Java反射派生类

Question

这是我的场景“我有一个抽象类。有许多派生类使用注释扩展这个抽象类。此外，我有一个抽象类的方法，它反射(reflect)了一个特定派生类中的所有符号”。

// Here's a definition of annotation
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface SampleAnnotation {
   int sample();
}

public abstract class A { 

 // Here's a method to reflect all annotations
 // in particular derived class like B or C
 @Override
 public void foo() {

 }}

public class B extends A {
  @SampleAnnotation (sample = 1)
  public void step1() {}

  @SampleAnnotation (sample = 2)
  public void step2() {}

}

public class C extends A {
  @SampleAnnotation (sample = 1)
  public void step1() {}

  @Sample (stage = 2)
  public void step2() {}
}

如何使用 java 反射来反射(reflect)特定派生类(如 B 或 C)中的所有注释？

Answer 1

也许你想到的是这个Reflections图书馆。

Using Reflections you can query your metadata such as:

• get all subtypes of some type
• get all types/methods/fields annotated with some annotation, w/o annotation parameters matching
• get all resources matching matching a regular expression