查看“Application.yml参数注入到数组”的源代码

=== 首先，因为 @Value 的实现机制，下面这种注入是不支持的 ===

==== application.yml ====
<syntaxhighlight lang="yaml">
include:
  - E:\record\2022
  - E:\record\2023
</syntaxhighlight>




==== Application.java ====
<syntaxhighlight lang="java">
@SpringBootApplication
@Slf4j
@Data
public class Application implements CommandLineRunner {

    @Value("${include}")
    String[] include;

    public static void main(String[] args) {
        log.info("STARTING THE APPLICATION");
        SpringApplication.run(Application.class, args);
        log.info("APPLICATION FINISHED");
    }

    @Override
    public void run(String... args) {

        for (String str:include) {
            log.info(str);
        }
        
    }

}
</syntaxhighlight>会报错：<syntaxhighlight lang="console">
……
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'include' in value "${include}"
	at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:178) ~[spring-core-5.3.1.jar:5.3.1]
	at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.3.1.jar:5.3.1]
	at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239) ~[spring-core-5.3.1.jar:5.3.1]
……
</syntaxhighlight>


=== 可以作为对象的属性注入 ===

==== application.yml ====
<syntaxhighlight lang="yaml">
args:
  include:
    - E:\record\2022
    - E:\record\2023
</syntaxhighlight>



==== Args.java ====
<syntaxhighlight lang="java">
@Component
@ConfigurationProperties(prefix="args")
@Data
public class Args {

    private String[] include;

}
</syntaxhighlight>

==== Application.java ====
<syntaxhighlight lang="java">
@SpringBootApplication
@Slf4j
@Data
public class Application implements CommandLineRunner {


    @Autowired
    Args args;

    public static void main(String[] args) {
        log.info("STARTING THE APPLICATION");
        SpringApplication.run(Application.class, args);
        log.info("APPLICATION FINISHED");
    }

    @Override
    public void run(String... args) {

        log.info("EXECUTING : command line runner");
        for (String str:this.args.getInclude()) {
            log.info(str);
        }

    }

}
</syntaxhighlight>