Search Results

Search found 33575 results on 1343 pages for 'java bear'.

Page 926/1343 | < Previous Page | 922 923 924 925 926 927 928 929 930 931 932 933  | Next Page >

  • Null Pointer Exception

    - by user1507835
    I am getting a null pointer exception, but I dont know why. I checked to see if the cell was null before I read it to a string. So, why is that string null? private void fillArray() private void fillArray() { try { readBook = new HSSFWorkbook(readFile); } catch (IOException e) { System.out .println("If we know what we're doing, no one should ever see this line."); } if (readBook != null) {HSSFSheet infoSheet = readBook.getSheetAt(0); HSSFRow headingsRow = infoSheet.getRow(0); int i = 0; HSSFCell cell = headingsRow.getCell(i); String columnHeading = cell.toString(); while (cell != null && !(cell.toString().equals(""))) { cell = headingsRow.getCell(i); columnHeading = cell.toString(); columnHeadings.add(columnHeading); i++; } if(columnListIsSetup == false) { createList(); columnListIsSetup = true; } }

    Read the article

  • Q about AbstractApplicationContext.getBeansOfType() and getBean()

    - by Paul Reiners
    We have the following legacy 2.0.7 Spring code: final Map<String, MyClass> secondaryFactories = (Map<String, MyClass>) context.getBeansOfType(MyClass.class, false, true); return (MyClass) context.getBean("myClass"); where context is an instance of org.springframework.context.support.AbstractApplicationContext Note that we ignore the return value of getBeansOfType(). This works just fine, but the problem is that the call to getBeansOfType() is time-consuming. However, even though we ignore the return value of this call, if we try to eliminate this call, then the instance of MyClass returned by getBean() is not fully initialized. (So, apparently, the call to getBeansOfType() is having some sort of side-effects that we need.) We suspect that the call to getBeansOfType() is overkill and we could do something more lightweight so that the instance of MyClass obtained by the call to getBean() would be fully initialized (but it's not null and no exception is thrown). So, is there a more efficient way of doing this?

    Read the article

  • from Hibernate hbm to JPA annotations, a challenging one

    - by nodje
    Hi, I've been struggling with this one for quite some time already. It appears a lot less simple than I thought it'd be: This is included in the "COTISATION" table mapping an uses SynchroDataType, extending Hibernate UserType. This works really great, and I can't find a way to translate it to proper JPA, while keeping the convenience of it. Does someone has a solution for that kind of one-to-one mapping? cheers

    Read the article

  • Ques: Which method will be called and y?

    - by Gaurav
    Ques: Which method will be called and y? public class Test { public void method(Object o){ System.out.println("object"); } public void method(String s) { System.out.println("String"); } public void method() { System.out.println("blank"); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Test test=new Test(); test.method(null); } }

    Read the article

  • Best resources to prepare for the "Spring Framework Certification"

    - by Johan Pelgrim
    Hi there I want to do the Spring Framework Certification (2.5), but there aren't many good resources to prepare for the exam. For the Sun certifications there are a lot of books and trainers (Enthuware / Whizlabs) but not for the Spring certification. Has somebody done the 2.5 exam already? What was your first impression? How did you prepare? What resources did you have and which are sufficient. Thanks in advance for your answers!

    Read the article

  • Speed of Synchronization vs Normal

    - by Swaranga Sarma
    I have a class which is written for a single thread with no methods being synchronized. class MyClass implements MyInterface{ //interface implementation methods, not synchronized } But we also needed a synchronized version of the class. So we made a wrapper class that implements the same interface but has a constructor that takes an instance of MyClass. Any call to the methods of the synchronized class are delegated to the instance of MyClass. Here is my synchronized class.. class SynchronizedMyClass implements MyInterface{ //the constructor public SynchronizedMyClass(MyInterface i/*this is actually an instance of MyClass*/) //interface implementation methods; all synchronized; all delegated to the MyInterface instance } After all this I ran numerous amounts of test runs with both the classes. The tests involve reading log files and counting URLs in each line. The problem is that the synchronized version of the class is consistently taking less time for the parsing. I am using only one thread for the teste, so there is no chance of deadlocks, race around condition etc etc. Each log file contains more than 5 million lines which means calling the methods more than 5 million times. Can anyone explain why synchronized versiuon of the class migt be taking less time than the normal one?

