@Configuration
public class ConfigA {
 @Bean
   public A a() {
  return new A();
 }
}
@Configuration
@Import(ConfigA.class)
public class ConfigB {
 @Bean
   public B b() {
  return new B();
 }
}

public static void main(String[] args) {
 ApplicationContext ctx = new AnnotationConfigApplicationContext(ConfigB.class);
 // now both beans A and B will be available...
 A a = ctx.getBean(A.class);
 B b = ctx.getBean(B.class);
}

@Configuration
public class ServiceConfig {
 @Bean
   public TransferService transferService(AccountRepository accountRepository) {
  return new TransferServiceImpl(accountRepository);
 }
}
@Configuration
public class RepositoryConfig {
 @Bean
   public AccountRepository accountRepository(DataSource dataSource) {
  return new JdbcAccountRepository(dataSource);
 }
}
@Configuration
@Import({
 ServiceConfig.class, RepositoryConfig.class
}
)
public class SystemTestConfig {
 @Bean
   public DataSource dataSource() {
  // return new DataSource
 }
}
public static void main(String[] args) {
 ApplicationContext ctx = new AnnotationConfigApplicationContext(SystemTestConfig.class);
 // everything wires up across configuration classes...
 TransferService transferService = ctx.getBean(TransferService.class);
 transferService.transfer(100.00, "A123", "C456");
}

@Configuration
public class ServiceConfig {
 @Autowired
   private AccountRepository accountRepository;
 @Bean
   public TransferService transferService() {
  return new TransferServiceImpl(accountRepository);
 }
}
@Configuration
public class RepositoryConfig {
 @Autowired
   private DataSource dataSource;
 @Bean
   public AccountRepository accountRepository() {
  return new JdbcAccountRepository(dataSource);
 }
}
@Configuration
@Import({
 ServiceConfig.class, RepositoryConfig.class
}
)
public class SystemTestConfig {
 @Bean
   public DataSource dataSource() {
  // return new DataSource
 }
}
public static void main(String[] args) {
 ApplicationContext ctx = new AnnotationConfigApplicationContext(SystemTestConfig.class);
 // everything wires up across configuration classes...
 TransferService transferService = ctx.getBean(TransferService.class);
 transferService.transfer(100.00, "A123", "C456");
}

@Configuration
public class ServiceConfig {
 @Autowired
   private RepositoryConfig repositoryConfig;
 @Bean
   public TransferService transferService() {
  // navigate 'through' the config class to the @Bean method!
  return new TransferServiceImpl(repositoryConfig.accountRepository());
 }
}

@Configuration
public class ServiceConfig {
 @Autowired
   private RepositoryConfig repositoryConfig;
 @Bean
   public TransferService transferService() {
  return new TransferServiceImpl(repositoryConfig.accountRepository());
 }
}
@Configuration
public interface RepositoryConfig {
 @Bean
   AccountRepository accountRepository();
}
@Configuration
public class DefaultRepositoryConfig implements RepositoryConfig {
 @Bean
   public AccountRepository accountRepository() {
  return new JdbcAccountRepository(...);
 }
}
@Configuration
@Import({
 ServiceConfig.class, DefaultRepositoryConfig.class
}
) // import the concrete config!
public class SystemTestConfig {
 @Bean
   public DataSource dataSource() {
  // return DataSource
 }
}
public static void main(String[] args) {
 ApplicationContext ctx = new AnnotationConfigApplicationContext(SystemTestConfig.class);
 TransferService transferService = ctx.getBean(TransferService.class);
 transferService.transfer(100.00, "A123", "C456");
}

@Override
public Boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
 if (context.getEnvironment() != null) {
  // Read the @Profile annotation attributes
  MultiValueMap<String, Object> attrs = metadata.getAllAnnotationAttributes(Profile.class.getName());
  if (attrs != null) {
   for (Object value : attrs.get("value")) {
    if (context.getEnvironment().acceptsProfiles(((String[]) value))) {
     return true;
    }
   }
   return false;
  }
 }
 return true;
}

@Configuration
public class AppConfig {
 @Autowired
   private DataSource dataSource;
 @Bean
   public AccountRepository accountRepository() {
  return new JdbcAccountRepository(dataSource);
 }
 @Bean
   public TransferService transferService() {
  return new TransferService(accountRepository());
 }
}

<beans>
  <!-- enable processing of annotations such as @Autowired and @Configuration -->
  <context:annotation-config/>
  <context:property-placeholder location="classpath:/com/acme/jdbc.properties"/>
  <bean class="com.acme.AppConfig"/>
  <bean class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="url" value="${jdbc.url}"/>
    <property name="username" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
  </bean>
</beans>

jdbc.properties
jdbc.url=jdbc:hsqldb:hsql://localhost/xdb
jdbc.username=sa
jdbc.password=

public static void main(String[] args) {
  ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:/com/acme/system-test-config.xml");
  TransferService transferService = ctx.getBean(TransferService.class);
  // ...
}

<beans>
  <!-- picks up and registers AppConfig as a bean definition -->
  <context:component-scan base-package="com.acme"/>
  <context:property-placeholder location="classpath:/com/acme/jdbc.properties"/>


  <bean class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="url" value="${jdbc.url}"/>
    <property name="username" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
  </bean>
</beans>

@Configuration
@ImportResource("classpath:/com/acme/properties-config.xml")
public class AppConfig {
 @Value("${jdbc.url}")
   private String url;
 @Value("${jdbc.username}")
   private String username;
 @Value("${jdbc.password}")
   private String password;
 @Bean
   public DataSource dataSource() {
  return new DriverManagerDataSource(url, username, password);
 }
}

<beans>
  <context:property-placeholder location="classpath:/com/acme/jdbc.properties"/>
</beans>

jdbc.url=jdbc:hsqldb:hsql://localhost/xdb
jdbc.username=sa
jdbc.password=

public static void main(String[] args) {
  ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class);
  TransferService transferService = ctx.getBean(TransferService.class);
  // ...
}