如何为@Scope("prototype")的每个Bean加载不同配置文件初始化？

我有一个标注了@Scope("prototype")的Spring Boot类ProviderSimulator，代码如下：

@Service
@Scope("prototype")
public class ProviderSimulator {
    @Value("${provider.description}")
    private String providerDescription;
    // 其他代码省略
}

目前通过以下代码从application.properties初始化其属性：

@Autowired
private ApplicationContext ctx;

ProviderSimulator p1 = ctx.getBean(ProviderSimulator.class);
ProviderSimulator p2 = ctx.getBean(ProviderSimulator.class);
ProviderSimulator p3 = ctx.getBean(ProviderSimulator.class);

p1、p2、p3是不同的Bean实例，但它们的providerDescription都取自application.properties中的provider.description值。请问是否有办法让每个Bean实例从不同的配置文件初始化？比如p1读取p1.properties，p2读取p2.properties等？

方案1：手动加载配置文件并注入属性 #

这种方式最直接，放弃@Value自动注入，改为创建实例后手动加载对应配置文件并设置属性。

实现步骤： #

• 修改ProviderSimulator，添加属性setter方法：

@Service
@Scope("prototype")
public class ProviderSimulator {
    private String providerDescription;

    public void setProviderDescription(String providerDescription) {
        this.providerDescription = providerDescription;
    }

    // 其他方法省略
}

• 编写工具方法加载指定配置文件的属性：

private String loadPropertyFromFile(String fileName, String key) throws IOException {
    Properties properties = new Properties();
    try (InputStream is = new ClassPathResource(fileName).getInputStream()) {
        properties.load(is);
    }
    return properties.getProperty(key);
}

• 创建实例时加载对应配置文件并设置属性：

@Autowired
private ApplicationContext ctx;

// 创建p1并加载p1.properties
ProviderSimulator p1 = ctx.getBean(ProviderSimulator.class);
p1.setProviderDescription(loadPropertyFromFile("p1.properties", "provider.description"));

// 创建p2并加载p2.properties
ProviderSimulator p2 = ctx.getBean(ProviderSimulator.class);
p2.setProviderDescription(loadPropertyFromFile("p2.properties", "provider.description"));

方案2：保留@Value注入，用动态PropertySource实现 #

通过ThreadLocal传递配置文件名，结合自定义PropertySource动态加载对应配置，无需修改原有ProviderSimulator结构。

实现步骤： #

• 创建ThreadLocal存储当前要使用的配置文件名：

public class ConfigFileContextHolder {
    private static final ThreadLocal<String> CONFIG_FILE_NAME = new ThreadLocal<>();

    public static void setConfigFileName(String fileName) {
        CONFIG_FILE_NAME.set(fileName);
    }

    public static String getConfigFileName() {
        return CONFIG_FILE_NAME.get();
    }

    public static void clear() {
        CONFIG_FILE_NAME.remove();
    }
}

• 自定义PropertySource，动态加载指定配置文件：

public class DynamicPropertySource extends PropertySource<Properties> {
    public DynamicPropertySource() {
        super("dynamicPropertySource");
    }

    @Override
    public Object getProperty(String name) {
        String fileName = ConfigFileContextHolder.getConfigFileName();
        if (fileName == null) {
            return null;
        }
        try {
            Properties properties = new Properties();
            try (InputStream is = new ClassPathResource(fileName).getInputStream()) {
                properties.load(is);
            }
            return properties.getProperty(name);
        } catch (IOException e) {
            throw new RuntimeException("加载配置文件失败: " + fileName, e);
        }
    }
}

• 将自定义PropertySource添加到Spring环境中：

@Configuration
public class DynamicConfigConfig {
    @Autowired
    private ConfigurableEnvironment environment;

    @PostConstruct
    public void addDynamicPropertySource() {
        environment.getPropertySources().addFirst(new DynamicPropertySource());
    }
}

• 创建实例时先设置配置文件名，再获取Bean：

@Autowired
private ApplicationContext ctx;

// 创建p1
ConfigFileContextHolder.setConfigFileName("p1.properties");
ProviderSimulator p1 = ctx.getBean(ProviderSimulator.class);
ConfigFileContextHolder.clear();

// 创建p2
ConfigFileContextHolder.setConfigFileName("p2.properties");
ProviderSimulator p2 = ctx.getBean(ProviderSimulator.class);
ConfigFileContextHolder.clear();

方案3：用@ConfigurationProperties绑定多配置文件 #

为每个配置文件创建对应配置类，通过构造器注入不同配置实例到Prototype Bean中。

实现步骤： #

• 定义配置属性类：

@ConfigurationProperties(prefix = "provider")
public class ProviderProperties {
    private String description;

    // getter、setter
    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

• 创建多个配置类加载不同配置文件：

@Configuration
@PropertySource("classpath:p1.properties")
public class P1Config {
    @Bean
    @Scope("prototype")
    public ProviderProperties p1ProviderProperties() {
        return new ProviderProperties();
    }
}

@Configuration
@PropertySource("classpath:p2.properties")
public class P2Config {
    @Bean
    @Scope("prototype")
    public ProviderProperties p2ProviderProperties() {
        return new ProviderProperties();
    }
}

• 修改ProviderSimulator通过构造器注入配置：

@Service
@Scope("prototype")
public class ProviderSimulator {
    private String providerDescription;

    public ProviderSimulator(ProviderProperties properties) {
        this.providerDescription = properties.getDescription();
    }

    // 其他方法省略
}

• 创建实例时传入对应配置Bean：

@Autowired
private ApplicationContext ctx;

ProviderSimulator p1 = ctx.getBean(ProviderSimulator.class, ctx.getBean("p1ProviderProperties"));
ProviderSimulator p2 = ctx.getBean(ProviderSimulator.class, ctx.getBean("p2ProviderProperties"));

内容的提问来源于stack exchange，提问作者Marc Le Bihan