Help creating a hash from a hash map

Question

I managed to read a four-column text file into a hash file and make it write to the output file. However, I need to get the second column (different values) in the hashset and write to the output file. I was able to create a hashset, but it captures everything and does not sort it. By the way, I'm a newbie, so please bear in mind when you answer. Thanks

Answer 1

Neither HashSetare HashMapintended for sorting. These are fundamentally unsorted data structures. You should use an implementation SortedSet, for example TreeSet.

Answer 2

Some of the speculations associated with Mr Skeets are also responsible for the apparent confusion ...

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