How to get annotation's parameters from a class in jar file

Question

I want to get a class's (packaged in jar file) annotation parameters by java reflect.

1. My annotation like this

   @Documented
   @Retention(RUNTIME)
   @Target(TYPE)    
   public @interface TestPlugin {
       public String moduleName();
       public String plugVersion();
       public String minLeapVersion();    
   }
   

2. My class like this

   @TestPlugin(moduleName="xxx", plugVersion="1.0.0", minLeapVersion="1.3.0")
   
   public class Plugin {
   
     ......
   
   }
   

3. My access code like this

   Class<?> clazz = this.loadClass(mainClassName);  // myself classloader
   
   Annotation[] annos = clazz.getAnnotations();
   
   for (Annotation anno : annos) {
       Class<? extends Annotation> annoClass = anno.annotationType();
   
       /* Question is here
       This code can get right annotationType: @TestPlugin. 
       Debug windows show anno is $Proxy33. 
       But I can't find any method to get annotation membervalues even though I can find them in debug windows.
       How can I get annotation's parameters?
       */
   }
   

   Debug windows info

Answer 1

The "real" annotation classes used by the Java VM are Dynamic Proxies for some technical reasons. This shouldn't bother you. They still "implement" your annotation class. Just use

TestPlugin plugin = clazz.getAnnotation(TestPlugin.class);

plugin.getClass() == TestPlugin.class; // false - is Dynamic proxy
TestPlugin.class.isAssignableFrom(plugin.getClass()); // true - Dynamic proxy implements TestPlugin interface

EDIT: Just found in another answer, that you could also ask your anno object in your loop, but do not use getClass(). Use .annotationType().