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  • 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?

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  • Code casing question for private class fields

    - by user200295
    Take the following example public class Class1{ public string Prop1{ get {return m_Prop1;} set {m_Prop1 = value; } } private string m_Prop1; // this is standard private property variable name // how do we cap this variable name? While the compiler can figure out same casing // it makes it hard to read private Class2 Class2; // we camel case the parameter public Class1(Class2 class2){ this.Class2 = class2; } } Here are my stock rules The class name is capitalized (Class1) The public properties are capitalized (Prop1) The private field tied to a public property has m_ to indicate this. My coworker prefers _ There is some debate if using m_ or _ should be used at all, as it is like Hungarian notation. Private class fields are capitalized. The part I am trying to figure out is what do I do if when the Class name of a private field matches the private field name. For example, private Class2 Class2; This is confusing. If the private field name is not the same class, for example private string Name; , there isn't much issue. Or am I thinking about the issue wrong. Should my classes and private fields be named in such a way that they don't collide?

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  • Beginner Question ; About Prime Generation in "C" - What is wrong with my code ? -

    - by alorsoncode
    I'm a third year irregular CS student and ,i just realized that i have to start coding. I passed my coding classes with lower bound grades so that i haven't a good background in coding&programming. I'm trying to write a code that generates prime numbers between given upper and lower bounds. Not knowing C well, enforce me to write a rough code then go over it to solve. I can easily set up the logic for intended function but i probably create a wrong algorithm through several different ways. Here I share my last code, i intend to calculate that when a number gives remainder Zero , it should be it self and 1 , so that count==2; What is wrong with my implementation and with my solution generating style? I hope you will warm me up to programming world, i couldn't find enough motivation and courage to get deep into programming. Thanks in Advance :) Stdio and Math.h is Included int primegen(int down,int up) { int divisor,candidate,count=0,k; for(candidate=down;candidate<=up;candidate++) { for(divisor=1;divisor<=candidate;divisor++) { k=(candidate%divisor); } if (k==0) count++; if(count==2) { printf("%d\n", candidate); count=0; } else { continue; } } } int main() { primegen(3,15); return 0; }

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  • Dynamic Array of Objects Sans Vector Class

    - by Connor Black
    I am doing a homework assignment for my summer OO class and we need to write two classes. One is called Sale and the other is called Register. I've written my Sale class; here's the .h file: enum ItemType {BOOK, DVD, SOFTWARE, CREDIT}; class Sale { public: Sale(); // default constructor, // sets numerical member data to 0 void MakeSale(ItemType x, double amt); ItemType Item(); // Returns the type of item in the sale double Price(); // Returns the price of the sale double Tax(); // Returns the amount of tax on the sale double Total(); // Returns the total price of the sale void Display(); // outputs sale info private: double price; // price of item or amount of credit double tax; // amount of sales tax double total; // final price once tax is added in. ItemType item; // transaction type }; For the Register class we need to include a dynamic array of Sale objects in our member data. We cannot use the vector class. How is this done? Here's my 'Register' '.h' class Register{ public: Register(int ident, int amount); ~Register(); int GetID(){return identification;} int GetAmount(){return amountMoney;} void RingUpSale(ItemType item, int basePrice); void ShowLast(); void ShowAll(); void Cancel(); int SalesTax(int n); private: int identification; int amountMoney; };

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  • C++: Vector of objects vs. vector of pointers to new objects?

    - by metamemetics
    Hello, I am seeking to improve my C++ skills by writing a sample software renderer. It takes objects consisting of points in a 3d space and maps them to a 2d viewport and draws circles of varying size for each point in view. Which is better: class World{ vector<ObjectBaseClass> object_list; public: void generate(){ object_list.clear(); object_list.push_back(DerivedClass1()); object_list.push_back(DerivedClass2()); or... class World{ vector<ObjectBaseClass*> object_list; public: void generate(){ object_list.clear(); object_list.push_back(new DerivedClass1()); object_list.push_back(new DerivedClass2()); ?? Would be using pointers in the 2nd example to create new objects defeat the point of using vectors, because vectors automatically call the DerivedClass destructors in the first example but not in the 2nd? Are pointers to new objects necessary when using vectors because they handle memory management themselves as long as you use their access methods? Now let's say I have another method in world: void drawfrom(Viewport& view){ for (unsigned int i=0;i<object_list.size();++i){ object_list.at(i).draw(view); } } When called this will run the draw method for every object in the world list. Let's say I want derived classes to be able to have their own versions of draw(). Would the list need to be of pointers then in order to use the method selector (-) ?

