This annotation is not applicable to target 'local variable - spring

Question

I want to get value from application.yml, but I got "This annotation is not applicable to target 'local variable" for this part，how to solve this problem?
#Value("\${aws.secretsManager.secretName}")
val secretName: String? = ""
#Configuration
#EnableConfigurationProperties
#ConfigurationProperties
fun getSecret() {
#Value("\${aws.secretsManager.secretName}")
val secretName: String? = ""
val region = "us-west-2"
val logger: Logger = LoggerFactory.getLogger(GetSecretConfig::class.java)
// Create a Secrets Manager client
val client = AWSSecretsManagerClientBuilder.standard().withRegion(region).build()
val getSecretValueRequest = GetSecretValueRequest().withSecretId(secretName)
var getSecretValueResult: GetSecretValueResult? = try {
client.getSecretValue(getSecretValueRequest)
}
}
application.yml
aws:
secretsManager:
secretName: "test-mvp"
region: "us-west-2"
user: "root"
password: "root"

Answer 1

From the #Value javadoc:
Annotation used at the field or method/constructor parameter level that indicates a default value expression for the annotated element.
The #Value annotation is defined as follow:
#Target(value = {FIELD, METHOD, PARAMETER, ANNOTATION_TYPE})
#Retention(value = RUNTIME)
#Documented
public #interface Value
As you see by the #Target, the #Value annotation it's not intended to be used in a LOCAL_VARIABLE.
The solution is to define the secretName variable outside of the function - as a field of the class.

Answer 2

Workaround logic here:
(Using Java 8 though - shouldn't matter anyways)
Create a configuration class annotated with #Configuration like so:
#Configuration
public class ApplicationSecretsConfig {
public ApplicationSecretsConfig(){}
#Value("${aws.secretsManager.secretName}")
private String secretName;
public String getSecretName(){
return secretName;
}
}
Then in your class, autowire the SecretsConfig dependency and get the value of secretName using its getter.
// class initialization done here
...
#Autowired
ApplicationSecretsConfig applicationSecretsConfig
public String getSecret() {
String secret = applicationSecretsConfig.getSecretName();
// continue your logic
...
}
Hopefully that helps someone.

Answer 3

there is no need to do a custom implementation for fetch secrets. Spring provides it, using spring-cloud-starter-aws-secrets-manager-config dependency, just need to do an small config:
spring.config.import=aws-secretsmanager:my-secret
there is working sample on documentation:
https://github.com/awspring/spring-cloud-aws/tree/main/spring-cloud-aws-samples/spring-cloud-aws-parameter-store-sample
and here you could find a db working too:
https://github.com/nekperu15739/aws-secrets-manager