Search Results

Search found 42585 results on 1704 pages for 'java api'.

Page 1027/1704 | < Previous Page | 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034  | Next Page >

  • avoid NullPointerException at the first cycle

    - by user1508419
    I have this piece of code: EventSnapshot snapshotEvent = new EventSnapshot(); EventSnapshot currentEvent = new EventSnapshot(); do { ... currentEvent.setContent(in_stats); ... if(!snapshotEvent.equals(currentEvent)) snapshotEvent.setContent(in_stats); } while(true); At the first cycle I get a NullPointerException because obviously the object snapshotEvent is empty. At the second cycle this doesn't happen.how can avoid this problem?

    Read the article

  • What happens if an exception is thrown during finalize()

    - by Psykocyber
    What would happen if an exception is thrown during the execution of finalize()? Is the stack unwind like normally? Does it continue finalize() and ignore the exception? Does it stop finalize() and continue GC the object? Or something else? I'm not looking for guidelines of using finalize() there are plently of pages explaining that.

    Read the article

  • Iterating over hashmap in JSP in struts application

    - by Rozer
    I have a HashMap object that I am getting on a JSP page. HashMap<Integer,Gift_product> gift_hm = new HashMap<Integer,Gift_product>(); gift_hm.put(17,new Gift_product("doll",67)); Now I need to iterate this and display content on JSP. The Gift_product class contains two fields: name and price. JSP output should be serial no. product name price 17 Doll 67 How can I achieve it?

    Read the article

  • Correct usage of "<T extends SuperClass>"

    - by yusaku
    I am not familiar with "Generics". Is it a correct use of "<T extends SuperClass>" ? And do you agree that the codes after using generics are better? Before using Generics ================================================= public abstract class SuperSample { public void getSomething(boolean isProcessA) { doProcessX(); if(isProcessA){ doProcessY(new SubASample()); }else{ doProcessY(new SubBSample()); } } protected abstract void doProcessX(); protected void doProcessY(SubASample subASample) { // Nothing to do } protected void doProcessY(SubBSample subBSample) { // Nothing to do } } public class SubASample extends SuperSample { @Override protected void doProcessX() { System.out.println("doProcessX in SubASample"); } @Override protected void doProcessY(SubASample subASample) { System.out.println("doProcessY in SubASample"); } } public class Sample { public static void main(String[] args) { SubASample subASample = new SubASample(); subASample.getSomething(true); } } After using Generics ================================================= public abstract class SuperSample { public void getSomething(boolean isProcessA) { doProcessX(); if(isProcessA){ doProcessY(new SubASample()); }else{ doProcessY(new SubBSample()); } } protected abstract void doProcessX(); protected abstract <T extends SuperSample> void doProcessY(T subSample); } public class SubASample extends SuperSample { @Override protected void doProcessX() { System.out.println("doProcessX in SubASample"); } @Override protected <T extends SuperSample> void doProcessY(T subSample) { System.out.println("doProcessY in SubASample"); } } public class Sample { public static void main(String[] args) { SubASample subASample = new SubASample(); subASample.getSomething(true); } }

    Read the article

  • NOT replacing ? with letter guessed

    - by user3720541
    i need my code to replace the ? with the letter guessed. The ? needs to be replaced with a for only those to spots. The word in array is parameter. public static void replace(String[] wordOne, String blanks, char guess) { int i; blanks = wordOne[0]; for (i = 0; i < wordOne.length; i++) { for (int j = 0; j < wordOne[0].length(); j++) { blanks = blanks.replace(blanks.charAt(j), '?'); if (wordOne[0].charAt(i) == guess) { blanks = blanks.replace(blanks.charAt(i), guess); } } } System.out.println(blanks); } }

    Read the article

  • multiple search fields

    - by user234194
    What will be the best approach if I have search fields for 20 or more and any combination should be valid. Is there any special way to do it in openJPA or native SQL is better. Any idea would be helpful.Thanks.

    Read the article

  • multiple search fields

    - by user234194
    What will be the best approach if I have search fields for 20 or more and any combination should be valid. Is there any special way to do it in openJPA or native SQL is better. Any idea would be helpful.Thanks.

