CODEWITHSUNDEEP
scalareflection
leo
leo

Reputation: 3749

dynamical creating a new instance of a case class in scala

Given a reference to a case class companion object t and a sequence of parameter seq how can I invoke a new instance of the case class?

I can create a class when I type the number of the parameter by myself.

scala> case class B(n:String,a:Int,b:Int)
defined class B

scala> val t:AnyRef = B
t: AnyRef = B

scala> val m = t.getClass.getMethods.filter{m => m.getName == "apply"}.
    filterNot {_.getReturnType.getName == "java.lang.Object"}(0)
m: java.lang.reflect.Method = public B B$.apply(java.lang.String,int,int)

scala> m.invoke(t,"name",1:java.lang.Integer,2:java.lang.Integer)
res99: Object = B(name,1,2)

The problem I couldn't solve is to call invoke with a sequence of arguments like Seq("name",1:java.lang.Integer,2:java.lang.Integer). Any help how to do that is greatly appreciated.

I use scala 2.10.0.

Upvotes: 7

Views: 1588

Answers (1)

leo
leo

Reputation: 3749

Just found it out by myself (respectively have seen it over here https://stackoverflow.com/a/2060503/55070). It's

method.invoke(t,seq: _*)

Sometimes it really helps to just write it down ;-)

Upvotes: 5

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