Groovy

Archived

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Misc

Interactive shell

groovysh
  • When defining variables in the Groovy shell, drop the def: 
    data = new URL('http://localhost:8080').getText()

Strings

Convert a string to lower case

s = s.toLowerCase()

Replace characters in a string

s = s.replaceAll(' ', '-')

Convert a string to an integer

if (s.isInteger()) {
    s = s.toInteger()
}

Lists

Create a new empty list

def myList = []

Method signature when returning a list literal

Use List<E>:
List<String> myfunction() {...

Check if an item is in a list

1 in [1, 2, 3]

Check if an item is not in a list

!(1 in [1, 2, 3])

Iterate over a list

myList.each{
    println it

To name the item:

myList.each{ item ->
    println item

Add an item to a list

myList.add(item)

Get the size/length of a list

myList.size()

Transform each item of a list and return as a list

Use .collect:

return myList.collect { someMethod(it) }

Maps

General

Groovy maps are java.util.LinkedHashMap

Create a new empty map

def map = [:]

Method signature when returning a map literal

Use Map<K, V>:

Map<String, String> myfunction() {...

Check if an item is in a map

[a:1,b:2,c:3].containsValue(3)
[a:1,b:2,c:3].containsKey('a')