The purpose of this tutorial is to show a way of compiling Kotlin into your developed library as a “fat” JAR (a JAR file containing all necessary dependencies and classes bundled in).
Compared to Java the programming language, Kotlin has additional powerful language features such as: Data Classes, Default Arguments, Extensions, Elvis Operator, and Destructuring Declarations.
Required tools:
Kotlinc
SimpleLibraryCompiler
Imagination
Here are a few example Kotlin functions:
Compile the above into a Jar using kotlinc
Now write a simple wrapper:
Compared to Java the programming language, Kotlin has additional powerful language features such as: Data Classes, Default Arguments, Extensions, Elvis Operator, and Destructuring Declarations.
Required tools:
Kotlinc
SimpleLibraryCompiler
Imagination
Here are a few example Kotlin functions:
B4X:
@file:JvmName("B4XUtils")
package demo
import java.util.Random;
class b4akotlin
val random = Random()
fun printsout() {
println("Hello Kotlin meet B4A!")
}
fun rand(from: Int, to: Int) : Int {
return random.nextInt(to - from) + from
}
fun sum(a: IntArray): Int {
var result=0
for (number in a)
result += number
return result
}
fun main(args: Array<String>) {
println("Hello World!")
}
fun findPairless(a: IntArray) = a.fold(0, {accum, x -> accum xor x})Compile the above into a Jar using kotlinc
B4X:
kotlinc hello.kt -include-runtime -d h:\path_to_project_lib\hello.jarNow write a simple wrapper:
B4X:
package com.Kotlin;
import anywheresoftware.b4a.BA;
import anywheresoftware.b4a.BA.DependsOn;
import anywheresoftware.b4a.BA.ShortName;
import anywheresoftware.b4a.BA.Version;
import anywheresoftware.b4a.BA.Author;
@Version(1.8f)
@ShortName("Kotlin")
@DependsOn(values={"hello"})
public class Kotlin {
public void consoleprintout() {
new demo.b4akotlin();
demo.B4XUtils.printsout();
}
public int randomnumber(int x,int z) {
new demo.b4akotlin();
return demo.B4XUtils.rand(x , z);
}
public static int summ(int[] a) {
new demo.b4akotlin();
return demo.B4XUtils.sum(a);
}
public static int findpairs(int[] a) {
new demo.b4akotlin();
return demo.B4XUtils.findPairless(a);
}
}
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