    Read the article

  • Image creation performance / image caching

    - by Kilnr
    Hello, I'm writing an application that has a scrollable image (used to display a map). The map background consists of several tiles (premade from a big JPG file), that I draw on a Graphics object. I also use a cache (Hashtable), to prevent from having to create every image when I need it. I don't keep everything in memory, because that would be too much. The problem is that when I'm scrolling through the map, and I need an image that wasn't cached, it takes about 60-80 ms to create it. Depending on screen resolution, tile size and scroll direction, this can occur multiple times in one scroll operation (for different tiles). In my case, it often happens that this needs to be done 4 times, which introduces a delay of more than 300 ms, which is extremely noticeable. The easiest thing for me would be that there's some way to speed up the creation of Images, but I guess that's just wishful thinking... Besides that, I suppose the most obvious thing to do is to load the tiles predictively (e.g. when scrolling to the right, precache the tiles to the right), but then I'm faced with the rather difficult task of thinking up a halfway decent algorithm for this. My actual question then is: how can I best do this predictive loading? Maybe I could offload the creation of images to a separate thread? Other things to consider? Thanks in advance.

    Read the article

  • Get first character of each word and its position in a sentence/paragraph

    - by Radhika
    I am trying to create a map by taking the first character of each word and it's position in a sentence/paragraph. I am using regex pattern to achieve this. Regex is a costly operation. Are there are any ways to achieve this? Regex way: public static void getFirstChar(String paragraph) { Pattern pattern = Pattern.compile("(?<=\\b)[a-zA-Z]"); Map newMap = new HashMap(); Matcher fit = pattern.matcher(paragraph); while (fit.find()) { newMap.put((fit.group().toString().charAt(0)), fit.start()); } }

    Read the article

  • About NullPointer Exception in Arraylist

    - by user2234456
    List<PrcSubList> listSl = new ArrayList<PrcSubList>(); if (listSl == null || listSl.size() == 0) { PrcSubList subListAdd=coreService.addSubListByAddAlert(childSub); System.out.println("sublist after insert db :" + subListAdd.getName()); listSl.add(subListAdd); System.out.println(listSl.size() +" sublist after insert list:" + listSl.get(0).getName()); } Ouput with first System.out.println("sublist after insert db :" + subListAdd.getName()); sublist after insert db :SYSTEM_ALERT_12312313 Problem But i have NullPointerException with 2nd System.out.println(listSl.size() +" sublist after insert list:" + listSl.get(0).getName()); Can you help me!

    Read the article

  • I have a feeling that adding fields marked with @Transient annotation to entity is very bug-prone. A

    - by Roman
    I have some philosophical feeling that adding to an entity fields which doesn't mapped to the DB is a wrong way of solving problems. But are there any concrete situations where using @Transient fields leads to implicit and hard fixing problems? For example, is it possible that adding/removing 2nd level cache will break our app when there are @Transient fields in our entities?

    Read the article

  • Method parameters confusion

    - by elec
    Often time methods take more than 3 parameters which are all of the same type, eg. void mymethod (String param1, String param2, String param3) then it's very easy for the client to mix up the parameters orders, for instance inverting param1 and param2: mymethod (param2, param1, param3); ...which can be the cause of much time spent debugging what should be a trivial matter. Any tips on how to avoid this sort of mistake (apart from unit tests) ?

    Read the article

  • JPA + EJB + JSF: how can design complicated query

    - by Harry Pham
    I am using netbean 6.8 btw. Let say that I have 4 different tables: Company, Facility, Project, and Document. So the relationship is this. A company can have multiple facilities. A facility can have multiple projects, and a project can have multiple documents. Company: +companyNum: PK +facilityNum: FK Facility: +facilityNum: PK +projectNum: FK Project: +projectNum: PK +drawingNum: FK So when I create Entity Class From Database in netbean 6.8, I have 4 entity classes that named after the above 4 tables. So if I want to see all the Document in the database, then it is easy. In my SessionBean, I would do this: @PersistenceContext private EntityManager em; List<Document> documents = em.createNamedQuery("Document.findAll").getResultList(); However, that is not all what I need. Let say that I want to know all the Document from a particular Company, or all the Document from a particular Project from a particular Facility from a particular Company. I am very new to JPA + EJB + JSF as a whole. Please help me out.

