当从命令行提供附加配置位置时，未从外部配置加载的属性

Question

我正在使用 spring-boot 2.2.7.RELEASE

在控制器中，我想从外部配置文件中获取一些值。但是即使属性在外部配置中可用，应用程序也不会启动。

您能否建议如何仅从外部配置加载特定属性。

注意：我也试过 spring.config.additional-location，但它不起作用

谢谢

控制器

import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class ExternalPropTestController {

    @Value("${com.x.db.url}")
    private String url;

    @Value("${com.x.db.secret}")
    private String secret;

    @GetMapping("/")
    public ResponseEntity<String> greet() {
        return new ResponseEntity<>(url+" : "+secret, HttpStatus.OK);
    }
}

config.yml

com:
  x:
    db:
      url: external url
      secret: external secret

启动应用程序的命令

java -jar application.jar -Dspring-boot.run.arguments=--spring.config.location=file:///C://some-external-path//config//config.yml

启动应用程序时出现以下错误

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'externalPropTestController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'com.x.db.url' in value "${com.x.db.url}" at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean[=14=](AbstractBeanFactory.java:323) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:895) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) at com.x.y.CrewDocServiceApp.main(CrewDocServiceApp.java:65) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) at org.springframework.boot.loader.Launcher.launch(Launcher.java:51) at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:52) Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'com.x.db.url' in value "${com.x.db.url}" at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:178) at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:236) at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210) at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties[=14=](PropertySourcesPlaceholderConfigurer.java:175) at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:912) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1226) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ... 23 common frames omitted

Answer 1

根据 documentation，Spring应用程序将任何命令行选项参数（即以 -- 开头的参数，例如 --server.port=9000）转换为属性并将它们添加到 Spring 环境中。

-D 通过 Maven 在运行时工作。尝试：java -jar application.jar --spring.config.location=file:///C://your//path//config.yml.

通过 maven：mvn spring-boot:run -Dspring.config.location="file:///C://your//path//config.yml"

Answer 2

对我来说这失败了：

java -jar application.jar -Dspring.config.location=/config/config.yml

但这行得通：

java -Dspring.config.location=/config/config.yml -jar application.jar

我怀疑 JVM 将 -D 作为参数传递给前者的 main()，而不是使用它来为 spring 引导设置 JVM 环境。

这是我在 openjdk-17 / alpine 上观察到的行为...

java --version
openjdk 17-ea 2021-09-14
OpenJDK Runtime Environment (build 17-ea+14)
OpenJDK 64-Bit Server VM (build 17-ea+14, mixed mode, sharing)

Answer 3

尝试绝对路径而不是相对路径，以指定外部的位置属性

当从命令行提供附加配置位置时，未从外部配置加载的属性

properties not loaded from external configuration, when additional config location is provided from command line

java

spring

properties-file

spring-boot