Spring Boot yaml configuration for a list of strings
From the spring boot docs https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html
YAML lists are represented as property keys with [index] dereferencers, for example this YAML:
my:
servers:
- dev.bar.com
- foo.bar.com
Would be transformed into these properties:
my.servers[0]=dev.bar.com
my.servers[1]=foo.bar.com
To bind to properties like that using the Spring DataBinder utilities (which is what @ConfigurationProperties
does) you need to have a property in the target bean of type java.util.List
and you either need to provide a setter, or initialize it with a mutable value, e.g. this will bind to the properties above. Here is what the question's code would look like.
@ConfigurationProperties(prefix="ignore")
public class Filenames {
private List<String> ignoredFilenames = new ArrayList<String>();
public List<String> getFilenames() {
return this.ignoredFilenames;
}
}
use comma separated values in application.yml
ignoreFilenames: .DS_Store, .hg
java code for access
@Value("${ignoreFilenames}")
String[] ignoreFilenames
It is working ;)
My guess is, that the @Value
can not cope with "complex" types. You can go with a prop class like this:
@Component
@ConfigurationProperties('ignore')
class IgnoreSettings {
List<String> filenames
}
Please note: This code is Groovy - not Java - to keep the example short! See the comments for tips how to adopt.
See the complete example https://github.com/christoph-frick/so-springboot-yaml-string-list