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Java Vector quesion

I am creating a class that extends Vector. The vector will consists of 4 elements in this order:
String, String, Date, double

How do I set this up?
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allelopath
Asked:
allelopath
3 Solutions
 
CEHJCommented:
>>I am creating a class that extends Vector.

Why? ;)
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for_yanCommented:
I don't think you need to extend Vector

You rather make a class


public class  FourElements {
String one;
AString two;
Date d;
double x;

}


then you want constructor etc.

and then you make Vectorb which would hole ielements - each one ionstance of your class




}
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for_yanCommented:
Or you can have class which will have Vectopr with your four element as
varaiable so it will be not inheritance but

HAS a Vector

relationship
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for_yanCommented:
It is hard to imagine situation where you want to extend Vector
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for_yanCommented:
seee here a rather good discussion which comes to the conclusin that it is normally not a good
idea to extend Vector:

http://forums.whirlpool.net.au/archive/1309754



The author of this code [whic was extending Vector, see link above] was probably thinking something along the lines of "a product catalog is a kind of vector, since it stores a bunch of products, just like a vector stores a bunch of items".

The "is a kind of" relation is most often represented with inheritance.

Unfortunately, the author of this code made the wrong decision. A product catalog is not a kind of vector:

    A product catalog doesn't necessarily entail a particular ordering between its entries; a vector does.
    A product catalog has certain rules and constraints about its entries, such as that every element must be a Product, and that the catalog should only be modified in ways that maintain these constraints. A vector doesn't have these rules and constraints.

For these reasons, this ProductCatalog class does not meet the second requirement in my previous post.

At another level, it's a wrong design decision because they're locking in the implementation of their product catalog in such a way that it'd be particularly hard to change in the future.

Even if it is thought that it will not need to be changed in the future, it's the wrong data structure anyhow: a product catalog would probably need to be searched with a variety of different criteria (e.g. by product type, by price, by colour), and a single vector does not make this straight-forward.
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gordon_vt02Commented:
Also, its generally much better to use one of the other List implementations than Vector -- using the utilities in java.util.concurrent if you need synchronized access to the List.  Vector does a lot of internal synchronization which makes it much slower when only accessed by a single thread.
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allelopathAuthor Commented:
ok, it was a stupid idea, driven by a DefaultTableModel constructor :
DefaultTableModel(Vector data, Vector columnNames)
but still not a good way to go.
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CEHJCommented:
>>ok, it was a stupid idea, driven by a DefaultTableModel constructor :

If you'd answered my question and told me that right away, i would have answered differently - and differently from any of the other answers above ;)
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