Sending and receiving heartbeat requests (#9265)

2 files changed, 70 insertions, 39 deletions

diff --git a/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java b/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
index a8852fe9fa..d2deb70190 100644
--- a/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
+++ b/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
@@ -230,6 +230,8 @@ public class ApplicationConnection {
 
         rootConnector.init(cnf.getRootPanelId(), this);
         showLoadingIndicator();
+
+        scheduleHeartbeat();
     }
 
     /**
@@ -2520,4 +2522,72 @@ public class ApplicationConnection {
     public SerializerMap getSerializerMap() {
         return serializerMap;
     }
+
+    /**
+     * Schedules a heartbeat request.
+     * 
+     * @see #sendHeartbeat()
+     */
+    private void scheduleHeartbeat() {
+        final int interval = 1000 * getConfiguration().getHeartbeatInterval();
+        if (interval > 0) {
+            new Timer() {
+                @Override
+                public void run() {
+                    sendHeartbeat();
+                }
+            }.schedule(interval);
+        }
+    }
+
+    /**
+     * Sends a heartbeat request to the server.
+     * <p>
+     * Heartbeat requests are used to inform the server that the client-side is
+     * still alive. If the client page is closed or the connection lost, the
+     * server will eventually close the inactive Root.
+     * <p>
+     * <b>TODO</b>: Improved error handling, like in doUidlRequest().
+     * 
+     * @see #scheduleHeartbeat()
+     * @see com.vaadin.ui.Root#heartbeat()
+     */
+    private void sendHeartbeat() {
+        final String uri = addGetParameters(
+                translateVaadinUri(ApplicationConstants.APP_PROTOCOL_PREFIX
+                        + ApplicationConstants.HEARTBEAT_REQUEST_PATH),
+                ApplicationConstants.ROOT_ID_PARAMETER + "="
+                        + getConfiguration().getRootId());
+
+        final RequestBuilder rb = new RequestBuilder(RequestBuilder.POST, uri);
+
+        final RequestCallback callback = new RequestCallback() {
+
+            @Override
+            public void onResponseReceived(Request request, Response response) {
+                int status = response.getStatusCode();
+                if (status == Response.SC_OK) {
+                    // TODO Permit retry in some error situations
+                    scheduleHeartbeat();
+                } else {
+                    VConsole.error("Heartbeat request failed with status code "
+                            + status);
+                }
+            }
+
+            @Override
+            public void onError(Request request, Throwable exception) {
+                VConsole.error("Heartbeat request resulted in exception");
+                VConsole.error(exception);
+            }
+        };
+
+        rb.setCallback(callback);
+
+        try {
+            rb.send();
+        } catch (RequestException re) {
+            callback.onError(null, re);
+        }
+    }
 }
diff --git a/client/src/com/vaadin/terminal/gwt/client/ui/root/RootConnector.java b/client/src/com/vaadin/terminal/gwt/client/ui/root/RootConnector.java
index 0a0e0e5082..39702e6ba0 100644
--- a/client/src/com/vaadin/terminal/gwt/client/ui/root/RootConnector.java
+++ b/client/src/com/vaadin/terminal/gwt/client/ui/root/RootConnector.java
@@ -23,16 +23,10 @@ import com.google.gwt.core.client.Scheduler;
 import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.Position;
-import com.google.gwt.http.client.Request;
-import com.google.gwt.http.client.RequestBuilder;
-import com.google.gwt.http.client.RequestCallback;
-import com.google.gwt.http.client.RequestException;
-import com.google.gwt.http.client.Response;
 import com.google.gwt.user.client.Command;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.Event;
 import com.google.gwt.user.client.History;
-import com.google.gwt.user.client.Timer;
 import com.google.gwt.user.client.Window;
 import com.google.gwt.user.client.ui.RootPanel;
 import com.google.gwt.user.client.ui.Widget;
@@ -90,14 +84,6 @@ public class RootConnector extends AbstractComponentContainerConnector
                 com.google.gwt.user.client.Window.setTitle(title);
             }
         });
-        final int heartbeatInterval = getState().getHeartbeatInterval();
-        new Timer() {
-            @Override
-            public void run() {
-                sendHeartbeat();
-                schedule(heartbeatInterval);
-            }
-        }.schedule(heartbeatInterval);
     }
 
     @Override
@@ -455,29 +441,4 @@ public class RootConnector extends AbstractComponentContainerConnector
             }
         });
     }
-
-    private void sendHeartbeat() {
-        RequestBuilder rb = new RequestBuilder(RequestBuilder.POST, "url");
-
-        rb.setCallback(new RequestCallback() {
-
-            @Override
-            public void onResponseReceived(Request request, Response response) {
-                // TODO Auto-generated method stub
-
-            }
-
-            @Override
-            public void onError(Request request, Throwable exception) {
-                // TODO Auto-generated method stub
-
-            }
-        });
-
-        try {
-            rb.send();
-        } catch (RequestException re) {
-
-        }
-    }
 }