Bridge.kt
  1. 1fun titleFrom(view: TextView): String {
  2. 2 return view.text?.toString().orEmpty()
  3. 3}

Bridge.kt

Calling Java without pretending

Most of the Android SDK was written in Java. Kotlin calls it directly. Annotations such as @Nullable and @NotNull help the compiler, and where they are missing the type is a platform type.

A Kotlin data class is not automatically a Java bean. @JvmStatic, @JvmOverloads, and @JvmField exist for the cases where Java code has to call back in a familiar shape.

The lesson stops at the boundary: check null, keep the Kotlin side typed, and do not hide a Java null inside a non-null property.

Danville · educational · 2018AboutDeskFAQOffice