JoinPoints in AOP

• It is a specific point in executing a program's code where an aspect can be applied to introduce cross-cutting concerns.
• It is the execution point in the program's flow.
• It is the point where the aspect is executed.

Example:

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LoggingAspect {

    @Before("execution(* com.example.bank.BankService.transferFunds(..))")
    public void logBeforeTransfer(JoinPoint joinPoint) {
        System.out.println("Before transferring funds...");
    }

    @After("execution(* com.example.bank.BankService.transferFunds(..))")
    public void logAfterTransfer(JoinPoint joinPoint) {
        System.out.println("After transferring funds...");
    }
}

package com.example.bank;

import org.springframework.stereotype.Service;

@Service
public class BankService {

    public void transferFunds(double amount, String fromAccount, String toAccount) {

        System.out.println("Transferring $" + amount + " from " + fromAccount + " to " + toAccount);
    }
}

Output:

Before transferring funds...
Transferring $100.0 from SavingsAccount to CheckingAccount
After transferring funds...