我想(静态)反映这样的示例类:
case class Foo[T,U](stuff:T, more:U, age:Int) {
val ignore:Boolean = false
}
我是这样开始的:
val symbol = currentMirror.classSymbol(clazz) // symbol is universe.ClassSymbol
// I want to know about type placeholders T and U
val typeParamArgs = symbol.typeParams.map( tp => tp.name.toString)
if( symbol.isCaseClass ) {
val tsig = symbol.typeSignature
println(tsig)
}
好的,此时如果我打印tsig,我会看到:
[T, U]scala.AnyRef
with scala.Product
with scala.Serializable {
val stuff: T
private[this] val stuff: T
val more: U
private[this] val more: U
val age: scala.Int
private[this] val age: scala.Int
def <init>(stuff: T,more: U,age: scala.Int): co.blocke.Foo[T,U]
val ignore: scala.Boolean
private[this] val ignore: scala.Boolean
def copy[T, U](stuff: T,more: U,age: scala.Int): co.blocke.Foo[T,U]
def copy$default$1[T, U]: T @scala.annotation.unchecked.uncheckedVariance
def copy$default$2[T, U]: U @scala.annotation.unchecked.uncheckedVariance
def copy$default$3[T, U]: scala.Int @scala.annotation.unchecked.uncheckedVariance
override def productPrefix: java.lang.String
def productArity: scala.Int
def productElement(x$1: scala.Int): scala.Any
override def productIterator: Iterator[scala.Any]
def canEqual(x$1: scala.Any): scala.Boolean
override def hashCode(): scala.Int
override def toString(): java.lang.String
override def equals(x$1: scala.Any): scala.Boolean
}
使用&lt; init&gt;?查看中间的那一行那是我想要反省的宣言。它得到了我需要的东西。
如何选择tsig(universe.Type)来获取有关&lt; init&gt;的信息?(我不想要了解&#39;忽略&#39;。)
答案 0 :(得分:3)
不是检查类的.typeSignature
,而是使用.primaryConstructor.typeSignature
检查构造函数的类型签名:
val csig = symbol.primaryConstructor.typeSignature
val params = csig.paramLists.head // paramLists returns a List of Lists
这为您提供了主构造函数的参数列表,因此您可以查询名称,类型等:
scala> params(1).name
res47: reflect.runtime.universe.Symbol#NameType = more
scala> params(2).typeSignature
res48: reflect.runtime.universe.Type = scala.Int