+----+---------+--------+
|col1|     col2|    col3|
+----+---------+--------+
|   1|pi number|3.141592|
|   2| e number| 2.71828|
+----+---------+--------+

// read Spark Output Fixed width table:
val t = spark.read
    .option("header","true")
    .option("inferSchema","true")
    .option("delimiter","|")
    .option("comment","+")
    .csv("file:///temp/spark.out")
// select not-null columns
val cols = t.columns.filterNot(c => c.startsWith("_c")).map(a => t(a))
// trim spaces from columns
val colsTrimmed = t.columns.filterNot(c => c.startsWith("_c")).map(c => c.replaceAll("\s+",""))
// reanme columns using 'colsTrimmed'
val df = t.select(cols:_*).toDF(colsTrimmed:_*)

scala> df.show
+----+---------+--------+
|col1|     col2|    col3|
+----+---------+--------+
| 1.0|pi number|3.141592|
| 2.0| e number| 2.71828|
+----+---------+--------+

scala> df.printSchema
root
 |-- col1: double (nullable = true)
 |-- col2: string (nullable = true)
 |-- col3: double (nullable = true)

// read Spark Output Fixed width table:
val t = spark.read
    .option("header","true")
    .option("inferSchema","true")
    .option("delimiter","|")
    .option("parserLib","UNIVOCITY")
    .option("ignoreLeadingWhiteSpace",true)
    .option("ignoreTrailingWhiteSpace",true)
    .option("comment","+")
    .csv("file:///temp/spark.out")
// select not-null columns
val cols = t.columns.filterNot(c => c.startsWith("_c")).map(a => t(a))
// reanme columns using 'colsTrimmed'
val df = t.select(cols:_*)