Adding a Pre-constructed Bean to a Spring Application Context

public void run(javax.sql.DataSource dataSource);

<bean id="dataSource" abstract="true" />

<bean id="dao" class="my.Dao">
  <property name="dataSource" ref="dataSource" />
</bean>

//create parent BeanFactory
DefaultListableBeanFactory parentBeanFactory = new DefaultListableBeanFactory();
//register your pre-fabricated object in it
parentBeanFactory.registerSingleton("dataSource", dataSource);
//wrap BeanFactory inside ApplicationContext
GenericApplicationContext parentContext =
        new GenericApplicationContext(parentBeanFactory);

//create your "child" ApplicationContext that contains the beans from "beans.xml"
//note that we are passing previously made parent ApplicationContext as parent
ApplicationContext context = new ClassPathXmlApplicationContext(
        new String[] {"beans.xml"}, parentContext);

public class PlaceholderBean implements BeanNameAware, FactoryBean {

    public static Map<String, Object> beansByName = new HashMap<String, Object>();

    private String beanName;

    @Override
    public void setBeanName(String beanName) {
        this.beanName = beanName;
    }

    @Override
    public Object getObject() {
        return beansByName.get(beanName);
    }

    @Override
    public Class<?> getObjectType() {
        return beansByName.get(beanName).getClass();
    }

    @Override
    public boolean isSingleton() {
        return true;
    }

}

<bean id="dataSource" class="PlaceholderBean" />

public void run(DataSource externalDataSource) {
    PlaceholderBean.beansByName.put("dataSource", externalDataSource);
    ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
    assert externalDataSource == context.getBean("dataSource");
}

public class DataSourceWrapper implements DataSource {

DataSource dataSource;

public void setDataSource(DataSource dataSource) {
	this.dataSource = dataSource;
}

@Override
public Connection getConnection() throws SQLException {
	return dataSource.getConnection();
}

@Override
public Connection getConnection(String username, String password)
		throws SQLException {
	return dataSource.getConnection(username, password);
}
//delegate to all the other DataSource methods
}

ObjectToBeAddedDynamically objectInst = new ObjectToBeAddedDynamically();
  DefaultListableBeanFactory parentBeanFactory = new DefaultListableBeanFactory();
  parentBeanFactory.registerSingleton("parameterObject", objectInst);

  GenericApplicationContext parentContext = new GenericApplicationContext(parentBeanFactory);

  XmlBeanDefinitionReader xmlReader = new XmlBeanDefinitionReader(parentContext);
   xmlReader.loadBeanDefinitions(new FileSystemResource("beandefinitions.xml"));
   parentContext.refresh();

   ObjectUsingDynamicallyAddedObject userObjectInst= (ObjectUsingDynamicallyAddedObject )parentContext.getBean("userObject");

<?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.xsd">

    <bean id="userObject" class="com.beanwiring.ObjectUsingDynamicallyAddedObject"
      >
      <constructor-arg ref="parameterObject" />

</bean>

</beans>