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  • TFS merging for users that are used to VSS

    - by JacksonD
    I just migrated a team of 7 developers from VSS to TFS. I migrated all of their code into a DEV folder which I then branched into a QA folder (which I branched into a PROD folder). The developers usually don't work on the same files, but there are some shared utility classes. All of the code is for a large ASP.NET web site. When the developers are ready to merge from DEV to QA, they only want to merge their changes. For example, let's say that Developer1 has been working on a project for the last 3 months and he's ready to merge all of his code into QA. However, Developer2 has been working on a different project for the last 2 months which is not ready to be merged. Developer1 and Developer2's changes are not in any way dependent on each other, but they are not separated into different folder structures and they each regularly do a get latest. There doesn't seem to be a way for developer1 to only merge his changes without also merging all of developer2's changes. Currently, developer1 is going through the Pending Changes window and 'Undoing Pending Changes' for all of Developer2's changes, but this is time consuming. They could merge each file individually, but this is also time consuming. Is there an easier way? I am going to have a coronary if I hear one more person explain how much easier it was to work in VSS.

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  • Implementing IEnumeralbe on Non-Listed Items

    - by Stacey
    I have a class that contains a static number of objects. This class needs to be frequently 'compared' to other classes that will be simple List objects. public partial class Sheet { public Item X{ get; set; } public Item Y{ get; set; } public Item Z{ get; set; } } the items are obviously not going to be "X" "Y" "Z", those are just generic names for example. The problem is that due to the nature of what needs to be done, a List won't work; even though everything in here is going to be of type Item. It is like a checklist of very specific things that has to be tested against in both code and runtime. This works all fine and well; it isn't my issue. My issue is iterating it. For instance I want to do the following... List<Item> UncheckedItems = // Repository Logic Here. UncheckedItems contains all available items; and the CheckedItems is the Sheet class instance. CheckedItems will contain items that were moved from Unchecked to Checked; however due to the nature of the storage system, items moved to Checked CANNOT be REMOVED from Unchecked. I simply want to iterate through "Checked" and remove anything from the list in Unchecked that is already in "Checked". So naturally, that would go like this with a normal list. foreach(Item item in Unchecked) { if( Checked.Contains(item) ) Unchecked.Remove( item ); } But since "Sheet" is not a 'List', I cannot do that. So I wanted to implement IEnumerable so that I could. Any suggestions? I've never implemented IEnumerable directly before and I'm pretty confused as to where to begin.

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  • Rails nested association issue

    - by Ben Langfeld
    Ok, so I'm new to both Ruby and Rails and I'm trying to do what I believe is called a nested association (please correct me if this is the wrong terminology). I currently have a User model and a Domains model and I have many to many associations setup (using has_many :through) between the two, and this works fine. I now want to extend this to allow for a single role per domain per user (eg User1 is a member of Domain1 and has the role "Admin"). I have setup a Roles model with a single field (name:string) and have created three roles. I have also added a role_id column to the join table (memberships). I expected (and this is probably the issue) to be able to just use user1 = User.find(1) user1.domains.first => <some domain object> user1.domains.first.role => <some role object> but this returns a method not defined error. Can anyone tell me what I'm failing to grasp here? My model classes can be seen at http://gist.github.com/388200

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  • How to use the Zend_Log instance that was created using the Zend_Application_Resource_Log in a model

