使用Groovy DSL委托getter覆盖现有属性

Question

在下面的示例中，我想用我自己的委托人的逻辑覆盖all属性。但是我只能对不存在的属性执行此操作，在编译时已知的属性保持不变。

是否可以全部处理？

def dsl(Closure action) {
    action.delegate = new Object() {
        Object getProperty(String name) {
            println "overriding property [$name] => Ross"
            return "Ross"
        }
    }
    action()
}

dsl {
    def existingSymbol = "Joe"
    println "existingSymbol: $existingSymbol"
    println "inexistentSymbol: $inexistentSymbol"
}

输出：

existingSymbol: Joe     <--- expecting "Ross" here
overriding property [inexistentSymbol] => Ross
inexistentSymbol: Ross

Answer 1

def existingSymbol = "Joe"中的问题

通过使用def，您声明了具有最高优先级的新局部变量。

检查以下代码：

def dsl(Closure action) {
    def delegate = new Object() {
        Object getProperty(String name) {
            return "Ross"
        }
    }
    action=action.rehydrate(delegate,delegate,delegate)
    action.call()
}

dsl {
    def existingSymbol = "Joe"
    println "1 existingSymbol: ${existingSymbol}"
    println "2 existingSymbol: ${this.existingSymbol}"
}
dsl {
    existingSymbol = "Joe"
    println "3 existingSymbol: ${existingSymbol}"
    println "4 existingSymbol: ${this.existingSymbol}"
}

输出：

1 existingSymbol: Joe
2 existingSymbol: Ross
3 existingSymbol: Ross
4 existingSymbol: Ross