解决问题

在开发或测试环境中某些依赖的服务不能使用，需要通过mock依赖服务。

解决思路

ByteBuddy + BeanPostProcessor + @Profile
在Bean初始化时通过ByteBuddy对方法返回值进行替换，通过@Profile指定执行环境。代码示例如下

import net.bytebuddy.ByteBuddy;
import net.bytebuddy.implementation.FixedValue;
import net.bytebuddy.matcher.ElementMatchers;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Component;

@Component
@Profile("test")
public class ByteBuddyBeanPostProcessor implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if (bean instanceof targetService) {   //确认拦截的类
            return mockData();
        }
        return bean;
    }

     private Object mockData() {
         try {
             return new ByteBuddy()
                     .subclass(targetService.class)
                     .method(ElementMatchers.named("targetMethod")) //要拦截的方法
                     .intercept(FixedValue.value(""))// 设置返回值
                     .make()
                     .load(getClass().getClassLoader())
                     .getLoaded()
                     .newInstance();
         } catch (InstantiationException e) {
             throw new RuntimeException(e);
         } catch (IllegalAccessException e) {
             throw new RuntimeException(e);
         }
     }

}