注解的使用场景

public enum class Method{
    GET,
    POST
}
@Target(AnnotationTarget.CLASS)
@Retention(AnnotationRetention.RUNTIME)
annotation class HttpMethod(val method:Method)

interface Api{
    val name:String
    val version:String
    get() = "1.0"

}

//class ApiGetArticle(override val name: String) :Api{}
@HttpMethod(Method.POST)
class ApiGetArticle:Api{
    override val name: String
        get() = "/api.articles"
}

fun fire(api: Api){
    //获取所有注解
    val annotations = api.javaClass.annotations
    val method = annotations.find { it is HttpMethod } as? HttpMethod
    println("通过注解得知该接口需要通过：${method?.method}请求")
}

fun main(){
    fire(ApiGetArticle())
}