Search Results

Search found 33297 results on 1332 pages for 'java java ee'.

Page 801/1332 | < Previous Page | 797 798 799 800 801 802 803 804 805 806 807 808  | Next Page >

  • When to use LinkedList<> over ArrayList<>?

    - by sdellysse
    I've always been one to simply use List<String> names = new ArrayList<String>(); I use the interface as the type name for portability, so that when I ask questions such as these I can rework my code. When should LinkedList should be used over ArrayList and vice-versa?

    Read the article

  • JDO, GAE: Load object group by child's key

    - by tiex
    I have owned one-to-many relationship between two objects: @PersistenceCapable(identityType = IdentityType.APPLICATION) public class AccessInfo { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private com.google.appengine.api.datastore.Key keyInternal; ... @Persistent private PollInfo currentState; public AccessInfo(){} public AccessInfo(String key, String voter, PollInfo currentState) { this.voter = voter; this.currentState = currentState; setKey(key); // this key is unique in whole systme } public void setKey(String key) { this.keyInternal = KeyFactory.createKey( AccessInfo.class.getSimpleName(), key); } public String getKey() { return this.keyInternal.getName(); } and @PersistenceCapable(identityType = IdentityType.APPLICATION) public class PollInfo { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Key key; @Persistent(mappedBy = "currentState") private List<AccessInfo> accesses; ... I created an instance of class PollInfo and make it persistence. It is ok. But then I want to load this group by AccessInfo key, and I am getting exception NucleusObjectNotFoundException. Is it possible to load a group by child's key?

    Read the article

  • JSF 2.0 method invocation with argument from var of dataGrid

    - by little_b
    Hello I use primefaces with facelets and i have a quastion: for example i have dataGrid and i want to call method of bean, that registered in faces-config, to include some dynamic content: <p:dataGrid var="provider" value="#{paymentFormBean.providers}"> <ui:include src="contentFactory.getSpecificForm('some attribute')"/> </p:dataGrid> How could i invoke getSpecificForm method with argument from var of dataGrid? Something like: <p:dataGrid var="provider" value="#{paymentFormBean.providers}"> <ui:include src="contentFactory.getSpecificForm(provider.formName)"/> </p:dataGrid> Could anyone help me? Thank you

    Read the article

  • Stub web calls in Scala

    - by Dennis Laumen
    I'm currently writing a wrapper of the Spotify Metadata API to learn Scala. Everything's fine and dandy but I'd like to unit test the code. To properly do this I'll need to stub the Spotify API and get consistent return values (stuff like popularity of tracks changes very frequently). Does anybody know how to stub web calls in Scala, the JVM in general or by using some external tool I could hook up into my Maven setup? PS I'm basically looking for something like Ruby's FakeWeb... Thanks in advance!

    Read the article

  • How to use pom.xml/Maven to initialize a local thoughtsite (App Engine sample) project in Eclipse?

    - by ovr
    This sample app ("thoughtsite") for App Engine contains a pom.xml in its trunk: http://code.google.com/p/thoughtsite/source/browse/#svn/trunk But I don't know what command to run in Maven to set up the project locally. (The README doesn't mention anything about Maven.) I tried to just import the project code directly into Eclipse but it doesn't look like it's in an appropriate format for a direct import. So I assume I need to do something with Maven to get it set up correctly. I haven't really used Maven before so I'm not sure what command I would need to run to set everything up. The pom.xml seems like it downloads a bunch of dependencies for the project like the Spring jar files which I don't see anywhere else in the svn repository.

    Read the article

  • select and jstl query

    - by sarah
    Hi All, I am displaying data in combo box using ${role} the requirement is on clcik of edit i want to show the preselected value in the drop down ,suppose i have cat,rat and i selected rat and i saved it in database ,now when i want to edit the details i want to show rat first in drop down as pre selected and then cat,how to od this ?

