--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/sample/nio/chatserver/ClientReader.java	Tue Apr 12 09:04:57 2011 +0200
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2011 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import java.nio.ByteBuffer;
+import java.nio.channels.CompletionHandler;
+
+/**
+ * Handles a cycle of reading / writing on the {@code Client}.
+ */
+class ClientReader {
+    private final DataReader callback;
+    private final ChatServer chatServer;
+
+    ClientReader(ChatServer chatServer, DataReader callback) {
+        this.chatServer = chatServer;
+        this.callback = callback;
+    }
+
+    public boolean acceptsMessages() {
+        return callback.acceptsMessages();
+    }
+
+    /**
+     * Runs a cycle of doing a beforeRead action and then enqueing a new
+     * read on the client. Handles closed channels and errors while reading.
+     * If the client is still connected a new round of actions are called.
+     */
+    public void run(final Client client) {
+        callback.beforeRead(client);
+        client.read(new CompletionHandler<Integer, ByteBuffer>() {
+            @Override
+            public void completed(Integer result, ByteBuffer buffer) {
+                // if result is negative or zero the connection has been closed or something gone wrong
+                if (result < 1) {
+                    client.close();
+                    System.out.println("Closing connection to " + client);
+                    chatServer.removeClient(client);
+                } else {
+                    callback.onData(client, buffer, result);
+                    // enqueue next round of actions
+                    client.run();
+                }
+            }
+
+            @Override
+            public void failed(Throwable exc, ByteBuffer buffer) {
+                client.close();
+                chatServer.removeClient(client);
+            }
+        });
+    }
+}