    - by Alex
    Our Zend_Log is initialized by only adding the following lines to application.ini resources.log.stream.writerName = "Stream" resources.log.stream.writerParams.mode = "a" So Zend_Application_Resource_Log will create the instance for us. We are already able to access this instance in controllers via the following: public function getLog() { $bootstrap = $this->getInvokeArg('bootstrap'); //if (is_null($bootstrap)) return false; if (!$bootstrap->hasPluginResource('Log')) { return false; } $log = $bootstrap->getResource('Log'); return $log; } So far, so good. Now we want to use the same log instance in model classes, where we can not access the bootstrap. Our first idea was to register the very same Log instance in Zend_Registry to be able to use Zend_Registry::get('Zend_Log') everywhere we want: in our Bootstrap class: protected function _initLog() { if (!$this->hasPluginResource('Log')) { throw new Zend_Exception('Log not enabled'); } $log = $this->getResource('Log'); assert( $log != null); Zend_Registry::set('Zend_Log', $log); } Unfortunately this assertion fails == $log IS NULL --- but why?? It is clear that we could just initialize the Zend_Log manually during bootstrapping without using the automatism of Zend_Application_Resource_Log, so this kind of answers will not be accepted.

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  • Joining tables with composite keys in a legacy system in hibernate

    - by Steve N
    Hi, I'm currently trying to create a pair of Hibernate annotated classes to load (read only) from a pair of tables in a legacy system. The legacy system uses a consistent (if somewhat dated) approach to keying tables. The tables I'm attempting to map are as follows: Customer CustomerAddress -------------------------- ---------------------------- customerNumber:string (pk) customerNumber:string (pk_1) name:string sequenceNumber:int (pk_2) street:string postalCode:string I've approached this by creating a CustomerAddress class like this: @Entity @Table(name="CustomerAddress") @IdClass(CustomerAddressKey.class) public class CustomerAddress { @Id @AttributeOverrides({ @AttributeOverride(name = "customerNumber", column = @Column(name="customerNumber")), @AttributeOverride(name = "sequenceNumber", column = @Column(name="sequenceNumber")) }) private String customerNumber; private int sequenceNumber; private String name; private String postalCode; ... } Where the CustomerAddressKey class is a simple Serializable object with the two key fields. The Customer object is then defined as: @Entity @Table(name = "Customer") public class Customer { private String customerNumber; private List<CustomerAddress> addresses = new ArrayList<CustomerAddress>(); private String name; ... } So, my question is: how do I express the OneToMany relationship on the Customer table?

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  • Could this be considered a well-written class (am I using OOP correctly)?

    - by Ben Dauphinee
    I have been learning OOP principals on my own for a while, and taken a few cracks at writing classes. What I really need to know now is if I am actually using what I have learned correctly, or if I could improve as far as OOP is concerned. I have chopped a massive portion of code out of a class that I have been working on for a while now, and pasted it here. To all you skilled and knowledgeable programmers here I ask: Am I doing it wrong? class acl extends genericAPI{ // -- Copied from genericAPI class protected final function sanityCheck($what, $check, $vars){ switch($check){ case 'set': if(isset($vars[$what])){return(1);}else{return(0);} break; } } // --------------------------------- protected $db = null; protected $dataQuery = null; public function __construct(Zend_Db_Adapter_Abstract $db, $config = array()){ $this->db = $db; if(!empty($config)){$this->config = $config;} } protected function _buildQuery($selectType = null, $vars = array()){ // Removed switches for simplicity sake $this->dataQuery = $this->db->select( )->from( $this->config['table_users'], array('tf' => '(CASE WHEN count(*) > 0 THEN 1 ELSE 0 END)') )->where( $this->config['uidcol'] . ' = ?', $vars['uid'] ); } protected function _sanityRun_acl($sanitycheck, &$vars){ switch($sanitycheck){ case 'uid_set': if(!$this->sanityCheck('uid', 'set', $vars)){ throw new Exception(ERR_ACL_NOUID); } $vars['uid'] = settype($vars['uid'], 'integer'); break; } } private function user($action = null, $vars = array()){ switch($action){ case 'exists': $this->_sanityRun_acl('uid_set', $vars); $this->_buildQuery('user_exists_idcheck', $vars); return($this->db->fetchOne($this->dataQuery->__toString())); break; } } public function user_exists($uid){ return($this->user('exists', array('uid' => $uid))); } } $return = $acl_test->user_exists(1);

