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Spring aop proxy object

Now I am reading a Spring book written in Korean and my English is bad. Please understand.

The book says that Spring AOP initiates the class using a dynamic proxy if it uses an interface, and it uses CGLIB to run the class if there is no interface. I do not quite understand what this means. could you help me understand its deep meaning.

I do not know if this question is stupid or not. but I'm just curious thanks.

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A proxy is essentially an intermediary between the client and the object, so that it implements non-finite methods of the object. Proxying an interface is relatively simple because the interface is just a list of methods that you need to implement, which makes it easy to intercept method calls.

The Java Proxy class is a class that implements a list of interfaces that are specified at runtime. Then the proxy has an InvocationHandler associated with it , which delegates method calls made in the proxy to the proxied object. It acts as a level of indirection, so methods are not called on the object itself, but rather on its proxy. InvocationHandlerhas only one method that needs to be implemented:

public Object invoke(Object proxy, Method method, Object[] args)

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public abstract class LazilyLoadedObject implements InvocationHandler {

    private Object target;

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        if (target == null) {
            target = loadObject();
        }
        return method.invoke(target, args);
    }

    /**
     * Loads the proxied object. This might be an expensive operation
     * or loading lots of objects could consume a lot of memory, so
     * we only load the object when it needed.
     */
     protected abstract Object loadObject();

}

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