Java 在 Spring Boot 中根据配置文件读取 .env 和 properties.yml 文件

别慌！它是/must be在工作...

从简单开始:

1. quickstart-maven, dependencies: web (only)个

2. 只是一个演示(否/空application.properties,according to 102 we can refer to any 100/custom "property"；):

   package com.example.demo;
   
   import org.springframework.beans.factory.InitializingBean;
   import org.springframework.beans.factory.annotation.Value;
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.context.annotation.Bean;
   
   @SpringBootApplication
   public class DemoConfigApplication {
   
     public static void main(String[] args) {
       SpringApplication.run(DemoConfigApplication.class, args);
     }
   
     @Bean
     InitializingBean test(
         @Value("${foo.bar:undefined}") String fooBar,
         @Value("${foo.baz:undefined}") String fooBaz
     ) {
       return () -> {
         System.err.format("foo.bar: %s%n", fooBar);
         System.err.format("foo.baz: %s%n", fooBaz);
       };
     }
   
   }
   

3. 建房

   ./mvnw clean test
   

   打印:

   ...
   foo.bar: undefined
   foo.baz: undefined
   ...
   

要通过(springot-)maven-plugin设置这些插件，我们可以:

(转到)

1. 通过"命令行参数" (用空白，用我的胜利+gitbash:

   GNU bash, version 5.2.12(1)-release (x86_64-pc-msys)
   

   )

   Syntax:

   ./mvnw spring-boot:run -Dspring-boot.run.arguments="--foo.bar='Foo Bar' --foo.baz='Foo Baz'"
   

   (输出):

   ...
   2023-03-15T13:45:52.849+01:00  INFO 4196 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1106 ms
   foo.bar: Foo Bar
   foo.baz: Foo Baz
   ...
   

2. 通过"系统属性"(Same Git Bash):

   Syntax:

   ./mvnw spring-boot:run -Dspring-boot.run.jvmArguments="-Dfoo.bar='Foo Bar' -Dfoo.baz='Foo Baz'"
   

使(例如)在……工作

Cmd.exe

(版本10.0.19045.2673)，引用与gitbash相同:

.\mvnw.cmd spring-boot:run -Dspring-boot.run.arguments="--foo.bar='Foo Bar' --foo.baz='Foo Baz'"

Powershell

(v7.3.3) 更复杂，由于/有ref:

.\mvnw.cmd spring-boot:run '-Dspring-boot.run.arguments="--foo.bar=""Foo Bar"" --foo.baz=""Foo Baz"""'

...