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  • How to iterate & retrieve values from NSArray of NSArrays of NSDictionaries

    - by chinjazz
    I'm stumpped on how iterate and get values for an Array of Arrays of NSDictionaries (different classes/entities). Here's what I'm currently doing: 1) Constructing two separate arrays of NSDictionaries (different entities) 2) Combining both arrays with: NSMutableArray *combinedArrayofDicts = [[NSMutableArray alloc] initWithObjects: sizesArrayOfDicts, wishListArrayOfDicts , nil]; 3) Then archive combinedArrayofDicts : NSData *dataToSend = [NSKeyedArchiver archivedDataWithRootObject:combinedArrayofDicts]; 4) Transmit over GameKit [self.session sendDataToAllPiers:dataToSend withDataMode: GKSendDataReliable error:nil]; 5) How would I manage traversing thru this array on the receiving end? I want to fetch values by for each class which is key'ed by classname: Here's how it looks via NSLog (2 Sizes Dicts, and 1 Wishlist Dict) Printing description of receivedArray: <__NSArrayM 0xbc65eb0>( <__NSArrayM 0xbc651f0>( { classname = Sizes; displayOrder = 0; share = 1; sizeType = Neck; value = "13\" or 33 (cm)"; }, { classname = Sizes; displayOrder = 0; share = 1; sizeType = Sleeve; value = "34\" or 86 (cm)"; } ) , <__NSArrayM 0xbc65e80>( { classname = Wishlist; detail = ""; displayOrder = 0; imageString = ""; latitude = "30.33216666666667"; link = "http://maps.google.com/maps?q=loc:30.332,-81.41"; longitude = "-81.40949999999999"; name = bass; share = 1; store = ""; } ) ) (lldb) In my for loop I'm issuing this: NSString *value = [dict objectForKey:@"classname"]; and get an exception: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayM objectForKey:]: unrecognized selector sent to instance 0xbc651f0' Is this frowned upon as far as mixing object types in arrays of arrays?

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  • Automatic adition of `using` in CodeRush.

    - by drasto
    I just installed CodeRush Pro (evaluation trial) for Visual Studio and I can say I like it much so far. Comparing to Resharper there is only one type of feature I'm really missing. It is the way CodeRush deals with using. When I type some class name that is not declared in some package listed in using, CodeRush underlines it red as an error(what it is) but if I hover over it with cursor it does not offer me to add using, it merely says it is "Undeclared element". I have to use VS default using addition (move caret to the identifier, hover cursor over that really small box that appears under first letter, click the button that appears and choose for example using System form a drop down menu). Is there a way how to configure CodeRush to offer mi add using when I hover a cursor over highlighted "issue"(that says Undeclared element)? The second part of this is that Resharper has somethink called Type name completion. It some improved intellisense. Lets say you have no using declaration in your file. Then you type something like ICompar and press CTRL+SPACE. Of cause there will be no suggestions. But with Resharper you can press CTRL+ALT+SPACE and you get suggestions of all classes starting with ICompar even if they are not in using. When you choose one of them the correct using is automatically added for you. Is there a way to make CodeRush behave this way ?

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  • when is a v-table created in C++?

    - by saminny
    When exactly does the compiler create a virtual function table? 1) when the class contains at least one virtual function. OR 2) when the immediate base class contains at least one virtual function. OR 3) when any parent class at any level of the hierarchy contains at least one virtual function. A related question to this: Is it possible to give up dynamic dispatch in a C++ hierarchy? e.g. consider the following example. #include <iostream> using namespace std; class A { public: virtual void f(); }; class B: public A { public: void f(); }; class C: public B { public: void f(); }; Which classes will contain a V-Table? Since B does not declare f() as virtual, does class C get dynamic polymorphism?

