当一个类返回lambda表达式为什么不反思工作 [英] Why doesn't reflection work when a class returns Lambdas

问题描述

我曾经遇到过一个有些奇怪的行为。我使用标注与特定的目的，以纪念某一类，然后我用org.reflections库来找到所有与特定注释的类。然而，当一个类实现返回lambda函数的方法，反射不会再找到注解的类。类的签名是不变的。

I have encountered a somewhat strange behaviour. I use annotations to mark certain classes with a particular purpose, and then I use org.reflections library to find all the classes with the particular annotation. However when a class implements a method that returns a lambda function, the reflection won't find the annotated class anymore. The signature of the class is unchanged.

注释的例子：

@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
   String someValue();
}

使用注释（编辑 - 添加了BaseClass的）：

Using the annotation (EDIT - added the BaseClass):

public class BaseClass {

    public Consumer<Integer> doSomething(){ return null;}
}


@MyAnnotation(someValue = "a")
public class FooBar extends BaseClass {

    @Override
    public Consumer<Integer> doSomething() {
        return null;
    }
}



@MyAnnotation(someValue = "bazbar")
public class BarClass extends BaseClass {

    @Override
    public  Consumer<Integer> doSomething(){
        return (x) -> {};
    }
}

查找注释

private static final Reflections reflections = new Reflections("com.mypackage");

Set<Class<?>> clazzes  = reflections.getTypesAnnotatedWith(MyAnnotation.class);

现在 - 设定clazzes仅包含 1单班的FooBar的类。如果我从BazBar类中删除拉姆达返回值，一个也显示了，但只要一方法的类返回一个lambda反射不会工作。

Now - the set 'clazzes' only contains 1 single class, the FooBar class. If I remove the lambda return value from the BazBar class that one too shows up, but as soon as one method in the class returns a lambda the reflection wont work.

我迷路了，任何想法？

推荐答案

从的问题列表看来，这个库不适合用于Java尚未8功能。我认为最好的办法是报告这一问题，也许提供了一个补丁。

From the issues list it seems that this library isn't fit for Java 8 features yet. I think your best bet is reporting this problem and maybe provide a fix.

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