration files across multiple plug-ins. Is this because each plug-in has its own class-loader? What is the best way to proceed to make this work with the existing plug-ins and Hibernate?

    Read the article

  • How can I find out if two arguments are instances of the same, but unknown class?

    - by Ingmar
    Let us say we have a method which accepts two arguments o1 and o2 of type Object and returns a boolean value. I want this method to return true only when the arguments are instances of the same class, e.g.: foo(new Integer(4),new Integer(5)); Should return true, however: foo(new SomeClass(), new SubtypeSomeClass()); should return false and also: foo(new Integer(3),"zoo"); should return false. I believe one way is to compare the fully qualified class names: public boolean foo(Object o1, Object o2){ Class<? extends Object> c1 = o1.getClass(); Class<? extends Object> c2 = o2.getClass(); if(c1.getName().equals(c2.getName()){ return true;} return false; } An alternative conditional statement would be : if (c1.isAssignableFrom(c2) && c2.isAssignableFrom(c1)){ return true; } The latter alternative is rather slow. Are there other alternatives to this problem?

    Read the article

  • How do I sort an ArrayList lexicographically?

    - by Jake
    I am trying to sort an ArrayList of Strings that represent card values. So, some cards contain letters ("King") and some contain Strings containing only a number ("7"). I know to use Collections.sort, but it only sorts Strings that contain letters. How do I get the ArrayList to be sorted by number as well as alphabetically?

    Read the article

  • Hibernate constraint ConstraintViolationException. Is there an easy way to ignore duplicate entries?

    - by vincent
    Basically I've got the below schema and I'm inserting records if they don't exists. However when it comes to inserting a duplicate it throws and error as I would expect. My question is whether there is an easy way to make Hibernate to just ignore inserts which would in effect insert duplicates? CREATE TABLE IF NOT EXISTS `method` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `name` varchar(10) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `name` (`name`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ; SEVERE: Duplicate entry 'GET' for key 'name' Exception in thread "pool-11-thread-4" org.hibernate.exception.ConstraintViolationException: could not insert:

    Read the article

< Previous Page | 809 810 811 812 813 814 815 816 817 818 819 820  | Next Page >