How to set alert instead of showing unhandled exception in J2ME?

I am designin开发者_Go百科g an application which shows unhandled exception due to lot of reason. So I want my application to show alert in catch block instead.

You could do something like this:

private Alert alert;
private Display display;
// Obtain display with display = Display.getDisplay(this); in consturctor

catch(Exception e) {
    alert = new Alert("Error occurred", "Message: " + e.getMessage(), null, AlertType.ERROR);
    alert.setTimeout(Alert.FOREVER);
    display.setCurrent(alert, form);
}

Hope this helps.

I think you can just put the alert handling in the catch block:

catch(Exception e) {
         // create new alert and 
}

The problem I think this guy is having, is that the exceptions are appearing seemingly randomly, i.e. he won't know which piece of code is throwing it.

Some J2ME handsets (e.g. Nokias) have a habit of showing the exception name to the user in an alert, while others (e.g. Sony Ericssons) silently swallow them.

You need to identify all the points at which code can be executed (i.e. all the threads you're creating, and all the MIDP lifecycle methods that the framework could be calling for you), and wrap all of those in try/catch blocks, to ensure that no exceptions can be shown in this way.

That will probably slow your code down a lot though, so you should get to the bottom of what causes these exceptions to appear, and fix the problem!