Kalle Richter [https://community.jboss.org/people/krichter] created the discussion "mapping of parameter and generic parameter types" To view the discussion, visit: https://community.jboss.org/message/749365#749365 -------------------------------------------------------------- Hallo together, I'm wondering whether the length of the arrays returned by java.lang.reflect.Constructor.getParameterTypes() and getGenericParameterTypes() should be always equal, i.e. whether it's a bug if they're not or whether I'm doing something wrong. You can run the program below and you'll understand my problem immediately :) package org.h9t2.javassistbug;   import java.io.*; import java.util.List; import java.util.Set; import javassist.*;   public class App {     private final static ClassPool pool = ClassPool.getDefault();       public static void main( String[] args ) throws NotFoundException, IOException, CannotCompileException {                CtClass ctClass1 = pool.get(Clazz.class.getName());         CtClass clone1 = createClone(ctClass1);         CtConstructor cloneConstructor1 = clone1.getConstructors()[0];         cloneConstructor1.addParameter(pool.get(List.class.getName()));         cloneConstructor1.addParameter(pool.get(Set.class.getName()));         Class clazz1 = clone1.toClass();                 System.out.println(clazz1.getConstructors()[0].getParameterTypes().length);         System.out.println(clazz1.getConstructors()[0].getGenericParameterTypes().length);   }             private static int classNameSuffix = 1;             private static CtClass createClone(CtClass ctClass) throws IOException {         ByteArrayOutputStream classFileByteStream =new ByteArrayOutputStream();         DataOutputStream classFileStream = new DataOutputStream(classFileByteStream);         if(ctClass.isFrozen()) {             ctClass.defrost();         }         ctClass.getClassFile().write(classFileStream);         byte[] classFileBytes = classFileByteStream.toByteArray();         InputStream classFileCloneStream = new ByteArrayInputStream(classFileBytes);         CtClass retValue = pool.makeClass(classFileCloneStream);         retValue.setName(ctClass.getName()+"V"+classNameSuffix++);         return retValue;     } }   class Clazz {       public Clazz(         List<Boolean> parameter0,         int b     ) {} }   Or is it the fault of my createClone method? Any help or hint is appreciated Best regards -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/749365#749365] Start a new discussion in Javassist at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]