JFreeChart and OpenCSV
A developer that uses JFreeChart asked me how they should go about using it with data from a CSV file (that is, a text file containing a table of comma-separated values). There are many different approaches that could be taken, so here I will give one example that makes use of the OpenCSV project. We are going to create a chart showing excess death statistics by country during the COVID19 crisis (the source of the data is https://ourworldindata.org/excess-mortality-covid). The end result looks like this: