Spring boot ignores additional properties files

Question

I have the following Maven multi module setup with the application.properties and the corresponding properties class plus configuration in Module A:

@Component
@ConfigurationProperties(prefix = "city")
@Getter
@Setter
@ToString
public class CityProperties {
    private int populationAmountWorkshop;
    private double productionInefficientFactor;
    private Loaner loaner = new Loaner();
    private Tax tax = new Tax();
    private Guard pikeman = new Guard();
    private Guard bowman = new Guard();
    private Guard crossbowman = new Guard();
    private Guard musketeer = new Guard();

    @Getter
    @Setter
    @ToString
    public static class Loaner {
        private int maxRequest;
        private int maxAgeRequest;
        private int maxNbLoans;
    }

    @Getter
    @Setter
    @ToString
    public static class Tax {
        private double poor;
        private double middle;
        private double rich;
        private int baseHeadTax;
        private int basePropertyTax;
    }

    @Getter
    @Setter
    @ToString
    public static class Guard {
        private int weeklySalary;
    }
}

The application.properties:

#City
# Amount of inhabitants to warrant the city to have one workshop
city.populationAmountWorkshop=2500
# Factor that is applied on the efficient production to get the inefficient production
city.productionInefficientFactor=0.6
# Maximum requests per loaner
city.loaner.maxRequest=6
# Maximum  age of loan request in weeks
city.loaner.maxAgeRequest=4
# Maximum loan offers per loaner
city.loaner.maxNbLoans=3
# Weekly tax value factor for the various population per 100 citizens
city.tax.poor=0
city.tax.middle=0.6
city.tax.rich=2.0
city.tax.baseHeadTax=4
city.tax.basePropertyTax=280
city.pikeman.weeklySalary=3
city.bowman.weeklySalary=3
city.crossbowman.weeklySalary=4
city.musketeer.weeklySalary=6

And the Configuration

@Configuration
@ComponentScan(basePackageClasses = AConfiguration.class)
public class AConfiguration {
}

Then there is Module C with my application:

@SpringBootApplication
@Import({CConfiguration.class})
public class SpringBootApp {

    public static void main(String[] args) {
        SpringApplicationBuilder builder = new SpringApplicationBuilder(SpringBootApp.class);
        ApplicationContext context = builder.profiles("server").run();
        CityProperties cityProperties = context.getBean(CityProperties.class);
        System.out.println(cityProperties);
    }
}

The correlating Configuration:

@Configuration
@Import(AConfiguration.class)
@ComponentScan(basePackageClasses = {CConfiguration.class, DComponents.class})
@PropertySource("classpath:bean-test.properties")
public class CConfiguration {
    @Autowired
    @Qualifier("serverThreadPool")
    private Executor serverThreadPool;
    @Autowired
    private SubscriberExceptionHandler subscriptionExceptionHandler;

    @Bean
    public AsyncEventBus serverEventBus() {
        return new AsyncEventBus(serverThreadPool, subscriptionExceptionHandler);
    }

    @Bean
    @Primary
    @ConfigurationProperties(prefix = "city")
    public CityProperties cityProperties() {
        return new CityProperties();
    }
}

And the bean-test.properties file:

spring.main.allow-bean-definition-overriding=true

When removing the last bean from CConfiguration, then the application starts. However with that bean definition in place I get this error:

Description: The bean 'cityProperties', defined in class path resource [c/CConfiguration.class], could not be registered. A bean with that name has already been defined in file [/module1/target/classes/a/CityProperties.class] and overriding is disabled.

Action: Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true

That is exactly what I defined in bean-test.properties. However that seems to be ignored. At first I thought that the properties file was not even loaded, but when misspelling it's name in PropertySource I get the error, that the file cannot be found on the classpath, which suggests that the file is picked up by Spring, but it's content is ignored.

Answer 1

I think that

@PropertySource("classpath:bean-test.properties")

will be used only for custom properties, not for spring properties. Try to put

spring.main.allow-bean-definition-overriding=true

in the application.properties.