I'm currently developing a project for school using Java ME and Intellij. I need to create both a client and server using the javax.microedition.io library. However, I tried running some sample code for creating both a server and a client and I get a return value of null for both of these lines:
ServerSocketConnection server = (ServerSocketConnection) Connector.open("socket://:" + port);
SocketConnection client = (SocketConnection) Connector.open("socket://" + hostname + ":" + port);
Is there something I'm missing? Intellij has networking permissions and I'm simply trying to test this on my local host. I haven't been able to find any documentation to indicate why these functions would return null. I've tried other protocols as well (including bogus ones) and no exceptions are being thrown at all.
EDIT
Turns out all the classes I have found under javax.microedition.io are unimplmented (i.e. simply return null or similar values such as 0) I will make a new post regarding this problem.
Related
I am trying to create a communication interface between a python socket server and a Metatrader 5 Expert Advisor.
I've tried multiple approaches and tutorial's I found online for both sockets and websockets. All of these approaches yield the same problem.
Whenever I start a debug on live/historical data, I get a Socket creation error with code 4014. According to the error codes it is a "Function is not allowed for call" error.
Multiple sources recommended to allow web request from specified URL's. Ive done this as well for 127.0.0.1 and localhost. (Tools > options > Expert Advisors)
Why am I getting a function not allowed for call error, and how can this be fixed?
Expert code:
int socket=SocketCreate();
int OnInit()
{
if(SocketConnect(socket,"127.0.0.1",9090,1000))
{
Print("Connected to "," 127.0.0.1",":",9090);
}
else
{
Print(GetLastError());
}
return(INIT_SUCCEEDED);
}
void OnDeinit(const int reason)
{
SocketClose(socket);
}
void OnTick()
{
SocketClose(socket);
}
We had similar issue in the past and was resolved it by adding the hostname/IP to connect to to the list of allowed URLs in Tools->Options->Expert Advisor.
You can also use a MetaApi service to communicate with MetaTrader via developer-friendly SDKs and code your expert advisor in Javascript, Java or Python.
Hope this is useful to some degree.
I faced the same problem.
Works for me: to point exactly '127.0.0.1' (without upper commas) in address input field.
Also, check your firewall settings - it may block your ports.
The best regards.
I have a windows desktop application on .NET Framework that a user can interact with. There is a "connect" button that sets up Apache Geode client connection to Geode Server.
When Geode Server is down (Locator - there is only 1) the desktop application hangs indefinitely and needs to be forcefully closed.
This is how we connenect to the server and hangs on last line indefinitely:
PoolFactory poolFactory = _cache.GetPoolManager()
.CreateFactory()
.SetSubscriptionEnabled(true)
.AddLocator(_host, _port);
return poolFactory.Create(_serviceName);
I would like to add a time-out period for this method to return or throw exceptions or anything.
Alternatively, I've wrapped it on a different kind of timer outside of this to just return, but when trying to run the above code again (to try to connect the application again) the pool is still trying to connect.
I have tried to destroy it like this:
//destroy the pool
var poolManager = _cache.GetPoolManager();
if (poolManager != null)
{
var pool = poolManager.Find(_serviceName);
if (pool != null && pool.Destroyed == false)
pool.Destroy();
}
But then the pool.Destroy(); hangs indefinateley
How can I have a mechanism to attempt to connect to the Geode server, return if not connected within 10 seconds, then leave and are able to try to connect again using the same cache?
Note above was trying to re-use the same cache, probably setting cache to null and trying all over again would work, but I am looking for a more correct way to do it.
Depending on what version of .NET native client you are using. There is a property in 10.x connect-timeout that should work. Additionally, you can wrap your connection code under try{...}catch{} block and handle an exception for Apache.Geode.Client.TimeoutException and/or ": No locators available".
Example:
var _cache = new CacheFactory()
.Set("log-level", "config")
.Set("log-file", "C:\temp\test.log")
.Set("connect-timeout", "26000ms")
.Create();
_cache.GetPoolManager()
.CreateFactory()
.SetSubscriptionEnabled(true)
.AddLocator(hostname-or-ip", port-number)
.Create("TestPool");
I'm setting up a new mqtt conection in my app but there is a problem when i would like to create the main connection of mqtt.
I'm using mqtt.js.
I've tried all what is done in MQTT documentation but nothing happens..
mqttFunction(){
var mqtt = require('mqtt');
var client = mqtt.connect([{host: 'localhost', port: '1883'},]);
client.subscribe('presence')
client.on('message', function (topic, message) {
console.log(message);
});
}
I expect the output of the mqtt broker to be 'ON' when i asked it to respond.
The error is: ERROR ReferenceError: process is not defined
The documentation you followed is intended for Node.js and various other back-end JavaScript frameworks. Even though it uses NPM, Ionic ultimately produces a front-end framework, and its applications run a bit differently.
