领域特定语言

void body(@DelegatesTo(BodySpec) Closure cl) {
    // ...
}

void body(@DelegatesTo(strategy=Closure.DELEGATE_ONLY, value=BodySpec) Closure cl) {
    // ...
}

def exec(Object target, Closure code) {
   def clone = code.rehydrate(target, this, this)
   clone()
}

def email = new Email()
exec(email) {
   from '...'
   to '...'
   send()
}

def exec(@DelegatesTo.Target Object target, @DelegatesTo Closure code) {
   def clone = code.rehydrate(target, this, this)
   clone()
}

class Greeter {
   void sayHello() { println 'Hello' }
}
def greeter = new Greeter()
exec(greeter) {
   sayHello()
}

void fooBarBaz(Closure foo, Closure bar, Closure baz) {
    ...
}

class Foo { void foo(String msg) { println "Foo ${msg}!" } }
class Bar { void bar(int x) { println "Bar ${x}!" } }
class Baz { void baz(Date d) { println "Baz ${d}!" } }

void fooBarBaz(@DelegatesTo(Foo) Closure foo, @DelegatesTo(Bar) Closure bar, @DelegatesTo(Baz) Closure baz) {
   ...
}

void fooBarBaz(
    @DelegatesTo.Target('foo') foo,
    @DelegatesTo.Target('bar') bar,
    @DelegatesTo.Target('baz') baz,

    @DelegatesTo(target='foo') Closure cl1,
    @DelegatesTo(target='bar') Closure cl2,
    @DelegatesTo(target='baz') Closure cl3) {
    cl1.rehydrate(foo, this, this).call()
    cl2.rehydrate(bar, this, this).call()
    cl3.rehydrate(baz, this, this).call()
}

def a = new Foo()
def b = new Bar()
def c = new Baz()
fooBarBaz(
    a, b, c,
    { foo('Hello') },
    { bar(123) },
    { baz(new Date()) }
)

public <T> void configure(List<T> elements, Closure configuration) {
   elements.each { e->
      def clone = configuration.rehydrate(e, this, this)
      clone.resolveStrategy = Closure.DELEGATE_FIRST
      clone.call()
   }
}

@groovy.transform.ToString
class Realm {
   String name
}
List<Realm> list = []
3.times { list << new Realm() }
configure(list) {
   name = 'My Realm'
}
assert list.every { it.name == 'My Realm' }

public <T> void configure(
    @DelegatesTo.Target List<T> elements,
    @DelegatesTo(strategy=Closure.DELEGATE_FIRST, genericTypeIndex=0) Closure configuration) {
   def clone = configuration.rehydrate(e, this, this)
   clone.resolveStrategy = Closure.DELEGATE_FIRST
   clone.call()
}

class Mapper<T,U> {                             (1)
    final T value                               (2)
    Mapper(T value) { this.value = value }
    U map(Closure<U> producer) {                (3)
        producer.delegate = value
        producer()
    }
}

def mapper = new Mapper<String,Integer>('Hello')
assert mapper.map { length() } == 5

Static type checking] - Cannot find matching method TestScript0#length()

class Mapper<T,U> {
    final T value
    Mapper(T value) { this.value = value }
    U map(@DelegatesTo(type="T") Closure<U> producer) {  (1)
        producer.delegate = value
        producer()
    }
}

withConfig(configuration) {
   imports { // imports customizer
      normal 'my.package.MyClass' // a normal import
      alias 'AI', 'java.util.concurrent.atomic.AtomicInteger' // an aliased import
      star 'java.util.concurrent' // star imports
      staticMember 'java.lang.Math', 'PI' // static import
      staticMember 'pi', 'java.lang.Math', 'PI' // aliased static import
   }
}

withConfig(conf) {
   ast(Log) (1)
}

withConfig(conf) {
   ast(Log, value: 'LOGGER') (2)
}

withConfig(conf) {
   secureAst {
       closuresAllowed = false
       methodDefinitionAllowed = false
   }
}

withConfig(configuration){
    source(extension: 'sgroovy') {
        ast(CompileStatic) (1)
    }
}

withConfig(configuration){
    source(extensions: ['sgroovy','sg']) {
        ast(CompileStatic) (2)
    }
}

withConfig(configuration) {
    source(extensionValidator: { it.name in ['sgroovy','sg']}) {
        ast(CompileStatic) (2)
    }
}

withConfig(configuration) {
    source(basename: 'foo') {
        ast(CompileStatic) (3)
    }
}

withConfig(configuration) {
    source(basenames: ['foo', 'bar']) {
        ast(CompileStatic) (4)
    }
}

withConfig(configuration) {
    source(basenameValidator: { it in ['foo', 'bar'] }) {
        ast(CompileStatic) (4)
    }
}

withConfig(configuration) {
    source(unitValidator: { unit -> !unit.AST.classes.any { it.name == 'Baz' } }) {
        ast(CompileStatic) (5)
    }
}

withConfig(configuration) {
    inline(phase:'CONVERSION') { source, context, classNode ->  (1)
        println "visiting $classNode"                           (2)
    }
}

