java - FAT JAR 外部的 Spring Boot 属性

Question

我正在处理一个项目，并且有一个用例，我需要从 JAR 外部为 Spring Boot 提供 application.properties 文件。

根据 Baeldung , 获取 application.properties 的优先顺序是

1. 当前目录的/config 子目录
2. 当前目录
3. 类路径/配置包
4. 类路径根

前两个的问题是我需要导航到包含运行 JAR 配置的目录。在本地工作时这听起来没问题，但在通过 CI/CD 框架部署到远程主机时，这不是一个可行的解决方案。

我试图找到一种使用类路径的机制，并避免使用 here 中提到的 spring boot 命令行选项或设置环境变量。

我无法弄清楚如何在运行 FAT JAR 时设置类路径并一起指定配置。如果可以，请帮我解决一下!

提前致谢:)

编辑:我知道有一些方法可以使用 Spring Boot 的命令行选项(例如 spring.config 或 loader.path 等)来实现这一点。

我试图找到一个基于类路径和目录结构的更隐式的解决方案，只是为了减少它与正在使用 Spring Boot 的事实的耦合。

Answer 1

根据Spring docs ，您可以使用 spring.config.location 属性定义外部配置位置。更具体地说:

If spring.config.location contains directories (as opposed to files), they should end in / (and, at runtime, be appended with the names generated from spring.config.name before being loaded, including profile-specific file names). Files specified in spring.config.location are used as-is, with no support for profile-specific variants, and are overridden by any profile-specific properties.

Config locations are searched in reverse order. By default, the configured locations are:

classpath:/,classpath:/config/,file:./,file:./config/.

The resulting search order is the following:

file:./config/ file:./ classpath:/config/ classpath:/

When custom config locations are configured by using spring.config.location, they replace the default locations. For example, if spring.config.location is configured with the value

classpath:/custom-config/,file:./custom-config/ the search order becomes the following:

file:./custom-config/ classpath:custom-config/

Alternatively, when custom config locations are configured by using spring.config.additional-location, they are used in addition to the default locations. Additional locations are searched before the default locations. For example, if additional locations of classpath:/custom-config/,file:./custom-config/ are configured, the search order becomes the following:

file:./custom-config/ classpath:custom-config/ file:./config/ file:./ classpath:/config/ classpath:/

包含外部配置的目录的示例用法如下:

java -jar myproject.jar --spring.config.location=file:/custom-config-dir/

或者直接到外部配置文件:

java -jar myproject.jar --spring.config.location=file:/custom-config-dir/custom-config.properties