Parsing a fixed-width formatted file in Java

Question

I\'ve got a file from a vendor that has 115 fixed-width fields per line. How can I parse that file into the 115 fields so I can use them in my code?

My first thought

Answer 1

Most suitable for Scala, but probably you could use it in Java

I was so fed up with the fact that there is no proper library for fixed length format that I have created my own. You can check it out here: https://github.com/atais/Fixed-Length

A basic usage is that you create a case class and it's described as an HList (Shapeless):

case class Employee(name: String, number: Option[Int], manager: Boolean)

object Employee {

    import com.github.atais.util.Read._
    import cats.implicits._
    import com.github.atais.util.Write._
    import Codec._

    implicit val employeeCodec: Codec[Employee] = {
      fixed[String](0, 10) <<:
        fixed[Option[Int]](10, 13, Alignment.Right) <<:
        fixed[Boolean](13, 18)
    }.as[Employee]
}

And you can easily decode your lines now or encode your object:

import Employee._
Parser.decode[Employee](exampleString)
Parser.encode(exampleObject)