在Java代码中获取spring配置文件中的配置项

myconfig.item.url=http://127.0.0.1:8080/proj/test

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component("constants")
public class Constants {

    @Value("${myconfig.item.url}")
    private String myconfigItemUrl;

    public String getMyconfigItemUrl() {
        return myconfigItemUrl;
    }

}

    @Autowired
    private Constants constants;

    public void test(){
        String url = constants.getMyconfigItemUrl();
    }