    Read the article

  • Creating an instance within the Class itself

    - by didxga
    What's going on when the assignment statement executed at Line 4, does compiler ignore the new operator and keep the foo variable being null or something else happen to handle this awkward moment? public class Foo { // creating an instance before its constructor has been invoked, suppose the "initializing" // gets printed in constructor as a result of the next line, of course it will not print it private Foo foo = new Foo();//Line 4 public Foo() { System.out.println("initializing"); } }

    Read the article

  • Swing: Programmatically select a text

    - by HH
    Hey everyone, I have a very simple Swing GUI with just a JTetxtArea. I am trying to programmatically select a part of text using: textArea.select(startSelection,endSelection); This work. However as soon as I add some other components to the GUI I do not see selection anymore frame.getContentPane().add(button); frame.getContentPane().add(textArea); textArea.select(startSelection,endSelection); I suspect that during layouting the gui, some event causes the text to be deselected. Am I right? And could anybody suggest a solution? My goal is to have a program which displays a text, and allows the user to input start and end selection position, and a selection appears between these two position. Thank you.

    Read the article

  • Hibernate query cache automatically refreshed on external update?

    - by artgon
    I'm creating a service that has read-only access to the database. I have a query cache and a second level cache enabled (READ_ONLY mode) in Hibernate to speed up the service, as the tables being accessed change rarely. My question is, if someone goes into the DB and changes the tables manually (i.e. outside of Hibernate), does the cache recognize automatically that it needs to be cleared? Is there a time limit on the cache?

    Read the article

  • Unusual "static" method declaration

    - by Jason
    public class Card { public enum Rank { DEUCE, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, TEN, JACK, QUEEN, KING, ACE } public enum Suit { CLUBS, DIAMONDS, HEARTS, SPADES } private final Rank rank; private final Suit suit; private Card(Rank rank, Suit suit) { this.rank = rank; this.suit = suit; } public Rank rank() { return rank; } public Suit suit() { return suit; } public String toString() { return rank + " of " + suit; } private static final List<Card> protoDeck = new ArrayList<Card>(); // Initialize prototype deck **static** { for (Suit suit : Suit.values()) for (Rank rank : Rank.values()) protoDeck.add(new Card(rank, suit)); } public static ArrayList<Card> newDeck() { return new ArrayList<Card>(protoDeck); // Return copy of prototype deck } } I have a quick question. The code block that starts right after the static keyword declaration, what type of method is that ? I haven't ever seen that before. If anyone could enlighten me, that would be greatly appreciated. Thanks.

    Read the article

  • How do I specify the foreign key on a many-to-one relationship when is not a property on the object

    - by jjujuma
    I'm trying to map a many-to-one relationship from MarketMenuBranch to Market. My classes look like: public class Market implements Serializable { private int id; private String name; private List<MarketMenuBranch> marketMenuBranches; // accessors / mutators etc... public class MarketMenuBranch implements Serializable { private MarketMenuBranchId id; private String name; // accessors / mutators etc... public class MarketMenuBranchId implements Serializable { private int marketId; private int sequence; // accessors / mutators etc... But I don't know what I can put for the property name (where I have ???? below). I really want to put id.marketId but that seems to be wrong. <class name="MarketMenuBranch" table="MARKET_MENU_BRANCH"> <composite-id name="id" class="MarketMenuBranchId"> <key-property name="marketId"/> <key-property name="sequence"/> </composite-id> <property name="name"/> <many-to-one name="????????"/> </class> How can I do this?

    Read the article

  • Redirects in Glassfish (adding trailing slash)

    - by echox
    Is it possible to add a trailing slash to the default context of an application? Example: http://www.uri.com/foo -> http://www.uri.com/foo/ I added the following redirect to the server properties: redirect_1: from=/foo url-prefix=/foo/ and this ends up in a loop... Several other configurations also didn't work :-/ I'm using glassfish v2.1-b60e.

