注释属性的值必须是常量表达式 [英] value for the annotation attribute must be constant expression

问题描述

我有一个属性文件，我通过这样的 spring 注释读取

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

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

获得平台参数后，我想根据platform 参数值读取第二个参数.

after I get the platform parameter, I would like to read a second parameter depending on platform parameter value.

    @Value("${url." + platform + ."ws}")
    private String url;

但这会产生错误，注释属性的值必须是常量表达式".由于根据平台"值有很多参数更改，因此我正在寻找通用解决方案.

but this gives error, "value for the annotation attribute must be constant expression". since there are lots of parameter changes depending on "platform" value, I am looking for a generic solution.

推荐答案

您不能直接在 @Value 表达式中访问 platform，但您可以使用 Spring 表达式语言来实现您的最终目标.

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;

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