Can the Spring active profiles be set through a property file? - spring

Question

I want to be able to read the active profiles from a property file so that different environments (dev,prod etc) can be configured with different profiles in a Spring MVC based web application. I know that the active profiles can be set through JVM params or system properties. But I would like to do it through a property file instead. The point is that I dont know the active profile statically and instead want to read it from a properties file. It looks like this is not possible. For eg., if I had 'spring.profiles.active=dev' in application.properties, and allow it to be overridden in override.properties like so:
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="ignoreResourceNotFound" value="true" />
<property name="locations">
<list>
<value>classpath:/application.properties</value>
<value>file:/overrides.properties</value>
</list>
</property>
</bean>
the profile is not being picked up in the environment. I guess this is because the active profiles are being checked before bean initialization, and therefore do not honor the property being set in a properties file. The only other option I see is to implement an ApplicationContextInitializer that will load those property files in order of priority(override.properties first if it exists, else application.properties) and set the value in context.getEnvironment(). Is there a better way to do it from properties files?

Answer 1

One solution to do it is to read necessary property file with specified profile "manually" - without spring - and set profile at context initialization:
1) Write simple properties loader:
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.util.Properties;
public class PropertiesLoader
{
private static Properties props;
public static String getActiveProfile()
{
if (props == null)
{
props = initProperties();
}
return props.getProperty("profile");
}
private static Properties initProperties()
{
String propertiesFile = "app.properties";
try (Reader in = new FileReader(propertiesFile))
{
props = new Properties();
props.load(in);
}
catch (IOException e)
{
System.out.println("Error while reading properties file: " + e.getMessage());
return null;
}
return props;
}
}
2) Read profile from properties file and set it during Spring container initialization (example with Java-based configuration):
public static void main(String[] args)
{
AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
ctx.getEnvironment().setActiveProfiles(PropertiesLoader.getActiveProfile());
ctx.register(AppConfig.class);
ctx.refresh();
// you application is running ...
ctx.close();
}