How can you access private fields of an object through reflection?

In Java, reflection can be used to access private fields of an object by changing their accessibility with the setAccessible(true) method. This allows reading and modifying the values of such fields.

Example:

import java.lang.reflect.Field;

public class Example {
    private String secret = "hidden";

    public static void main(String[] args) throws Exception {
        Example obj = new Example();

        Field field = Example.class.getDeclaredField("secret");
        field.setAccessible(true); // remove access restriction

        // Read the value of the private field
        String value = (String) field.get(obj);
        System.out.println("Secret value: " + value);

        // Change the value of the private field
        field.set(obj, "revealed");
        System.out.println("New secret value: " + field.get(obj));
    }
}

It is important to remember that using setAccessible(true) can break encapsulation and should be used with caution.