spring java config not present in web.xml

Following is my spring java config. I am not referencing ApplicationContext.java anywhere in my web.xml. Yet, methods in following bean are called and my application context is being initialized successfully. How is that possible?

@Configuration
@EnableTransactionManagement(mode = AdviceMode.ASPECTJ)
@PropertySource({ "file:/etc/XXX/core/database.properties", "file:/etc/XXX/core/mail.properties" })
public class ApplicationContext {

    @Value("${database.password}")
    private String databasePassword;

    @Value("${database.url}")
    private String databaseUrl;

    @Value("${database.username}")
    private String databaseUsername;

    @Value("${database.driverClassName}")
    private String databaseDriverClassName;

...
}