I'm trying to create a simple server in vala using libsoup.
I am wondering if it is a good way to start a Soup.Server from a GLib.Application. Since using it synchronously (run is deprecated) is not recommended, the only way I found to keep it alive is to hold the default application.
public class Simple.Server : Soup.Server
{
public Server () {
Application.get_default ().hold ();
add_handler(null, null_handler);
}
private void null_handler (Soup.Server server, Soup.Message message,
string path, HashTable<string,string>? query,
Soup.ClientContext client) {
GLib.message ("path: %s", path);
message.status_code = 404;
message.set_response ("text/plain", Soup.MemoryUse.COPY, "".data);
}
}
public class Simple.App : Application
{
private Simple.Server server;
App () {
Object (application_id: "org.dev.simple-server",
flags: ApplicationFlags.FLAGS_NONE);
}
protected override void activate () {
base.activate ();
server = new Simple.Server();
try {
server.listen_all(8080, 0);
}
catch (Error e) {
GLib.message ("Error n°%u: %s", e.code, e.message);
}
}
protected override void shutdown () {
base.shutdown ();
server.disconnect ();
}
static int main (string[] args) {
App app = new Simple.App();
return app.run (args);
}
}
This is mimic of my code.
So here is the question, is it a good practice for starting the server, still using GLib.Application, or should I use (like examples say) only the server, starting/stopping manually the MainLoop ?
thanks.
Related
My MVC application(SQL as database server) use Redis cache(Windows) inorder to improve performance and also to reduce the load on database server. Redis cache is hosted on separate VM(Single node) and stackexchange.redis is the client used to connect to Redis server.
I want to make my application resilient to redis cache server failure.
So, Incase of Redis server failure,instead of throwing error to user,application should still be able to fetch it from database.
Is there any fall back mechanism that i can use in my application code in case of Redis Cache server failure?
Thanks in Advance.
Below is my RedisCacheService class. I'm using DI container to inject IConnectionMultiplexer.
public class RedisCacheService :IRedisCacheService
{
private readonly IConnectionMultiplexer _connectionMultiplexer;
private readonly IDatabase _redisCache;
public RedisCacheService(IConnectionMultiplexer connectionMultiplexer)
{
try
{
_connectionMultiplexer = connectionMultiplexer;
_connectionMultiplexer.ErrorMessage += _connectionMultiplexer_ErrorMessage;
_connectionMultiplexer.ConnectionFailed += _connectionMultiplexer_ConnectionFailed;
_connectionMultiplexer.ConnectionRestored += _connectionMultiplexer_ConnectionRestored;
_redisCache = _connectionMultiplexer.GetDatabase();
}
catch (Exception ex)
{
}
}
private void _connectionMultiplexer_ErrorMessage(object sender, RedisErrorEventArgs e)
{
//throw new NotImplementedException();
}
private void _connectionMultiplexer_ConnectionRestored(object sender, ConnectionFailedEventArgs e)
{
//throw new NotImplementedException();
}
private void _connectionMultiplexer_ConnectionFailed(object sender, ConnectionFailedEventArgs e)
{
//throw new NotImplementedException();
}
public T JsonGet<T>(RedisKey key, CommandFlags flags = CommandFlags.None)
{
RedisValue cacheData = _redisCache.StringGet(key, flags);
if (!cacheData.HasValue)
return default;
T rgv = JsonConvert.DeserializeObject<T>(cacheData);
return rgv;
}
public RedisValue GetCacheData(RedisKey key, CommandFlags flags = CommandFlags.None)
{
RedisValue cacheData = _redisCache.StringGet(key, flags);
if (!cacheData.HasValue)
return default;
//T rgv = JsonConvert.DeserializeObject<T>(cacheData);
return cacheData;
}
public bool SetCacheData(RedisKey key, object value, TimeSpan? expiry = null, When when = When.Always, CommandFlags flags = CommandFlags.None)
{
if (value == null) return false;
return _redisCache.StringSet(key, JsonConvert.SerializeObject(value), expiry, when, flags);
}
}
I have an external dll written in C# and I studied from the assemblies documentation that it writes its debug messages to the Console using Console.WriteLine.
this DLL writes to console during my interaction with the UI of the Application, so i don't make DLL calls directly, but i would capture all console output , so i think i got to intialize in form load , then get that captured text later.
