I need to make an ArrayList of ArrayLists thread safe. I also cannot have the client making changes to the collection. Will the unmodifiable wrapper make it thread safe or do I need two wrappers on the collection? ...
I often make a collection field unmodifiable before returning it from a getter method: private List<X> _xs; .... List<X> getXs(){ return Collections.unmodifiableList(_xs); } But I can't think of a convenient way of doing that if the X above is itself a List: private List<List<Y>> _yLists; ..... List<List<Y>> getYLists() { return ...
In Java, one can use the Collections#unmodifiableList() method to create an unmodifiable list from an existing List object. Is there any counterpart in C# ? I'm new to the language and haven't been able to find anything like this in the MSDN docs. ...
How would one do this? I have tried creating a new, empty list, then copying unmodifiable list's elements to it, but I'm getting unsupported operation error. Any help is appreciated. ...
Here I can see that "Collections.unmodifiableSet" returns an unmodifiable view of the specified set. But I do not understand why we cannot just use final modifier to create an unmodifiable set. In my understanding final declare a constant (i.e. something that cannot be modified). So, if a set is declared as a constant it cannot be modif...
final Integer[] arr={1,2,3}; arr[0]=3; System.out.println(Arrays.toString(arr)); I tried the above code to see whether a final array's variables can be reassigned[ans:it can be].I understand that by a final Integer[] array it means we cannot assign another instance of Integer[] apart from the one we have assigned initially.I would like...
I have a map of constants, like this: private static Map<String, Character> _typesMap = new HashMap<String, Character>() { { put ("string", 'S'); put ("normalizedString", 'N'); put ("token", 'T'); // (...) } Do I really need to use Collections.unmodifiableMap() to...