Ktor框架中能否在请求内获取路由的原始路径字符串？

Absolutely, you don't have to store the route path in a variable to reuse it—Ktor provides a way to fetch the original, unprocessed route template directly within your handler. Here's how to do it:

Step 1: Access the Current Route via call.route #

Ktor's ApplicationCall has a route property that gives you the Route instance matching the incoming request. This object holds all metadata about the route you defined, including its raw template.

Step 2: Fetch the Full Route Template #

The Route class has a path property that returns the template segment for that specific route. If you have nested routes (like /api/user/{user_id}), you'll need to recursively combine path segments from parent routes to get the complete template.

Here's a reusable extension function to handle both flat and nested routes:

import io.ktor.server.routing.*

// Extension function to get the full raw route template
fun Route.fullRouteTemplate(): String {
    val parentTemplate = parent?.fullRouteTemplate().orEmpty()
    return parentTemplate + path
}

Step 3: Use It in Your Handler #

Now you can call this function within your route handler to get the exact template you defined:

routing {
    get("/user/{user_id}") {
        val rawTemplate = call.route?.fullRouteTemplate()
        // Verify the template matches what we defined
        assert(rawTemplate == "/user/{user_id}")
    }

    // Example with nested routes
    route("/api") {
        get("/posts/{post_id}") {
            val fullRawTemplate = call.route?.fullRouteTemplate()
            assert(fullRawTemplate == "/api/posts/{post_id}")
        }
    }
}

Key Notes: #

• Always handle the nullable call.route value (it could be null if the request didn't match any defined route).
• The path property returns the exact template string you used when defining the route—no filled-in parameters (like /user/123) will be included.

This approach keeps your code clean and avoids duplicating route path strings across your codebase.

内容的提问来源于stack exchange，提问作者Dave Challis