Type mismatch in invokin a method using reflection

I'm trying to figure out how to invoke a method. I get it all but it's not working. Here's my code:

public class WrapperGenerator {

    public static void generateWrapper(Class wrappedClass)
            throws /*...*/ {

        String className = wrappedClass.getSimpleName()+"Wrapper";
        Object wrappedInstance = wrappedClass.newInstance();
        JCodeModel jcm = new JCodeModel();
        JDefinedClass jdc = jcm._class(className);
        Method[] methods = wrappedClass.getDeclaredMethods();
        for(Method method : methods) {
            JMethod jm = jdc.method(0, method.getReturnType(), method.getName());
            Object[] params = new Object[method.getParameters().length];
            for(int i=0,size=method.getParameters().length ; i<size ; ++i) {
                Parameter param = method.getParameters()[i];
                params[i] = jm.param(0, param.getType(), "arg" + (i++));
            }
            method.invoke(wrappedInstance//exception thrown here
                    , params);
            jm.body()._return();
        }
        File file = new File("./");
        file.mkdirs();
        jcm.build(file);
    }
}

and here is the stack trace:

java.lang.IllegalArgumentException: argument type mismatch
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at types.WrapperGenerator.generateWrapper(WrapperGenerator.java:54)
    at types.Main.main(Main.java:15)

I have no idea what is wrong, as only the first argument(so far) is wrong. But I found out on the Internet that it should be a newInstance and it makes sens. Any ideas?

EDIT:

I made a short version to avoid confusion, heres, the code(stack trace's pretty much the same):

public class Wrapper {
    public static void generateWrapper(Class wrappedClass) 
            throws InstantiationException, IllegalAccessException, 
            IllegalArgumentException, InvocationTargetException {

        Object wrappedInstance = wrappedClass.newInstance();
        Method[] methods = wrappedClass.getDeclaredMethods();
        for(Method method : methods) {
            Object[] params = new Object[method.getParameters().length];
            for(int i=0,size=method.getParameters().length ; i<size ; ++i) {
                params[i] = method.getParameters()[i];
            }
            method.invoke(wrappedInstance//exception here
                    , params);
        }
        File file = new File("./src/types/");
        file.mkdirs();
    }
}