I often have a need to take a list of objects and group them into a Map based on a value contained in the object. Eg. take a list of Users and group by Country. My code for this usually looks like: Map<String, List<User>> usersByCountry = new HashMap<String, List<User>>(); for(User user : listOfUsers) { if(usersByCountry.containsKe...
Hi, I have a class with 3 List collections like the following. I am trying to have a logic which will iterate through the object's "collection" properties and do some operation using the data stored in those collections. I am just wondering if there is an easy way of doing it using foreach. thanks public class SampleChartData {...
I'm looking for a C library that provides generic collection data structures such as lists, associative arrays, sets, etc. The library should be stable and well tested. I'm basically looking for something better than the crappy C standard library. What C libraries fit this description? EDIT: I'd prefer that the library was cross-platfo...
I have several jQuery UI Sliders and I want to collect their values. Thought it would be a simple task, but when I was going to do it I got stuck and not quite sure what to do anymore :p The object I would like to end up with should look something like this: { a: 80, b: 90, c: 20, ... } I can do it manually like this: va...
I did following: create or replace type my_row as object ( lname varchar2(30), fname varchar2(30), MI char(1), hohSSN char (9), hohname VARCHAR2(63), hohDob char(10), dob DATE ); create or replace type eiv.my_rec as table of eiv.my_row; but then doing query like: my_records my_rec sele...
I am working on to create a custom control inherited by CheckboxList control. We can add items from ListItem collection editior at the design time. In this ListItem Collection editor there are 4 properties 1) Enabled 2) Selected3) Text4) valueI really need to add some new properties such as "ImageURL" and "IsClear". Do you have any idea...
I'm learning WPF and would like to have a collection similar to a LinkedList, to where I can add and remove strings. And I want to have a ListView that listen to that collection with databinding. How can I do bind a simple list collection to a ListView in XAML? My idea (not working) is something like this: <Window x:Class="TestApp.Main...
For a while at my company we've used a home-grown ObjectPool<T> implementation that provides blocking access to its contents. It's pretty straightforward: a Queue<T>, an object to lock on, and an AutoResetEvent to signal to a "borrowing" thread when an item is added. The meat of the class is really these two methods: public T Borrow() ...
Can anybody Explain me why records are required. Can't we perform the same operation in pl/sql using loop and all. Also when multiset, records query can be used i.e. in which type of situation and which one will be the preference. ...
I need a sorted set of objects and am currently using the TreeSet. My problem is that the compareTo of the objects will often return 0, meaning the order of those two objects is to be left unchanged. TreeMap (used by TreeSet by default) will then regard them as the same object, which is not true. What alternative to TreeMap can I use? ...
am converting a vb.net component to c#, i get this error Using the generic type 'System.Collections.ObjectModel.Collection<T>' requires '1' type arguments This is what i did in VB.NET i had this Private _bufferCol As Collection i did this in c# private Collection _bufferCol = new Collection(); My declaration is using Microsof...
We have a two tier Swing application using Hibernate. Sometimes we manipulate an object in one session (A), which we know in another session (B) as well (two different Java Instances, same database record). In this case after commit and closing of A, we refresh the object in session B, in order to show the updated state in the UI. Works...
I am populating a "Dictionary" with the results of an sp call. The key is the field name and the value is whatever value the sp returns for the field. This is all well and good but I'd like developers to have a predefined list of keys to access this list, for safety and documentation reasons. What I'd like to do is have something like an...
Is it possible to have a foreach statement that will traverse through a Collections object in reverse order? If not a foreach statement is there any other way? Thanks. ...
I know there are already some posts regarding this subject, but although I tried using them as a reference, I am still stuck. I have a persistent class as follows: @PersistenceCapable(identityType = IdentityType.APPLICATION) public class GameObject implements IMySerializable{ @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy....
So, I have a class with a constructor like this: public FilterList(Set<Integer> labels) { ... } and I want to construct a new FilterList object with an empty set. Following Joshua Bloch's advice in his book Effective Java, I don't want to create a new object for the empty set; I'll just use Collections.emptySet() instead: FilterL...
I've added the following Extensions to my Project in order to create a thread safe list: Extensions If I want to conduct a simple operation on my list <Extension()> _ Public Sub Action(Of T)(ByVal list As List(Of T), ByVal action As Action(Of List(Of T))) SyncLock (list) action(list) End SyncLock ...
Hey, I'd like to convert an array to a set in Java. There are some obvious ways of doing this (i.e. with a loop) but I would like something a bit neater, something like: java.util.Arrays.asList(Object[] a); Any ideas? Cheers, Pete ...
I'm trying to call DisplayFor and DisplayForModel to iterate an IEnumerable<> with various element types from within a view. I have Templates defined for each element/Model type. What I would like to do is check the ViewData.ModelMetadata.ContainerType from within the Template so that Template can determine if it was called as part of a...
I have defined a collection in Hibernate like this: ... public class Item { ... @ElementCollection List<Object> relatedObjects; } It creates a mapping table with colums item_id and object_id. The problem is that object_id seems to be unique. In other words I can not have two different items being related to the same objec...