[FIXED] Spring read values for @Bean class from properties file

Issue

I am trying to create Spring beans using only annotations. I am not able to load values for my @Bean class from properties file.

Here is my code:

This is my main class

public class AnnotationDI {

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext(ConfigurationProvider.class);
    
    ApplicationProperties properties = (ApplicationProperties)context.getBean(ApplicationProperties.class);
    
    System.out.println(properties);
    
}}

Configuration class

@Configuration
public class ConfigurationProvider {

private ApplicationProperties m_applicationProperties;

@Bean
public ApplicationProperties getApplicationProperties() {
    return new ApplicationProperties();
}
}

Bean class

@PropertySource(value = { "classpath:application.properties" })
public class ApplicationProperties {

@Value("${longThreadCount}")
private String m_longProcessThread;

@Value("${routeTimeout}")
private String m_routeTimeout;

@Value("${updateDirectoryPath}")
private String m_updateDirectoryPath;

public String getLongProcessThread() {
    return m_longProcessThread;
}
@Override
public String toString() {
    return "ApplicationProperties [m_longProcessThread=" +m_longProcessThread"]";
}
}

when i run this program, I get following output

m_longProcessThread=${longThreadCount}

Any idea what am i doing wrong?

Solution

To be able to have @Value with placeholders resolved you need to register a PropertySourcesPlaceholderConfigurer. As this is a BeanFactoryPostProcessor it needs to be registered as a static bean so that it can be detected early on in the process.

@Bean
public static PropertySourcesPlaceholderConfigurer placeholderConfigurer() {
     return new PropertySourcesPlaceholderConfigurer();
}

Answered By - M. Deinum