如何截击获得物体

public class UserService {
    public void createUser(String username) {
        System.out.println("Creating user: " + username);
    }
}

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

public class LoggingProxy implements InvocationHandler {
    private final Object target;

    public LoggingProxy(Object target) {
        this.target = target;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("Before method: " + method.getName());
        Object result = method.invoke(target, args);
        System.out.println("After method: " + method.getName());
        return result;
    }

    public static <T> T createProxy(T target, Class<T> interfaceType) {
        return (T) Proxy.newProxyInstance(
                interfaceType.getClassLoader(),
                new Class<?>[]{interfaceType},
                new LoggingProxy(target)
        );
    }

    public static void main(String[] args) {
        UserService userService = new UserService();
        UserService proxy = LoggingProxy.createProxy(userService, UserService.class);
        proxy.createUser("Alice");
    }
}