I would like to redirect all the output to a string variable.
I tried Console.SetOut, but its use to redirect to string is not easy.
As it seems like you want to catch the Console output in realtime, I figured out that you might create your own TextWriter implementation that fires an event whenever a Write or WriteLine happens on the Console.
The writer looks like this:
public class ConsoleWriterEventArgs : EventArgs
{
public string Value { get; private set; }
public ConsoleWriterEventArgs(string value)
{
Value = value;
}
}
public class ConsoleWriter : TextWriter
{
public override Encoding Encoding { get { return Encoding.UTF8; } }
public override void Write(string value)
{
if (WriteEvent != null) WriteEvent(this, new ConsoleWriterEventArgs(value));
base.Write(value);
}
public override void WriteLine(string value)
{
if (WriteLineEvent != null) WriteLineEvent(this, new ConsoleWriterEventArgs(value));
base.WriteLine(value);
}
public event EventHandler<ConsoleWriterEventArgs> WriteEvent;
public event EventHandler<ConsoleWriterEventArgs> WriteLineEvent;
}
If it's a WinForm app, you can setup the writer and consume its events in the Program.cs like this:
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
using (var consoleWriter = new ConsoleWriter())
{
consoleWriter.WriteEvent += consoleWriter_WriteEvent;
consoleWriter.WriteLineEvent += consoleWriter_WriteLineEvent;
Console.SetOut(consoleWriter);
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
static void consoleWriter_WriteLineEvent(object sender, Program.ConsoleWriterEventArgs e)
{
MessageBox.Show(e.Value, "WriteLine");
}
static void consoleWriter_WriteEvent(object sender, Program.ConsoleWriterEventArgs e)
{
MessageBox.Show(e.Value, "Write");
}
It basically amounts to the following:
var originalConsoleOut = Console.Out; // preserve the original stream
using(var writer = new StringWriter())
{
Console.SetOut(writer);
Console.WriteLine("some stuff"); // or make your DLL calls :)
writer.Flush(); // when you're done, make sure everything is written out
var myString = writer.GetStringBuilder().ToString();
}
Console.SetOut(originalConsoleOut); // restore Console.Out
So in your case you'd set this up before making calls to your third-party DLL.
You can also call SetOut with Console.OpenStandardOutput, this will restore the original output stream:
Console.SetOut(new StreamWriter(Console.OpenStandardOutput()));
Or you can wrap it up in a helper method that takes some code as an argument run it and returns the string that was printed. Notice how we gracefully handle exceptions.
public string RunCodeReturnConsoleOut(Action code)
{
string result;
var originalConsoleOut = Console.Out;
try
{
using (var writer = new StringWriter())
{
Console.SetOut(writer);
code();
writer.Flush();
result = writer.GetStringBuilder().ToString();
}
return result;
}
finally
{
Console.SetOut(originalConsoleOut);
}
}
Using solutions proposed by #Adam Lear and #Carlo V. Dango I created a helper class:
public sealed class RedirectConsole : IDisposable
{
private readonly Action<string> logFunction;
private readonly TextWriter oldOut = Console.Out;
private readonly StringWriter sw = new StringWriter();
public RedirectConsole(Action<string> logFunction)
{
this.logFunction = logFunction;
Console.SetOut(sw);
}
public void Dispose()
{
Console.SetOut(oldOut);
sw.Flush();
logFunction(sw.ToString());
sw.Dispose();
}
}
which can be used in the following way:
public static void MyWrite(string str)
{
// print console output to Log/Socket/File
}
public static void Main()
{
using(var r = new RedirectConsole(MyWrite)) {
Console.WriteLine("Message 1");
Console.WriteLine("Message 2");
}
// After the using section is finished,
// MyWrite will be called once with a string containing all messages,
// which has been written during the using section,
// separated by new line characters
}
