如何在方法onClick（View v）中抛出例外

Question

First, I already reviewed some similar questions but the answers didn't help me :(

I trying to program an Android application and this is my problem

public void onClick(View v)  {
        String url = Buscar_Random();
        //do something with the variable url

I want to call the method Buscar_Random , this method throws an IOException , so I need to call this exception in the method onClick . So i tried this:

public void onClick(View v) throws  IOException {

But onClick is an override method, so I receive this message: overridden method does not throw 'java.io.IOException'

I also tried this:

    public void onClick(View v)  {
    try {
        String url = Buscar_Random.main();
        //do something with the variable url
    } catch (IOException e){
        e.printStackTrace();
    }

And this is the weirdest part, the app compiles but when i call the method in the app in my Android, the app closes itself (and doesn't even show me the message "Unfortunately blahblah has stopped working"

I also tried to use a RuntimeException , but neither worked :(

What can I do?

Thanks

Answer 1

Your second example is doing it right.

As for the crash, just because a method doesn't specifically declare that it throws a certain Exception doesn't mean it won't. It could be throwing a NullPointerException, RemoteException, IllegalArgumentException, etc. Also, just because there's no "App has stopped" message doesn't mean the app didn't crash. That dialog isn't always shown.

If you want to just ignore any and all errors from that method (probably a bad idea, since the current crash is probably a bug you need to fix), just catch Exception:

try {
    //whatever
} catch (Exception e) {}

However, you should really look at the Logcat viewer (bottom toolbar) in Android Studio. Filter by your app only, and set the level to Error and find out why your app is crashing.