如何动态地将一个类的所有方法添加到另一个类中 [英] How to dynamically add all methods of a class into another class

问题描述

我在Jenkins上有一个全局共享库隐式加载到所有管道上，那么我的Jenkinsfile就像这样:

I have a global shared library on Jenkins implicitly loaded on all pipelines, then my Jenkinsfile is like that:

new com.company.Pipeline()()

然后共享库在目录src/com/company上的Pipeline.groovy类下面有一些文件:

And then the shared library has on directory src/com/company some files, below the Pipeline.groovy class:

package com.company  

import static Utils.*

def call() {
  // some stuff here...
}

问题是，这样我必须静态声明所有方法，因此如果没有Pipeline类的实例，我将失去上下文并且无法轻松访问jenkins的方法.如您所见，在此处，他们将this传递给方法mvn.

The problem is, this way I have to static declare all methods, thus I lose the context and cannot access jenkins' methods easly without the Pipeline class' instance. As you can see here they passing this to the method mvn.

想避免这种情况，我想知道通过调用Utils.install this而不是使用import static Utils.*动态地将所有方法添加为闭包，然后我的Utils.groovy就是这样:

Thinking of avoid this I was wondering about dynamically add all methods as closures by calling Utils.install this instead of using import static Utils.*, then my Utils.groovy is something like that:

package com.company

private Utils() {}

static def install(def instance) {
  def utils = new Utils()
  // Some extra check needed here I know, but it is not the problem now
  for (def method in (utils.metaClass.methods*.name as Set) - (instance.metaClass.methods*.name as Set)) {
    def closure = utils.&"$method"
    closure.delegate = instance
    instance.metaClass."$method" = closure
  }
}

def someMethod() {
  // here I want to use sh(), tool(), and other stuff freely.
}

但是它引发了GStringImpl无法转换为String的错误，我相信.&不适用于变量，如何将方法转换为在变量上具有方法名称的闭包?我的 MetaMethod 主要是 CachedMethod 例如，如果有可能将其设为

But it raises an GStringImpl cannot be cast to String error, I believe .& do not work with variables, how can I convert a method into closure having the method name on a variable? I have the MetaMethod mostly being a CachedMethod instance, if it were possible to turn it a ClosureMetaMethod instance maybe the problem can be solved, but whenever I search for method to closure conversion for groovy I just found the .& solution!

如果我使用instance.metaClass.someMethod = utils.&someMethod，它确实可以工作，但是我希望它像动态的一样，因为我添加了新方法而不必担心共享它.

If I use instance.metaClass.someMethod = utils.&someMethod it do work, but I want it to be dinamic as I add new methods without needing to worry about sharing it.

推荐答案

有一种方法可以动态地做到这一点.表示法utils.&someMethod返回 MethodClosure 对象，可以使用其构造函数简单地实例化:

There is a way to do it dynamically. Notation utils.&someMethod returns a MethodClosure object that can be simply instantiated with its constructor:

MethodClosure(Object owner, String method)

考虑以下示例:

class Utils {
    def foo() {
        println "Hello, Foo!"
    }
    def bar() {
        println "Hello, Bar!"
    }
}

class Consumer {
}

def instance = new Consumer()
def utils = new Utils()

(utils.metaClass.methods*.name - instance.metaClass.methods*.name).each { method ->
    def closure = new MethodClosure(utils, method)
    closure.delegate = instance
    instance.metaClass."$method" = closure
}

instance.foo() // Prints "Hello, Foo!"
instance.bar() // Prints "Hello, Bar!"

在此示例中，我使用def closure = new MethodClosure(utils, method)获取对象方法引用，然后将此方法添加到instance对象.希望对您有帮助.

In this example I use def closure = new MethodClosure(utils, method) to get object method reference and then add this method to instance object. I hope it helps.

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