    Read the article

  • convert pixels into image

    - by Zeta Op
    what i am trying to do is to convert a pixel from a video cam, into an image to expalin it better imagine a 3d model so.. the pixels would be each polying, and i want to do is to conver each polyigon into an image. what i have so far is this ** import processing.video.*; PImage hoja; Capture cam; boolean uno, dos, tres, cuatro; import ddf.minim.*; Minim minim; AudioPlayer audio; float set; void setup() { //audio minim = new Minim(this); // audio = minim.loadFile("audio"); // audio.loop(); // uno=false; dos=false; tres=false; cuatro=true; size(640, 480); hoja=loadImage("hoja.gif"); cam = new Capture(this, width, height); cam.start(); } void draw() { if (cam.available() == true) { cam.read(); if (uno==true) { filtroUno(); image(cam, 0, 0, 640, 480); } if (dos==true) { filtroDos(); } if(tres==true){ filtroTres(); } if(cuatro==true){ filtroCuatro(); image(cam, set, 0,640,480); } } // The following does the same, and is faster when just drawing the image // without any additional resizing, transformations, or tint. //set(0, 0, cam); } void filtroUno() { cam.loadPixels(); hoja.loadPixels(); for (int i=0;i<cam.pixels.length;i++) { if (brightness(cam.pixels[i])>110) { cam.pixels[i]=color(0, 255, 255); } else { cam.pixels[i]=color(255, 0, 0); } } for (int i=0;i<cam.width;i+=10) { for (int j=0;j<cam.height;j+=10) { int loc=i+(j*cam.width); if (cam.pixels[loc]==color(255, 0, 0)) { for (int x=i;x<i+10;x++) { for (int y=j;y<j+10;y++) { // println("bla"); int locDos=i+(j*cam.width); cam.pixels[locDos]=hoja.get(x, y); } } } } } cam.updatePixels(); } ** the broblem is that each pixel is creating me a matrix, so.. is not recreating what id that to do. i had the method filtroUno but it wasn't showing ok.. and was the result void filtroUno() { cam.loadPixels(); hoja.loadPixels(); for (int i=0;i<cam.pixels.length;i++) { if (brightness(cam.pixels[i])>110) { cam.pixels[i]=color(0, 255, 255); } else { cam.pixels[i]=color(255, 0, 0); } } for (int i=0;i<cam.width;i+=10) { for (int j=0;j<cam.height;j+=10) { int loc=i+j*hoja.width*10; if (cam.pixels[loc]==color(255, 0, 0)) { for (int x=i;x<i+10;x++) { for (int y=j;y<j+10;y++) { // println("bla"); int locDos=x+y*hoja.height*10; cam.pixels[locDos]=hoja.get(x, y); } } } } } cam.updatePixels(); } i hope you can help me thanks note: each red pixel should be the gif image the imge size is 10x10

    Read the article

  • Timer Service in ejb 3.1 - schedule calling timeout problem

    - by Greg
    Hi Guys, I have created simple example with @Singleton, @Schedule and @Timeout annotations to try if they would solve my problem. The scenario is this: EJB calls 'check' function every 5 secconds, and if certain conditions are met it will create single action timer that would invoke some long running process in asynchronous fashion. (it's sort of queue implementation type of thing). It then continues to check, but as long as long running process is there it won't start another one. Below is the code I came up with, but this solution does not work, because it looks like asynchronous call I'm making is in fact blocking my @Schedule method. @Singleton @Startup public class GenerationQueue { private Logger logger = Logger.getLogger(GenerationQueue.class.getName()); private List<String> queue = new ArrayList<String>(); private boolean available = true; @Resource TimerService timerService; @Schedule(persistent=true, minute="*", second="*/5", hour="*") public void checkQueueState() { logger.log(Level.INFO,"Queue state check: "+available+" size: "+queue.size()+", "+new Date()); if (available) { timerService.createSingleActionTimer(new Date(), new TimerConfig(null, false)); } } @Timeout private void generateReport(Timer timer) { logger.info("!!--timeout invoked here "+new Date()); available = false; try { Thread.sleep(1000*60*2); // something that lasts for a bit } catch (Exception e) {} available = true; logger.info("New report generation complete"); } What am I missing here or should I try different aproach? Any ideas most welcome :) Testing with Glassfish 3.0.1 latest build - forgot to mention

