Can't bind properties with @Bean and @ConfigurationProperties

Question

I am reading configuration from properties file. Now I am having an error that I think is related to sequence of initialization of spring bean.

If I do private Map name = new HashMap<>(); It can be successfully load from properties file.

But now I am having Could not bind properties to ServiceNameConfig

I don't know why this happen and how to deal with it.

@ConfigurationProperties(prefix = "amazon.service")
@Configuration
@EnableConfigurationProperties(ServiceNameConfig.class)
public class ServiceNameConfig {

   //If I do private Map<String, String> name = new HashMap<>(); It can be successfully load from properties file.
    private Map<String, String> name;

    @Bean(value = "serviceName")
    public Map<String, String> getName() {
        return name;
    }

    public void setName(Map<String, String> name) {
        this.name = name;
    }

} 

its usage;

@Autowired
@Qualifier("serviceName")
Map<String, String> serviceNameMap;

Answer 1

You can replace your config class to be like this (simpler);

@Configuration
public class Config {

    @Bean
    @ConfigurationProperties(prefix = "amazon.service")
    public Map<String, String> serviceName() {
        return new HashMap<>();
    }
}

For @ConfigurationProperties injection, you'd need to supply an empty instance of the bean object. Check more about it on baeldung

---

Or an alternative way, you can use a pojo class to handle the configuration. For example;

You have properties like;

amazon:
  service:
    valueA: 1
    valueB: 2
    details:
      valueC: 3
      valueD: 10

and you can use a pojo like the following;

class Pojo {

    private Integer valueA;
    private Integer valueB;
    private Pojo2 details;

    // getter,setters

    public static class Pojo2 {

        private Integer valueC;
        private Integer valueD;

        // getter,setters
    }
}

and use it in the config class like;

@Configuration
public class Config {

    @Bean
    @ConfigurationProperties(prefix = "amazon.service")
    public Pojo serviceName() {
        return new Pojo();
    }
}