I want to lock the current ui of the server when communication is down. It will be unlocked when the server communication is established again. But i wasn't able to find a way to detect the server status when communication is down (eg when network cable is unplugged). is there a way to do that. any help would be appreciated...
Please try this code:
JavaScript.getCurrent().addFunction("isOnline", new JavaScriptFunction() {
#Override
public void call(JSONArray arguments) throws JSONException, org.json.JSONException {
try {
String message = arguments.getString(0);
Notification.show("Message: " + message);
} catch (JSONException e) {
Notification.show("Error: " + e.getMessage());
}
}
});
Link link = new Link( "Send Message", new ExternalResource( "javascript:isOnline(navigator.onLine)"));
this.addComponent(link);
Related
We have a syslog client in our application and it is implemented using Cloudbees- TcpSyslogMessageSender. We are creating the context and connHow to reuse the session and port number in TCP-TLS communication using Cloudbees- TcpSyslogMessageSender.
Will it be handled by Cloudbees or we have to configure any settings explicitly. Here is our code.
With this code, it is using a new port everytime.
TcpSyslogMessageSender messageSendertcp = new TcpSyslogMessageSender();
messageSendertcp.setSyslogServerHostname("localhost");
messageSendertcp.setSyslogServerPort("6514");
messageSendertcp.setMessageFormat(MessageFormat.RFC_5425);
messageSendertcp.setDefaultMessageHostname(this.getHostName());
messageSendertcp.setDefaultAppName("test");
messageSendertcp.setDefaultFacility("local0"));
messageSendertcp.setDefaultSeverity("notice");
logger.info("entering getsslcontext");
SSLContext context = getSSLContext(); //SSLContext is formed using client keystore and trustores
logger.info("context object");
messageSendertcp.setSSLContext(context);
messageSendertcp.setSsl(true);
}
try {
logger.info("sending message tcp");
messageSendertcp.sendMessage(syslogMessage);
} catch (IOException e) {
return false;
} finally {
try {
if (messageSendertcp != null)
messageSendertcp.close();
} catch (IOException e) {
return false;
}
}
Here Every Time your code is closing TCP object and and whenever new message comes it is again creating and using new socket. So in order to send the message on same port do not close the socket(TCP object) and use the Server details cache. For example this cache implemented using map that contains Server Details as the map and TCP object as key. And do not close the TCP object.
Below is my code to connect to the hub.
I used the below code for connecting the hub and send a message.
public ChatService(){
connection = new HubConnection(Services.ServerConstant.BaseUrl);
proxy = ChatServices._connection.CreateHubProxy("HubName");
}
//to start connection
Void async Start(){
var http = new Microsoft.AspNet.SignalR.Client.Http.DefaultHttpClient();
await _connection.Start(new WebSocketTransportLayer(http));
}
//For Connection
Void SendMessage(){
chatServices = DependencyService.Get<IChatServices>();
chatServices.Connect();
connection.Start();
await connection.Send("Test");
}
You are recreating connection to hub every time you send the message. That's wrong approach. Instead you should check connection status and reconnect only in case the connection is lost.
Example
private async Task CheckConnection()
{
if (connection.State == ConnectionState.Connected)
{
return;
}
try
{
await connection.Start();
await proxy.Invoke("Connect");
}
catch (Exception ex)
{
// your exception handler goes here
}
}
I'm attempting to configure my app to use WNS instead of MPNS (I am using Xamarin Forms and have a Win Phone 8.1 Silverlight project with an Azure Notification hub for the back end), for that I updated my code to use the the mobile service to register the phone for push notifications and changed the Notification Service in the WMAppManifest.xml to WNS. After implementing these changes when I check the phones registration through azure it says its MPNS. Below are some screen captures of my configuration and code snippets of how im registering the app.
WMAppManifest.xml
Package.appxmanifest
NotificationManager Code
public class PushNotificationManager : IPushNotificationManager
{
private PushNotificationChannel channel;
public PushNotificationManager() { }
public static MobileServiceClient MobileService = new MobileServiceClient(Utilities.Constants.ApplicationURL, Utilities.Constants.ApplicationKey);
public async Task RegisterDevice()
{
try
{
channel = await PushNotificationChannelManager.CreatePushNotificationChannelForApplicationAsync();
channel.PushNotificationReceived += Channel_PushNotificationReceived;
await this.RegisterWinDevice(channel.Uri);
NotificationTask.UnregisterBackgroundTask();
NotificationTask.RegisterBackgroundTask();
}
catch (Exception ex)
{
throw ex;
}
}
protected void Channel_PushNotificationReceived(PushNotificationChannel sender, PushNotificationReceivedEventArgs args)
{
try
{
//Create notification
}
catch (Exception ex)
{
throw ex;
}
}
public async Task UnregisterDevice()
{
if(channel != null)
{
channel.Close();
}
await MobileService.GetPush().UnregisterNativeAsync();
}
private async Task RegisterWinDevice(string channelUri)
{
try
{
var tags = new List<string>() { };
User user = LocalStorage.GetUserInfo();
tags.Add(user.Id.ToString());
await MobileService.GetPush().RegisterNativeAsync(channelUri, tags.ToArray());
}
catch (Exception ex)
{
throw ex;
}
}
private void CreateNotification(string title, string message)
{
//Show Toast
}
}
In azure I have set the windows Package SID and client secret. I also have unauthenticated push notifications enabled (Although from my understanding this is for MPNS).
