如何根据指定RabbitTemplate对象获取对应的Spring Bean名称？

问题场景 #

已定义两个RabbitTemplate类型的Bean：

@Bean("name1")
public RabbitTemplate template1(RabbitProperties properties, ConnectionFactory factory) {
    return rabbitCreateOneTemplate(factory, properties.getTemplate());
}

@Bean("name2")
public RabbitTemplate template2(RabbitProperties properties, ConnectionFactory factory) {
    return rabbitCreateTwoTemplate(factory, properties.getTemplate());
}

通过@Qualifier注入指定Bean后，希望从已注入的template对象获取其对应的Bean名称（如"name1"）。

实现方案 #

方案一：借助BeanFactory遍历匹配 #

注入BeanFactory后，遍历同类型Bean的名称，对比实例一致性来获取目标名称：

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.support.BeanFactoryUtils;
import org.springframework.stereotype.Component;

@Component
public class Const {
    private final RabbitTemplate template;
    private final BeanFactory beanFactory;

    public Const(@Qualifier("name1") RabbitTemplate template, BeanFactory beanFactory) {
        this.template = template;
        this.beanFactory = beanFactory;
    }

    public String getTemplateBeanName() {
        String[] rabbitTemplateNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(beanFactory, RabbitTemplate.class);
        for (String name : rabbitTemplateNames) {
            if (template.equals(beanFactory.getBean(name))) {
                return name;
            }
        }
        return null;
    }
}

方案二：自定义BeanPostProcessor缓存实例与名称映射 #

通过BeanPostProcessor在Bean初始化时记录实例与名称的对应关系，后续直接查询：

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.stereotype.Component;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

@Component
public class BeanInstanceNameCache implements BeanPostProcessor {
    private static final Map<Object, String> INSTANCE_TO_NAME = new ConcurrentHashMap<>();

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        INSTANCE_TO_NAME.put(bean, beanName);
        return bean;
    }

    public static String getBeanName(Object bean) {
        return INSTANCE_TO_NAME.get(bean);
    }
}

在需要获取名称的类中直接调用：

private final RabbitTemplate template;

public Const(@Qualifier("name1") RabbitTemplate template) {
    this.template = template;
}

public String getTemplateBeanName() {
    return BeanInstanceNameCache.getBeanName(template);
}

注意事项 #

• 方案一适合单例Bean场景，若使用原型Bean，每次获取的实例会不同，对比可能失效；
• 方案二若处理原型Bean，建议改用WeakHashMap避免内存泄漏；
• 两种方案均仅适用于Spring容器管理的Bean实例。

内容的提问来源于stack exchange，提问作者Kirill Zhurbin