kotlinx sockets (🥚 🥚 🥚 incubating) 
Kotlinx.sockets is a library to bring rich coroutines experience to NIO sockets, eliminate terrible callbacks and selector loops and related difficult code.
With the library and kotlin coroutines you can simply write async NIO code in usual synchronous style.
Consider example (full source)
fun main(args: Array<String>) {
runBlocking { // start coroutines
aSocket().tcp().connect(InetSocketAddress(InetAddress.getByName("google.com"), 80)).use { socket ->
println("Connected") // now we are connected
// chain of async write
socket.send("GET / HTTP/1.1\r\n")
socket.send("Host: google.com\r\n")
socket.send("Accept: text/html\r\n")
socket.send("Connection: close\r\n")
socket.send("\r\n")
// loop to read bytes and write to the console
val bb = ByteBuffer.allocate(8192)
while (true) {
bb.clear()
if (socket.read(bb) == -1) break // async read
bb.flip()
System.out.write(bb)
System.out.flush()
}
println()
}
}
}Getting started
Maven
<dependencies>
<dependency>
<groupId>org.jetbrains.kotlinx</groupId>
<artifactId>kotlin-sockets</artifactId>
<version>0.0.4</version>
</dependency>
</dependencies>
<repositories>
<repository>
<snapshots>
<enabled>false</enabled>
</snapshots>
<id>bintray-kotlin-kotlin-dev</id>
<name>kotlin-dev</name>
<url>http://dl.bintray.com/kotlin/kotlin-dev</url>
</repository>
</repositories>Gradle
repositories {
maven { url "http://dl.bintray.com/kotlin/kotlin-dev" }
}
dependencies {
compile 'org.jetbrains.kotlinx:kotlin-sockets:0.0.4'
}