codenameone: how to handle exception java.net.ConnectionException explicitly - codenameone

Question

codenameone: how to handle exception java.net.ConnectionException explicitly
I want to handle exception explicitly.Currently when I am handling exception It handled implicitly first in which shows the exception message on screen in detail.I don't want to show in detail error message on screen(pop up dialog).
right now it shows the exception Java.net.Connection Exception: Connection refused for URL http:localhost/login connection refused.instead of this message i just want to show "connection refused" message on pop-up dialog
Can you please let me know how to resolve it.

Answer 1

On mobile devices the error might be quite different to the one on the simulator since we are dealing with native API's under the surface. See the error handling section of the networking section in the developer guide:
There are two distinct placed where you can handle a networking error:
The ConnectionRequest - by overriding callback methods
The NetworkManager error handler
Notice that the NetworkManager error handler takes precedence thus allowing you to define a global policy for network error handling by consuming errors.
E.g. if I would like to block all network errors from showing anything to the user I could do something like this:
NetworkManager.getInstance().addToQueue(request);
NetworkManager.getInstance().addErrorListener((e) -> e.consume());
The error listener is invoked first with the NetworkEvent matching the error. Consuming the event prevents it from propagating further down the chain into the ConnectionRequest callbacks.
We can also override the error callbacks of the various types in the request e.g. in the case of a server error code we can do:
ConnectionRequest request = new ConnectionRequest(url, false) {
protected void handleErrorResponseCode(int code, String message) {
if(code == 444) {
// do something
}
}
protected void handleException(Exception err) {
// handle exception that occurred. Notice you can either have this or have the listener on the NetworkManager
}
protected void readResponse(InputStream input) {
// just read from the response input stream
}
};
NetworkManager.getInstance().addToQueue(request);