Here is a standard format csv file:
Use Java to do this: Use the specified multiple column numbers as parameters to retrieve the corresponding columns from the csv file, and parse them as a two-dimensional table. For example, when the parameters are "#1,#3,#5", we have the following result:
Write the following SPL code:
=T(\"d:\result.csv\":T(\"d:\data.csv\",${arg_cols}))
T()parses a file or writes data to a file; it supports specifying multiple column numbers. ${} treats a string as an expression to execute.
Read How to Call a SPL Script in Java to find how to integrate SPL into a Java application.
This is one of the problems on StackOverflow. You can click on it to see that the conventional solution is quite complicated, but the SPL approach is really simple and efficient.