kotlin reflection get list of fields

Question

is there an equivalent for the java reflection foo.getClass().getFields() in Kotlin? I could only find that I can access a field when I know it\'s name, but I would

Answer 1

You can't do this in Kotlin, but there is a dirty unreliable way to do this in java. You can use java reflection. Like this:

public class TestClass {

    trait EmptyTrait
    class EmptyClass

    public var anotherVar:Int? = null
    public val contant:Float = 10f
    private var emptyTrait:EmptyTrait? = null
    val emptyClass:EmptyClass = EmptyClass()

    public fun setVal(fieldName: String, value: Int) {
        javaClass.getDeclaredField(fieldName).set(this, value);
    }

    public fun getFieldNames(): String {
        return javaClass.getDeclaredFields().map{it.getName()}.join(", ")
    }    
}

Let's test it:

val t = TestClass()
Log.v("MainActivity", "Fields: " + t.getFieldNames())
Log.v("MainActivity", "anotherVar: " + t.anotherVar)
t.setVal("anotherVar", 10)
Log.v("MainActivity", "anotherVar: " + t.anotherVar)

Results:

Fields: anotherVar, emptyClass, emptyTrait, contant, $kotlinClass
anotherVar: null
anotherVar: 10

it works )