    Read the article

  • LRU LinkedHashMap that limits size based on available memory

    - by sanity
    I want to create a LinkedHashMap which will limit its size based on available memory (ie. when freeMemory + (maxMemory - allocatedMemory) gets below a certain threshold). This will be used as a form of cache, probably using "least recently used" as a caching strategy. My concern though is that allocatedMemory also includes (I assume) un-garbage collected data, and thus will over-estimate the amount of used memory. I'm concerned about the unintended consequences this might have. For example, the LinkedHashMap may keep deleting items because it thinks there isn't enough free memory, but the free memory doesn't increase because these deleted items aren't being garbage collected immediately. Does anyone have any experience with this type of thing? Is my concern warranted? If so, can anyone suggest a good approach? I should add that I also want to be able to "lock" the cache, basically saying "ok, from now on don't delete anything because of memory usage issues".

    Read the article

  • Which is the 'correct' way to do this (if statement)

    - by frinkz
    I've got plenty of these lying around, and I'm wondering if I'm going to face any trouble - or performance problems. I have method A: MyClass monkey; ... if(monkey != null) { ... } Or method B: boolean hasMonkey; //This is set to TRUE when monkey is not null MyClass monkey; ... if(hasMonkey) { ... } On a functional level, they both do the same thing. Right now, I'm using method A. Is that a bad way of doing things? Which is going to perform better?

    Read the article

  • JPA 2.0 Provider Hibernate Spring MVC 3.0

    - by user558019
    Dear All i have very strange problem we are using jpa 2.0 with hibernate and spring 3.0 mvc annotations based Database generated through JPA DDL is true and MySQL as Database; i will provide some refference classes and then my porblem. public abstract class Common implements serializable{ @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id", updatable = false) private Long id; @ManyToOne @JoinColumn private Address address; //with all getter and setters //as well equal and hashCode } public class Parent extends Common{ private String name; @OneToMany(cascade = {CascadeType.MERGE,CascadeType.PERSIST}, mappedBy = "parent") private List<Child> child; //setters and rest of class } public class child extends Common{ //some properties with getter/setters } public class Address implements Serializable{ @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id", updatable = false) private Long id; private String street; //rest of class with get/setter } as in code you can see that parents and child classes extends Common class so both have address property and id , the problem occurs when change the address refference in parent class it reflect same change in all child objects in list and if change address refference in child class then on merge it will change address refference of parent as well i am not able to figure out is it is problem of jpa or hibernate or spring thanks in advance

    Read the article

  • Why the generated key size is not constant?

    - by Tom Brito
    The following code prints randomly 634, 635, 636, each time I run it. Why its not constant? public static void main(String[] args) throws Exception { KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA", "BC"); keyPairGen.initialize(1024); RsaKeyPair keyPair = new RsaKeyPair(keyPairGen.generateKeyPair()); System.out.println(keyPair.getPrivate().getEncoded().length); }

    Read the article

  • Background image JFrame with content

    - by Petr Safar
    I have a JFrame with BorderLayout, there are panels on all sides (North, East ,...). In the panels there are labels and buttons mostly. Now I want the frame to have a background image, some research told me that i had to change the content pane of my frame. When I try this however, the content gets put in the background and isn't visible. Also, I don't know how to resize the image if the frame is resized. Is there an easy fix for this or will I have to rework most of my code?

    Read the article

  • Generation of abstract class with JCodeModel

    - by SadJokerBY
    I'm trying to generate top-level abstract class with JCodeModel library, but I can't find any way to change class modifiers. It's possible for nested classes (JDefinedClass API provides methods that get modifiers as parameters). But for creation of top level classes I found only JCodeModel API methods that get fully qualified name with or without ClassType (class/interface/annotation/enum) as parameters. Does anybody can suggest me how to change modifiers of JDefinedClass to make it abstract?

    Read the article

< Previous Page | 922 923 924 925 926 927 928 929 930 931 932 933  | Next Page >