Understanding AOP proxies

As you know that, Spring AOP is proxy-based. It mean Spring creates the proxy to weave the aspect between the business logic that is, in target object. It is based on the Proxy and Decorator design pattern. Let's see TransferServiceImpl class as an implementation of TransferService interface:

    package com.packt.patterninspring.chapter6.bankapp.service; 
    import org.springframework.stereotype.Service; 
    public class TransferServiceImpl implements TransferService { 
      @Override 
      public void transfer(String accountA, String accountB, Long 
      amount) { 
        System.out.println(amount+" Amount has been tranfered from 
        "+accountA+" to "+accountB); 
      } 
    } 

Caller invokes this service (transfer() method) directly by the object reference, let's see the following figure to illustrate more:

As you can see that caller could directly call the service and do the task assigned to it.

But you declare this TransferService as a target for the...