Sorting data

Introduction:

In the issue I had at hand we needed to sort the data to create a matrix. So actually we needed to morph a list to a matrix form. 

The problems:

At first hand I was thinking about using the states of the data to figure out where in the matrix it should find its place. As soon I made a drawing about my idea, I stopped working at it. I needed to create a complex structure with a lot of if statements. I understood that, if I choose this way I might run into a lot of bugs. I needed to think harder. 

The solution:

I turned the whole idea around and looked at it from the other side. Instead of creating the matrix directly from the list I could something like a pre-sort. The next question obvisiouly would be: How the hell do I do that? The answer was actually quite simple looking back at the issue. I took a LinkedhashMap and a Treemap. I made sure that the query returned everything sorted by date. 

In the LinkedHashmap I used as a key the date and the Treemap. The LinkedHashmap keeps things in order of incoming. So it kept the order of the query I created by date. The second ordering would be by currency  where the payment was in done.  This I used as a key in the TreeMap together with the rest of the object. The Treemap sorts on aliphatic or numeric order using the black and red sorting algorithm. 

Now All I had to do was write a double loop for both of the maps and put the data I needed in place. 

Conclusion:

Sometimes it is better to make that drawing and have a better look at what you need to-do. I believe that part is the greatest joy in my job. Create something that gives me the proud feeling.

Have fun!