    Read the article

  • form inside tabview doesn't work

    - by user3536737
    i am working with jsf and primefaces , and here is what 've tried well i want to creat a tabview that get data from an arraylist in my bean i get for exemple 4 tabs , and inside each one i've created a hidden panel where i have a form with 2 input text to update informations , do i display the panel when i click on the second button Update , after that my panel is not hidden anymore , and i set the new values and click on the second button to update the informations , the problem is that the updating and the execution is working only for the first tab , it means when i try to update the new informations it works for the first one and for the other tabs it doesn't here is the code <p:tab title="#{rr.nom_ressource}"> <h:panelGrid> <h:graphicImage value="Ressources/images/emp.jpg" style="vertical-align:middle" /> <span style="font-size:15px; width:170px; display:inline-block;"> Nom : #{rr.nom_ressource} Type: #{rr.type_ressource} Specification: #{rr.experience} </span> <h:commandButton image="Ressources/images/delete.jpg" actionListener="#{SelectBean.act}" update=":form" style="vertical-align:middle" > Update </h:commandButton> <h:commandButton update=":outPanel" actionListener="#{SelectBean.mod1()}" image="Ressources/images/update.png" style="vertical-align:middle" > Modifier </h:commandButton> <h:form id="form111"> <p:growl id="growl" showDetail="true" sticky="true" /> <p:panel rendered ="#{SelectBean.bol}" closable="true" toggleable="true" id="outPanel" styleClass="outPanel" widgetVar="outpanel"> <h:outputLabel value="Nom " /> <h:inputText value="#{SelectBean.nom}" /> <br/> <h:outputLabel value="Experience " /> <h:inputText value="#{SelectBean.exp}" /> <br/> <h:commandButton value="Update" action="#{SelectBean.done}"/> </p:panel> </h:form> </h:panelGrid> </p:tab> for my managedbean the code is correct i think the problem is here

    Read the article

  • A hard Question ?

    - by the-ifl
    Hi Guys , I try To find a solution to a question .... we have a number , example : 20 ... and we have 6 number :{ a ,b , c , d , e , f} < 20 , t try to find all values of these numbers , but only if we can combinate (whit + or -) whit 2 of this numbers and getting all the value below to 20 : for example we choose 31 : a = 22 b = 21 c = 14 d = 11 e = 9 f = 5 we have : 22 - 21 = 1 ; 11 - 9 = 2 ; 14 - 11 = 3 ; 9 - 5 = 4 ; f = 5 ; 11 - 5 = 6 ; 21 - 14 = 7 ; .... .... .... .... .... 21 + 9 = 30 ; 9 + 22 = 31 ;

    Read the article

  • Passing DataSource object from a servlet to a JavaBean

    - by Slavko
    I like the ease of using @Resource annotation to get a DataSource, but as far as I know, it's not possible to use it in a regular JavaBean. Would it be considered a bad practice if I pass the DataSource object from a servlet to a bean along with the other data to avoid having that lookup code in the bean?

    Read the article

  • Full and Partial Matching of Sets

    - by jeffrey
    I have several sets of the same type [Y, M, D] and am trying to write a function to search these sets and return an array of the available sets that fit my parameters. ReturnedSets = return_matches(Y,M,D); I want the three parameters of the function return_matches to be optional. Which means any combination of values can be used to return the sets. For example, one could write - return_matches(13,null,2); - and the function would look for all sets that contain [13, anyValue, 2]; I'm writing this in PHP, to allow users to manage dated files on my website, but I'd like to be able to use this function again for other uses. Thanks! edit: (This, or variations of this, is all I can come up with so far... There is something extra that I don't understand, because this function ends up / would not work to return sets that contain y and d, but leaving m arbitrary. if(y == s[0]){ if(m == s[1]){ if(d == s[2]){ print "day match"; } } else {print "month match";} } else {print "year match";} } else {print "no match";}

    Read the article

  • MySQL Connection Error with JSP

    - by voidmain
    Hello, I am trying to connect to mysql database from jsp page. The connection code is as below InitialContext ic=new InitialContext(); DataSource ds=(DataSource)ic.lookup("jdbc:mysql://localhost:3306/"); Connection con=ds.getConnection(); Statement stmt = con.createStatement(); when i open the page i get the following error javax.servlet.ServletException: javax.naming.NamingException: Lookup failed for 'jdbc:mysql://localhost:3306/' in SerialContext [Root exception is javax.naming.NameNotFoundException: jdbc:mysql:] can some one please tell me what is wrong with this...

    Read the article

< Previous Page | 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034  | Next Page >