I am trying to load an array of strings from application.yml file. This is the config:
ignore:
filenames:
- .DS_Store
- .hg
This is the class:
@Value("${ignore.filenames}")
private List<String> igonoredFileNames = new ArrayList<>();
There are other configurations in the same class that loads just fine. There are no tabs in my yaml file. Still I get the following exception:
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'ignore.filenames' in string value "${ignore.filenames}"
This question is related to
spring-boot
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;
}
}
In addition to Ahmet's answer you can add line breaks to the coma separated string using >
symbol.
application.yml:
ignoreFilenames: >
.DS_Store,
.hg
Java code:
@Value("${ignoreFilenames}")
String[] ignoreFilenames;
@Value("${your.elements}")
private String[] elements;
yml file:
your:
elements: element1, element2, element3
Well, the only thing I can make it work is like so:
servers: >
dev.example.com,
another.example.com
@Value("${servers}")
private String[] array;
And dont forget the @Configuration above your class....
Without the "," separation, no such luck...
Works too (boot 1.5.8 versie)
servers:
dev.example.com,
another.example.com
In my case this was a syntax issue in the .yml file. I had:
@Value("${spring.kafka.bootstrap-servers}")
public List<String> BOOTSTRAP_SERVERS_LIST;
and the list in my .yml file:
bootstrap-servers:
- s1.company.com:9092
- s2.company.com:9092
- s3.company.com:9092
was not reading into the @Value-annotated field. When I changed the syntax in the .yml file to:
bootstrap-servers >
s1.company.com:9092
s2.company.com:9092
s3.company.com:9092
it worked fine.
@Value("#{'${your.elements}'.split(',')}")
private Set<String> stringSet;
yml file:
your:
elements: element1, element2, element3
There is lot more you can play with spring spEL.
Ahmet's answer provides on how to assign the comma separated values to String array.
To use the above configuration in different classes you might need to create getters/setters for this.. But if you would like to load this configuration once and keep using this as a bean with Autowired annotation, here is the how I accomplished:
In ConfigProvider.java
@Bean (name = "ignoreFileNames")
@ConfigurationProperties ( prefix = "ignore.filenames" )
public List<String> ignoreFileNames(){
return new ArrayList<String>();
}
In outside classes:
@Autowired
@Qualifier("ignoreFileNames")
private List<String> ignoreFileNames;
you can use the same list everywhere else by autowiring.
use comma separated values in application.yml
ignoreFilenames: .DS_Store, .hg
java code for access
@Value("${ignoreFilenames}")
String[] ignoreFilenames
It is working ;)
Source: Stackoverflow.com