import com.example.proxy.service.OrderService;
import com.example.proxy.service.impl.OrderServiceInvocationHandler;
import com.example.proxy.service.impl.RealOrderServiceImpl;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.lang.reflect.Proxy;

@SpringBootTest
class ProxyApplicationTests {

    @Test
    void contextLoads() {

        // 创建代理对象
        OrderService proxy = (OrderService) Proxy.newProxyInstance(
                // 接口
                OrderService.class.getClassLoader(),
                new Class[]{OrderService.class},
                // 具体实现类
                new OrderServiceInvocationHandler(new RealOrderServiceImpl()));

        proxy.placeOrder();
    }
}

import com.example.proxy.service.OrderService;
import com.example.proxy.service.impl.OrderServiceInvocationHandler;
import com.example.proxy.service.impl.RealOrderServiceImpl;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.cglib.proxy.Enhancer;
import org.springframework.cglib.proxy.MethodInterceptor;
import org.springframework.cglib.proxy.MethodProxy;

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

@SpringBootTest
class ProxyApplicationTests {

    @Test
    void contextLoads() {

        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(RealOrderServiceImpl.class);
        enhancer.setCallback(new MethodInterceptor() {
            @Override
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                System.out.println("Before placing order");
                Object invoke = methodProxy.invokeSuper(o, objects);
                System.out.println("After placing order");
                return invoke;
            }
        });

        OrderService proxy = (OrderService) enhancer.create();
        proxy.placeOrder();
    }
}

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>

import java.lang.annotation.*;

@Target({ElementType.METHOD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Log {

    /* 日志描述 */
    String value() default "";
}

@Aspect
@Component
@Slf4j
public class LogAspect {

    @AfterReturning(pointcut = "@annotation(controllerLog)", returning = "result")
    public void doAfterReturning(JoinPoint joinPoint, Object result, Log controllerLog){
        log.info("方法返回值：{}", result);
        log.info("注解描述：{}", controllerLog.value());
        log.info("方法名：{}", joinPoint.getSignature().getName());

    }
}

@Service
public class AopServiceImpl {

    @Log("AOP test")
    public String test(){
        System.out.println("AOP test");
        return "AOP success";
    }
}

@Service
public class DataService {

    @Autowired
    private UserMapper userMapper;

//    @MyDataSource("master")
    @MyDataSource("slaver")
    public void test()
    {
        userMapper.insertUser("aop", "aop");
        System.out.println("动态数据源切换成功！");
    }
}