And finally here's a screen capture of how it registers with the following code:
If anyone has any idea how to get it to properly register to WNS I'd greatly appreciate the help. Thanks!
Just an update as to how I resolved my problem in case anyone comes across this. I had to switch my winphone project to a non silverlight application (I'm guessing its not supported with this version). Once I did this everything started working correctly.
I have added the web service to my WPF windows phone store app, when i run my app in emulator it works, but sometime it get creshes cause lack of internet connectivity.
i'm checking my emulator IMEI is registerd or not in database using WCF service on main_pageload event
my code looks like this
private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
SchoolWebService.SchoolAppWebServiceSoapClient proxy = new SchoolAppWebServiceSoapClient();
proxy.CheckIMEIRegisteredOrNotCompleted += new EventHandler<CheckIMEIRegisteredOrNotCompletedEventArgs>(proxy_CheckIMEIRegisteredOrNotCompleted);
proxy.CheckIMEIRegisteredOrNotAsync(strIMEI);
}
in this service im checking the mobile IMEI registerd or not. i have checked by debugging the app it goes upto proxy.CheckIMEIRegisteredOrNotAsync(strIMEI);
when it leave the context it throuw the error
An exception of type 'System.ServiceModel.CommunicationException' occurred in System.ServiceModel.ni.dll but was not handled in user code
please suggest me some advice,,,thanks in advance
To check if the Internet connection is available I just simply create a method to check it and execute it then application is launching or page is loading. This method I create in App.xaml.cs:
public bool CheckInternetConnection()
{
bool connection = true;
ConnectionProfile currentConnection = NetworkInformation.GetInternetConnectionProfile();
if (currentConnection == null)
{
connection = false;
}
return connection;
}
Then in some page_loaded event I execute it:
private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
bool connection = ((App)Application.Current).CheckInternetConnection();
if (connection == false)
{
MessageBox.Show("Internet connection is not available", "Internet connection", MessageBoxButton.OK);
Application.Current.Terminate();
}
}
Now then a client don't have the Internet connection available it won't crash, but it will show a message for the user. I hope it will help.
I am calling a web service from BlackBerry using J2ME code. When I try to open a connection using HttpConnection, it is checking only the GPRS connection. Now, I want to check the Wi-Fi connection and call a webservice through Wi-Fi.
The following code is my connection section. How to change the code for a Wi-Fi connection?
public boolean HttpUrl()
{
HttpConnection conn = null;
OutputStream out = null;
String url = "http://www.google.com";
try
{
conn = (HttpConnection) new ConnectionFactory().getConnection(url).getConnection();
if (conn != null)
{
conn.setRequestMethod(HttpConnection.POST);
conn.setRequestProperty("Content-Length", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("User-Agent", "Profile/MIDP-2.0 Configuration/CLDC-1.0");
}
}
catch (Exception e)
{
return false;
}
finally
{
try
{
out.close();
}
catch (Exception e2)
{
}
}
//Only if exception occurs, we close the connection.
//Otherwise the caller should close the connection himself.
try
{
conn.close();
}
catch (Exception e1)
{
}
return true;
}
Check this way:
HttpConnection conn = null;
String URL = "http://www.myServer.com/myContent;deviceside=true;interface=wifi";
conn = (HttpConnection)Connector.open(URL);
source
Making Connections
Rafael's answer will certainly work if you know you'll only be using Wi-Fi.
However, if you only need to support BlackBerry OS 5.0 - 7.1, I would recommend that you do use the ConnectionFactory. Normally, you will not limit your code to only using one transport. You'll normally support (almost) any transport the device has, but you may want to code your app to choose certain transports first.
For example,
class ConnectionThread extends Thread
{
public void run()
{
ConnectionFactory connFact = new ConnectionFactory();
connFact.setPreferredTransportTypes(new int[] {
TransportInfo.TRANSPORT_TCP_WIFI,
TransportInfo.TRANSPORT_BIS_B,
TransportInfo.TRANSPORT_MDS,
TransportInfo.TRANSPORT_TCP_CELLULAR
});
ConnectionDescriptor connDesc;
connDesc = connFact.getConnection("http://www.google.com");
if (connDesc != null)
{
HttpConnection httpConn;
httpConn = (HttpConnection)connDesc.getConnection();
try
{
// TODO: set httpConn request method and properties here!
final int iResponseCode = httpConn.getResponseCode();
UiApplication.getUiApplication().invokeLater(new Runnable()
{
public void run()
{
Dialog.alert("Response code: " +
Integer.toString(iResponseCode));
}
});
}
catch (IOException e)
{
System.err.println("Caught IOException: "
+ e.getMessage());
}
}
}
}
will choose the Wi-Fi transport if Wi-Fi is available, but use the GPRS connection if it isn't. I think this is generally considered best practice for the 5.0+ devices.
Request Properties
This code
conn.setRequestProperty("Content-Length", "application/x-www-form-urlencoded");
is not right. Content-Length should be the size, in bytes, of your HTTP POST parameters. See an example here.
Threading
Remember that making network connections is slow. Do not block the user interface by running this code on the main/UI thread. Put your code into a background thread to keep the UI responsive while you request remote content.