withConfig(configuration) {
   ast(ToString)
   ast(EqualsAndHashCode)
}

withConfig(configuration) { (1)
   ast(groovy.transform.CompileStatic)
}

groovyc -configscript src/conf/config.groovy src/main/groovy/MyClass.groovy

System.setProperty('spock.iKnowWhatImDoing.disableGroovyVersionCheck', 'true')

class LogHandler extends org.xml.sax.helpers.DefaultHandler {

    String log = ''

    void startElement(String uri, String localName, String qName, org.xml.sax.Attributes attributes) {
        log += "Start Element: $localName, "
    }

    void endElement(String uri, String localName, String qName) {
        log += "End Element: $localName, "
    }
}

def handler = new LogHandler()
def builder = new groovy.xml.SAXBuilder(handler)

builder.root() {
    helloWorld()
}

assert handler.log == 'Start Element: root, Start Element: helloWorld, End Element: helloWorld, End Element: root, '

def factory = javax.xml.stream.XMLOutputFactory.newInstance()
def writer = new StringWriter()
def builder = new groovy.xml.StaxBuilder(factory.createXMLStreamWriter(writer))

builder.root(attribute:1) {
    elem1('hello')
    elem2('world')
}

assert writer.toString() == '<?xml version="1.0" ?><root attribute="1"><elem1>hello</elem1><elem2>world</elem2></root>'

@Grab('org.codehaus.jettison:jettison:1.3.3')
@GrabExclude('stax:stax-api') // part of Java 6 and later
import org.codehaus.jettison.mapped.*

def writer = new StringWriter()
def mappedWriter = new MappedXMLStreamWriter(new MappedNamespaceConvention(), writer)
def builder = new groovy.xml.StaxBuilder(mappedWriter)

builder.root(attribute:1) {
     elem1('hello')
     elem2('world')
}

assert writer.toString() == '{"root":{"@attribute":"1","elem1":"hello","elem2":"world"}}'

String recordsXML = '''
    <records>
      <car name='HSV Maloo' make='Holden' year='2006'>
        <country>Australia</country>
        <record type='speed'>Production Pickup Truck with speed of 271kph</record>
      </car>
      <car name='P50' make='Peel' year='1962'>
        <country>Isle of Man</country>
        <record type='size'>Smallest Street-Legal Car at 99cm wide and 59 kg in weight</record>
      </car>
      <car name='Royale' make='Bugatti' year='1931'>
        <country>France</country>
        <record type='price'>Most Valuable Car at $15 million</record>
      </car>
    </records>'''

def reader = new StringReader(recordsXML)
def doc = groovy.xml.DOMBuilder.parse(reader)

def records = doc.documentElement
use(groovy.xml.dom.DOMCategory) {
    assert records.car.size() == 3
}

def nodeBuilder = new NodeBuilder()
def userlist = nodeBuilder.userlist {
    user(id: '1', firstname: 'John', lastname: 'Smith') {
        address(type: 'home', street: '1 Main St.', city: 'Springfield', state: 'MA', zip: '12345')
        address(type: 'work', street: '2 South St.', city: 'Boston', state: 'MA', zip: '98765')
    }
    user(id: '2', firstname: 'Alice', lastname: 'Doe')
}

assert [email protected](', ') == 'John, Alice'
assert userlist.user.find { it.@lastname == 'Smith' }.address.size() == 2

String carRecords = '''
    {
        "records": {
        "car": {
            "name": "HSV Maloo",
            "make": "Holden",
            "year": 2006,
            "country": "Australia",
            "record": {
              "type": "speed",
              "description": "production pickup truck with speed of 271kph"
            }
          }
      }
    }
'''

JsonBuilder builder = new JsonBuilder()
builder.records {
  car {
        name 'HSV Maloo'
        make 'Holden'
        year 2006
        country 'Australia'
        record {
            type 'speed'
            description 'production pickup truck with speed of 271kph'
        }
  }
}
String json = JsonOutput.prettyPrint(builder.toString())

JsonAssert.assertJsonEquals(json, carRecords)

import groovy.json.*

def generator = new JsonGenerator.Options()
        .excludeNulls()
        .excludeFieldsByName('make', 'country', 'record')
        .excludeFieldsByType(Number)
        .addConverter(URL) { url -> "https://groovy-lang.cn" }
        .build()

JsonBuilder builder = new JsonBuilder(generator)
builder.records {
  car {
        name 'HSV Maloo'
        make 'Holden'
        year 2006
        country 'Australia'
        homepage new URL('http://example.org')
        record {
            type 'speed'
            description 'production pickup truck with speed of 271kph'
        }
  }
}

assert builder.toString() == '{"records":{"car":{"name":"HSV Maloo","homepage":"https://groovy-lang.cn"}}}'

String carRecords = """
    {
      "records": {
        "car": {
          "name": "HSV Maloo",
          "make": "Holden",
          "year": 2006,
          "country": "Australia",
          "record": {
            "type": "speed",
            "description": "production pickup truck with speed of 271kph"
          }
        }
      }
    }
"""

