Question

I want a library that I can give it a file and a config param of column length, name, and possibly type and from that get back a map of the columns of each row.

This isn’t difficult thing to do on my own, but I would be surprised if there wasn’t already a great solution. I’ve tried searching for one, but have had no luck.

Answer 1

You can always use FlatFileItemReader from Spring Batch that will return a structure like JDBC ResultSet.

But it might be overkill and make it more complex. For Groovy I find it easy to read and write code like this:

file = '''\
JOHN      DOE       123       
JANE      ROE       456       
'''

names = []
file.eachLine { names << [
    first: it[0..9].trim(), 
    last:  it[10..19].trim(),
    age:   it[20..22].toInteger()
]}

assert names[0].first == 'JOHN'
assert names[1].age == 456