1. only loaded classpath:concepts/dao/jpa/accessdb.properties
INFO : org.springframework.context.support.PropertySourcesPlaceholderConfigurer - Loading properties file from class path resource [concepts/dao/jpa/accessdb.properties]
2. why exception because classpath:concepts/dao/jpa/hsqldb.properties
was not loaded. So 'url' could not be resolved.
3. 1 possible solution:
4. The best is yet to come. (propose a better one if have.)
for you scenario you only need one, there is nothing wrong with loading multiple propery files using one configurer. If you really needed multiples you should use the 'order' property.