How can I specify an instance-specific @Value in a @Scope("prototype") bean using annotations?

Question

I have a bean that contains two autowired instances of the same component:

@Component
public SomeBean {
    @Autowired
    private SomeOtherBean someOtherBean1;
    @Autowired
    private SomeOtherBean someOtherBean2;
    ...
}

SomeOtherBean has a prototype scope:

@Component
@Scope("prototype")
public SomeOtherBean {
    @Value("...")
    private String configurable;
}

The configurable value needs to be different for each autowired SomeOtherBean and will be supplied via a property placeholder:

configurable.1=foo
configurable.2=bar

Ideally I would like to use annotations to specify the value of the configurable property.

Doing this via XML would be easy but I would like to know whether this is

a) impossible with annotations or
b) how it can be done.

You mean as qualifying the @Autowired dependency? That would still not define how to specify the two particular values in the SomeOtherBean instances. — Ben Turner, Sep 25 '13 at 12:18
did you ever find a solution to this? I asked a similar question and have not received any support. This was easily accomplished with xml and setters, but seems not to have made it into annotation-based configurations. — thedarklord47, Jan 24 '18 at 23:57

Jonathan · Answer 1 · 2013-09-25T12:28:20.117

1

Perhaps this is slightly different to what you are thinking but you could do it easily with an @Configuration-based approach, for example:

@Configuration
public class Config {

    @Bean
    @Scope("prototype")
    public SomeOtherBean someOtherBean1(@Value("${configurable.1}") String value) {
        SomeOtherBean bean = new SomeOtherBean();
        bean.setConfigurable(value);
        return bean;
    }

    @Bean
    @Scope("prototype")
    public SomeOtherBean someOtherBean2(@Value("${configurable.2}") String value) {
        // etc...
    }
}

edited Sep 25 '13 at 12:28

answered Sep 25 '13 at 12:21

Jonathan

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Good idea Jonathan, that solution does work as desired. However it does clutter up my code with very Spring-specific code that has no business use at all - the very opposite of what Spring annotations should be :-) – Ben Turner Sep 25 '13 at 12:30
And why does that clutter your code? This is basically only configuration, which you otherwise would put in xml. – M. Deinum Sep 25 '13 at 14:16
As I said, the solution proposed by Jonathan works as desired, but it doesn't answer my question. I would still like to know whether there is some mechanism that allows `@Scope("prototype")` defined `@Component`s to be configured automagically with different `@Value`s. It might not be possible. – Ben Turner Sep 26 '13 at 08:25

How can I specify an instance-specific @Value in a @Scope("prototype") bean using annotations?

1 Answers1