Kotlin真的會取代JAVA嗎？

#自從Kotlin 成為Android 開發一級語言，Kotlin確實以其實用，高效贏得了海外很多公司和開發者的認可，比如Square的Jake大神一直在推Kotlin 。 Kotlin在國外至少有將近2年的應用生產環境的實踐(非JetBrains內部實務應用)。在行動開發中，比起iOS程式設計師，Android程式設計師總是很幸運，因為我們有很多優秀好用的工具（Android Studio等），選用Kotlin，則是Google 為開發者提供高效的開發工具的一貫作風。先來曬一曬Kotlin的幾大特點：

Kotlin是靜態型別程式語言，用於現代多平台應用，100％可與Java™和Android™互通[java] view plain copy

Kotlin是非常簡介的程式語言

Create a POJO with getters, setters, equals(), hashCode(), toString() and copy() in a single line:

data class Customer(val name: String, val email: String, val company: String)
Or filter a list using a lambda expression:

val positiveNumbers = list.filter { it > 0 }
##val positiveNumbers = list.filter { it > 0 }

##val positiveNumbers = list.filter { it > 0 }

##val positiveNumbers = list.filter { it > 0 }
Want a singleton? Create an object:

object ThisIsASingleton {

val companyName: String = "JetBrains"

}

[java] view plain copy

#Kotlin 很安全

Get rid of those pesky NullPointerExceptions, you know, The Billion Dollar Mistake

var output: String

output = null // Compilation error
Kotlin protects you from mistakenly operating on nullable types

val name: String? = null // Nullable type

println(name.length()) // Compilation error
And if you check a type is right, the compiler will auto-cast it for you

fun calculateTotal(obj: Any) {

if (obj is Invoice)

obj.calculateTotal()

}

##[java] view plain copy

方便使用兼容JVM上現有library

Use any existing library on the JVM, as there's 100% compatibility, including SAM support.

import io.reactivex.Flowable
import io.reactivex.schedulers.Schedulers

Flowable
.fromCallable {
Thread.sleep(1000) // imitate expensive computation
" Done"
}
.subscribeOn(Schedulers.io())

.observeOn(Schedulers.single())

.subscribe(::println, Throwable::printStackTrace)

Target either the JVM or JavaScript. Write code in Kotlin and decide where you want to deploy to

import kotlin.browser.window

fun onLoad() {

window.document.body!! .innerHTML += "