codingtim · April 5, 2017 10:44 · Apr 5, 2017
diff --git a/UdpServer.kt b/UdpServer.kt
@@ -0,0 +1,55 @@
+import io.netty.bootstrap.Bootstrap
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.SimpleChannelInboundHandler
+import io.netty.channel.nio.NioEventLoopGroup
+import io.netty.channel.socket.nio.NioDatagramChannel
+import io.netty.util.CharsetUtil
+import io.netty.util.concurrent.DefaultThreadFactory
+import kotlinx.coroutines.experimental.async
+import kotlinx.coroutines.experimental.newFixedThreadPoolContext
+
+
+fun main(args: Array<String>) {
+    val port: Int
+    if (args.isNotEmpty()) {
+        port = Integer.parseInt(args[0])
+    } else {
+        port = 5514
+    }
+    DiscardServer(port).run()
+}
+
+class DiscardServer(private val port: Int) {
+    private val acceptFactory = DefaultThreadFactory("accept")
+    private val acceptGroup = NioEventLoopGroup(1, acceptFactory)
+
+    @Throws(Exception::class)
+    fun run() {
+        val b = Bootstrap()
+        b.group(acceptGroup)
+                .channel(NioDatagramChannel::class.java)
+                .handler(Handler())
+        b.bind(port).sync()
+    }
+
+    fun shutdown() {
+        acceptGroup.shutdownGracefully()
+    }
+
+}
+
+class Handler : SimpleChannelInboundHandler<io.netty.channel.socket.DatagramPacket>() {
+
+    private val coroutineContext = newFixedThreadPoolContext(4, "LogPool")
+
+    override fun channelRead0(ctx: ChannelHandlerContext?, msg: io.netty.channel.socket.DatagramPacket?) {
+        if (msg != null) {
+            val message = msg.content().toString(CharsetUtil.UTF_8)
+            async(coroutineContext) {
+                System.err.println(Thread.currentThread().name)
+                System.err.println(message + "\r\n")
+            }
+        }
+    }
+
+}