Is it possible to get the parameter names of a method in scala

As far as I know, we can't do this in Java. Can we do this in scala?

Suppose there is a method as following:

def insert(name:String, age:Int) {
    // insert new user
}

Is it possible to get the parameter names name and age in scala?

开发者_如何学编程UPDATE

I want to do this, because I want to bind the parameters of methods automaticlly.

For example, this is a web app, it has some actions defined as:

class UsersController extends Controller {
    def create(name: String, age: Int) {
          // insert the user
    }
}

A client clicked the submit button of a creating-user form. The url will be /users/create and with some parameters sending.

On the server side, when we get a url named /users/create, we will find a method create in the controller UsersController, found one now. Then I have to get the parameter names of that method, then we can get the values of them:

val params = getParamsFromRequest()
val method = findMethodFromUrl("/users/create")
val paramNames = getParamNamesOfMethod(method)
val paramValues = getValues(params, paramNames)

// then invoke
method.invoke(controller, paramValues)

Now, the key is how to get the parameter names of a method?

It's still very much a work in progress, but you should be able to:

import scalaj.reflect._
for {
  clazz <- Mirror.ofClass[UsersController].toSeq
  method <- clazz.allDefs.find(_.name == "insert").toSeq
  params <- method.flatParams
} yield params

Sorry about the toSeqs, they're to work around a known issue using Options in a for-comprehension.

Please don't push it too hard, it's still very young and fragile. I'm certainly not at the stage yet where I'd accept bug reports :)

UPDATE

Well... I know that I said I'm not accepting bug reports, but this one seemed so useful that I've pushed it up to github anyway.

To do the job dynamically (from a String class name):

import scalaj.reflect._
for {
  clazz <- Option(Class forName "x.y.UsersController")
  mirror <- Mirror.ofClass(clazz).toSeq
  method <- mirror.allDefs.find(_.name == "insert").toSeq
  params <- method.flatParams
} yield params

This question has some insight on how it is done in Java: Is there a way to obtain names of method parameters in Java?

Why not just using different method names (to reflect the parameters that may be passed)? Like, craeteWithNameAndAgeAndGender (pretty standard approach). You won't anyways be able to have multiple methods with the same names(/arity/parameter types and order) and just different parameter names - method overloading doesn't work this way.