Groovy

Groovy is a general purpose language that runs on the top of the JVM, the Java Virtual Machine that seems to allow developers to be a lot more productive than using Java.

My primary reason for looking into it is that it is the language used for the Jenkins Pipelines.

Oh and you can also grab my Groovy book.

Articles

Hello World in Groovy print, println
Reading from STDIN in Groovy Console, System, readLine, System.in.newReader().readLine() as Integer
Groovy types boolean, int, byte, Integer
Groovy: Undeclared variable - runtime exception - groovy.lang.MissingPropertyException def, MissingPropertyException
Groovy: Number guessing game Random, nextInt, System.in.newReader().readLine
Determine type of an object in Groovy instanceof, getClass
Lists in Groovy List, ArrayList, LinkedList, size, for, each, eachWithIndex, count
Sum of numbers File, readLines, LineNumberReader, newReader, readLine
Solution to the "Color selector" exercise
Read CSV file in Groovy @Grab, import, File, getText, parseCSV, separators, readFirstLine
Solution to the count digits exercies
reading and writing files - appending content in Groovy File, getText, readLines, newReader, readLine, write, append
listing the content of a directory, traversing a directory tree eachFile, eachFileRecurse
Groovy - Regular Expressions - regexes
Groovy map (dictionary, hash, associative array.md) map, containsKey, key, value, keySet, sort (keys, values)
Groovy Read/Write JSON files
Groovy: Date, Time, Timezone
Groovy: import and use functions from another file
Groovy: Random numbers, random selection from list of values
Groovy: Closures
Groovy: remove spaces from a string (replaceAll)
Groovy: temporary file with auto delete (File, createTempFile, deleteOnExit, absolutePath)
Groovy: relative path (SourceURI, Path, Paths, get, getParent, resolveSibling)
Return multiple values from a function
String length
Substring
for loop - break - continue
Groovy code reuse
Groovy functions
Groovy: evaluate code in another file
Groovy classes
Groovy function overloading
Groovy variable scope (def)
Recursive functions
Groovy command line arguments (args.md)
Command line parameters
Groovy exit - System.exit - early exit from Groovy script
Groovy file and directory attributes File, canExecute, isFile, isDirectory
Groovy join elements of array (join)
Groovy pop push
Groovy: Formatted printing with printf and sprintf
Groovy system properties
Groovy path to current executable script
Exception handling (try, catch, Exception)
Throw (raise.md) exception
Casting Integer, String, ...
Printing Unicode characters from Groovy
Import standard libraries
Iterate over map keys
Get the list of keys of a map as an ArrayList
STDOUT/STDERR
Read/Write YAML files
Read/Write INI files
Read/Write XML files
HTTP request

Other resources

enum planets {
   Mercury,
   Venus,
   Earth,
   Mars,
   Jupiter,
   Saturn,
   Uranus,
   Neptune
}

println("hi")

println(planets)
println(planets.Earth)

Elapsed time

import groovy.time.TimeCategory
import groovy.time.TimeDuration

def start = new Date()
println(start)
print("Press any key ...")
def name = System.in.newReader().readLine()
def stop = new Date()
println(stop)
diff = stop - start
println(diff)


TimeDuration td = TimeCategory.minus( stop, start )
println td

Groovy regex

Interpolation can be used
matcher.matches vs being null ?
\b to mark end of word

def exp = 'line'

def matcher = (text =~ /\b$exp\b/)
println("hi")
if (matcher) {
    println("match")
}

groovy time duration - elapsed time

import groovy.time.TimeDuration

tdx = new TimeDuration(0, 0 , 0, 2000)
println(tdx)

http://docs.groovy-lang.org/2.4.9/html/gapi/groovy/time/TimeDuration.html

duration: