如何通过编程方式获取Spring RabbitMQ配置属性值（非@Value方式）

除了@Value注解，还有以下几种常用的编程方式获取Spring RabbitMQ的配置属性：

1. 利用Spring Environment对象 #

Spring的Environment是全局环境配置的核心载体，可以直接通过它读取任意配置属性：

import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;

@Component
public class RabbitConfigReader {
    private final Environment environment;

    public RabbitConfigReader(Environment environment) {
        this.environment = environment;
    }

    public String getVirtualHost() {
        return environment.getProperty("spring.rabbitmq.virtual-host");
    }
}

在任何Spring管理的Bean中注入Environment后，调用getProperty()方法就能获取指定的RabbitMQ配置项。

2. 使用@ConfigurationProperties绑定配置类 #

通过自定义配置类结合@ConfigurationProperties注解，可批量绑定spring.rabbitmq前缀的所有配置属性，方便统一管理：

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties(prefix = "spring.rabbitmq")
public class RabbitCustomProperties {
    private String virtualHost;
    private String host;
    private int port;

    // Getter和Setter方法
    public String getVirtualHost() {
        return virtualHost;
    }

    public void setVirtualHost(String virtualHost) {
        this.virtualHost = virtualHost;
    }

    public String getHost() {
        return host;
    }

    public void setHost(String host) {
        this.host = host;
    }

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }
}

使用时直接注入该配置类，通过getter方法获取对应属性值即可。

3. 直接注入Spring Boot内置的RabbitProperties类 #

Spring Boot内置了RabbitProperties类，它自动绑定了所有spring.rabbitmq开头的配置属性，无需自定义配置类：

import org.springframework.boot.autoconfigure.amqp.RabbitProperties;
import org.springframework.stereotype.Component;

@Component
public class RabbitPropReader {
    private final RabbitProperties rabbitProperties;

    public RabbitPropReader(RabbitProperties rabbitProperties) {
        this.rabbitProperties = rabbitProperties;
    }

    public String getVirtualHost() {
        return rabbitProperties.getVirtualHost();
    }
}

RabbitProperties封装了所有RabbitMQ相关配置，包括虚拟主机、主机地址、端口、认证信息等，直接调用对应getter方法就能获取值。

内容的提问来源于stack exchange，提问作者Martin Schröder