stravag

fun getKey(): Key? {
  val keyStore: KeyStore = KeyStore.getInstance("AndroidKeyStore").apply { 
    load(null) 
  }
  return keyStore.getKey("MY_KEY", null)
}

fun getDecryptCipher(key: Key, iv: ByteArray): Cipher {
  val algorithm = KeyProperties.KEY_ALGORITHM_AES
  val blockMode = KeyProperties.BLOCK_MODE_CBC

stravag

fun createKey(): SecretKey {
  val algorithm = KeyProperties.KEY_ALGORITHM_AES
  val provider = "AndroidKeyStore"
  val keyGenerator = KeyGenerator.getInstance(algorithm, provider)
  
  val keyName = "MY_KEY"
  val purposes = KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
  val keyGenParameterSpec = KeyGenParameterSpec.Builder(keyName, purposes)
          .setBlockModes(BLOCK_MODE)
          .setEncryptionPaddings(PADDING)

stravag

/**
 * Very helpful comment.
 */
typealias KotlinFunctionAlias = (Item) -> String

fun delegateAliasWork(f: KotlinFunctionAlias): String {
  return f.invoke(item)
}

stravag

interface KotlinInterface {
    fun doSomething(item: Item): String
}

class KotlinComponent(private val item: Item = Item()) {

    fun delegateWork(f: KotlinInterface): String {
        return f.doSomething(item)
    }

stravag

class KotlinComponent(private val item: Item = Item()) {

    fun delegateWork(f: JavaInterface): String {
        return f.doSomething(item)
    }

    fun delegateOtherWork(f: (Item) -> String): String {
        return f.invoke(item)
    }
}

stravag

@FunctionalInterface
interface JavaInterface {

    String doSomething(Item item);
}

class JavaComponent {

    private Item item = new Item();

stravag

@FunctionalInterface
interface JavaInterface {
    String doSomething(Item item);
}

String delegateWork(JavaInterface f) {
    return f.doSomething(item);
}

String delegateOtherWork(Function<Item, String> f) {

stravag

interface JavaInterface {
    String doSomething(Item item);
}

String delegateWork(JavaInterface f) {
    return f.doSomething(item);
}

void doWork() {
    delegateWork(new JavaInterface() {