    Read the article

  • Access JBOSS Tomcat Web Application from Remote Computer

    - by Rod
    Hi, I just deployed a web application on JBOSS 4.2. It can be accessed locally only (http://localhost:8080/myApp). I cant access it from remote computer by typing its domain: (www.hostname.com:8080/myApp). I added Port 8080 as Exception in Windows Firewall. Note that the host (www.hostname.com) is reachable from remote computers via IIS on port 80. Thanks, Rod

    Read the article

  • JBoss Clustered Service that sends emails from txt file

    - by michael lucas
    I need a little push in the right direction. Here's my problem: I have to create an ultra-reliable service that sends email messages to clients whose addresses are stored in txt file on FTP server. Single txt file may contain unlimited number of entries. Most often the file contains about 300,000 entries. Service exposes interface with just two simple methods: TaskHandle sendEmails(String ftpFilePath); ProcessStatus checkProcessStatus(TaskHandle taskHandle); Method sendEmails() returns TaskHandle by which we can ask for ProcessStatus. For such a service to be reliable clustering is necessary. Processing single txt file might take a long time. Restarting one node in a cluster should have no impact on sending emails. We use JBoss AS 4.2.0 which comes with a nice HASingletonController that ensure one instance of service is running at given time. But once a fail-over happens, the second service should continue work from where the first one stopped. How can I share state between nodes in a cluster in such a way that leaves no possibility of sending some emails twice?

    Read the article

  • How to find the Mac address of a 'shutdown' system on local lan (is it possible?)

    - by pirates-iiita
    hello everyone, Can anyone please tell the way to find out the mac address of a system which is: Shutdown Power plugged in Connected to Lan Nic card ON. Kindly post the solution as i urgently need it in my project... thank you Update I am asking how to find out the mac address of some other system which is already shutdown.... and which is on lan.. I want to find out its mac from my system.... and to be clear... i want to tell that.. arp table can be populated by using ping .. i.e. if 172.16.3.12 is not in arp table then it can be added by just ping 172.16.3.12 but a system can be pinged only if its on ... a shutdown system can't be pinged...

    Read the article

  • Getting fewer columns with hibernate

    - by Gandalf StormCrow
    I have a table with 11 columns, but I need to get only 2 of them in my application, I'm using spring/hibernate/DAO combination. For now I have a domain class which includes all 11 fields, and mapping file which maps all 11 columns in table. How do I use get just 2 of them not all?

    Read the article

  • ExecutionException and InterruptedException while using Future class's get() method

    - by java_geek
    ExecutorService executor = Executors.newSingleThreadExecutor(); try { Task t = new Task(response,inputToPass,pTypes,unit.getInstance(),methodName,unit.getUnitKey()); Future<SCCallOutResponse> fut = executor.submit(t); response = fut.get(unit.getTimeOut(),TimeUnit.MILLISECONDS); } catch (TimeoutException e) { // if the task is still running, a TimeOutException will occur while fut.get() cat.error("Unit " + unit.getUnitKey() + " Timed Out"); response.setVote(SCCallOutConsts.TIMEOUT); } catch (InterruptedException e) { cat.error(e); } catch (ExecutionException e) { cat.error(e); } finally { executor.shutdown(); } } How should i handle the InterruptedException and ExecutionException in the code? And in what cases are these exceptions thrown?

