How to get parameter names and types via reflection in Scala/Java methods?

Question

We can use reflection to get method names as follows:

object Foo { def bar(name:String, age:Int) = {} } 
val foo = Foo.getClass
val methods = foo.getMethods.filter(_.getName.startsWith("b"))
methods.foreach(m => println(m.getName))

I now need to get the parameter types and names.

• Are the parameter names stored in the byte-code? If answer is yes, how to access them?
• If answer above is no, can we store the names somehow using annotations?
• Can someone given an example to read the types, and how to use them. I am interested only in functions having String and/or Array[String] type parameters.

[EDIT:] Java version of the solution also ok.

[EDIT:] Annotations seems to be one way to do it. However, Scala annotation support is not that good. Related SO question.

Answer 1

I've not tried it, but http://paranamer.codehaus.org/ is designed for this task.