如何从Spring中的application.properties重新加载@Value属性？ [英] How to reload a @Value property from application.properties in Spring?

问题描述

我有一个 spring-boot 应用程序。在run文件夹下，还有一个额外的配置文件：

I have a spring-boot application. Under the run folder, there is an additional config file:

dir / config / application.properties

当应用程序启动时，它会使用文件中的值并将它们注入：

When the applications starts, it uses the values from the file and injects them into:

@Value("${my.property}")
private String prop;

问题：如何触发重新加载 @Value 属性？
我希望能够在运行时更改 application.properties 配置，并拥有 @Value 字段已更新（可能通过在应用程序内调用 / reload servlet来触发更新）。

Question: how can I trigger a reload of those @Value properties? I want to be able to change the application.properties configuration during runtime, and have the @Value fields updated (maybe trigger that update by calling a /reload servlet inside the app).

但如何？

推荐答案

使用下面的bean每1秒重新加载config.properties。

Use the below bean to reload config.properties every 1 second.

@Component
public class PropertyLoader {

    @Autowired
    private StandardEnvironment environment;

    @Scheduled(fixedRate=1000)
    public void reload() throws IOException {
        MutablePropertySources propertySources = environment.getPropertySources();
        PropertySource<?> resourcePropertySource = propertySources.get("class path resource [config.properties]");
        Properties properties = new Properties();
        InputStream inputStream = getClass().getResourceAsStream("/config.properties");
        properties.load(inputStream);
        inputStream.close();
        propertySources.replace("class path resource [config.properties]", new PropertiesPropertySource("class path resource [config.properties]", properties));
    }
}

您的主配置如下所示：

@EnableScheduling
@PropertySource("classpath:/config.properties")
public class HelloWorldConfig {
}

而不是使用@Value，每次你想要使用最新的属性时

The instead of using @Value, each time you wanted the latest property you would use

environment.get("my.property");

这篇关于如何从Spring中的application.properties重新加载@Value属性？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！