Re: Generics for a multiplevalue hashmap
 

Thanks for all your replies.

I have done this

public class MultipleValueHashMap<T, U> implements Map<T, java.util.List<U>> {

I want to implement Map rather than extend HashMap as per Josh Bloch's Effective Java item 16. http://java.sun.com/docs/books/effective/toc.html

So I do not want to do this.
public class MM2<T,U> extends HashMap<T, List<U>> {
}

Thanks for all your help. I will look into some of the other answers later in the week.

Many thanks
Richard

Re: Generics for a multiplevalue hashmap
 

On 7/19/2011 4:32 PM, Richard wrote:
> I have done this
>
> public class MultipleValueHashMap<T, U> implements Map<T, java.util.List<U>> {
>
> I want to implement Map rather than extend HashMap as per Josh Bloch's Effective Java item 16. http://java.sun.com/docs/books/effective/toc.html
>
> So I do not want to do this.
> public class MM2<T,U> extends HashMap<T, List<U>> {
> }


Note the word "favor".

You should evaluate not just choose without thinking.

Arne

Re: Generics for a multiplevalue hashmap
 

Arne Vajhøj wrote:
> Richard wrote:
>> I have done this
>
>> public class MultipleValueHashMap<T, U> * implements Map<T, java.util.List<U>> *{
>
>> I want to implement Map rather than extend HashMap as per Josh Bloch's Effective Java item 16.http://java.sun.com/docs/books/effective/toc.html
>
>> So I do not want to do this.
>> public class MM2<T,U> *extends HashMap<T, List<U>> * {
>> }
>
> Note the word "favor".
>
> You should evaluate not just choose without thinking.

At the very least, consider extending java.util.AbstractMap<K,V>.

--
Lew