The documentation of CtBehavior#getParameterAnnotations only states "@return an array of annotation-type objects".

It doesn't mention what is returned when none of the parameters is annotated. However, most of the introspective methods mirror the ones in the regular reflection API, so one would expect it to behave like java.lang.Method#getParameterAnnotations.

The following test case shows that it doesn't :

import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
import javassist.NotFoundException;
import junit.framework.TestCase;

public class TestCtMethod extends TestCase {

 public void test() throws NoSuchMethodException, NotFoundException, ClassNotFoundException {
 Method equalsReflection=Object.class.getMethod("equals", Object.class);
 Annotation[][] annotationsReflection=equalsReflection.getParameterAnnotations();

 ClassPool pool=ClassPool.getDefault();
 CtClass objectCtClass=pool.get("java.lang.Object");
 CtClass[] parameterTypes=new CtClass[1];
 parameterTypes[0]=pool.get("java.lang.Object");
 CtMethod equalsJavassist=objectCtClass.getDeclaredMethod("equals", parameterTypes);
 Object[][] annotationsJavassist=equalsJavassist.getParameterAnnotations();

 assertEquals(annotationsReflection.length, annotationsJavassist.length);
 }
}

Is the current behaviour really what was intended? In that case the documentation needs to be expanded and perhaps stress that it doesn't mirror its reflection API equivalent.

Can one of the developers please confirm which it is? Thanks.