风格指南

String toString() { return "a server" }
String toString() { "a server" }

def props() {
    def m1 = [a: 1, b: 2]
    m2 = m1.findAll { k, v -> v % 2 == 0 }
    m2.c = 3
    m2
}

def foo(n) {
    if(n == 1) {
        "Roshan"
    } else {
        "Dawrani"
    }
}

assert foo(1) == "Roshan"
assert foo(2) == "Dawrani"

def String name = "Guillaume"

String name = "Guillaume"

void doSomething(def param1, def param2) { }

void doSomething(param1, param2) { }

class MyClass {
    def MyClass() {}
}

class MyClass {
    MyClass() {}
}

public class Server {
    public String toString() { return "a server" }
}

class Server {
    String toString() { "a server" }
}

class Server {
    @PackageScope Cluster cluster
}

println "Hello"
method a, b

println("Hello")
method(a, b)

list.each( { println it } )
list.each(){ println it }
list.each  { println it }

def foo(n) { n }
def bar() { 1 }

println foo 1 // won't work
def m = bar   // won't work

connection.doPost(BASE_URI + "/modify.hqu", params, ResourcesResponse.class)

connection.doPost("${BASE_URI}/modify.hqu", params, ResourcesResponse)

resourceGroup.getResourcePrototype().getName() == SERVER_TYPE_NAME
resourceGroup.resourcePrototype.name == SERVER_TYPE_NAME

resourcePrototype.setName("something")
resourcePrototype.name = "something"

class Person {
    private String name
    String getName() { return name }
    void setName(String name) { this.name = name }
}

class Person {
    String name
}

class Server {
    String name
    Cluster cluster
}

def server = new Server()
server.name = "Obelix"
server.cluster = aCluster

def server = new Server(name: "Obelix", cluster: aCluster)

server.name = application.name
server.status = status
server.sessionCount = 3
server.start()
server.stop()

server.with {
    name = application.name
    status = status
    sessionCount = 3
    start()
    stop()
}

def person = new Person().with {
    name = "Ada Lovelace"
    it // Note the explicit mention of it as the return value
}

def person = new Person().tap {
    name = "Ada Lovelace"
}

status != null && status.equals(ControlConstants.STATUS_COMPLETED)

status == ControlConstants.STATUS_COMPLETED

throw new Exception("Unable to convert resource: " + resource)

throw new Exception("Unable to convert resource: ${resource}")

throw new Exception("Unable to convert resource: $resource")

int i = 3

def s1 = "i's value is: ${i}"
def s2 = "i's value is: ${-> i}"

i++

assert s1 == "i's value is: 3" // eagerly evaluated, takes the value on creation
assert s2 == "i's value is: 4" // lazily evaluated, takes the new value into account

throw new PluginException("Failed to execute command list-applications:" +
    " The group with name " +
    parameterMap.groupname[0] +
    " is not compatible group of type " +
    SERVER_TYPE_NAME)

throw new PluginException("Failed to execute command list-applications: \
The group with name ${parameterMap.groupname[0]} \
is not compatible group of type ${SERVER_TYPE_NAME}")

throw new PluginException("""Failed to execute command list-applications:
    The group with name ${parameterMap.groupname[0]}
    is not compatible group of type ${SERVER_TYPE_NAME)}""")

assert "foooo/baaaaar" ==~ /fo+\/ba+r/

def list = [1, 4, 6, 9]

// by default, keys are Strings, no need to quote them
// you can wrap keys with () like [(variableStateAcronym): stateName] to insert a variable or object as a key.
def map = [CA: 'California', MI: 'Michigan']

// ranges can be inclusive and exclusive
def range = 10..20 // inclusive
assert range.size() == 11
// use brackets if you need to call a method on a range definition
assert (10..<20).size() == 10 // exclusive

def pattern = ~/fo*/

// equivalent to add()
list << 5

// call contains()
assert 4 in list
assert 5 in list
assert 15 in range

// subscript notation
assert list[1] == 4

// add a new key value pair
map << [WA: 'Washington']
// subscript notation
assert map['CA'] == 'California'
// property notation
assert map.WA == 'Washington'

// matches() strings against patterns
assert 'foo' ==~ pattern

def x = 1.23
def result = ""
switch (x) {
    case "foo": result = "found foo"
    // lets fall through
    case "bar": result += "bar"
    case [4, 5, 6, 'inList']:
        result = "list"
        break
    case 12..30:
        result = "range"
        break
    case Integer:
        result = "integer"
        break
    case Number:
        result = "number"
        break
    case { it > 3 }:
        result = "number > 3"
        break
    default: result = "default"
}
assert result == "number"

import java.util.List as UtilList
import java.awt.List as AwtList
import javax.swing.WindowConstants as WC

UtilList list1 = [WC.EXIT_ON_CLOSE]
assert list1.size() instanceof Integer
def list2 = new AwtList()
assert list2.size() instanceof java.awt.Dimension

import static java.lang.Math.abs as mabs
assert mabs(-4) == 4

if (name != null && name.length > 0) {}

if (name) {}

if (order != null) {
    if (order.getCustomer() != null) {
        if (order.getCustomer().getAddress() != null) {
            System.out.println(order.getCustomer().getAddress());
        }
    }
}

println order?.customer?.address

def check(String name) {
    // name non-null and non-empty according to Groovy Truth
    assert name
    // safe navigation + Groovy Truth to check
    assert name?.size() > 3
}

def result = name != null ? name : "Unknown"

def result = name ?: "Unknown"

try {
    // ...
} catch (Exception t) {
    // something bad happens
}

try {
    // ...
} catch (any) {
    // something bad happens
}