i am trying to develop an application in c# which acts as a server for an android phone.i am using 32feet.net for bluetooth in c# and i have a server running in android, which simply sends a socket to server. the server running in pc need to listen the connection and display ,the status of connection. all these things are base for my project. the server code is as shown :
namespace testserver
{
class Program
{
static void Main(string[] args)
{
BluetoothClient bc = new BluetoothClient();
BluetoothDeviceInfo[] dev;
BluetoothDeviceInfo td=null;
Guid id = new Guid("{00112233-4455-6677-8899-aabbccddeeff}");
// Console.WriteLine(id.ToString());
// Console.Read();
dev = bc.DiscoverDevices();
foreach (BluetoothDeviceInfo d in dev)
{
if (d.DeviceName == "ST21i")//my phone name
{
td=d;
break;
}
}
try
{
BluetoothAddress addr = td.DeviceAddress;
BluetoothListener bl = new BluetoothListener(addr, id);
bl.Start();
if (bl.AcceptSocket() != null)
Console.WriteLine("Success");
}
catch (Exception e)
{
Console.WriteLine("Exception : "+e.Message);
Console.Read();
}
}
}
}
and here is my android code :
public class MainActivity extends Activity {
BluetoothAdapter adapter;
BluetoothDevice bd;
BluetoothSocket sock;
OutputStream ostr;
int REQUEST_ENABLE_BT;
String str="5C:AC:4C:DD:CC:0D";
private static final UUID id=UUID.fromString("00112233-4455-6677-8899- aabbccddeeff");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
adapter=BluetoothAdapter.getDefaultAdapter();
if (!adapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
Button b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "clicked button", Toast.LENGTH_LONG).show();
try
{
bd=adapter.getRemoteDevice(str); Toast.makeText(getApplicationContext(),"Server is running at "+bd.getName().toString()+"...", Toast.LENGTH_LONG).show();
sock=bd.createInsecureRfcommSocketToServiceRecord(id); sock.connect();
ostr=sock.getOutputStream();
ostr.write(0);
}
catch(Exception e)
{
Toast.makeText(getApplicationContext(),e.getMessage(), Toast.LENGTH_LONG).show();
}
}
});
}
}
my problems are :
1) in pc i am getting an exception, the requested address is not valid in its context(so that server cant run )
2)in phone, the service discovery failed( because of unavailability of server)
how can i correct the server and run the program ?
i changed the bluetooth listener object's creation from
BluetoothListener bl = new BluetoothListener(addr, id); to
BluetoothListener bl = new BluetoothListener(id); and everything worked fine..
Hi friends i am trying to read incoming sms but getting warning like this . Invocation of questionable method: java.lang.String.(String) found in: mypackage.MyApp$ListeningThread.run()
Here is my code is
public class MyApp extends UiApplication {
//private ListeningThread listener;
public static void main(String[] args) {
MyApp theApp = new MyApp();
theApp.enterEventDispatcher();
}
public MyApp() {
invokeAndWait(new Runnable() {
public void run() {
ListeningThread listener = new ListeningThread();
listener.start();
}
});
pushScreen(new MyScreen());
}
private static class ListeningThread extends Thread {
private boolean _stop = false;
private DatagramConnection _dc;
public synchronized void stop() {
_stop = true;
try {
_dc.close(); // Close the connection so the thread returns.
} catch (IOException e) {
System.err.println(e.toString());
}
}
public void run() {
try {
_dc = (DatagramConnection) Connector.open("sms://");
for (;;) {
if (_stop) {
return;
}
Datagram d = _dc.newDatagram(_dc.getMaximumLength());
_dc.receive(d);
String address = new String(d.getAddress());
String msg = new String(d.getData());
if(msg.startsWith("START")){
Dialog.alert("hello");
}
System.out.println("Message received: " + msg);
System.out.println("From: " + address);
System.exit(0);
}
} catch (IOException e) {
System.err.println(e.toString());
}
}
}
}
Please correct me where i am wrong.Is possible give me some code to read incoming sms content in blackberry.