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  • Experiences wanted: producing a jar artifact in IntelliJ

    - by skiaddict1
    Developing with IntelliJ 9.0.2 Community Edition, on the Mac. This is a follow-up to this post about including jar files in an artifact, which has not received any replies. I'm hoping that the reason is that somehow, in creating my artifact (or setting my project settings), I unwittingly did something which people don't tend to do, and which is causing my problem, and that by asking people here to share how they create jar artifacts and set up projects, I will discover what it is. To recap: I have a Java project which depends on two library files. I need to package up the entire thing, with the jars inlined (such that on doing jar -tfv <filename> I see ALL the classes listed, including the ones in the two libraries), into a single jar file. I can make an artifact, I can add the library files to the Output Layout pane, but I CANNOT, no matter what I do, I cannot get the "Inline Artifact" item in the context menu to be selectable (i.e. non-grey) when I right-click on one or other library file. The thing is, making a jar which contains library files as well as the project code is NOT an unusual situation in the Java world! So I figure there are lots of IntelliJ folks out there who have done what I need to do. And I would really like to hear from you folks. What project settings do you use? (be specific, please :-) And exactly how do you set up your jar artifacts? (again, as many specific details as possible, please :-) Clearly, I'd be particularly interested to hear from folks with similar setups to mine (above) who are successfully doing what I need to do. Grateful thanks in advance, folks.

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  • What is a better, cleaner way of using List<T>

    - by Tim Meers
    I'm looking to implement a few nicer ways to use List in a couple of apps I'm working on. My current implementation looks like this. MyPage.aspx.cs protected void Page_Load(object sender, EventArgs e) { BLL.PostCollection oPost = new BLL.PostCollection(); oPost.OpenRecent(); rptPosts.DataSource = oArt; rptPosts.DataBind(); } BLL Class(s) public class Post { public int PostId { get; set; } public string PostTitle { get; set; } public string PostContent { get; set; } public string PostCreatedDate { get; set; } public void OpenRecentInitFromRow(DataRow row) { this.PostId = (int) row["id"]; this.PostTitle = (string) row["title"]; this.PostContent = (string) row["content"]; this.PostCreatedDate = (DateTime) row["createddate"]; } } public class PostCollection : List<Post> { public void OpenRecent() { DataSet ds = DbProvider.Instance().Post_ListRecent(); foreach (DataRow row in ds.Tables[0].Rows) { Post oPost = new Post(); oPost.OpenRecentInitFromRow(row); Add(oPost); } } } Now while this is working all well and good, I'm just wondering if there is any way to improve it, and just make it cleaner that having to use the two different classes do to something I think can happen in just one class or using an interface.

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  • Java: How ArrayList memory management

    - by cka3o4nik
    In my Data Structures class we have studies the Java ArrayList class, and how it grows the underlying array when a user adds more elements. That is understood. However, I cannot figure out how exactly this class frees up memory when lots of elements are removed from the list. Looking at the source, there are three methods that remove elements: [code] public E remove(int index) { RangeCheck(index); modCount++; E oldValue = (E) elementData[index]; int numMoved = size - index - 1; if (numMoved 0) System.arraycopy(elementData, index+1, elementData, index, numMoved); elementData[--size] = null; // Let gc do its work return oldValue; } public boolean remove(Object o) { if (o == null) { for (int index = 0; index < size; index++) if (elementData[index] == null) { fastRemove(index); return true; } } else { for (int index = 0; index < size; index++) if (o.equals(elementData[index])) { fastRemove(index); return true; } } return false; } private void fastRemove(int index) { modCount++; int numMoved = size - index - 1; if (numMoved 0) System.arraycopy(elementData, index+1, elementData, index, numMoved); elementData[--size] = null; // Let gc do its work } {/code] None of them reduce the datastore array. I even started questioning if memory free up ever happens, but empirical tests show that it does. So there must be some other way it is done, but where and how? I checked the parent classes as well with no success.

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  • Can a member struct be zero-init from the constructor initializer list without calling memset?

