Groovy and Java classes
Any Groovy or Java class that is available to Nextflow at runtime can be used in a Nextflow script. The following classes are imported by default:
groovy.lang.*
groovy.util.*
java.io.*
java.lang.*
java.math.BigDecimal
java.math.BigInteger
java.net.*
java.util.*
All other classes must be referenced by their fully-qualified name:
def vals = [1, 2, 3]
println groovy.json.JsonOutput.toJson(vals)
Note
The set of classes in Nextflow’s runtime classpath can change between different Nextflow versions. As a best practice, any code that uses classes outside the Nextflow standard library should either be refactored to only use the Nextflow standard library or be refactored as a plugin with explicit dependencies.