A few points about your code:
That invokeAndWait call to launch a thread makes no sense. It doesn't harm, but is kind of waste. Use that method only to perform UI related operations.
You should try using "sms://:0" as param for Connector.open. According to the docs, a parameter with the form {protocol}://[{host}]:[{port}] will open the connection in client mode (which makes sense, since you are on the receiving part), whereas not including the host part will open it in server mode.
Finally, if you can't get it working, you could use instead the third method specified in this tutorial, which you probably have already read.
The error you quoted is complaining about the use of the String constructor that takes a string argument. Since strings are immutable in Java-ME, this is just a waste. You can use the argument string directly:
Invocation of questionable method: java.lang.String.(String) found in: mypackage.MyApp$ListeningThread.run()
//String address = new String(d.getAddress());
String address = d.getAddress();
// getData() returns a byte[], so this is a different constructor
// However, this leaves the character encoding unspecified, so it
// will default to cp1252, which may not be what you want
String msg = new String(d.getData());
I created app which user can start from menu and from icon. I do not use GlobalEventListener in my app, just register ApplicationMenuitem. And now I am getting error: previous instance still active when launch my app.
Steps to reproduce not so trivial:
launch app from icon
do not close it, just switch to another app
launch app from icon again
I founded article in blackberry's forum about it , but I can't find solution where I should remove my ApplicationMenuItem: it added on phone boot and should show all the time.
My code:
public class Jingu extends UiApplication {
public static void main(String[] args) {
ApplicationManager app = ApplicationManager.getApplicationManager();
boolean keepGoing = true;
while (keepGoing) {
if (app.inStartup()) {
try {
Thread.sleep(1000);
} catch (Exception e) {}
} else {
keepGoing = false;
}
}
Jingu theApp = new Jingu();
theApp.initMenuItem();
theApp.showMainScreen();
theApp.enterEventDispatcher();
}
public Jingu() {
}
public void showMainScreen() {
showScreen(new JinguMainScreen(this));
}
public void initMenuItem() {
// Create menu item
Object o = RuntimeStore.getRuntimeStore().get(JinguMenuItem.MY_MENU_ID);
// register only if not done already.
if (o == null) {
new JinguMenuItem(this).registerInstance();
}
}
public void showScreen(Screen aScreen) {
synchronized (Application.getEventLock()) {
try {
UiApplication.getUiApplication().popScreen(aScreen);
} catch (Exception e) {
}
UiApplication.getUiApplication().pushScreen(aScreen);
}
}
}
public class JinguMenuItem extends ApplicationMenuItem {
public static final long MY_MENU_ID = 0xb9739d5240d5943dL;
private final Jingu jingu;
public JinguMenuItem(Jingu jingu) {
super(0x350100);
this.jingu = jingu;
}
public void registerInstance() {
Object menuItem = RuntimeStore.getRuntimeStore().remove(MY_MENU_ID);
if (menuItem == null) {
ApplicationMenuItemRepository amir = ApplicationMenuItemRepository.getInstance();
amir.addMenuItem(ApplicationMenuItemRepository.MENUITEM_SYSTEM, this);
RuntimeStore.getRuntimeStore().put(MY_MENU_ID, this);
}
}
public Object run(Object context) {
jingu.setDefaultFont(Font.getDefault());
jingu.setMainApp(false);
jingu.setBbmEditField(null);
jingu.showMainScreen();
return context;
}
public String toString() {
return "My Menu";
}
}
plz advice where I should delete ApplicationMenuItem in my app?
my regards,
Vadim
If you are registering an ApplicationMenuItem from your application, as a user I would consider it bad style for your application to remove and exit, even if RIM provided a way to do this. You may want to separate your application into two parts. One provides the minimal support for responding to the ApplicationMenuItem selection, that starts automatically and runs in the background. The other has all the rest and can run and exit as needed.
My solution for this situation is:
create alternative entry point and run it on app load
register menu in it
do not use runtimeStore