Apache NiFi RecordPath Guide
Also available as:
PDF

toString

Converts a value to a String, using the given character set if the input type is "bytes". For example, given a schema such as:

{
  "type": "record",
  "name": "events",
  "fields": [
    { "name": "name", "type": "string" },
    { "name": "bytes", "type" : "bytes"}
  ]
}

and a record such as:

{
  "name" : "My Event",
  "bytes" : "Hello World!"
}

The following record path would parse the bytes field into a String:

toString( /bytes, "UTF-8")