Question

当我尝试将属性添加到自定义Closure类时...

class MyClosure extends Closure<Object> {
    def myProperty
    MyClosure() {
        super(null)
    }
    Object doCall(final Closure inner) {
        // do something...
    }
}
println new MyClosure().myProperty

我收到错误：

java.lang.NullPointerException: Cannot get property 'myProperty' on null object

这似乎与Closure类有关，我有一些行为我并不理解，因为当我删除implements部分时没有问题：

class MyClosure {
    def myProperty
}
println new MyClosure().myProperty

那么当我想将属性添加到自定义闭包时，我需要做什么？

Answer 1

您需要更改关闭解决策略：

class MyClosure extends Closure<Object> {
    def myProperty = "value"

    MyClosure() {
        super(null)
    }

    Object doCall(final Closure inner) {
        // do something...
    }
}

def closure = new MyClosure()
closure.resolveStrategy = Closure.TO_SELF
println closure.myProperty // value

如何向闭包添加属性？

1 个答案: