@Value annotation is always NULL

I am trying to get some values from my application.yml file using the @Value annotation in a ServiceImpl class, but variables with @Value annotation always stay NULL for some reason. Can someone please help me in fetching the values from the application.yml file using @Value annotation?

This is what is present in my application.yml file

aws:
  routeconfig: 
    rolearn: myrolearn
    bucketname: mybucket
    region: ap-southeast-1

These are the variables with @Value annotation which are always NULL

@Value("${aws.routeconfig.rolearn}")
String routeConfigRoleArn;

@Value("${aws.routeconfig.bucketname}")
String bucketName;

@Value("${aws.routeconfig.region}")
String awsRegion;

I think your yml is incorrect.

aws:
    routeconfig: rolearn
        bucketname: mybucket
        region: ap-southeast-1

You are referencing bucketname and region under a parent object of routeconfig property.

If you want to reference all the values under aws, it should be like so:

aws:
    routeconfig: rolearn
        bucketname: mybucket
        region: ap-southeast-1

Then your @Value annotation should work.

You can also configure a property class like so and inject it:

@Component
@ConfigurationProperties(prefix = "aws")
public class AwsConfig {

    private String routeConfig;
    private String bucketName;
    private String region;

    // getters and setter
}

Then instead of using @Value you can inject the AwsConfig class and retrieve the corresponding properties:

AwsConfig awsConfig;
awsConfig.getRouteConfig();
awsConfig.getBucketName();
awsConfig.getRegion()

wherever needed.

Can you try formatting your yaml like this:

aws:
  routeconfig: 
    rolearn: myrole
    bucketname: mybucket
    region: ap-southeast-1

Also, make sure you have only two spaces for indention and no tabs.

You check if you are doing something wrong.

There is no issue in application.yml.

aws:
  routeconfig: 
    rolearn: myrolearn
    bucketname: mybucket
    region: ap-southeast-1

Properties are loaded from application.yml file. It's working for me :

@Controller
public class Sample {
	
	@Value("${aws.routeconfig.rolearn}")
	String routeConfigRoleArn;

	@Value("${aws.routeconfig.bucketname}")
	String bucketName;

	@Value("${aws.routeconfig.region}")
	String awsRegion;
	
	@GetMapping("/test")
	public void load() {
		System.out.println(routeConfigRoleArn);
		System.out.println(bucketName);
		System.out.println(awsRegion);
		
	}

}

Output on console :

myrolearn
mybucket
ap-southeast-1

If you are still not able to solve, then you can go for this solution below :

You can do in this way to load properties.

Create a custom class so as to load custom properties. For example:

@Component
@ConfigurationProperties(prefix = "aws")
public class AWSProps {

	private Map<String, String> routeconfig;

	public Map<String, String> getRouteconfig() {
		return routeconfig;
	}

	public void setRouteconfig(Map<String, String> routeconfig) {
		this.routeconfig = routeconfig;
	}

	@Override
	public String toString() {
		return "AWSProps [routeconfig=" + routeconfig + "]";
	}

}

In the pom.xml, add this dependency :

<dependency>
    <groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-configuration-processor</artifactId>
	<optional>true</optional>
</dependency>

Now to test, just create sample controller :

@Controller
public class Sample {
	
	@Autowired
	private AWSProps props;
	
	@GetMapping("/test")
	public void load() {
		System.out.println(props);
	}

}

Output : AWSProps [routeconfig={rolearn=myrolearn, bucketname=mybucket, region=ap-southeast-1}]