Spring boot @ConfigurationProperties not loaded

Question

As the title says, I'm trying to use Typesafe Configuration Properties to load a list of DataSourceConfig objects. I have lombok for setter/getters

The main application class annotations

@Slf4j
@SpringBootApplication
@EnableConfigurationProperties
public class Application {

The configuration pojo

@Data
public class DataSourceConfig {
    private String key;
    private String dbname;
    private String dbpath;
}

The yml file

tenantdb:
    dataSourceConfig:
        -
            key: default 
            dbpath: file:eventstore/jdbc/database
            dbname: defaultdb
        -
            key: other
            dbpath: file:eventstore/jdbc/other
            dbname: dslfjsdf

Finally, the Spring Configuration class with the @ConfigurationProperties annotation.

@Configuration
@Profile("hsqldb")
@ImportResource(value = { "persistence-config.xml" })
@Slf4j
@ConfigurationProperties(prefix="tenantdb", locations={"datasources.yml"})
public class HsqlConfiguration {


    private List<DataSourceConfig> dataSourceConfig = new ArrayList<>();

    @Bean
    public List<DataSourceConfig> getDataSourceConfig() {
        return dataSourceConfig;
    }

With the config above, I get:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hsqlConfiguration': Could not bind properties to [unknown] (target=tenantdb, ignoreInvalidFields=false, ignoreUnknownFields=true, ignoreNestedProperties=false); nested exception is java.lang.NullPointerException
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:303)
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:250)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:408)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initia

I've tried various combinations. If I change the annotation to @ConfigurationProperties(prefix="tenantdb.dataSourceConfig"), I don't get the error but List<DataSourceConfig> is empty.

HELP!!

Answer 1

You should use configuration properties as simple POJO with only getters and setters and have separate HsqlConfiguration which has this properties injected.

Something like this:

@Component
@ConfigurationProperties(prefix="tenantdb", locations={"datasources.yml"})
public class TenantDbProperties {

  //DataSourceConfig is POJO with key, dbpath and dbname
  private List<DataSourceConfig> dataSourceConfigs;       

  public List<DataSourceConfig> getDataSourceConfigs(){
      return dataSourceConfigs;
  }

  public void setDataSourceConfigs(List<DataSourceConfig> dataSourceConfigs){
      this.dataSourceConfigs = dataSourceConfigs;
  }
}

And in separate class have this properties injected as:

@Configuration
@Profile("hsqldb")
@ImportResource(value = { "persistence-config.xml" })
@Slf4j
public class HsqlConfiguration {

    @Autowired
    private TenantDbProperties tenantDbProperties;

    //code goes here where you can use tenantDbProperties.getDataSourceConfigs()
}