    Read the article

  • question about polynomial multiplication

    - by davit-datuashvili
    i know that horners method for polynomial pultiplication is faster but here i dont know what is happening here is code public class horner{ public static final int n=10; public static final int x=7; public static void main(String[] args){ //non fast version int a[]=new int[]{1,2,3,4,5,6,7,8,9,10}; int xi=1; int y=a[0]; for (int i=1;i<n;i++){ xi=x*xi; y=y+a[i]*xi; } System.out.println(y); //fast method int y1=a[n-1]; for (int i=n-2;i>=0;i--){ y1=x*y+a[i]; } System.out.println(y1); } } result of this two methods are not same result of first method is 462945547 and result of second method is -1054348465 please help

    Read the article

  • How to make safe frequent DataSource switches for AbstractRoutingDataSource?

    - by serg555
    I implemented Dynamic DataSource Routing for Spring+Hibernate according to this article. I have several databases with same structure and I need to select which db will run each specific query. Everything works fine on localhost, but I am worrying about how this will hold up in real web site environment. They are using some static context holder to determine which datasource to use: public class CustomerContextHolder { private static final ThreadLocal<CustomerType> contextHolder = new ThreadLocal<CustomerType>(); public static void setCustomerType(CustomerType customerType) { Assert.notNull(customerType, "customerType cannot be null"); contextHolder.set(customerType); } public static CustomerType getCustomerType() { return (CustomerType) contextHolder.get(); } public static void clearCustomerType() { contextHolder.remove(); } } It is wrapped inside some ThreadLocal container, but what exactly does that mean? What will happen when two web requests call this piece of code in parallel: CustomerContextHolder.setCustomerType(CustomerType.GOLD); //<another user will switch customer type here to CustomerType.SILVER in another request> List<Item> goldItems = catalog.getItems(); Is every web request wrapped into its own thread in Spring MVC? Will CustomerContextHolder.setCustomerType() changes be visible to other web users? My controllers have synchronizeOnSession=true. How to make sure that nobody else will switch datasource until I run required query for current user? Thanks.

    Read the article

  • richfaces keepAlive not working

    - by Jurgen H
    I have a mediaOutput tag which, in its createContent attribute, requires the backing bean to be in a certain state. A list of values, which is filled in an init method, must be available. I therefore added a keepAlive tag for the whole backing bean. I now indeed see the backingBean in stead of some (richfaces) proxy bean, but the filled list is null again. How to make this possible? I checked that the init method was called and that the list is filled in in the init method. <a4j:keepAlive beanName="myBean" /> <a4j:mediaOutput createContent="#{myBean.writeChart}" ... /> The backing bean public class MyBean implements Serializable { public List list; public void init(ActionEvent event) { // call some resource to fill the list list = service.getItems(); } public void writeChart(final OutputStream out, final Object data) throws IOException { // list is null } // getters & setters }

    Read the article

  • NetBeans config file

    - by Ockonal
    Hi guys, my NetBeans has ugly fonts in interface. I'm going to make antialiasing for it. In internet I saw that there is should be -J-Dswing.aatext=true -J-Dawt.useSystemAAFontSettings=on in netbeans_default_options. This file should be located in /etc/netbeans.conf. But there isn't this file. I have NetBeans 6.8. Help, please.

    Read the article

  • Strategy for locale sensitive sort with pagination

    - by Thom Birkeland
    Hi, I work on an application that is deployed on the web. Part of the app is search functions where the result is presented in a sorted list. The application targets users in several countries using different locales (= sorting rules). I need to find a solution for sorting correctly for all users. I currently sort with ORDER BY in my SQL query, so the sorting is done according to the locale (or LC_LOCATE) set for the database. These rules are incorrect for those users with a locale different than the one set for the database. Also, to further complicate the issue, I use pagination in the application, so when I query the database I ask for rows 1 - 15, 16 - 30, etc. depending on the page I need. However, since the sorting is wrong, each page contains entries that are incorrectly sorted. In a worst case scenario, the entire result set for a given page could be out of order, depending on the locale/sorting rules of the current user. If I were to sort in (server side) code, I need to retrieve all rows from the database and then sort. This results in a tremendous performance hit given the amount of data. Thus I would like to avoid this. Does anyone have a strategy (or even technical solution) for attacking this problem that will result in correctly sorted lists without having to take the performance hit of loading all data? Tech details: The database is PostgreSQL 8.3, the application an EJB3 app using EJB QL for data query, running on JBoss 4.5.