    - by selbie
    Let's say I have the following structure declaration (simple struct with no constructor). struct Foo { int x; int y; int z; char szData[DATA_SIZE]; }; Now let's say this struct is a member of a C++ class as follows: class CFoobar { Foo _foo; public: CFoobar(); }; If I declare CFoobar's constructor as follows: CFoobar::CFoobar() { printf("_foo = {%d, %d, %d}\n", _foo.x, _foo.y,_foo.z); for (int x = 0; x < 100; x++) printf("%d\n", _foo.szData[x]); } As you would expect, when CFoobar's constructor runs, garbage data gets printed out Obviously, the easy fix is to memset or ZeroMemory &_foo. It's what I've always done... However, I did notice that if add _foo to the constructor's initialization list with no parameters as follows: CFoobar::CFoobar() : _foo() { That this appears to zero-out the member variables of _foo. At least that was the case with g++ on linux. Now here's my question: Is this standard C++, or is this compiler specific behavior? If it's standard behavior, can someone quote me a reference from an official source? Any "gotchas" in regards to implicit zero-init behavior with more complicated structs and classes?

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  • [Rails3] How to do multiple many to many relationships between the same two tables.

    - by Kurt
    Hi. I have a model of a club where I want to model the two entities Meeting and Member. There are actually two many-to-many relationships between these entities though, as for any meeting a Member can either be a Speaker or a Guest. Now I am an OO thinker, so would normally just create the two classes and each one would just have two arrays of the other inside, but rails is making me think a bit more data centric here, so I realise I need to break these M2M relationships up with join tables Speakers and Guests which I have done, but now I am having trouble describing the relationships in the models. The two join table models both have "belongs_to :meeting" and "belongs_to :member" and I think that should be sufficient. I am not however sure about the Meeting and Member models though. Each one has "has_many :guests" and "has_many: speakers" but I am not sure if I also want to go: has_many :members, :through = :guests has_many :members, :through = :speakers But I suspect that this is like declaring two "members" that will clash. I also thought about: has_many :guests, :through = :guests has_many :speakers, :through = :speakers Does that make sense? How would ActiveRecord know that they are in fact Members? I have found heaps of examples of polymorphic m2m relationships and m2m relationships where 1 table references itself, but no good examples to help me mode this situation where two separate tables have two different m2m relationships. Anyone got any tips?

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  • How can I differentiate two different touches on a layer ?

    - by srikanth rongali
    I am writing an app in cocos2d. I hava a sprite and a text in my scene. I have written two separate classes for sprite and text. And I added both of them to another class. In sprite class I have written - (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event And in text class I have written -(void) registerWithTouchDispatcher { [[CCTouchDispatcher sharedDispatcher]addTargetedDelegate:self priority:0 swallowsTouches:YES]; } -(BOOL) ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event { return YES; } -(void) ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event { NSLog(@"Recognized tOuches in Instructions");// CGSize windowSize = [[CCDirector sharedDirector] winSize]; CCNode *node = [self getChildByTag:kTagNode]; [node setPosition: ccp(text1.contentSize.width/2,text1.contentSize.height/2 - windowSize.height)]; } -(void) ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event { CGPoint touchLocation = [touch locationInView: [touch view]]; CGPoint prevLocation = [touch previousLocationInView: [touch view]]; touchLocation = [[CCDirector sharedDirector] convertToGL: touchLocation]; prevLocation = [[CCDirector sharedDirector] convertToGL: prevLocation]; CGPoint diff = ccpSub(touchLocation,prevLocation); CCNode *node = [self getChildByTag:kTagNode]; CGPoint currentPos = [node position]; [node setPosition: ccpAdd(currentPos, diff)]; } But, only touches in the text are recognized and touch of sprite is not recognized ? How can I differentiate the two touches.

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  • What to throw in a C++ class wrapping a C library ?

