Jenkins2 Learning Series 3 — Introduction to Groovy syntax

To write A Pipeline is to write Groovy code. Jenkins Pipeline is actually a DSL based on the Groovy language. It’s important to know some Groovy syntax

If you don’t want to install the Groovy environment locally, you can open groovy-playground to run through the Groovy code and see the results directly, which may require scientific surfing.

Necessary knowledge of Groovy syntax

• Define variables and methods using the def keyword,def name="jack"
• The semicolon at the end of the statement is not required
• Method calls can omit parentheses

def say(String name = "world") {
  return "hi "+ name} // Call say name ="jack"
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• Double quotes support interpolation, single quotes do not parse variables, and output as is

def name = 'world'// Result: Hello worldprint "hello ${name}"// Result: hello${name}
print 'hello ${name}'
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• Both triple double and triple single quotes support newlines, and only triple double quotes support interpolation

def foo = """ line one
line two
${name}
"""
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• Support closures

Def codeBlack = {def codeBlack = {print "hello closure"} def pipeline(closure) {closure()} codeBlack (codeBlack) {closure()} codeBlack (codeBlack)Copy the code

// If the brackets are not required, the result is the same as Jenkins pipeline

pipeline( {print "hello closure"} )
pipeline { 
  print "hello closure"
} 
pipeline codeBlack
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• Another use for closures

Def closure(String name, closure) {println name closure()}"stage name", {
   println "closure"}) closure */ * Stage name closure */ // In Groovy, you can write stage("stage name") {
  print "closure"
}
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