    Read the article

  • How to Canonicalize a Stax XML object.

    - by Enrique San Martín
    Hello, i want to Canonicalize a Stax object, the program it's doing it with DOM, but dom can't manage big XML documents (like 1GB), so STAX it's the solution. The Code that i have it's: File file=new File("big-1gb.xml"); org.apache.xml.security.Init.init(); DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance(); DocumentBuilder documentBuilder = dfactory.newDocumentBuilder(); Document doc = documentBuilder.parse(file); Canonicalizer c14n = Canonicalizer.getInstance("http://www.w3.org/TR/2001/REC-xml-c14n-20010315"); outputBytes = c14n.canonicalizeSubtree(doc.getElementsByTagName("SomeTag").item(0)); The idea it's do the code below with Stax... Thx :)

    Read the article

  • ORM framework that extends base class with database-implementation.

    - by aioobe
    I have a game consisting of a client / server + a webpage. A central notion in both client and game-/webserver is an Account. Accounts are stored in a database thus I'm in need of some ORM and recently had a look at Hibernate and Cayenne. My understanding however, is that both frameworks provide an "DatabaseBackedAccount"-class which I extend with my other Account methods. My problem is that the Account class is reused heavily on the client side, and I would obviously not want to include database-related code on the client implementation. My current solution is to have an Account class (shared by server and client) and extend this with a DatabaseBackedAccount (overriding setter-methods and providing a commit method) on the server side. I find this quite natural and nice, however I've had to implement all gory sql-details and ORM myself. Is there any way to "turn the table" in any existing ORM framework, so that the generated classes extend my existing class?

    Read the article

  • How do I recover from an unchecked exception?

    - by erickson
    Unchecked exceptions are alright if you want to handle every failure the same way, for example by logging it and skipping to the next request, displaying a message to the user and handling the next event, etc. If this is my use case, all I have to do is catch some general exception type at a high level in my system, and handle everything the same way. But I want to recover from specific problems, and I'm not sure the best way to approach it with unchecked exceptions. Here is a concrete example. Suppose I have a web application, built using Struts2 and Hibernate. If an exception bubbles up to my "action", I log it, and display a pretty apology to the user. But one of the functions of my web application is creating new user accounts, that require a unique user name. If a user picks a name that already exists, Hibernate throws an org.hibernate.exception.ConstraintViolationException (an unchecked exception) down in the guts of my system. I'd really like to recover from this particular problem by asking the user to choose another user name, rather than giving them the same "we logged your problem but for now you're hosed" message. Here are a few points to consider: There a lot of people creating accounts simultaneously. I don't want to lock the whole user table between a "SELECT" to see if the name exists and an "INSERT" if it doesn't. In the case of relational databases, there might be some tricks to work around this, but what I'm really interested in is the general case where pre-checking for an exception won't work because of a fundamental race condition. Same thing could apply to looking for a file on the file system, etc. Given my CTO's propensity for drive-by management induced by reading technology columns in "Inc.", I need a layer of indirection around the persistence mechanism so that I can throw out Hibernate and use Kodo, or whatever, without changing anything except the lowest layer of persistence code. As a matter of fact, there are several such layers of abstraction in my system. How can I prevent them from leaking in spite of unchecked exceptions? One of the declaimed weaknesses of checked exceptions is having to "handle" them in every call on the stack—either by declaring that a calling method throws them, or by catching them and handling them. Handling them often means wrapping them in another checked exception of a type appropriate to the level of abstraction. So, for example, in checked-exception land, a file-system–based implementation of my UserRegistry might catch IOException, while a database implementation would catch SQLException, but both would throw a UserNotFoundException that hides the underlying implementation. How do I take advantage of unchecked exceptions, sparing myself of the burden of this wrapping at each layer, without leaking implementation details?

