Exception trying to change a CGLib proxy field value

Question

I created a CGLib dynamic proxy of a class, but when I try to access any field declared in the original class, I obtain java.lang.NoSuchFieldException. I need to obtain the field in order to change its value.

By the way, this is the class the proxy is based on:

public class Person {

    private String name;
    ....
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    ...
}

And this is the code snippet (inside the "intercept" method of the "MethodInterceptor") that is raising the mentioned exception (more specifically the first line):

public Object intercept(Object instance, Method jdkMethod, Object[] args, MethodProxy method) throws Throwable {
...
Field field = instance.getClass().getField("name");
field.setAccessible(true);
field.set(instance, "foo");
....

Do you know any other way to access the needed field or change its value?

Thanks.

Answer 1

Apparently, a CGLib proxy is a subclass of the original class. So, the following code worked well:

Field field = instance.getClass().getSuperclass().getDeclaredField("name");

Answer 2

Try:

Field field = instance.getClass().getDeclaredField("name");

As mentioned in this SO answer, getField only works for public fields, but applies to the entire class hierarchy. You can think of it as inspecting the public interface of the class. getDeclaredField works for private fields, and will not inspect the class hierarchy; you can think of it as resolving the implementation of the class.