How does one convert application.properties to application.yml for maps

Question

I tried this, it doesn't work, where am I going wrong?

application.properties (works fine)

document-contact={name:'joe',email:'[email protected]'}

application.yml (doesn't work; stacktrace below)

document-contact:
  name: 'joe'
  email: '[email protected]'

Java:

    @Value("#{${document-contact}}")
    private Map<String, String> contact;

Stacktrace:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'consolidatedSwaggerDocumentationController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'document-contact' in value "#{${document-contact}}"
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:403) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1429) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.0.RELEASE.jar:5.2.0.RELEASE]

Answer 1

Your application.yml is not equivalent to the application.properties you're using.

Rather than reading separate properties, you only have a single property called document-contract (= ${document-contract}), which contains the following string:

"{name:'joe',email:'[email protected]'}"

To convert it to a Map, you're using Spring Expression Language (SpEL). That's why you need both #{...} and ${...}.

Your application.yml file on the other hand doesn't have a single property called document-contract, and thus, it doesn't work. If you want to do the same kind of thing within your YAML, it should be:

document-contract: "{name: 'joe', email: '[email protected]'}"

---

Alternatively, if you want to use multiple YAML properties like you did, you should be aware that @Value doesn't support Map structures. In stead, you should be using @ConfigurationProperties:

@ConfigurationProperties(prefix = "app")
public class ApplicationProperties {
    private Map<String, String> documentContact;

    // Getters + Setters
}

With @ConfigurationProperties, you would have to use a prefix though, so you should change your YAML structure to:

app:
  document-contact:
    name: joe
    email: [email protected]

For the reference, this would be the equivalent properties file:

app.document-contract.name=joe
[email protected]

Answer 2

you need use follow:

tes:
  maps:
    key1: 15
    key2: 2

and java code is:

@Data
@Component
@ConfigurationProperties(prefix = "tes")
public class MapTest {
    private Map<String, String> maps;
}