    Read the article

  • Reducer getting fewer records than expected

    - by sathishs
    We have a scenario of generating unique key for every single row in a file. we have a timestamp column but the are multiple rows available for a same timestamp in few scenarios. We decided unique values to be timestamp appended with their respective count as mentioned in the below program. Mapper will just emit the timestamp as key and the entire row as its value, and in reducer the key is generated. Problem is Map outputs about 236 rows, of which only 230 records are fed as an input for reducer which outputs the same 230 records. public class UniqueKeyGenerator extends Configured implements Tool { private static final String SEPERATOR = "\t"; private static final int TIME_INDEX = 10; private static final String COUNT_FORMAT_DIGITS = "%010d"; public static class Map extends Mapper<LongWritable, Text, Text, Text> { @Override protected void map(LongWritable key, Text row, Context context) throws IOException, InterruptedException { String input = row.toString(); String[] vals = input.split(SEPERATOR); if (vals != null && vals.length >= TIME_INDEX) { context.write(new Text(vals[TIME_INDEX - 1]), row); } } } public static class Reduce extends Reducer<Text, Text, NullWritable, Text> { @Override protected void reduce(Text eventTimeKey, Iterable<Text> timeGroupedRows, Context context) throws IOException, InterruptedException { int cnt = 1; final String eventTime = eventTimeKey.toString(); for (Text val : timeGroupedRows) { final String res = SEPERATOR.concat(getDate( Long.valueOf(eventTime)).concat( String.format(COUNT_FORMAT_DIGITS, cnt))); val.append(res.getBytes(), 0, res.length()); cnt++; context.write(NullWritable.get(), val); } } } public static String getDate(long time) { SimpleDateFormat utcSdf = new SimpleDateFormat("yyyyMMddhhmmss"); utcSdf.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles")); return utcSdf.format(new Date(time)); } public int run(String[] args) throws Exception { conf(args); return 0; } public static void main(String[] args) throws Exception { conf(args); } private static void conf(String[] args) throws IOException, InterruptedException, ClassNotFoundException { Configuration conf = new Configuration(); Job job = new Job(conf, "uniquekeygen"); job.setJarByClass(UniqueKeyGenerator.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); job.setMapperClass(Map.class); job.setReducerClass(Reduce.class); job.setInputFormatClass(TextInputFormat.class); job.setOutputFormatClass(TextOutputFormat.class); // job.setNumReduceTasks(400); FileInputFormat.addInputPath(job, new Path(args[0])); FileOutputFormat.setOutputPath(job, new Path(args[1])); job.waitForCompletion(true); } } It is consistent for higher no of lines and the difference is as huge as 208969 records for an input of 20855982 lines. what might be the reason for reduced inputs to reducer?

    Read the article

  • Overriding or overloading?

    - by atch
    Guys I know this question is silly but just to make sure: Having in my class method: boolean equal(Document d) { //do something } I'm overloading this method nor overriding right? I know that this or similiar question will be on upcoming egzam and would be stupid to not get points for such a simple mistake;

    Read the article

  • How can I get jsonp to play nice with my class?

    - by George Edison
    This whole jsonp thing is quite confusing... Here is what I want to do: I have a class DataRetriever The class has a method GetData GetData makes a jsonp request with the following code: var new_tag = document.createElement('script'); new_tag.type = 'text/javascript'; new_tag.src = 'http://somesite.com/somemethod?somedata'; // Add the element var bodyRef = document.getElementsByTagName("body").item(0); bodyRef.appendChild(new_tag); Now, the jsonp data from the server somesite.com can call a function in my code with the data. The problem is, how does the data get delivered to the instance of DataRetriever that requested it? I'm really stuck here.

    Read the article

< Previous Page | 797 798 799 800 801 802 803 804 805 806 807 808  | Next Page >