Java tutorial
import java.io.BufferedReader; import java.io.InputStreamReader; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.nio.ByteBuffer; import java.nio.channels.AsynchronousSocketChannel; import java.nio.channels.CompletionHandler; import java.nio.charset.Charset; import java.util.concurrent.Future; public class Main { public static void main(String[] args) throws Exception { AsynchronousSocketChannel channel = AsynchronousSocketChannel.open(); SocketAddress serverAddr = new InetSocketAddress("localhost", 8989); Future<Void> result = channel.connect(serverAddr); result.get(); System.out.println("Connected"); Attachment attach = new Attachment(); attach.channel = channel; attach.buffer = ByteBuffer.allocate(2048); attach.isRead = false; attach.mainThread = Thread.currentThread(); Charset cs = Charset.forName("UTF-8"); String msg = "Hello"; byte[] data = msg.getBytes(cs); attach.buffer.put(data); attach.buffer.flip(); ReadWriteHandler readWriteHandler = new ReadWriteHandler(); channel.write(attach.buffer, attach, readWriteHandler); attach.mainThread.join(); } } class Attachment { AsynchronousSocketChannel channel; ByteBuffer buffer; Thread mainThread; boolean isRead; } class ReadWriteHandler implements CompletionHandler<Integer, Attachment> { @Override public void completed(Integer result, Attachment attach) { if (attach.isRead) { attach.buffer.flip(); Charset cs = Charset.forName("UTF-8"); int limits = attach.buffer.limit(); byte bytes[] = new byte[limits]; attach.buffer.get(bytes, 0, limits); String msg = new String(bytes, cs); System.out.format("Server Responded: " + msg); try { msg = this.getTextFromUser(); } catch (Exception e) { e.printStackTrace(); } if (msg.equalsIgnoreCase("bye")) { attach.mainThread.interrupt(); return; } attach.buffer.clear(); byte[] data = msg.getBytes(cs); attach.buffer.put(data); attach.buffer.flip(); attach.isRead = false; // It is a write attach.channel.write(attach.buffer, attach, this); } else { attach.isRead = true; attach.buffer.clear(); attach.channel.read(attach.buffer, attach, this); } } @Override public void failed(Throwable e, Attachment attach) { e.printStackTrace(); } private String getTextFromUser() throws Exception { System.out.print("Please enter a message (Bye to quit):"); BufferedReader consoleReader = new BufferedReader(new InputStreamReader(System.in)); String msg = consoleReader.readLine(); return msg; } }