Groovy in Action(中文版)第136页明确说Closure的this指向Closure自己。并且从代码注释处作者也是这样理解的：
class Mother{
int field = 1
int foo(){
return 2
}
Closure birth(param){
def local = 3
def closure = { caller->
[
this,
field,
foo(),
local,
param,
caller,
this.owner
]
}
return closure
}
}
Mother julia = new Mother()
closure = julia.birth(4)
context = closure.call(this)
println context[0].class.name //(4) Script
............................................
assert context[6] instanceof Mother //作者认为this指向自己，所以this.owner指向Mother
但是，上面的代码实际是错误的，我用1.0和2.1分别运行，都是一样的结果。this，也就是context[0]是Mother的this,而不是Closeure的。并且this.owner报错，提示Mother找不到属性owner.
其实Closure中引用this是它所在的上下文的this.对于上例其实就是Mother.this，是closure的owner,这也是Closure的delegate的默认值.要想在Closure是引用自己，只有引用delegate,然后在外部调用时将closure的delegate指向自己：
class Mother{ int field = 1 int foo(){ return 2 } Closure birth(param){ def local = 3 def closure = { caller-> [ delegate, field, this.foo(), local, param, caller, delegate.owner ] } return closure }}Mother julia = new Mother()closure = julia.birth(4)closure.delegate = closurecontext = closure.call(this)println context[0].class.name
