Sorting Vector on Multiple Keys

[jsulman]

I am trying to sort a vector with mulitple keys. I can do it with one key by using a Comparator with the following code:

class CompTypeComparator implements Comparator {
public int compare(Object o1, Object o2) {
int j1 = ((CompType)o1).j;
int j2 = ((CompType)o2).j;
return (j1 < j2 ? -1 : (j1 == j2 ? 0 : 1));
}
}

I can even do it on two keys with the following code using the CompareTon where Name is a vector containing a first and last name.

public int compareTo(Object o)
{
Name n = (Name)o;
int lastCmp = lastName.compareTo(n.lastName);
System.out.println(lastName + &quot;/&quot; + n.lastName + &quot;/&quot; + lastCmp);
return (lastCmp!=0 ? lastCmp : firstName.compareTo(n.firstName));
}

How would I use one of these models, or any other, to sort 3 or more strings (keys) i.e. first, mi, and last name?

Thanks in advance.

Jeff Sulman

 

[hologram]

If it are all strings can't you just concatenate the strings in your compare method and do the compare with the concatenated strings. [You probably have to put a space or another seperator character between the strings]. This sounds too easy to be true.

 

[jsulman]

Hologram,
I was going to consider your solution but it would not allow for the ability to make each of the rows ascending or descending and they are not all strings - which is going to be a problem in and of itself.

Thank

Jeff

 

[hologram]

You can do it in the following way,but implementing could be cumbersome :
You just use your normal sort on the first column of your Vertor.
For the sort on the second column, you have to code a loop that goes over your Vector, and if it finds equals in the sorted columns (the first column), then create a subVector containing only the records where the already sorted field is equal. Then you sort this new Vector on the second column.
=============================
If would be faster if you could create the second (set of Vectors then) while sorting on the first column.
Store your data in a Vector of Vectors of Vectors...?
Or Arrays of arrays... and pass the from and to index to your sort...
=============================
You can repeat this for the other columns.
I think a variation of this appraoch is the best way to go.
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