value for the annotation attribute must be constant expression

Question

I have a properties file that I read by spring annotation like this

    @Value(\"${platform}\")
    private String platform;

after I get th

Answer 1

You can't access platform directly in the @Value expression, but you can use Spring Expression Language to accomplish your end goal.

@Value("${platform}")
private String platform;

@Value("#{'Url.'.concat(${platform}).concat('.ws')}")
private String url;

Answer 2

The parameter is evaluated in compilation time. So it needs to be final or static final among others (ie Enum).

I don't know if the @Value annotation allows that. But you can always implement your own annotation. Extending is not possible in Java annotations.