diff -r 000000000000 -r a0f15cb8c730 chat/server/src/main/java/org/apidesign/demo/chat/server/ChatServerResource.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/chat/server/src/main/java/org/apidesign/demo/chat/server/ChatServerResource.java	Fri Apr 22 05:56:47 2016 +0200
@@ -0,0 +1,103 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.apidesign.demo.chat.server;
+
+import java.util.ArrayList;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+import javax.inject.Singleton;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.DefaultValue;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.container.AsyncResponse;
+import javax.ws.rs.container.Suspended;
+import javax.ws.rs.core.MediaType;
+import org.apidesign.demo.chat.shared.Message;
+import org.apidesign.demo.chat.shared.Query;
+
+/** Server side of the chat application.*/
+@Path("/chat/") @Singleton
+public final class ChatServerResource {
+    private static final Logger LOG = Logger.getLogger(ChatServerResource.class.getName());
+    private static final long started = System.currentTimeMillis() - 10;
+    
+    private List<Message> msgs = new ArrayList<>();
+    {
+        Message welcome = new Message();
+        welcome.setUser("system");
+        welcome.setComment("Welcome and enjoy!");
+        welcome.setSince(10);
+        msgs.add(welcome);
+    }
+    
+    private final Map<AsyncResponse, Long> awaiting = new IdentityHashMap<>();
+    
+    @Produces(MediaType.APPLICATION_JSON)
+    @GET public synchronized void getResources(
+        @QueryParam("since") @DefaultValue("0") long since,
+        @Suspended AsyncResponse ar
+    ) {
+        Query q = new Query();
+        for (Message m : msgs) {
+            if (m.getSince()>= since) {
+                q.getMessages().add(m);
+            }
+        }
+        if (!q.getMessages().isEmpty()) {
+            ar.resume(q);
+        } else {
+            awaiting.put(ar, since);
+        }
+    }
+    
+    private void handleAwaiting(long newest) {
+        assert Thread.holdsLock(this);
+        AGAIN: for (;;) {
+            for (Map.Entry<AsyncResponse, Long> entry : awaiting.entrySet()) {
+                AsyncResponse ar = entry.getKey();
+                Long since = entry.getValue();
+                if (since <= newest) {
+                    awaiting.remove(ar);
+                    getResources(since, ar);
+                    continue AGAIN;
+                }
+            }
+            return;
+        }
+    }
+    
+    @POST @Consumes(value = MediaType.APPLICATION_JSON)
+    public synchronized Message publish(Message msg) {
+        msg.setSince(System.currentTimeMillis() - started);
+        msgs.add(msg);
+        handleAwaiting(msg.getSince());
+        return msg;
+    }
+}