First, not-so-clean version of the NIO server.

src/test/java/com.jenkov.nioserver/SelectorTest.java

@@ -0,0 +1,36 @@
+package com.jenkov.nioserver;
+
+import org.junit.Test;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.Selector;
+import java.nio.channels.SocketChannel;
+
+/**
+ * Created by jjenkov on 21-10-2015.
+ */
+public class SelectorTest {
+
+    @Test
+    public void test() throws IOException {
+        Selector selector = Selector.open();
+
+        SocketChannel socketChannel = SocketChannel.open();
+        socketChannel.bind(new InetSocketAddress("localhost", 9999));
+
+        socketChannel.configureBlocking(false);
+
+        SelectionKey key1 = socketChannel.register(selector, SelectionKey.OP_WRITE);
+        key1.cancel();
+
+        SelectionKey key2 = socketChannel.register(selector, SelectionKey.OP_WRITE);
+        key2.cancel();
+
+
+
+    }
+
+
+}