StringWriter writer = new StringWriter()
StreamingJsonBuilder builder = new StreamingJsonBuilder(writer)
builder.records {
    car {
        name 'HSV Maloo'
        make 'Holden'
        year 2006
        country 'Australia'
        record {
            type 'speed'
            description 'production pickup truck with speed of 271kph'
        }
    }
}
String json = JsonOutput.prettyPrint(writer.toString())

JsonAssert.assertJsonEquals(json, carRecords)

def generator = new JsonGenerator.Options()
        .excludeNulls()
        .excludeFieldsByName('make', 'country', 'record')
        .excludeFieldsByType(Number)
        .addConverter(URL) { url -> "https://groovy-lang.cn" }
        .build()

StringWriter writer = new StringWriter()
StreamingJsonBuilder builder = new StreamingJsonBuilder(writer, generator)

builder.records {
    car {
        name 'HSV Maloo'
        make 'Holden'
        year 2006
        country 'Australia'
        homepage new URL('http://example.org')
        record {
            type 'speed'
            description 'production pickup truck with speed of 271kph'
        }
    }
}

assert writer.toString() == '{"records":{"car":{"name":"HSV Maloo","homepage":"https://groovy-lang.cn"}}}'

import groovy.swing.SwingBuilder
import java.awt.BorderLayout as BL

count = 0
new SwingBuilder().edt {
  frame(title: 'Frame', size: [250, 75], show: true) {
    borderLayout()
    textlabel = label(text: 'Click the button!', constraints: BL.NORTH)
    button(text:'Click Me',
         actionPerformed: {count++; textlabel.text = "Clicked ${count} time(s)."; println "clicked"}, constraints:BL.SOUTH)
  }
}

import groovy.swing.SwingBuilder
import javax.swing.*
import java.awt.*

def swing = new SwingBuilder()

def sharedPanel = {
     swing.panel() {
        label("Shared Panel")
    }
}

count = 0
swing.edt {
    frame(title: 'Frame', defaultCloseOperation: JFrame.EXIT_ON_CLOSE, pack: true, show: true) {
        vbox {
            textlabel = label('Click the button!')
            button(
                text: 'Click Me',
                actionPerformed: {
                    count++
                    textlabel.text = "Clicked ${count} time(s)."
                    println "Clicked!"
                }
            )
            widget(sharedPanel())
            widget(sharedPanel())
        }
    }
}

import groovy.swing.SwingBuilder
import groovy.beans.Bindable

class MyModel {
   @Bindable int count = 0
}

def model = new MyModel()
new SwingBuilder().edt {
  frame(title: 'Java Frame', size: [100, 100], locationRelativeTo: null, show: true) {
    gridLayout(cols: 1, rows: 2)
    label(text: bind(source: model, sourceProperty: 'count', converter: { v ->  v? "Clicked $v times": ''}))
    button('Click me!', actionPerformed: { model.count++ })
  }
}

def ant = new groovy.ant.AntBuilder()          (1)
ant.echo('hello from Ant!')         (2)

def ant = new AntBuilder()
ant.zip(destfile: 'sources.zip', basedir: 'src')

// let's just call one task
ant.echo("hello")

// here is an example of a block of Ant inside GroovyMarkup
ant.sequential {
    echo("inside sequential")
    def myDir = "build/AntTest/"
    mkdir(dir: myDir)
    copy(todir: myDir) {
        fileset(dir: "src/test") {
            include(name: "**/*.groovy")
        }
    }
    echo("done")
}

// now let's do some normal Groovy again
def file = new File(ant.project.baseDir,"build/AntTest/some/pkg/MyTest.groovy")
assert file.exists()

// let's create a scanner of filesets
def scanner = ant.fileScanner {
    fileset(dir:"src/test") {
        include(name:"**/My*.groovy")
    }
}

// now let's iterate over
def found = false
for (f in scanner) {
    println("Found file $f")
    found = true
    assert f instanceof File
    assert f.name.endsWith(".groovy")
}
assert found

ant.junit {
    classpath { pathelement(path: '.') }
    test(name:'some.pkg.MyTest')
}

ant.echo(file:'Temp.java', '''
    class Temp {
        public static void main(String[] args) {
            System.out.println("Hello");
        }
    }
''')
ant.javac(srcdir:'.', includes:'Temp.java', fork:'true')
ant.java(classpath:'.', classname:'Temp', fork:'true')
ant.echo('Done')

// import of CliBuilder not shown                          (1)
// specify parameters
def cli = new CliBuilder(usage: 'groovy Greeter [option]') (2)
cli.a(longOpt: 'audience', args: 1, 'greeting audience')   (3)
cli.h(longOpt: 'help', 'display usage')                    (4)

// parse and process parameters
def options = cli.parse(args)                              (5)
if (options.h) cli.usage()                                 (6)
else println "Hello ${options.a ? options.a : 'World'}"    (7)

> groovy Greeter

Hello World

> groovy Greeter -h

usage: groovy Greeter [option]
 -a,--audience <arg>   greeting audience
 -h,--help             display usage

> groovy Greeter --audience Groovologist

Hello Groovologist