爪哇 - 加载注释类 [英] Java - loading annotated classes

问题描述

我知道有令人难以置信的一套Java中加载插件类的工具，但今天一个想法来到了我的脑海里。

I know there are incredible set of tools for loading plugin classes in java, but today an idea came to my mind.

如果我有一堆包org.home.junk注释和未标注类（有标注@AnnotatedClass注明）和那些类有注解的方法与注释说@AnnotatedMethod。

What if I have a bunch of annotated and un-annotated classes in package "org.home.junk" (annotated with annotation "@AnnotatedClass") and those classes have annotated methods with say annotation "@AnnotatedMethod".

第一个问题：我在运行时得到的所有类的数组/集合在特定的包，这样我可以检查哪一个的被注释和创建它们的实例。 （我知道但是如何检查Some.class在本指南的注释提供：<一href=\"http://isagoksu.com/2009/development/java/creating-custom-annotations-and-making-use-of-them/\">http://isagoksu.com/2009/development/java/creating-custom-annotations-and-making-use-of-them/)

First question: can I at run-time get an array/collection of all the classes in that specific package, so that I could check which one's are annotated and create an instance of them. (I am aware however how to check if Some.class has annotations courtesy of this guide: http://isagoksu.com/2009/development/java/creating-custom-annotations-and-making-use-of-them/)

第二个问题： - 如果我能做到在第一个问题想什么，我 - 这将是做到这一点的最政治的方式

Second question: - If I can do what I'd like in first question - what would be the most political way to do this?

我相信这是可能的，据我了解的JUnit载荷一些类似方式的测试用例类。

I believe it is possible, as I understand JUnit loads test-case classes in some similar manner.

此外它会很酷，如果这可以用最少的第三方库和来完成，例如，再 - 如果可能的话：）

Also it would be cool if this could be done with minimal third party libraries and such, again - if it's possible :)

推荐答案

第一个答案：看看的这个项目。

Reflections reflections = new Reflections("org.home.junk");
Set<Class<?>> annotated = reflections.getTypesAnnotatedWith(javax.persistence.Entity.class);

它返回从 org.home.junk 所有类与 javax.persistence.Entity 注解。

第二个答案：：要创建上面的类新实例，你可以做到这一点。

Second Answer: To create new instance of above classes you can do this

for (Class<?> clazz : annotated) {
    final Object newInstance = clazz.newInstance();
}

希望这回答了一切。

Hope this answers everything.

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