how to store the instances of this file

[aneuryzma]

I have a file with a list of mixed instances and I need to collect all instances in some java structure (I was wondering if I should use a List of lists for this):

File structure
ID, other content...
1, ...
3, ...
1, ...
2, ...
2, ...
3, ...

I need to store all rows starting with 1 in a List1, rows with 2 in List2 and so on..

all those lists should be in one single list so I can iterate among them.

I don't know in advance the amount of ids...
Is is a good approach ?

thanks

[JosAH]

Use a Map for that where the key values are the IDs and the value values are Lists of the lines from you file. a Map<Integer, List<String>> will do.

kind regards,

Jos