How does one programmatically create a Spring context?

Question

Does anyone know if there any way that I can programmatically create a bean context?

I want to be able to do something like:

ConfigurableApplicationContext c = new ConfigurableApplicationContext();
BeanDefinition bd = new BeanDefinition();
bd.setId("id");
bd.setClassName("classname");
bd.setProperty("propertyName", propertyValue");
...etc...

or better still be able to inject a ready made bean into the application context:

c.addBean("beanId", beanObject);

Or if I'm using annotations:

c.setAnnotationAware(true);
c.setAnnotationScanBasePackage("packagename");

or

c.addAnnotatedSpringClass("classnamethatisannotated");

The rationale for this is that I want to be able override bean definitions for the purpose of testing - In my test I create this new application context, configured with code in the test (not in xml) and then make this test application context have as a parent the SUT application context.

I haven't found any code in the spring libraries that can do this. Has anyone built something like this? Would it be possible to build something like this? I know the former approach is doable, I'm not 100% sure the latter approaches will work without conditions.

Answer 1

Try either:

• Spring JavaConfig
• Grails BeanBuilder
• new AtUnit

---

JavaConfig code sample

@Configuration
public class AppConfig {
    @Bean
    public TransferService transferService() {
        return new TransferServiceImpl();
    }
}

BeanBuilder code sample

def bb = new grails.spring.BeanBuilder()

bb.beans { 
  dataSource(BasicDataSource) { 
    driverClassName = "org.hsqldb.jdbcDriver" 
    url = "jdbc:hsqldb:mem:grailsDB" 
    username = "sa" 
    password = "" 
  } 

  sessionFactory(ConfigurableLocalSessionFactoryBean) { 
    dataSource = dataSource
    hibernateProperties = [ "hibernate.hbm2ddl.auto":"create-drop", "hibernate.show_sql":true ] 
  }   
}

AtUnit code sample

Unit test

@RunWith(AtUnit.class)
@Container(Container.Option.SPRING)
@MockFramework(MockFramework.Option.EASYMOCK)
public class ExampleSpringEasyMockTest {

    @Bean @Unit UserManagerImpl manager;
    @Bean("fred") User fred;
    @Bean("userDao") @Mock UserDao dao;
    @Bean("log") @Stub Logger log;

    @Test
    public void testGetUser() {
        expect(dao.load(1)).andReturn(fred);
        replay(dao);
        assertSame(fred, manager.getUser(1));
        verify(dao);
    }


}

Context file ( private for the test )

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd">

  <bean id="userManager" class="atunit.example.subjects.UserManagerImpl">
      <constructor-arg ref="log"/>
      <property name="userDao" ref="userDao"/>
  </bean>

  <bean id="fred" class="atunit.example.subjects.User">
      <property name="id" value="500"/>
      <property name="username" value="fred"/>
  </bean>

</beans>

Answer 2

Why don't you just use two different contexts? one for production, one for tests... you're going about this the hard way.