For example, Ionic programs may not have a global process variable like Node.js. mqtt.js expects this variable, with code like:
if (commist.parse(process.argv.slice(2)) !== null){...}
You could declare a process object, and get past this particular error. Other obstacles could come up.
var process = {env : {NODE_ENV: 'production'}}
If there are still issues with that, you could try the instructions for browser usage, which point to a specially compiled version, like https://unpkg.com/mqtt#3.0.0/dist/mqtt.min.js. I have had less luck with mqtt.js in the browser, and you may want an alternative like web-mqtt-cient / Paho if more complex connections are involved.
For the past 3 years we have used HTML/Js only with Firebase but now we are using Unity as well.
The current Unity/Firebase only works on Android/iOS when deployed and 99% of our work is on the windows store.
I've actually got a pretty decent Unity/Firebase codebase going but it requires me to use a full App Secret.
All the other libraries expose a method to login with Email/Password but the REST API only allows the use of a token or your app secret that it then states is ill advised to put into your client; I guess the thinking is if you're using a different library that you'll have your own auth/user method which we don't...
Now, I've pulled apart the web version and got this:
https://auth.firebase.com/v2/<myfirebase>/auth/password?&email=dennis%40<mysite>&password=<mypassword>v=js-2.2.9&transport=json&suppress_status_codes=true
So there IS an endpoint that I can send stuff to and I've tested it inside unity with good results.
Obviously the URL isn't guaranteed to stay working but I'm wondering if there is any reason NOT to use this?
Also, Why not just expose this endpoint in the official REST API?
As I understand it, that URL will continue to work for your Legacy Firebase project. You will have to do the same sort of reverse engineering if you want to update to the new Firebase 3.0 API. However, if you are still using a legacy Firebase project -- I encourage you to take a look at this. It has not been updated to work with Firebase 3.0 -- so I needed to do something similar to what you did to allow login to the new API.
I was able to do this with the new API using C# as follows (where FirebaseManager is a Singleton I wrote for Global variables and functions to write and read from/to the DB :
Hashtable loginData = new Hashtable();
loginData.Add ("email", <EMAIL-GOES-HERE>);
loginData.Add ("password", <PASSWORD-GOES-HERE>);
loginData.Add ("returnSecureToken", true);
UnityHTTP.Request loginRequest = new UnityHTTP.Request ("post",
"https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyPassword?key="
+ <YOUR-PROJECT-API-KEY-GOES-HERE>, loginData);
loginRequest.Send ((request) => {
Hashtable jsonResponse = (Hashtable)JSON.JsonDecode(request.response.Text);
if (jsonResponse == null) {
DisplayErrorMessage("Error logging in. Server returned null or malformed response");
}
FirebaseManager.Instance.idToken = (string)jsonResponse["idToken"]; // This is your auth token
FirebaseManager.Instance.uid = (string)jsonResponse["localId"]; // this is your "uid"
});
// I have a list of users in my db keyed by the "uid" -- I access them like this
UnityHTTP.Request fullnameRequest = new UnityHTTP.Request ("get",
<YOUR-DATABASE-ROOT-URL-HERE>
+ "/users/" + FirebaseManager.Instance.uid + ".json?auth=" + FirebaseManager.Instance.idToken);
fullnameRequest.Send ((request) => {
Debug.Log(request.response.Text);
Hashtable jsonResponse = (Hashtable)JSON.JsonDecode(request.response.Text);
if (jsonResponse == null) {
DisplayErrorMessage("Error getting user info. Server returned null or malformed response");
}
FirebaseManager.Instance.fullname = (string)jsonResponse["fullname"];
FirebaseManager.Instance.groupId = (string)jsonResponse["group"]; // just storing this in memory
});
So I don't think there is any harm in using the URL, just make sure you budget time for more work when things change.
I installed 3.0.3 OpenMeetings to test access via REST interface, everything worked ok for the methods in UserService and RoomService. But, when I try to upload a pdf file by ImportFile method (FileService), OpenMeetings returns an object FileImportError stating that the file is damaged, and that this may have occurred during the file transfer via http.
When I try to import the same file using the flex application of OpenMeetings everything works right. I'm using Ruby to call the method of ImportFile OpenMeeting, and to test whether my application is wrong, I called the method using Firefox and got the same error.
I am using the following method call (sample only, not the real ruby code):
ImportFile (SID externalUserId, externalFileId, externalType, room_id, isOwner, path,
parentFolderId, fileSystemName)
SID = one string with the ID of the session
externalUserId = 'extuser' (string)
externalType = 'exttype' (string)
room_id = 2 (existing room in OpenMeetings)
isOwner = false
path = 'http://10.1.1.25/default.pdf' (The path to the file on an Apache server)
parentFolderId = 0
fileSystemName = 'default.pdf'
Also used Eclipse in remote debug to see what was happening and realized that the problem occurs in the conversion of the received file.
I would appreciate some help to solve the problem.
Thanks,
Fernando