1 閉包 閉包是一個代碼塊,用{}括起來。與java不同的是,groovy中程式代碼也成為一種資料,可以被一個變量所引用。 javascript中var f = function(){} 格式為 { 參數-> 代碼 } 具體例子如下: def clouser1 = { println it //it預設參數 } clouser1.call('zhang')
def closer2 = { text -> println text //一個參數 } closer2('this is close2')
def closer3 = { //多個參數 name,age-> println "This is ${name},${age} yeas old" } closer3('zhangsan',20) 額外說明:groovy的這種将代碼塊指派給變量的做法和javascript也有像,不過javascript的寫法是var f = function(){} 2 delegate 其實delegate和java中的上下文類似,delegate将指定待執行代碼的對象。類似于java中 的代碼: interface Target{ void surf(); } class Aoo implments Target{ public void surf(){ System.out.println("Aoo surfing"); } } class Boo implemets Target{ public void surf(){ System.out.println("Aoo surfing"); } private Target target; public Boo(){} public Boo(Target target){ this.target = target; } public void invoke(){ target.surf(); } } groovy的delegate屬性: class Net{ def work = { println 'Net is working' } def surf={ println 'Net is surfing' } }
class AdaptNet{
def work = { println 'AdaptNet is working' } def surf ={ println 'AdaptNet is surfing' } def invoke(closer){ closer.delegate = new Net() // closer.delegate = new AdaptNet()// close.surf将輸出"AdaptNet is surfing" closer.surf()//将輸出'Net is surfing work() } }
new AdaptNet().invoke{} 3閉包通路集合 def array =[1,2,3,4,5] array.each{ print it+' ' }
def maps = [name:'s1',age:10,score:85]
maps.each{ data-> print data.key+':'+data.value+' ' }