how to get multiple instances of same bean in spring?

Question

By default, spring beans are singletons. I am wondering if there is a way to get multiple instances of same bean for processing.

Here is what I do currently

Answer 1

Here is a simple example of how to register a desired number of beans of the same type

@Configuration
public class MultiBeanConfig implements ApplicationContextAware {

    @Value("${bean.quantity}")
    private int quantity;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        for (int i = 0; i < quantity; i++) {
            ((ConfigurableApplicationContext)applicationContext).getBeanFactory()
                    .registerSingleton("my-service-" + i, new MyService());
        }
        assert(applicationContext.getBeansOfType(MyService.class).size() == quantity);
    }

    class MyService {

    }
}

Answer 2

First you'll have to make MyService a Spring bean. You can do this by annotating the class with @Component. Next, as you say, Spring beans are Singletons by default, so this can be changed with one more annotation - @Scope("prototype").

A prototype bean scope means that each time you ask Spring for an instance of the bean, a new instance will be created. This applies to Autowiring, asking the application context for the bean with getBean(), or using a bean factory.