    - by ereOn
    I have to create a set of wrapping C++ classes around an existing C library. For many objects of the C library, the construction is done by calling something like britney_spears* create_britney_spears() and the opposite function void free_britney_spears(britney_spears* brit). If the allocation of a britney_spears fails, create_britney_spears() returns NULL. This is, as far as I know, a very common pattern. Now I want to wrap this inside a C++ class. //britney_spears.hpp class BritneySpears { public: BritneySpears(); private: boost::shared_ptr<britney_spears> m_britney_spears; }; And here is the implementation: // britney_spears.cpp BritneySpears::BritneySpears() : m_britney_spears(create_britney_spears(), free_britney_spears) { if (!m_britney_spears) { // Here I should throw something to abort the construction, but what ??! } } So the question is in the code sample: What should I throw to abort the constructor ? I know I can throw almost anything, but I want to know what is usually done. I have no other information about why the allocation failed. Should I create my own exception class ? Is there a std exception for such cases ? Many thanks.

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  • 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?

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  • How to create reference tables using fluent nhibernate

    - by Akk
    How can i create a 3 table schema from the following model classes. public class Product { public int Id {get; set;} public string Name {get; set;} public IList<Photo> Photos {get; set;} } public class Photo { public int Id {get; set;} public string Path {get; set;} } I want to create the following table structure in the database: Product ------- Id Name ProductPhotos ------------- ProductId (FK Products.Id) PhotoId (FK Photos.Id) Photos ------ Id Path How i can express the above Database Schema using Fluent NHibernate? I could only manage the following the Mapping but this does not get me the 3rd Photo ref table. public class ProductMap : ClassMap<Product> { public CityMap() { Id(x => x.Id); Map(x => x.Name); Table("Products"); HasMany(x => x.Photos).Table("ProductPhotos").KeyColumn("ProductId"); } }

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  • Mapping many-to-many association table with extra column(s)

    - by user635524
    My database contains 3 tables: User and Service entities have many-to-many relationship and are joined with the SERVICE_USER table as follows: USERS - SERVICE_USER - SERVICES SERVICE_USER table contains additional BLOCKED column. What is the best way to perform such a mapping? These are my Entity classes @Entity @Table(name = "USERS") public class User implements java.io.Serializable { private String userid; private String email; @Id @Column(name = "USERID", unique = true, nullable = false,) public String getUserid() { return this.userid; } .... some get/set methods } @Entity @Table(name = "SERVICES") public class CmsService implements java.io.Serializable { private String serviceCode; @Id @Column(name = "SERVICE_CODE", unique = true, nullable = false, length = 100) public String getServiceCode() { return this.serviceCode; } .... some additional fields and get/set methods } I followed this example http://giannigar.wordpress.com/2009/09/04/m ... using-jpa/ Here is some test code: User user = new User(); user.setEmail("e2"); user.setUserid("ui2"); user.setPassword("p2"); CmsService service= new CmsService("cd2","name2"); List<UserService> userServiceList = new ArrayList<UserService>(); UserService userService = new UserService(); userService.setService(service); userService.setUser(user); userService.setBlocked(true); service.getUserServices().add(userService); userDAO.save(user); The problem is that hibernate persists User object and UserService one. No success with the CmsService object I tried to use EAGER fetch - no progress Is it possible to achieve the behaviour I'm expecting with the mapping provided above? Maybe there is some more elegant way of mapping many to many join table with additional column?

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  • How to queue and call actual methods (rather than immediately eval) in java?

    - by alleywayjack
    There are a list of tasks that are time sensitive (but "time" in this case is arbitrary to what another program tells me - it's more like "ticks" rather than time). However, I do NOT want said methods to evaluate immediately. I want one to execute after the other finished. I'm using a linked list for my queue, but I'm not really sure how/if I can access the actual methods in a class without evaluating them immediate. The code would look something like... LinkedList<Method> l = new LinkedList<Method>(); l.add( this.move(4) ); l.add( this.read() ); l.removeFirst().call(); //wait 80 ticks l.removeFirst().call(); move(4) would execute immediately, then 80 ticks later, I would remove it from the list and call this.read() which would then be executed. I'm assuming this has to do with the reflection classes, and I've poked around a bit, but I can't seem to get anything to work, or do what I want. If only I could use pointers...

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